ISOLATION, PHENOTYPIC AND MOLECULAR CHARACTERIZATION OF ANAEROBIC ARSENATE REDUCING AND ARSENITE OXIDIZING BACTERIA FROM LAKE VAN AND DETERMINATION OF THEIR ARSENIC METABOLISM
Project no. 531 · Status: Kapanmış · 2015
Summary
Arsenic is responsible for water source contamination in many places in the World and presents a serious health risk for people. Due its growing threat on public health, arsenic bioremediation and thus arsenic resistant bacteria isolation and determination of their metabolism has started to become essential. Van lake was chosen for arsenic resistant bacteria isolation by the reasons of being the largest soda lake in the World with,having similar properties with the lakes which arsenic resistant bacteria have been isolated and also lack of studies(publication) in this context. It was aimed to isolate arsenate reducing and arsenite oxidizing anaerobic bacteria from Van Lake; phenotyping and molecular identification and determination of arsenic metabolism. As a result of 4 seasonal sampling, totally 81 arsenic resistant bacteria were obtained and their phenotypical and biochemical characteristics were determined. After cleaving 16S rRNA gene regions with restriction enzymes, 26 isolates were chosen accprding to their different band patterns and studies were continued with these isolates In conclusion, it was determined that Van Lake’s total arsenic amount changes seasonally and its highest concentration 26.070 ppb taken from sediment sample in fall. Isolates which are showing arsenic resistant isolates belonged to 8 different genus (Halomonas, Alkalimonas, Idiomarina, Marinobacter, Branchybacterium, Anaerobacillus, Microbacterium and Nitrincola), 7 strain were identified at species level, 18 strains were identified not more than genus level. Phsychochemical parameters effects on microbial activity, profiling of resistance against arsenate and arsenite and their determination of and susceptibilities to several antimicrobial agents conducted in both aerobic and anaerobic conditions and oxigenic conditions have an increasing or decreasing effect on growth within these parameters. 2 Anaerobacillus strains were seperated from other strains by its oxygen requirement in regard to being obligatory anaerobic. All arsenic resistant strains, hold their resistance gene regions on their chromosomes instead of plasmids and have arsC resistance gene but do not possess arsB and arrB genes in their genome.