FOOD SCIENCE ›› 2017, Vol. 38 ›› Issue (8): 117-121.doi: 10.7506/spkx1002-6630-201708019

• Bioengineering • Previous Articles     Next Articles

Isolation, Screening and Identification of a Bacterial Strain Producing Thermostable Pullulanase

GAO Tao, WANG Fang, BIE Xiaomei, Lü Fengxia, ZHAO Haizhen, ZHANG Chong, LU Zhaoxin   

  1. College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
  • Received:2017-04-26 Revised:2017-04-26 Online:2017-04-25 Published:2017-04-24

Abstract: themostable pullulanase-producing strain, designated as T-10, with enzymatic activity of 1.22 U/mL, was isolated from soil samples collected at a crater field. By applying morphological observation, physiological and biochemical tests and 16S rDNA sequence homology analysis, it was identified as Bacillus amyloliquefacienss. The optimum temperature for the pullulanase activity was 60 ℃ and more than 60% of its maximum activity was maintained after incubation at 70 ℃ for 4 h. The optimum pH value for the pullulanase activity was 6.0, and about 70% of its maximum activity was maintained in the range of 3.0?8.0 after incubation for 4 h. At present, only a few thermostable pullulanase-producing strains of B. amyloliquefaciens are available, and so this new strain of B. amyloliquefaciens has a good application prospect.

Key words: pullulanase, screening, physiological and biochemical characteristics, 16S rDNA, enzymatic properties

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