Tarabas O. Transformation of Sulfur and Nitrogen compounds by phototrophic purple bacteria isolated from man-made environment

In this dissertation we have investigated the patterns of use of sulfide and nitrite ions in a model environment and wastewater by phototrophic purple non-sulfur bacteria Rhodopseudomonas yavorovii IMB B-7620, isolated from the man-made Lake Yavorivske, and it is established the ability of these bacteria to generate electric current and produce hydrogen under different conditions cultivation. The amount of photosynthetic non-sulfur bacteria (PNSB) in the water of Lake Yavorivske and the spring-type water of the Roztochya reserve was determined in this work for the first time, and it was demonstrated that at a depth of 30 m, the number of PNSB was the highest and 21.8 times higher compared to the control. The abundance of PSB was the greatest at depths of 50 and 70 m and 222 and 314 times higher than the control, respectively. A strain of purple non-sulfur bacteria Ya-2016 was isolated from the water of Lake Yavorivske, which actively metabolizes organic substances and inorganic compounds of sulfur and nitrogen. The isolated purple non-sulfur bacteria Ya-2016 are motile, have a vibrioid shape, are negatively Gram-stained, do not form spores, belong to neutrophilic (optimal pH 6.8–7.3), mesophilic (optimal temperature 27…30 ºС) microorganisms. According to the results of sequencing of the conserved region of the 16S rRNA gene (GenBank accession number OL711631), it was established that the nucleotide sequence of bacteria strain Ya-2016 showed high similarity (99 % of identical residues in pairwise alignment by BLASTN) to the 16S rRNA of bacteria Rhodopseudomonas sp. A7, Rhodopseudomonas sp. J5-3, Rhodopseudomonas palustris DX-1, but the isolated bacteria differ from them in some of their physiological and biochemical properties. According to the results of the above-described studies, bacteria of the Ya-2016 strain were identified as representatives of the genus Rhodopseudomonas, and the name Rhodopseudomonas yavorovii IMV B-7620 was given to them (Certificate of deposit of the bacterial strain Rhodopseudomonas yavorovii Ya-2016 in the Depository of the D.K. Zabolotny Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine from 01.08.2017).