ANTROPOGENIC LOAD INFLUENCE ON MYCOBIOTA AND SANITARY STATE OF MUNICIPAL SAND BEACHES IN SAINT-PETERSBURG
Aim. The aim of the study was to identify seasonal dynamics of the quantity of fungi and bacteria in the beach sand, to establish the genera dominant in terms of the frequency and abundance and the types of microscopic fungi and to assess the microbiological features of the studied beaches. Material and methods. The sand from the beaches of park named after the 300th anniversary of St. Petersburg, Kurort village, and the Peter and Paul Fortress was studied. The beaches can be considered equitable in terms of recreational load. Sand samples were obtained 4 times during the year - in the winter (February), in the spring (May), in the summer (July) and in the fall (October) in 2008-2009. A total of 81 sand samples were examined. Czapek’s medium containing chloramphenicol for the purpose of fungi isolation and meat-peptone agar were used to account for bacteria cultures. Fungi were cultivated for 7-10 days at a temperature of 25°С. Bacteria were cultivated for 3-4 days at a temperature of 28-30°С. Determination of the quantitative content of organic matter was carried out by the gravimetric method with heating in a mufﬂe furnace. Results and discussion. Analysis of annual dynamics of fungi and bacteria quantity showed than bacteria is growing on all beaches during the year, reaching its maximum in October, which can eventually be explained by vegetation season, organics accumulation and anthropogenic pollution during the recreational season. According to this data we can make a conclusion, that the quantity of important microorganisms and micro-fungi in terms of sanitation is tightly related to the presence of organic substrate in the sand, such as anthropogenic pollution, for instance. Decomposition of such debris occurs with the help of the group of fast-growing enzyme-active kinds of fungi, many of which belong to the group of degraders and are potentially harmful for humans. The members of these groups, such as the species from Aspergillus, Chaetomium, Cladosporium, Penicillium, Trichoderma genera were noted as dominating on all studied beaches. 90% of revealed dominating species were degraders and about 60% are potentially harmful for humans. In average 69% of all types of microfungi, speciﬁed on the beaches in the study, belong to potential pathogens of the III-IV group of hazard. An average of 54% of fungi species belong to the group of degraders. Conclusion. The present study showed that the city beaches, especially small and having high recreational load are considerably affected by organic and microbial contamination, which usually reaches its maximum during summer recreational season. About 70% of all types of micromycetes, found in city beaches sand, are potentially harmful for human. Its high count can appear as a sanitary problem. Beach microbiological quality evaluation method development and sanitary control procedure implementation is needed.