Anoxybacillus sp. AH1, an [alpha]-amylase-producing thermophilic bacterium isolated from Dargeçit hot spring

• Published in: Biológia Vol. 70; no. 7; p. 853
• Main Authors: Acer, Ömer, Pirinççiglu, Hemse, Bekler, Fatma Matpan, Gül-Güven, Reyhan
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.07.2015
• Subjects: Bacteria; Enzymatic activity; Hot springs; Nitrogen sources; Peptones; Starch
• ISSN: 0006-3088; 1336-9563
• DOI: 10.1515/biolog-2015-0111

The present study was conducted to isolate α-amylase-producing thermophilic bacteria from Darge¸cit hot springs in Turkey. The morphological, biochemical and physiological characterisation, as well as genetic analysis by 16S rRNA sequences indicated that the isolated strain AH1 was a member of Anoxybacillus genus. The strain was aerobe, Gram-positive and spore-forming rod, exhibiting optimum growth temperature and pH of 60ºC and 7.0-7.5, respectively. Optimization of growth medium and enzyme assay conditions for extracellular α-amylase production by the novel thermophilic Anoxybacillus sp. AH1 were carried out in many different media containing a variety of carbon and nitrogen sources. Among various carbon and nitrogen sources, peptone (2054.1 U/mL) at 1% and maltose (1862.9 U/mL) at 0.5% increased α-amylase activity, compared to controls. Moreover, a high enzyme production was observed with potato starch at 0.5% and 1% (2668.4 U/mL and 3627 U/mL, respectively), as well as with 1% soluble starch (2051.9 U/mL). The enzyme activity was found to be rather high in the presence of CaCl[2] up to 100 mM.