ЕКОЛОГО-ТРОФІЧНІ ГРУПИ МІКРООРГАНІЗМІВ ВОДИ ОЗЕРА ЯВОРІВСЬКЕ

Abstract

The chemical composition of Yavorivskе lake water in the autumn of 2016 at different depths (0−70 m) was investigated and the main ecological trophic groups of microorganisms, involved in transformation of carbon, nitrogen and sulfur compounds, were studied. Acidity, mineralization and Na + , Ca 2+ , Mg 2+ , HCO 3 - , Cl - and NO 3 - content at all depths, K + , P 2 0 5 and NH 4 + at depths up to 20–50 m were insignificant and did not exceed the permissible norms. At all depths the content of SO 4 2- (913–1530 mg/l) and H 2 S (30–34 mg/l) at depths over 30 m significantly exceeded the norms. It was established that the change in the quantity of different ecological trophic groups of microorganisms and their ratio in the lake water, compared with the source type reservoir of Roztochya reserve, is an adaptive response of the microbial community to stress environmental factors. The total quantity of all ecological trophic groups of microorganisms in water of Yavorivske lake with depth decreases from 5.24×10 6 to 2.45×10 6 CFU/ml of water and is 2–5 times lower than in the control: 1.28×10 7 CFU/ml of water. In Yavorivske lake is formed new microbocenosis, in which on the surface and at depth of 30 m the most numerous ecological trophic groups are neutrophilic colorless sulfur oxidizing bacteria (39.3 and 13.3 %), microorganisms that use organic forms of nitrogen (21.6 and 42.9 %), nitrifying (7.3 and 9.4 % of phase I, 13.5 and 4.9 % of phase II of nitrification), denitrifying (7.1 and 11.3 %), oligonitrophilic bacteria (4.4 and 5.1 %), microorganisms that use mineral forms of nitrogen (5.8 and 1.4 % respectively) and phototrophic nonsulfur bacteria (4.9 % at depth of 30 m). Sulfate and sulfur reducing (42.9 and 44.9 %), phototropic sulfur (2.7 and 4.5 %) and nonsulfur bacteria (4.4 and 3.7 % respectively) are the most numerous ecological trophic groups of microorganisms at depths of 50 and 70 m of the lake. The quantity of acidophilic colorless sulfur oxidizing bacteria, cyanobacteria, cellulose degrading microorganisms and microscopic fungi at all depths was insignificant. In control the most numerous ecological trophic groups are microorganisms that use organic forms of nitrogen (28.3 %), oligonitrophilic (25.6 %), nitrifying (23.5 % of phase II and 15.7 % of phase I of nitrification), neutrophilic colorless sulfur oxidizing bacteria (3.0 %), microscopic fungi (1.9 %). Their number, besides neutrophilic colorless sulfur oxidizing bacteria, is much higher than in Yavorivske lake water.