Optimization of xylanase and ?-amylase production by alkaline and thermophilic Bacillus isolate KH-13

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Khodayari F., Cebeci Z., Özcan B. D.

Journal of Entomology and Zoology Studies, vol.2, no.5, pp.295-303, 2014 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Volume: 2 Issue: 5
  • Publication Date: 2014
  • Journal Name: Journal of Entomology and Zoology Studies
  • Journal Indexes: Chemical Abstracts Core
  • Page Numbers: pp.295-303
  • Çukurova University Affiliated: Yes

Abstract

Alkaline, and thermophilic Bacillus sp. strain KH-13, which produces α-amylase and xylanase was isolated from Caspian Sea in Iran. Characterization of strain KH-13 by 16S rRNA gene analysis found it closest member of Bacillus sp. M26 with a similarity of 98%. This bacterial isolate was mutagenized by treatment with Ethidium bromide (EtBr) and 4 mutant variants were obtained. Wild type strain KH-13 and its mutant variants KH13-M3, and KH13-M4 were selected for partial characterization. Maximum αamylase productions were achieved at the end of 12 h of growth for KH-13 and KH13-M3. Besides, maximum xylanase productions were achieved at the end of 24 and 48 h of growth for KH-13 and KH13- M4, respectively. The optimum temperature values of the KH-13 and KH13-M3 α-amylases were found to be 40 and 50 °C, respectively. An optimum pH value of the both enzymes was 6.5. The optimum temperature values of the KH-13 and KH13-M4 xylanases were found to be 50 and 60 °C, respectively. An optimum pH value of the both enzymes was 9.5.