DISTRIBUTION AND VARIABILITY OF THE HETEROTROPHIC, COLIMORPHIC AND LACTIC ACID BACTERIA NUMBER IN WATER AND AQUATIC ORGANISMS OF THE BLACK SEA

Abstract

Currently, there is an active revision of established positions in classical microbiology, both in the area of sanitary-microbiological indicators of water quality and the search for groups of microorganisms that were previously thought to be not to be present in seawater and the microbiota associated with its inhabitants. The results of the study of the numbers of the main groups of microorganisms that make up proxy indices for sanitary-microbiological indicators and the numbers of lactic acid bacteria were shown in this article.The aim of this study was to compare the total microbial number, lactic acid bacteria and colimorphic bacteria in sea water in microbiota associated with its inhabitants depending on the season. Materials and methods. To study the abundance index of various groups of microorganisms, classical microbiological methods were used. To calculate the presence of a relationship between signs, we used the «corrplot» package in program R 3.4.0.Research results. The presence of lactic acid bacteria in the water of the Black Sea and among the associated microbiota of aquatic organisms has been shown for the first time. It was shown that the maximum abundance of this group in water (1.5 ± 0.33×104 CFU/ml) was recorded in July, and the maximum abundance among the associated microbiota (1.66 ± 0.61×104CFU/ml) was recorded in October. The distribution of the number of colimorphic bacteria and bacteria that grew on bismuth-sulfide agar in the study of seawater was the opposite, and in the study of the associated microbiota was the same. The maximum of the total microbial contamination in water was recorded in October (1.1 ± 0.7×106 CFU/ml) in the associated microbiota of aquatic organisms in July. Correlation relationships between the number of bacteria characterizing the total microbial contamination, colimorphic bacteria and lactic acid microorganisms was revealed. Seasonal changes in the number of the studied groups of microorganisms were shown.Conclusions. Various principles of the distribution of heterotrophic, colimorphic and lactic acid microorganisms depending on the season and place of excretion have been identified.