explained: new terms - ecological chemomediators, ecological chemoregulators - that were coined
innovative paper:
Reference:
S. A. Ostroumov.
On the Concepts of Biochemical Ecology and Hydrobiology:
Ecological Chemomediators. -
Contemporary Problems of Ecology, 2008, Vol. 1, No. 2, pp. 238–244.
http://5bio5.blogspot.com/2012/08/concepts-of-biochemical-ecology-and.html
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new concepts, biochemical ecology, hydrobiology, new terms, ecological chemomediators, ecological chemoregulators, ecology, chemicals, **
On the Concepts of Biochemical Ecology and Hydrobiology:
Ecological Chemomediators
S. A. Ostroumov
Lomonosov Moscow State University, Vorob’evy Gory, Moscow, 119992 Russia
Abstract—Earlier, the author published two books and some papers, in which he described conceptual foundations of new scientific disciplines—biochemical ecology and biochemical hydrobiology. These trends in research include studies of the role of chemical substances in interorganismal interactions, in communication and regulation of supraorganismal systems. Another part of biochemical ecology concerns studies of the fate and transformation of external chemical substances when they interact with the organisms. Both natural and man-made compounds are interesting for biochemical ecology. The basic concepts of biochemical ecology include ecological chemomediators and ecological chemoregulators that have already been included in the body
of modern conceptions and are used in modern ecological literature. Application of biochemical ecology to aquatic ecosystems contributes to the basis for development of biochemical hydrobiology.
DOI: 10.1134/S1995425508020100
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Text of the paper:
The founding concepts of biochemical ecology were
formulated in the book “Introduction to biochemical
ecology” [1], published in 1986. The author had offered
a unified view of many facts on the border between
ecology and biochemistry, based on a number of previous
works [e.g., 2] and being in agreement with the approach
outlined in [3–5]. The further developments in
this field [e.g., 6–8] have endorsed the expediency of
distinguishing this direction of research, rooted in Vernadsky’s
doctrine of biosphere [9–12]. The present paper
summarizes several in-depth reviews [1, 8, 22] to
provide a brief analysis of this interdisciplinary field of
science and introduce some key concepts and terms.
The idea of the importance of chemical approaches
for studies of ecological and biospheric processes and
relationships between organisms and the environment,
including the hydrosphere, was thoroughly developed
in the works by Vernadsky [9–12] who stated that the
ocean in general should be regarded, at its every point,
as an unbreakable link between dead inert matter and
ever-changing living matter, chemically restructuring
the inert environment [9]. Following Vernadsky, the
heterogeneous living matter in the ocean, the marine
life as a whole, can be viewed as a special mechanism,
changing the sea chemistry entirely [11].
According to Vernadsky [11], the Earth’s biosphere,
in addition to living, biogenic and inert matter, includes
bioinert matter, produced at the same time both by living
organisms and by inert processes and representing
dynamic equilibrium systems of both [9]. In the biosphere,
we encounter various forms of biospheric matter:
dead inert low-activity matter, alive disperse matter,
very active chemically and geologically, and bioinert
matter, a natural structure from alive and inert matter.
The alive matter is a form of activated matter [9].
The importance of engaging chemical and biochemical
approaches for understanding ecosystems and biocenoses
has been underscored by many Vernadsky’s
followers working in ecology and hydrobiology.
The subsequent development of natural sciences
brought new questions from the border zone between
ecology, chemistry, and biochemistry. Among them,
there is a prominent problem of how well integrated is
living matter and the biosphere in general and what
are molecular mechanisms of regulation of biospheric
equilibria (“ecological equilibria” in modern terms,
which still need to be defined more precisely) and formation
of bodies of organic matter in the biosphere.
Studies of the features of ecological equilibria in the
biosphere and the mechanisms of their maintenance and
disturbance, including those involving various organic
compounds, especially secondary metabolites are currently
gaining much importance [13–20]. The main
reasons of growing interest to these problems are multifaceted.
First, the advances in ecosystem science have understandably
led to the accumulation of a wealth of data regarding
the structure and functioning of ecosystems,
their dynamics and stability. This information lays the
foundation for a new stage in the development of ecology,
with an increasing attention given to the factors
that regulate the formation of ecosystems’ structure,
their dynamics and functioning. A deep analysis of
the concept of ecologic equilibrium, still insufficiently
clear, is urgently needed [7].
Second, improvements in the chemical and biochemical
techniques used to study living organisms and
their environment reveal new features of biochemical
processes and chemical compounds, especially second-
ISSN 1995-4255, Contemporary Problems of Ecology, 2008, Vol. 1, No. 2, pp. 238–244. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © S.A. Ostroumov, 2006, published in Sibirskii Ekologicheskii Zhurnal, 2006, Vol. 13, No. 1, pp. 73–82.
238
ary metabolites, mediating and regulating many interactions
between organisms [6, 8, 21].
Third, the human impact on the biosphere has risen
sharply, including dangerous chemical pollution. This
process is understandably worrying because of the
growing disturbance of ecological processes and ecological
equilibria in many areas of the biosphere
[15–20].
Fourth, the intensifying and developing aquaculture
and the general rise in the consumption of biological resources
pose a problem of engineering artificial ecosystems
with sufficient stability and capacity for regulation.
Understanding of the mechanisms of maintenance
and disturbance of ecological equilibria (or ecosystem
stability) is critically dependent on the rapidly growing
information from the borderlines between ecology, biochemistry,
chemistry, and physiology.
Some important aspects of these problems are subject
of study in the adjacent fields, such as physiology,
behavioral science, zoology, toxicology, biochemistry,
biophysics, etc. Usually, however, such studies are
mainly concerned only with facts from the particular
field and neglect general ecological points. These narrowly
specialized approaches to the chemical aspects of
ecological interactions between organisms are necessary
but not sufficient for appreciation of the mechanisms
of regulation and destabilization of ecosystems.
The vast number of chemically mediated interactions,
influences, dependences, and signals in biogeocenoses
form a complicated large-scale system. Only painstaking
interdisciplinary studies can help us to understand
these systems and learn how to manage them.
At this point, it is pertinent to discuss biochemical
ecology in general, its subject, object, and methods, and
the characteristic features distinguishing it from other
scientific disciplines.
The field of science at the interface between ecology,
chemistry, and biochemistry is sometimes called
chemical ecology. According to Barbier [3], living organisms
from both plant and animal kingdom influence
their environment through intersecting action of various
molecules. These interactions may occur between
animals, between plants, between plants and animals,
and between animals and plants. The impact of abiotic
environment on animals and plants should also be considered.
The study of such interactions and their
chemical effectors is the subject of chemical ecology.
This definition, analyzed from the ecological point
of view, is notable for dividing the interactions between
living organisms into two important groups. First, there
are interactions involving substances and molecules as
sources of energy or building blocks for the organisms
that consume them. The second type of interactions engages
molecules that serve mainly or exclusively as
messengers transmitting certain information or as regulators
of such ecological processes as flows of energy
and matter through ecosystems.
Biochemical ecology can be appropriately restricted
to the compounds of the second group. Furthermore,
there is no need to encumber biochemical ecology with
many problems of the impact of abiotic environment on
animals and plants [3], e.g., uptake of inorganic nutrients
by living organisms, etc.
What, then, represents the main subject of study of
biochemical ecology? However incomplete and preliminary
our answer may be, it is reasonable to define this
mainly as ecological interactions between organisms
and their high-order systems (populations and communities)
mediated by chemical compounds, mostly those
that act exclusively or preferentially as informationtransmitting
messengers or as regulators of ecological
processes [1, 8]. Some aspects of anthropogenic impact
upon the biosphere, such as chemical pollution, may
also be considered a subject of biochemical ecology
[13–20].
The main objects of biochemical ecology are biochemically
interacting organisms, populations, and
communities, the substances that mediate and regulate
the wide spectrum of ecological interactions (including
both trophic and nontrophic interactions), and biochemical
reactions utilizing these compounds. Importantly,
biochemical ecology regards chemical compounds
and biochemical reactions first of all as components
of ecosystems and participants of ecological processes
in the biosphere [1, 8]. This conceptually distinguishes
biochemical ecology from biochemistry, where
the same compounds may be studied as products of
intracellular metabolism disregarding the ecological
perspective and context.
The set of methods of biochemical ecology includes
a wide assortment of techniques from biochemistry,
bioorganic chemistry, chemistry of natural compounds,
and various bioassays for the substances under study or
their mixtures. In addition to traditional toxicological
approaches, these assays may address physiological or
behavioral reactions to the substances and preparations
under study. Carefully done sophisticated bioassays are
no less important for biochemical ecology than highly
sensitive methods of structural analysis of organic molecules.
Finally, the concluding phase of many studies in
this field is chemical synthesis of the discovered natural
compound following determination of its structure and
ecological role. Therefore, the inventory of biochemical
ecology also includes methods of organic synthesis.
The compounds studied by biochemical ecology, as
a rule, are present in the organisms or excreted by them
in much lower amounts than those used mainly as energy
sources or building materials. Many of classes to
which these compounds belong have long been studied
biochemically with respect to their structure and metabolism,
most (but not all) of them belonging to the group
of secondary metabolites.
**
Thus, the methods of biochemical ecology include
modern techniques of purification and structural analysis
of natural compounds, and methods of discovery of
ecological functions of organic compounds, many of
which were developed or perfected in the past decades
[1, 8]. High sensitivity of modern analytical assays is
essential for revealing the interactions between organisms.
Avery important group of signal or regulatory compounds
are pheromones. Many aspects of their role in
information transmission, inter-individual communication,
and regulation, have been thoroughly reviewed
[1]. Since then, many new data have appeared regarding
the role of pheromones in the ecology of aquatic
and terrestrial organisms.We believe that the canonical
definition of pheromones, given in the works of Karlson
and L
uscher (reviewed in [1, 8]), needs to be
amended. Taking new data and concepts into account,
we suggest the following working definition of pheromones:
Pheromones are individual compounds or their mixtures
(complexes, sets, or combinations), which are secreted
by organisms into their environment (aerial,
aquatic, or onto the organisms’ outer surface), and
which have a function in signaling, information transmission,
or influence on the respondents usually of the
same biological species; pheromones can cause a defined
reaction (behavioral, physiological, or developmental)
in the respondents; pheromones can act as
stimuli activating or inhibiting some reactions, behaviors,
or physiological processes in the respondents [22].
The appropriateness of this particular definition is
based on the accumulated body of information on
pheromones, discussed in [22].
Various aspects of pheromones and the related compounds
have been investigated by many scientists in
Russia. V.E. Sokolov initiated studies in this direction
at the Severtsov Institute of Ecology and Evolution.
The list of authors having actively published in the field
of pheromones includes A. S. Isaev, K. V. Lebedeva,
V. A. Minyailo, Yu. B. Pyatnova, M. Barbier, S. N. Novikov,
E. P. Zinkevich, and many others. Yu. P. Kozlov
and colleagues have studied pheromones of fishes from
Lake Baikal. A new direction, sensory ecology, is actively
developed [21]. The study of pheromones is a
very important direction in the field of chemical communication
of fishes [6] and other aquatic and terrestrial
organisms [1, 22, 23].
In addition to pheromones, other terms can be suggested
to facilitate the characterization of roles of
chemical compounds in signaling and regulation of interaction
between organisms and higher-order systems
[1].
The most general term ecological chemomediators
describes natural chemical compounds acting as mediators
in interactions between organisms, transferring information
during signaling from one organism to
another [1]. They include sex and aggregation pheromones,
food attractants, etc.
Ecological chemoregulators are compounds that
regulate behavior, physiology, and development of
other organisms [1]. This term embraces many pheromones
of both aquatic and terrestrial organisms, and
plant compounds acting on herbivorous animals (including
arthropods) to disturb their development and
reproduction (e.g., plant-derived compounds acting as
juvenile hormones, molting hormones, phytoestrogens,
etc.). Another group of ecological chemoregulators are
compounds made by plants (allelopathic agents) and inhibiting
other plant species. They act as natural herbicides,
used by plants to compete and leading to
regulation of population density and species composition
in plant communities.
Ecological chemoeffectors is the most common
term, denoting all substances, both natural and anthropogenic,
influencing the ecology of living organisms to
a certain degree [1, 21, 22].
The action of many ecological chemomediators and
chemoeffectors is mediated through their activation by
enzymatic biochemical reactions. An example is given
by a number of substances of plant origin that protect
plants against pathogenic fungi or phytophages. On the
other hand, biochemical reactions and evolution of the
respective enzymes are extremely important for detoxification
of potentially harmful compounds produced by
the organism’s ecological partners; co-evolutional adaptation
of fungi or insects and the plants they eat
proceeds in this way.
The mechanisms of detoxification and biodegradation
of xenobiotics are becoming especially significant
because of the large-scale chemical pollution of
modern ecosystems. Detoxification and biodegradation
of the polluting agents usually employ the same biochemical
mechanisms that the cells use to neutralize
natural toxic substances or xenobiotics. Importantly,
chemical pollution of the environment can disrupt
chemical communication between organisms, which
involves ecological chemomediators, chemoeffectors,
and chemoregulators, as defined above. Therefore, the
problems of chemical pollution [13–17] can also be
regarded as part of biochemical ecology.
To conclude this brief description of the basic concepts
of biochemical ecology, it is worthy to underscore
its relations with the field that is increasingly termed
chemical ecology [3] or ecological biochemistry [4].
The above discussion shows that biochemical ecology
is distinct from and narrower than chemical ecology, if
the latter is defined, following M. Barbier, as chemistry
applied to ecology. Ecological biochemistry, sometimes
placed at the interface between ecology, chemistry,
and biochemistry, should encompass biochemical
mechanisms of adaptation of organisms to their environment,
and purely biochemical aspects of metabolism
of ecologically important compounds and mechanisms
of detoxification of xenobiotics. Biochemical
**
ecology is closer to ecology, while ecological biochemistry
is closer to biochemistry.
It must be reiterated that the above discourse is not
an attempt to give some set definitions but rather an invitation
to discuss a modern, highly dynamic and not
yet finally shaped field at the interface between many
traditional scientific disciplines and directions, not limited
to those already mentioned. This multitude of science
disciplines includes biogeochemistry, toxicology
and ecotoxicology, aquatic chemistry, studies of
“ecometabolism” and marine biochemistry (e.g., works
of Khailov [2]), public health aspects of hydrobiology
(see [8]), biochemical pharmacology, biochemical systematics,
chemistry of secondary metabolites and natural
compounds, etc. It will take time to provide final
definitions and draw firm borders between these
disciplines; to do so now is premature.
What can biochemical ecology contribute to solving
the problems of nature conservation and management,
biotechnology, and aquaculture? A brief answer (see
chapter 7 in [8] for a detailed discussion) requires consideration
of both theoretical and practical aspects.
From the theoretical point of view, biochemical ecology
brings into view yet another side of the material basis
of ecological equilibria in the biosphere. If one
compares energy and material flows in the ecosystems
to the street traffic, the compounds discussed here will
play the role of traffic lights or traffic police. Biochemical
ecology only starts to disentangle this complicated
system of ecological chemoregulators, which make an
important contribution to homeostasis and homeokinesis
(stability sensu lato) of ecosystems, including
aquatic ones.
Theoretical foundations of biotechnology will likely
benefit from the ideas of biochemical ecology that explain
the raison d’etre of secondary metabolites and
other biologically active substances, which are among
the most important objects of biotechnology despite the
lack of conceptual knowledge about their functions.
Furthermore, the biochemical-ecological approach
seems appropriate in the analysis of principles and
mechanisms of formation and functioning of producer
cells important in biotechnology.
From the practical point of view, biochemical ecology
together with other scientific disciplines can contribute
to lowering the pollution of the biosphere. Some
ways to achieve this include:
1) Increasing the self-purification capacity of natural
and anthropogenic ecosystems, including aquatic
ones [13–17]. Biotechnology and genetic engineering
can be promising here to construct and manage microorganisms
with an enhanced ability to destroy pollutants
[1, 8].
2) Development and introduction of compounds and
materials with increased capability for destruction in
the environment.
3) Lowering the use of pesticides through introduction
of alternative ways of population control [1, 8].
Such approaches would play a significant role in decreasing
human ecological footprint and lowering the
amount of pollutants introduced into the biosphere.
It has been pointed out that one aspect very important
for conservation is making consumption of all
biospheric resources more “green” [18–20]. This
means a significantly higher level of ecological competence
both when exploiting natural resources (including
marine and freshwater bioresources) and when constructing
any new ecosystem, either aquaculture or
biogeocenosis designed to processing and treatment of
sewage and polluted water. Knowledge of biochemical
ecology of the respective organisms and ecosystems allows
one to see an important aspect of their self-regulation
and maintenance of the stability of these
populations and biogeocenoses. Moreover, biochemical
ecology provides a key for practical management
and fine-tuning of ecological objects and processes, because
it reveals regulatory ecological functions of various
substances intrinsic for a given population or
ecosystem, and these compounds can be made and introduced
to biogeocenoses at will, varying time and
place of the intervention. Some of these problems have
been reviewed in several chapters of [1, 8].
No discussion of problems of biochemical ecology
is complete without mentioning biotransformation of
xenobiotics (both natural and anthropogenic) in organisms
and ecosystems. This topic is given a concise treatment
in chapter 6 of the book [8]. A more detailed
analysis of these problems is beyond the scope of this
brief review.
At this point, it is prudent to bring up several terms
of chemical and biochemical ecology often mentioned
in the literature.
1. Allelochemical (from the Greek , or
— reciprocal, (to) each other) is a substance
that has a certain ecological value (but not as an energy
source) for organisms belonging to biological species
other than the organism producing this substance. This
does not exclude the possibility that allelochemicals
can ultimately become important for their producers. A
wide class of substance can be considered allelochemicals
(chapters 2–4 and section 5.2 in [8]). At the
same time, they do not include such important substances
as pheromones [3, 4, 9, 21, 23] and some autoinhibitory
allelopathic agents (chapter 3 in [8]).
2. Exometabolite is a substance excreted to the environment
and generally believed to have some ecological
significance (not simply a waste product). The
etymology of this term is interesting; it is derived from
the Greek root with two Greek prefixes. The
first prefix, (
before vowels) means separation or
origin, also identifying movement from the inside to the
outside. The second prefix, , denotes commonality,
joint action, intermediate, sequence in space or
**
time, change, or movement. The term stems from the
word , a polysemantic verb meaning “to throw”
(as well as to put something on, to expel, to vent, to
pour, to sprinkle and even to get pregnant).
Exometabolites are a very wide and important class of
substances, especially important for understanding
aquatic ecosystems [1, 5, 8]. However, this concept is
hard or impossible to apply to many ecologically important
substances of terrestrial ecosystems, which can
act without being excreted to the environment, such as a
number of substances important for ecobiochemical
interactions of plants with fungi and animals.
3. Semiochemical is a substance that can de defined
[8] as a chemical involved in signal, information, or
other similar nontrophic interactions between organisms.
In practice, however, this term is used more narrowly
and applied to pheromones and some other
substances, including kairomones and allomones
(chapter 5 in [8]); many toxic substances of high ecological
importance are not adequately described by this
term because of its meaning. The first and fundamental
part of this word is derived from Greek
(... )—characteristics, symbol, sign, token, cue,
signal, banner, seal, etc. As such, the term “semiochemical”
is used in the cases when a chemical acts as a
signal, mark, or carrier of some information. At the
same time, many chemicals, e.g., toxins and chemosterilants
(chapters 2, 4 and 5 in [8]) and allelochemicals
(chapter 3 in [8]) use not as signals but more
directly, simply killing or sterilizing other organisms or
inhibiting their growth. Thus, the term semiochemical
is not universal either and not as widely encompassing
as some authors tend to define it.
These important definitions illustrate the point that
ecobiochemical interactions are very diverse. They are
analyzed in [1, 8], where ecological functions of chemicals
are used as a base to systematically explore a great
multitude of organisms and substances combined into a
single ecobiochemical continuum typical of biosphere
and especially of hydrosphere.
The wide diversity of producers of ecological
chemomediators and a great number of chemical structural
scaffolds of secondary metabolites should not
conceal the fact that the variety of the functions of these
compounds is limited. The following list of the most
important functions is by no means exhaustive [1, 8]:
1) protection from consumers
2) attacking the organisms used as food
3) restricting the competitors for common resources
4) attracting other organisms
5) regulation of interactions within a population,
group or kin
6) supplying precursor chemicals (e.g., precursors
of hormones or pheromones)
7) conditioning the environment, including aquatic
habitats
8) marking the environments and orientating the organisms
in time and space.
These functions are discussed in more detail in [1, 8]
with many examples of particular substances.
It should be underscored that there are several approaches
to classification of substances used in interactions
between organisms. One attempt at such classification
was undertaken by Whittaker and Feeny in
1971 (discussed in [1]). However, it has a substantial
disadvantage because it is based on an essentially anthropomorphic
concept of usefulness or benefit that organisms
gain from producing a certain chemical.
The concepts of ecological chemoregulators and
chemomediators proved useful for development and
modern interpretation of basic ideas of ecology [7, 24].
Biochemical ecology and biochemical hydrobiology.
Application of the approaches of biochemical
ecology to aquatic ecosystems unavoidably leads to the
idea of biochemical hydrobiology. This is appropriately
validated by the fact that aquatic organisms produce a
great variety of biologically active substances [1, 25,
26], many of which play ecologically important roles of
pheromones, toxins, repellents, antifeedants, etc. A review
of the existing data on the role of chemical signals
in the ecology of aquatic organisms is given in [1, 8].
The role of algal exometabolites is analyzed in [5]. Interesting
facts about the role of chemicals in the information
flow in freshwater ecosystems are covered in
[27, 28].
Some of the data forming the basis of biochemical
hydrobiology make important difference in comparison
with biochemical ecology of terrestrial organisms. At
least three groups of such facts can be emphasized.
First, excretion of fatty acids and other lipids with
properties of surface-active substances (SAS) into water
is of great importance. These natural SAS can be accumulated
on the water/air interface and form a surface
film. The chemical composition of this biogenic film
determines many of its properties, oxygen transfer
through it, heat balance of water surface and other important
parameters and processes [29]. Thus, biochemical
ecology and hydrobiology becomes intertwined
with ecological biophysics of aquatic systems and
hydrophysical processes of the ecosystem scale [29].
Second, the area of active research is the transport of
essential nutrients, including 3 polyunsaturated fatty
acids (PUFA), along food chains. Some available data
suggest that, under certain conditions, the composition
and amounts of PUFA can significantly influence the
functioning of populations and ecosystems. Thus, several
papers in this issue considering the problems of formation
and transfer of PUFA along side chains
(Sushchik and colleagues, Dubovskaya and colleagues)
are of great interest.
Third, natural bodies of water contain dissolved vitamins
[30].Water in lakes and ponds have been found
to contain vitamin B12 (0.001–0.85 g/l), thiamine
**
(0.001–12 g/l), biotin (0.0001–0.1 g/l), niacin (up to
3.3 g/l), pantothenic acid (up to 0.26 g/l), etc. (reviewed
in [30]). The presence of vitamins is due to their
production by some hydrobionts. For example, production
of vitamins by some cyanobacteria and associated
heterotrophic satellite bacteria has been shown [31].
The presence of vitamins in the water can possibly
stimulate those organisms that cannot produce these
chemicals on their own, providing yet another
possibility for interaction between organisms.
The common framework of all new information and
conceptual developments in biochemical ecology and
adjacent scientific disciplines is an increasingly deeper
perception of aquatic ecosystems with a multitude of
cooperative interactions between organisms to their direct
or indirect mutual benefits. The beneficial character
of these interactions is not always evident;
sometimes it appears that only one side benefits, although
in many cases it can be predicted that further
studies will find a mutually advantageous cooperation.
In some cases it may be possible to claim that aquatic
ecosystems are governed by the principle of synecological
cooperativity [32]. I am cautious to attempt any
generalization in this complex field; further studies
should help us to clarify the role of irreciprocally or
mutually beneficial interactions, includiong biochemical
ones, in the functioning of aquatic ecosystems.
Practical application of biochemical hydrobiology
will likely be in the modeling and prediction of the behavior
of aquatic ecosystems, optimization of screening
hydrobionts for potential drugs [1, 8, 25, 26], development
of aquaculture, deeper understanding of interactions
of pollutants with hydrobionts, and understanding
of molecular mechanisms and basics of the important
role that aquatic organisms play in the processes at the
ecosystem and biosphere scale.
CONCLUSIONS
The analysis of facts at the interface between ecology
and biochemistry shows the existence of a new
field of scientific knowledge, biochemical ecology. The
main concepts of biochemical ecology and biochemical
hydrobiology, its branch dealing with aquatic ecosystems,
are likely concerned with transfer of information
and regulatory interactions as chemical compounds.
The specific directions of practical applications of advances
in biochemical ecology and biochemical
hydrobiology encompass many economically important
areas, including aquaculture, environmental protection,
and prospecting for new drugs among the
secondary metabolites produced by hydrobionts. Further
studies of ecological chemomediators and ecological
chemoregulators will bring a better understanding
of the mechanisms of maintaining the ecological equilibrium
in the biosphere, which, paraphrasing Maximilian
Voloshin, is a world of tangible and steadfast
balance.
I thank many colleagues— A. S. Isaev,
V. A. Stonik, A. A. Zhuchenko, A. V. Kaluev,
A. O. Kasumyan, A. V. Oleskin, and others—for helpful
discussions. The help of O. S. Ostroumov is appreciated.
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Living Nature and Resources: Problems, Trends and
Prospects (Springer-Verlag, Berlin, 1991).
21. T. M. Dmitrieva, Basics of Sensor Ecology (RUDN,
Moscow, 1999) [in Russian].
22. S. A. Ostroumov, Ecological Studies, Hazards, Solutions
5, 83 (2001).
23. S. N. Novikov, Pheromones and Reproduction of Mammals
(Nauka, Leningrad, 1988) [in Russian].
24. S. A. Ostroumov, Dokl. Akad. Nauk 383, 571 (2002).
25. G. B. Elyakov and V. A. Stonik, Izv. Akad. Nauk. Ser.
Khim., No. 1, 1 (2003).
26. V. A. Stonik, Russian Chemical Reviews 70, 673 (2001).
27. A. F. Alimov, Elements of Theory of Functionality ofWater
Systems (Nauka, St. Petersburg, 2000) [in Russian].
28. E. S. Zadereev, Zh. Obshch. Biol. 63 (2), 159 (2002).
29. M. I. Gladyshev, Basics of Ecological Biophysics of Water
Ecosystems (Nauka, Novosibirsk, 1999) [in Russian].
30. B. Wetzel, Limnology (Academic Press, San Diego,
2001).
31. E. I. Andreyuk, Zh. P. Kopteva, and V. V. Zanina, Cyanobacteria
(Naukova Dumka, Kiev, 1990) [in Russian].
32. S. A. Ostroumov, Pollution, Self-Purification, and Recovery
of Water Ecosystem (MAKS-Press, Moscow,
2005) [in Russian].
**
innovative paper:
Reference:
S. A. Ostroumov.
On the Concepts of Biochemical Ecology and Hydrobiology:
Ecological Chemomediators. -
Contemporary Problems of Ecology, 2008, Vol. 1, No. 2, pp. 238–244.
http://5bio5.blogspot.com/2012/08/concepts-of-biochemical-ecology-and.html
**
DOI: 10.1134/S1995425508020100
Connection with the book Introduction to Biochemical Ecology: http://www.scribd.com/doc/63711272;
Indexed in the Web of Science.
**
In short: The paper explained the new terms (ecological chemomediators, ecological chemoregulators) that were coined in 1986 in the book S.A.Ostroumov ‘Introduction to Biochemical Ecology’. Since 1986, the book and the new terminology became a part of educational content of a number of courses in universities of at least five countries.
**
new concepts, biochemical ecology, hydrobiology, new terms, ecological chemomediators, ecological chemoregulators, ecology, chemicals, **
On the Concepts of Biochemical Ecology and Hydrobiology:
Ecological Chemomediators
S. A. Ostroumov
Lomonosov Moscow State University, Vorob’evy Gory, Moscow, 119992 Russia
Abstract—Earlier, the author published two books and some papers, in which he described conceptual foundations of new scientific disciplines—biochemical ecology and biochemical hydrobiology. These trends in research include studies of the role of chemical substances in interorganismal interactions, in communication and regulation of supraorganismal systems. Another part of biochemical ecology concerns studies of the fate and transformation of external chemical substances when they interact with the organisms. Both natural and man-made compounds are interesting for biochemical ecology. The basic concepts of biochemical ecology include ecological chemomediators and ecological chemoregulators that have already been included in the body
of modern conceptions and are used in modern ecological literature. Application of biochemical ecology to aquatic ecosystems contributes to the basis for development of biochemical hydrobiology.
DOI: 10.1134/S1995425508020100
**
Text of the paper:
The founding concepts of biochemical ecology were
formulated in the book “Introduction to biochemical
ecology” [1], published in 1986. The author had offered
a unified view of many facts on the border between
ecology and biochemistry, based on a number of previous
works [e.g., 2] and being in agreement with the approach
outlined in [3–5]. The further developments in
this field [e.g., 6–8] have endorsed the expediency of
distinguishing this direction of research, rooted in Vernadsky’s
doctrine of biosphere [9–12]. The present paper
summarizes several in-depth reviews [1, 8, 22] to
provide a brief analysis of this interdisciplinary field of
science and introduce some key concepts and terms.
The idea of the importance of chemical approaches
for studies of ecological and biospheric processes and
relationships between organisms and the environment,
including the hydrosphere, was thoroughly developed
in the works by Vernadsky [9–12] who stated that the
ocean in general should be regarded, at its every point,
as an unbreakable link between dead inert matter and
ever-changing living matter, chemically restructuring
the inert environment [9]. Following Vernadsky, the
heterogeneous living matter in the ocean, the marine
life as a whole, can be viewed as a special mechanism,
changing the sea chemistry entirely [11].
According to Vernadsky [11], the Earth’s biosphere,
in addition to living, biogenic and inert matter, includes
bioinert matter, produced at the same time both by living
organisms and by inert processes and representing
dynamic equilibrium systems of both [9]. In the biosphere,
we encounter various forms of biospheric matter:
dead inert low-activity matter, alive disperse matter,
very active chemically and geologically, and bioinert
matter, a natural structure from alive and inert matter.
The alive matter is a form of activated matter [9].
The importance of engaging chemical and biochemical
approaches for understanding ecosystems and biocenoses
has been underscored by many Vernadsky’s
followers working in ecology and hydrobiology.
The subsequent development of natural sciences
brought new questions from the border zone between
ecology, chemistry, and biochemistry. Among them,
there is a prominent problem of how well integrated is
living matter and the biosphere in general and what
are molecular mechanisms of regulation of biospheric
equilibria (“ecological equilibria” in modern terms,
which still need to be defined more precisely) and formation
of bodies of organic matter in the biosphere.
Studies of the features of ecological equilibria in the
biosphere and the mechanisms of their maintenance and
disturbance, including those involving various organic
compounds, especially secondary metabolites are currently
gaining much importance [13–20]. The main
reasons of growing interest to these problems are multifaceted.
First, the advances in ecosystem science have understandably
led to the accumulation of a wealth of data regarding
the structure and functioning of ecosystems,
their dynamics and stability. This information lays the
foundation for a new stage in the development of ecology,
with an increasing attention given to the factors
that regulate the formation of ecosystems’ structure,
their dynamics and functioning. A deep analysis of
the concept of ecologic equilibrium, still insufficiently
clear, is urgently needed [7].
Second, improvements in the chemical and biochemical
techniques used to study living organisms and
their environment reveal new features of biochemical
processes and chemical compounds, especially second-
ISSN 1995-4255, Contemporary Problems of Ecology, 2008, Vol. 1, No. 2, pp. 238–244. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © S.A. Ostroumov, 2006, published in Sibirskii Ekologicheskii Zhurnal, 2006, Vol. 13, No. 1, pp. 73–82.
238
ary metabolites, mediating and regulating many interactions
between organisms [6, 8, 21].
Third, the human impact on the biosphere has risen
sharply, including dangerous chemical pollution. This
process is understandably worrying because of the
growing disturbance of ecological processes and ecological
equilibria in many areas of the biosphere
[15–20].
Fourth, the intensifying and developing aquaculture
and the general rise in the consumption of biological resources
pose a problem of engineering artificial ecosystems
with sufficient stability and capacity for regulation.
Understanding of the mechanisms of maintenance
and disturbance of ecological equilibria (or ecosystem
stability) is critically dependent on the rapidly growing
information from the borderlines between ecology, biochemistry,
chemistry, and physiology.
Some important aspects of these problems are subject
of study in the adjacent fields, such as physiology,
behavioral science, zoology, toxicology, biochemistry,
biophysics, etc. Usually, however, such studies are
mainly concerned only with facts from the particular
field and neglect general ecological points. These narrowly
specialized approaches to the chemical aspects of
ecological interactions between organisms are necessary
but not sufficient for appreciation of the mechanisms
of regulation and destabilization of ecosystems.
The vast number of chemically mediated interactions,
influences, dependences, and signals in biogeocenoses
form a complicated large-scale system. Only painstaking
interdisciplinary studies can help us to understand
these systems and learn how to manage them.
At this point, it is pertinent to discuss biochemical
ecology in general, its subject, object, and methods, and
the characteristic features distinguishing it from other
scientific disciplines.
The field of science at the interface between ecology,
chemistry, and biochemistry is sometimes called
chemical ecology. According to Barbier [3], living organisms
from both plant and animal kingdom influence
their environment through intersecting action of various
molecules. These interactions may occur between
animals, between plants, between plants and animals,
and between animals and plants. The impact of abiotic
environment on animals and plants should also be considered.
The study of such interactions and their
chemical effectors is the subject of chemical ecology.
This definition, analyzed from the ecological point
of view, is notable for dividing the interactions between
living organisms into two important groups. First, there
are interactions involving substances and molecules as
sources of energy or building blocks for the organisms
that consume them. The second type of interactions engages
molecules that serve mainly or exclusively as
messengers transmitting certain information or as regulators
of such ecological processes as flows of energy
and matter through ecosystems.
Biochemical ecology can be appropriately restricted
to the compounds of the second group. Furthermore,
there is no need to encumber biochemical ecology with
many problems of the impact of abiotic environment on
animals and plants [3], e.g., uptake of inorganic nutrients
by living organisms, etc.
What, then, represents the main subject of study of
biochemical ecology? However incomplete and preliminary
our answer may be, it is reasonable to define this
mainly as ecological interactions between organisms
and their high-order systems (populations and communities)
mediated by chemical compounds, mostly those
that act exclusively or preferentially as informationtransmitting
messengers or as regulators of ecological
processes [1, 8]. Some aspects of anthropogenic impact
upon the biosphere, such as chemical pollution, may
also be considered a subject of biochemical ecology
[13–20].
The main objects of biochemical ecology are biochemically
interacting organisms, populations, and
communities, the substances that mediate and regulate
the wide spectrum of ecological interactions (including
both trophic and nontrophic interactions), and biochemical
reactions utilizing these compounds. Importantly,
biochemical ecology regards chemical compounds
and biochemical reactions first of all as components
of ecosystems and participants of ecological processes
in the biosphere [1, 8]. This conceptually distinguishes
biochemical ecology from biochemistry, where
the same compounds may be studied as products of
intracellular metabolism disregarding the ecological
perspective and context.
The set of methods of biochemical ecology includes
a wide assortment of techniques from biochemistry,
bioorganic chemistry, chemistry of natural compounds,
and various bioassays for the substances under study or
their mixtures. In addition to traditional toxicological
approaches, these assays may address physiological or
behavioral reactions to the substances and preparations
under study. Carefully done sophisticated bioassays are
no less important for biochemical ecology than highly
sensitive methods of structural analysis of organic molecules.
Finally, the concluding phase of many studies in
this field is chemical synthesis of the discovered natural
compound following determination of its structure and
ecological role. Therefore, the inventory of biochemical
ecology also includes methods of organic synthesis.
The compounds studied by biochemical ecology, as
a rule, are present in the organisms or excreted by them
in much lower amounts than those used mainly as energy
sources or building materials. Many of classes to
which these compounds belong have long been studied
biochemically with respect to their structure and metabolism,
most (but not all) of them belonging to the group
of secondary metabolites.
**
Thus, the methods of biochemical ecology include
modern techniques of purification and structural analysis
of natural compounds, and methods of discovery of
ecological functions of organic compounds, many of
which were developed or perfected in the past decades
[1, 8]. High sensitivity of modern analytical assays is
essential for revealing the interactions between organisms.
Avery important group of signal or regulatory compounds
are pheromones. Many aspects of their role in
information transmission, inter-individual communication,
and regulation, have been thoroughly reviewed
[1]. Since then, many new data have appeared regarding
the role of pheromones in the ecology of aquatic
and terrestrial organisms.We believe that the canonical
definition of pheromones, given in the works of Karlson
and L
uscher (reviewed in [1, 8]), needs to be
amended. Taking new data and concepts into account,
we suggest the following working definition of pheromones:
Pheromones are individual compounds or their mixtures
(complexes, sets, or combinations), which are secreted
by organisms into their environment (aerial,
aquatic, or onto the organisms’ outer surface), and
which have a function in signaling, information transmission,
or influence on the respondents usually of the
same biological species; pheromones can cause a defined
reaction (behavioral, physiological, or developmental)
in the respondents; pheromones can act as
stimuli activating or inhibiting some reactions, behaviors,
or physiological processes in the respondents [22].
The appropriateness of this particular definition is
based on the accumulated body of information on
pheromones, discussed in [22].
Various aspects of pheromones and the related compounds
have been investigated by many scientists in
Russia. V.E. Sokolov initiated studies in this direction
at the Severtsov Institute of Ecology and Evolution.
The list of authors having actively published in the field
of pheromones includes A. S. Isaev, K. V. Lebedeva,
V. A. Minyailo, Yu. B. Pyatnova, M. Barbier, S. N. Novikov,
E. P. Zinkevich, and many others. Yu. P. Kozlov
and colleagues have studied pheromones of fishes from
Lake Baikal. A new direction, sensory ecology, is actively
developed [21]. The study of pheromones is a
very important direction in the field of chemical communication
of fishes [6] and other aquatic and terrestrial
organisms [1, 22, 23].
In addition to pheromones, other terms can be suggested
to facilitate the characterization of roles of
chemical compounds in signaling and regulation of interaction
between organisms and higher-order systems
[1].
The most general term ecological chemomediators
describes natural chemical compounds acting as mediators
in interactions between organisms, transferring information
during signaling from one organism to
another [1]. They include sex and aggregation pheromones,
food attractants, etc.
Ecological chemoregulators are compounds that
regulate behavior, physiology, and development of
other organisms [1]. This term embraces many pheromones
of both aquatic and terrestrial organisms, and
plant compounds acting on herbivorous animals (including
arthropods) to disturb their development and
reproduction (e.g., plant-derived compounds acting as
juvenile hormones, molting hormones, phytoestrogens,
etc.). Another group of ecological chemoregulators are
compounds made by plants (allelopathic agents) and inhibiting
other plant species. They act as natural herbicides,
used by plants to compete and leading to
regulation of population density and species composition
in plant communities.
Ecological chemoeffectors is the most common
term, denoting all substances, both natural and anthropogenic,
influencing the ecology of living organisms to
a certain degree [1, 21, 22].
The action of many ecological chemomediators and
chemoeffectors is mediated through their activation by
enzymatic biochemical reactions. An example is given
by a number of substances of plant origin that protect
plants against pathogenic fungi or phytophages. On the
other hand, biochemical reactions and evolution of the
respective enzymes are extremely important for detoxification
of potentially harmful compounds produced by
the organism’s ecological partners; co-evolutional adaptation
of fungi or insects and the plants they eat
proceeds in this way.
The mechanisms of detoxification and biodegradation
of xenobiotics are becoming especially significant
because of the large-scale chemical pollution of
modern ecosystems. Detoxification and biodegradation
of the polluting agents usually employ the same biochemical
mechanisms that the cells use to neutralize
natural toxic substances or xenobiotics. Importantly,
chemical pollution of the environment can disrupt
chemical communication between organisms, which
involves ecological chemomediators, chemoeffectors,
and chemoregulators, as defined above. Therefore, the
problems of chemical pollution [13–17] can also be
regarded as part of biochemical ecology.
To conclude this brief description of the basic concepts
of biochemical ecology, it is worthy to underscore
its relations with the field that is increasingly termed
chemical ecology [3] or ecological biochemistry [4].
The above discussion shows that biochemical ecology
is distinct from and narrower than chemical ecology, if
the latter is defined, following M. Barbier, as chemistry
applied to ecology. Ecological biochemistry, sometimes
placed at the interface between ecology, chemistry,
and biochemistry, should encompass biochemical
mechanisms of adaptation of organisms to their environment,
and purely biochemical aspects of metabolism
of ecologically important compounds and mechanisms
of detoxification of xenobiotics. Biochemical
**
ecology is closer to ecology, while ecological biochemistry
is closer to biochemistry.
It must be reiterated that the above discourse is not
an attempt to give some set definitions but rather an invitation
to discuss a modern, highly dynamic and not
yet finally shaped field at the interface between many
traditional scientific disciplines and directions, not limited
to those already mentioned. This multitude of science
disciplines includes biogeochemistry, toxicology
and ecotoxicology, aquatic chemistry, studies of
“ecometabolism” and marine biochemistry (e.g., works
of Khailov [2]), public health aspects of hydrobiology
(see [8]), biochemical pharmacology, biochemical systematics,
chemistry of secondary metabolites and natural
compounds, etc. It will take time to provide final
definitions and draw firm borders between these
disciplines; to do so now is premature.
What can biochemical ecology contribute to solving
the problems of nature conservation and management,
biotechnology, and aquaculture? A brief answer (see
chapter 7 in [8] for a detailed discussion) requires consideration
of both theoretical and practical aspects.
From the theoretical point of view, biochemical ecology
brings into view yet another side of the material basis
of ecological equilibria in the biosphere. If one
compares energy and material flows in the ecosystems
to the street traffic, the compounds discussed here will
play the role of traffic lights or traffic police. Biochemical
ecology only starts to disentangle this complicated
system of ecological chemoregulators, which make an
important contribution to homeostasis and homeokinesis
(stability sensu lato) of ecosystems, including
aquatic ones.
Theoretical foundations of biotechnology will likely
benefit from the ideas of biochemical ecology that explain
the raison d’etre of secondary metabolites and
other biologically active substances, which are among
the most important objects of biotechnology despite the
lack of conceptual knowledge about their functions.
Furthermore, the biochemical-ecological approach
seems appropriate in the analysis of principles and
mechanisms of formation and functioning of producer
cells important in biotechnology.
From the practical point of view, biochemical ecology
together with other scientific disciplines can contribute
to lowering the pollution of the biosphere. Some
ways to achieve this include:
1) Increasing the self-purification capacity of natural
and anthropogenic ecosystems, including aquatic
ones [13–17]. Biotechnology and genetic engineering
can be promising here to construct and manage microorganisms
with an enhanced ability to destroy pollutants
[1, 8].
2) Development and introduction of compounds and
materials with increased capability for destruction in
the environment.
3) Lowering the use of pesticides through introduction
of alternative ways of population control [1, 8].
Such approaches would play a significant role in decreasing
human ecological footprint and lowering the
amount of pollutants introduced into the biosphere.
It has been pointed out that one aspect very important
for conservation is making consumption of all
biospheric resources more “green” [18–20]. This
means a significantly higher level of ecological competence
both when exploiting natural resources (including
marine and freshwater bioresources) and when constructing
any new ecosystem, either aquaculture or
biogeocenosis designed to processing and treatment of
sewage and polluted water. Knowledge of biochemical
ecology of the respective organisms and ecosystems allows
one to see an important aspect of their self-regulation
and maintenance of the stability of these
populations and biogeocenoses. Moreover, biochemical
ecology provides a key for practical management
and fine-tuning of ecological objects and processes, because
it reveals regulatory ecological functions of various
substances intrinsic for a given population or
ecosystem, and these compounds can be made and introduced
to biogeocenoses at will, varying time and
place of the intervention. Some of these problems have
been reviewed in several chapters of [1, 8].
No discussion of problems of biochemical ecology
is complete without mentioning biotransformation of
xenobiotics (both natural and anthropogenic) in organisms
and ecosystems. This topic is given a concise treatment
in chapter 6 of the book [8]. A more detailed
analysis of these problems is beyond the scope of this
brief review.
At this point, it is prudent to bring up several terms
of chemical and biochemical ecology often mentioned
in the literature.
1. Allelochemical (from the Greek , or
— reciprocal, (to) each other) is a substance
that has a certain ecological value (but not as an energy
source) for organisms belonging to biological species
other than the organism producing this substance. This
does not exclude the possibility that allelochemicals
can ultimately become important for their producers. A
wide class of substance can be considered allelochemicals
(chapters 2–4 and section 5.2 in [8]). At the
same time, they do not include such important substances
as pheromones [3, 4, 9, 21, 23] and some autoinhibitory
allelopathic agents (chapter 3 in [8]).
2. Exometabolite is a substance excreted to the environment
and generally believed to have some ecological
significance (not simply a waste product). The
etymology of this term is interesting; it is derived from
the Greek root with two Greek prefixes. The
first prefix, (
before vowels) means separation or
origin, also identifying movement from the inside to the
outside. The second prefix, , denotes commonality,
joint action, intermediate, sequence in space or
**
time, change, or movement. The term stems from the
word , a polysemantic verb meaning “to throw”
(as well as to put something on, to expel, to vent, to
pour, to sprinkle and even to get pregnant).
Exometabolites are a very wide and important class of
substances, especially important for understanding
aquatic ecosystems [1, 5, 8]. However, this concept is
hard or impossible to apply to many ecologically important
substances of terrestrial ecosystems, which can
act without being excreted to the environment, such as a
number of substances important for ecobiochemical
interactions of plants with fungi and animals.
3. Semiochemical is a substance that can de defined
[8] as a chemical involved in signal, information, or
other similar nontrophic interactions between organisms.
In practice, however, this term is used more narrowly
and applied to pheromones and some other
substances, including kairomones and allomones
(chapter 5 in [8]); many toxic substances of high ecological
importance are not adequately described by this
term because of its meaning. The first and fundamental
part of this word is derived from Greek
(... )—characteristics, symbol, sign, token, cue,
signal, banner, seal, etc. As such, the term “semiochemical”
is used in the cases when a chemical acts as a
signal, mark, or carrier of some information. At the
same time, many chemicals, e.g., toxins and chemosterilants
(chapters 2, 4 and 5 in [8]) and allelochemicals
(chapter 3 in [8]) use not as signals but more
directly, simply killing or sterilizing other organisms or
inhibiting their growth. Thus, the term semiochemical
is not universal either and not as widely encompassing
as some authors tend to define it.
These important definitions illustrate the point that
ecobiochemical interactions are very diverse. They are
analyzed in [1, 8], where ecological functions of chemicals
are used as a base to systematically explore a great
multitude of organisms and substances combined into a
single ecobiochemical continuum typical of biosphere
and especially of hydrosphere.
The wide diversity of producers of ecological
chemomediators and a great number of chemical structural
scaffolds of secondary metabolites should not
conceal the fact that the variety of the functions of these
compounds is limited. The following list of the most
important functions is by no means exhaustive [1, 8]:
1) protection from consumers
2) attacking the organisms used as food
3) restricting the competitors for common resources
4) attracting other organisms
5) regulation of interactions within a population,
group or kin
6) supplying precursor chemicals (e.g., precursors
of hormones or pheromones)
7) conditioning the environment, including aquatic
habitats
8) marking the environments and orientating the organisms
in time and space.
These functions are discussed in more detail in [1, 8]
with many examples of particular substances.
It should be underscored that there are several approaches
to classification of substances used in interactions
between organisms. One attempt at such classification
was undertaken by Whittaker and Feeny in
1971 (discussed in [1]). However, it has a substantial
disadvantage because it is based on an essentially anthropomorphic
concept of usefulness or benefit that organisms
gain from producing a certain chemical.
The concepts of ecological chemoregulators and
chemomediators proved useful for development and
modern interpretation of basic ideas of ecology [7, 24].
Biochemical ecology and biochemical hydrobiology.
Application of the approaches of biochemical
ecology to aquatic ecosystems unavoidably leads to the
idea of biochemical hydrobiology. This is appropriately
validated by the fact that aquatic organisms produce a
great variety of biologically active substances [1, 25,
26], many of which play ecologically important roles of
pheromones, toxins, repellents, antifeedants, etc. A review
of the existing data on the role of chemical signals
in the ecology of aquatic organisms is given in [1, 8].
The role of algal exometabolites is analyzed in [5]. Interesting
facts about the role of chemicals in the information
flow in freshwater ecosystems are covered in
[27, 28].
Some of the data forming the basis of biochemical
hydrobiology make important difference in comparison
with biochemical ecology of terrestrial organisms. At
least three groups of such facts can be emphasized.
First, excretion of fatty acids and other lipids with
properties of surface-active substances (SAS) into water
is of great importance. These natural SAS can be accumulated
on the water/air interface and form a surface
film. The chemical composition of this biogenic film
determines many of its properties, oxygen transfer
through it, heat balance of water surface and other important
parameters and processes [29]. Thus, biochemical
ecology and hydrobiology becomes intertwined
with ecological biophysics of aquatic systems and
hydrophysical processes of the ecosystem scale [29].
Second, the area of active research is the transport of
essential nutrients, including 3 polyunsaturated fatty
acids (PUFA), along food chains. Some available data
suggest that, under certain conditions, the composition
and amounts of PUFA can significantly influence the
functioning of populations and ecosystems. Thus, several
papers in this issue considering the problems of formation
and transfer of PUFA along side chains
(Sushchik and colleagues, Dubovskaya and colleagues)
are of great interest.
Third, natural bodies of water contain dissolved vitamins
[30].Water in lakes and ponds have been found
to contain vitamin B12 (0.001–0.85 g/l), thiamine
**
(0.001–12 g/l), biotin (0.0001–0.1 g/l), niacin (up to
3.3 g/l), pantothenic acid (up to 0.26 g/l), etc. (reviewed
in [30]). The presence of vitamins is due to their
production by some hydrobionts. For example, production
of vitamins by some cyanobacteria and associated
heterotrophic satellite bacteria has been shown [31].
The presence of vitamins in the water can possibly
stimulate those organisms that cannot produce these
chemicals on their own, providing yet another
possibility for interaction between organisms.
The common framework of all new information and
conceptual developments in biochemical ecology and
adjacent scientific disciplines is an increasingly deeper
perception of aquatic ecosystems with a multitude of
cooperative interactions between organisms to their direct
or indirect mutual benefits. The beneficial character
of these interactions is not always evident;
sometimes it appears that only one side benefits, although
in many cases it can be predicted that further
studies will find a mutually advantageous cooperation.
In some cases it may be possible to claim that aquatic
ecosystems are governed by the principle of synecological
cooperativity [32]. I am cautious to attempt any
generalization in this complex field; further studies
should help us to clarify the role of irreciprocally or
mutually beneficial interactions, includiong biochemical
ones, in the functioning of aquatic ecosystems.
Practical application of biochemical hydrobiology
will likely be in the modeling and prediction of the behavior
of aquatic ecosystems, optimization of screening
hydrobionts for potential drugs [1, 8, 25, 26], development
of aquaculture, deeper understanding of interactions
of pollutants with hydrobionts, and understanding
of molecular mechanisms and basics of the important
role that aquatic organisms play in the processes at the
ecosystem and biosphere scale.
CONCLUSIONS
The analysis of facts at the interface between ecology
and biochemistry shows the existence of a new
field of scientific knowledge, biochemical ecology. The
main concepts of biochemical ecology and biochemical
hydrobiology, its branch dealing with aquatic ecosystems,
are likely concerned with transfer of information
and regulatory interactions as chemical compounds.
The specific directions of practical applications of advances
in biochemical ecology and biochemical
hydrobiology encompass many economically important
areas, including aquaculture, environmental protection,
and prospecting for new drugs among the
secondary metabolites produced by hydrobionts. Further
studies of ecological chemomediators and ecological
chemoregulators will bring a better understanding
of the mechanisms of maintaining the ecological equilibrium
in the biosphere, which, paraphrasing Maximilian
Voloshin, is a world of tangible and steadfast
balance.
I thank many colleagues— A. S. Isaev,
V. A. Stonik, A. A. Zhuchenko, A. V. Kaluev,
A. O. Kasumyan, A. V. Oleskin, and others—for helpful
discussions. The help of O. S. Ostroumov is appreciated.
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3. M. Barbier, Introduction to Chemical Ecology (Mir,
Moscow, 1978) [Russian translation].
4. J. Harborn, Introduction to Ecological Biochemistry
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(Mosk. Gos. Univ., Moscow, 1984) [in Russian].
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Gos. Univ., Moscow, 2002) [in Russian].
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**