FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (2): 208-214.doi: 10.7506/spkx1002-6630-20181116-186

• Bioengineering • Previous Articles     Next Articles

Isolation of Bacillus subtilis natto from Chinese Traditional Fermented Soybean Foods and Their Use in Fermentation of Natto

LIU Yanmin, SHEN Lu, WANG Kang, YAN Jinping, CHAGAN Irbis   

  1. (College of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China)
  • Received:2020-01-20 Revised:2020-01-20 Online:2020-01-25 Published:2020-01-19

Abstract: In this study, 8 strains of Bacillus subtilis were isolated from Chinese traditional fermented soybean food and straw samples, which were found to have similar properties to B. subtilis natto based on protease and nattokinase activities, poly-L-glutamic acid (γ-PGA) production ability and biotin-dependent properties. Phylogenetic analysis of the isolated strains was performed using the 16S–23S rRNA internal transcribed spacer (ITS) sequence. The results showed that these strains shared high similarity (93%–97%) to the reported strains of B. subtilis natto and they were clustered into one cluster, independent of other strains of B. subtili. The nattokinase activities of natto prepared from strains TC100 and TC103 were the highest, which were 550 and 519 U/mL, respectively. The natto products fermented by strains HN48 and TC100 scored the highest (19 points) in sensory evaluation. In summary, all these strains were identified as B. subtilis natto according to their morphology and the phylogenetic analysis based on the ITS sequence. They could be promising as an industrial strain for natto production.

Key words: natto, Bacillus subtilis natto, nattokinase, fermentation process, sensory evaluation

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