2. Production of Microflora . (Yu. I. Sorokin) 



The microflora of the seas and oceans is represented by 

 heterotrophic bacteria and fungi (mold, fungi, actinomycetes, yeast). 

 Among these, the bacteria have the greatest significance from the 

 standpoint of participation in production and metabolism of the 

 community. Some researchers also include phytoplankton and 

 heterotrophic zooflagellata among the marine microflora (Wood, 1965), 

 but this is ecologically unjustified. 



The microflora represent the most important components in the 

 marine ecosystems (Sorokin, 1971a, 1971b, 1973c). It represents over 

 60%, usually about 80%, of the total energy flow passing through the 

 heterotrophic portion of the community, and over 50% of all expenditures 

 of the community in metabolism (Table 4, Fig. 12). 



Considering that the effectiveness factor of biosynthesis (K^) for 

 bacteria is close to that of aquatic invertebrates--about 0.25--we must 

 consider that the production of the microbial population is 

 significantly greater than the total production of protozoa, and all 

 remaining forms of zooplankton. Therefore, a reliable estimate of 

 biomass, production and metabolism of the microbial population is a 

 necessary condition for an accurate ecologic analysis of marine 

 ecosystems. In this section, we shall study primarily the production 

 phase, as well as a few problems of the biogeochemical activity of 

 marine microflora, directly related to the processes of biosynthesis and 

 destruction. 



2.1 Methodologic Problems 



In order to determine the productive significance of the microflora 

 in marine communities, we must determine the characteristics of the 

 vertical structure of microbial communities and their aggregation; 

 biomass, production, and metabolic rate of the microbial population; 

 sources of energy for bacterial biosynthesis; food value of microbes; 

 contribution of microbes to production, metabolism and transformation of 

 energy in marine ecosystems. 



The production of microflora in bodies of water is determined by 

 holding freshly taken samples of water in bottles for 12-24 h at the 

 temperature in situ . The intensity of multiplication of the 

 bacterioplankton in the bottles is measured on the basis of the increase 

 in population (comparison of total number of bacteria at the beginning 

 and at the end of exposure by direct counting) or by measurement of the 

 intensity of biosynthesis. This is determined primarily by the 

 radiocarbon method (Sorokin, 1971a, 1973g). The method was offered by 

 Romanenko (1964) for fresh water. It is based on the existence of an 

 empirical relationship between the dark assimilation of 



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