Transformation of the structure of microbial communities in the process of Fe (III) reduction in the bottom sediments in lake Serebryanka (Samarskaya Luka)

The research results of the structure of microbial communities of detrital silt in lake Serebryanka (Samarskaya Luka), taking part in the biogeneze mineral vivianit - Fe 3(PO 4) 2 × 8H 2O are represented. The formation of vivianit took place in model experiment in anaerobic process of Fe(III) reduction. Dominant species in natural microbial community of silt, involved in formation of fosfat-holding the minerals iron are representatives of the genera Butyrivibrio, Clostridium, Eubacterium, Fe(III)-reducing bacteria ( Shewanella, Desulfuromonas, Geobacter, Geovibrio ), Desulfovibrio. The species Spirochaeta "M", Bacillus, Propionibacterium, Actinomadura, Nocardia, Rhodococcus, Pseudonocardia also are active. In the process of anaerobic Fe(III) reduction aerobic and mikroaerofil hemoorganotrofic organisms with respiratory type of metabolism accomplishing decomposition of cellulose, hydrocarbons, ammonifixing, azotfikxing, oxidation of iron were depressed or quitted community. Anaerobic fermentantes, dissimilatory Fe(III)-reducing bacteria, sulfate-reducing bacteria, nokardioformic аctinomyces, some types of anaerobic hemoorganotrofs, on the contrary, became active.