Molecular taxonomy of thermophilic bacteria isolated from hot springs in the provinces of Aydin and Izmir, and characterization of glucose isomerase of the isolate D1021

Thermophilic environments are rich resources for thermophilic organisms which synthesize a variety of enzymes that have important industrial applications. Thermophilic bacteria isolations from Hisarkoy Hot Spring (Balikesir), Dikili-Bergama Kaynarca Hot Spring (İzmir), Camkoy Camur Hot Spring (Aydin) and Hidirlar Hot Spring (Çanakkale) were made. Systematics of these isolates belonging to Geobacillus (12 izolates), Anoxybacillus (18 izolates), Brevibacillus (9 isolates), Thermus (5 isolates), Aneurinibacillus (4 isolates) ve Pseudoxanthomonas (1 isolate), Schlegelella (1 isolate) ve Chelatococcus (1 isolate) genus were studied to be made at the species level in these study. D1021 isolates belonging to Anoxybacillus genus from İzmir Kaynarca hot spring was new species designated as A. kaynarcensis D1021T. Based on genetipic analyses, some isolates had potential of being new species belonging to Brevibacillus and Geobacillus genus. Gene coding for thermophilic glucose isomerase of A. gonensis G2T was isolated and its complete nucleotide sequence was determined. The gene has been cloned to plasmid vector pET-28a+ and overexpressed in E. coli BL21(DE3). The enzyme was purified by colon chromatography techniques. The purified GI showed optimal activity at 80°C in pH 7.0. Its Km and Vmax value wase 101,75 mM and 14,06 ?mol/dk/mg protein respectively.