China Animal Husbandry & Veterinary Medicine ›› 2011, Vol. 38 ›› Issue (1): 36-38.

• 生理生化 • Previous Articles     Next Articles

Screening of Protease and Cellulose Producing Bacillus Subtilis Natto Strains and their Biological Characteristics

XI Xiao-qi1，2，WANG Jia-qi2，BU Deng-pan2，SUN yan2，ZHOU ling-yun2，WEI Hong-yang2   

  1. （1.College of Animal Science and Technology， Northeast Agricultural University,Harbin 150030, China;2.State Key Laboratory of Animal Nutrition,Institute of Animal Sciences，Chinese Academic of Agricultural Sciences,Beijing 100193,China）
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-01-01 Published:2011-01-01
  • Contact: WANG Jia-qi

Abstract: Using casein plate and carboxymethylcellulose sodium（CMC-Na） plate screening method, ten protease activity producing Bacillus Subtilis Natto strains（NY-1 to NY-10） and ten cellulose producing Bacillus Subtilis Natto strains（NS-1 to NS-10） were screened from Beijing, Dalian and Japanese Natto. NY-1 and NS-1 were selected from the examined strains for their highest protease activity and highest cellulose activity, respectively. NY-1 and NS-1 were studied with respect to their biological characteristics, including growth curves, sporulation curve, dynamic changes of enzyme activity and passage stability. The experimental results demonstrated that for strain NY-1 the best culture time was 16 h， the maximum logarithm of spores were (6.92±0.047) at 28 h, the maximum protease activity was （44.12±1.48） U/mL at 18 h ;for strain NS-1 the best culture time was 14 h， the maximum logarithm of spores was (8.41±0.0060) at 28 h, the maximum cellulose activity was （60.94±1.22） U/mL at 40 h. Protease activity of NY-1 and cellulose activity of NS-1 will keep a good passage stability within seven generations.

Key words: Bacillus Subtilis Natto; growth curve; spore; protease; screening; passaging

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