i.e., the type of water-body. Through the efforts of Soviet Scientists, 

 the total number of bacteria has been investigated in detail in waters of 

 differing type. These investigations may, in general outline, be repre- 

 sented as in Table 1 . 



TABLE 1. CONTENTS OF BACTERIA IN WATERS OF VARYING TROPHIC DEGREE. 



Type of Quantity of Bacteria - 

 Water-Body mln/ml Water-Body 



Oligotrophic 0.1-0.5 Lakes Onega, Baikal 



Mesotrophic 0.5-1.5 Rybinskoe Reservoir 



Eutrophic 1.5-10 Tsymlyanskoe, Kakhovskoe 



Reservoirs 



Oistrophic 1.5-3 Lake Melnezers in Latvia 



In water-bodies of the oligotrophic type with clean water, the number 

 of bacteria varies from 0.1 to 0.5 mln/ml. With an increase in the 

 trophic degree, the number of bacteria also increases. In mesotrophic 

 water bodies the number reaches 0.5-1.5 mln/ml, and in eutrophic waters, 

 1.5 to 10 mln/ml. Distrophic waters are distinguished by high water 

 color values. The content of bacteria in them are the similar to the 

 mesotrophic condition, but the activity of these forms is considerably re- 

 duced. 



The methodology associated with determination of the total number of 

 bacteria in water appeared as a result of the development of the ideas of 

 Vinogradski (1952) on the content of bacteria in soils. There are several 

 varieties of estimated strengths of bacteria in water (Kuznetsov and 

 Karzinkin, 1930). The most suitable of these methodologies, used at the 

 present time by most research workers, is the one suggested by Razumov 

 (1932). 



For calculation of bacterial numbers, 1 to 50 ml of water, depending 

 on the trophic degree of the water body, is filtered through a membrane 

 filter with a pore size 0.2-0.3 mm. The filters are dried, stained with 

 laboratory conditioned erythrosine and the cell production is counted 

 under the immersion microscope. Calculations are made with due considera- 

 tion of the volume of filtered water (Rodina, 1965). 



Determination of Living Bacteria by the Method of Titer in Sterile Water 

 Using C-Hydrolysate of Protein 



A distinguishing feature of many microorganisms is the fact that they 

 do not develop on classic nutrient media (meat-peptone agar, meat-peptone 

 gelatine, etc.). As has been demonstrated (Romanenko, 1973), they grow 



57 



