4 Use of Radioisotopic Methodology
in Aquatic Microbial Ecology
4.1 Introduction
Microbial ecology is among the most important options in hydrobiological
studies of water basins simply because the aquatic microbial communities
are indisputable main agents, which provide the cycling of elements in water
habitats, the energy flows, the self-purification processes, the production
and decomposition of organic matter, and the buildup of particulated food
resources for the hydrofauna. The share of bacterial population in wholecommunity respiration and energy flow are evaluated within 40 to 90%
(Sorokin 1972a, 1978b, 1981c; Fenchel and Blackburn 1979; Cole et al. 1988).
At present, microbial ecology is among the most successful and rapidly developing branches of hydro biology. The most significant problems which are faced
now by microbial ecology are:
1. The characterization of microbial communities as the structural components of planktonic and benthic subecosystems, including their cell size,
composition, and morphology, their aggregation state, their ability to form
microbiocoenosess around particles and within the surface film, their
spatial distribution, and their density, expressed as the total number of
microbial cells and the biomass.
2. The evaluation of possible energy sources needed to support the functional
activity and the biomass reproduction of aquatic microbial communities
and the location of microbial activity in native environments.
3. Measuring in situ rates of microbial processes of organic matter production
and decomposition, the separation of the processes of heterotrophic and
autotrophic bacterial production.
4. The evaluation of the importance of natural microbial populations as the
components of aquatic food webs.
5. The evaluation roles of microbial populations in the cycling of
nutrients and other biologically important elements such as S, Fe, Mn, and
Co.
Each of the problems listed above needs an appropriate experimental
resolution. The use of radioisotopes in this field has completely transformed
the methodological base of traditional aquatic microbiology. The letter needs
a lot of sterile glassware and cultivation media, as well as sterile water bottles
for sampling, while repaying the efforts with minor knowledge about the
ambiental microbial populations and their in situ activities because only a part
in Aquatic Microbial Ecology
4.1 Introduction
Microbial ecology is among the most important options in hydrobiological
studies of water basins simply because the aquatic microbial communities
are indisputable main agents, which provide the cycling of elements in water
habitats, the energy flows, the self-purification processes, the production
and decomposition of organic matter, and the buildup of particulated food
resources for the hydrofauna. The share of bacterial population in wholecommunity respiration and energy flow are evaluated within 40 to 90%
(Sorokin 1972a, 1978b, 1981c; Fenchel and Blackburn 1979; Cole et al. 1988).
At present, microbial ecology is among the most successful and rapidly developing branches of hydro biology. The most significant problems which are faced
now by microbial ecology are:
1. The characterization of microbial communities as the structural components of planktonic and benthic subecosystems, including their cell size,
composition, and morphology, their aggregation state, their ability to form
microbiocoenosess around particles and within the surface film, their
spatial distribution, and their density, expressed as the total number of
microbial cells and the biomass.
2. The evaluation of possible energy sources needed to support the functional
activity and the biomass reproduction of aquatic microbial communities
and the location of microbial activity in native environments.
3. Measuring in situ rates of microbial processes of organic matter production
and decomposition, the separation of the processes of heterotrophic and
autotrophic bacterial production.
4. The evaluation of the importance of natural microbial populations as the
components of aquatic food webs.
5. The evaluation roles of microbial populations in the cycling of
nutrients and other biologically important elements such as S, Fe, Mn, and
Co.
Each of the problems listed above needs an appropriate experimental
resolution. The use of radioisotopes in this field has completely transformed
the methodological base of traditional aquatic microbiology. The letter needs
a lot of sterile glassware and cultivation media, as well as sterile water bottles
for sampling, while repaying the efforts with minor knowledge about the
ambiental microbial populations and their in situ activities because only a part