Journal of Radiation Research and Radiation Proces ›› 2015, Vol. 33 ›› Issue (4): 40401-040401.doi: 10.11889.j.1000-3436.2015.rrj.33.040401

• RADIATION TECHNOLOGY APPLICATION • Previous Articles     Next Articles

Combined mutation of Flavobacterium sp. producing vitamin K2 and optimization of the fermentation

TAN Mu  ZHAO Genhai  LIU Hui  LI Zhemin  SUN Xiaowen  ZHENG Zhiming   

  1. (Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei 230031, China)
  • Received:2015-04-20 Revised:2015-04-30 Online:2015-08-20 Published:2015-07-21


The study was to enhance vitamin K2 production of Flavobacterium sp. by combined mutation of N-methyl-N-nitro-N-nitroso-guanidine (NTG) and low energy N+ ion beam implantation, and optimize the fermentation conditions. The best mutation conditions were as follows: induced dose and time of NTG were 0.8 mg/mL and 20 min; induced energy and dose of N+ implantation were 15 keV and 80 (2.6×1013 cm−2). Vitamin K2 production of the mutant strain reached 6.12 mg/L, which was 159% higher than that of the original. After 6 generations of propagation, the mutant strain with high stability was obtained. Optimal fermentation conditions were obtained when 2% seed culture was inoculated into 250-mL flasks with 30 mL fermentation medium (pH=7.0) and incubated at 37 oC and 120 r/min. Meanwhile, after 72 h of fermentation, Arachis hypogaea in dose of 3 mg/mL was added into the medium as a useful inducer. Vitamin K2 production after optimized-fermentation was 31% higher than that of the mutant strain before optimization.

Key words: Flavobacterium sp., N-methyl-N-nitro-N-nitroso-guanidine (NTG), N+ implantation, Vitamin K2

CLC Number: 

  • TQ924