Efficient production of menaquinone (vitamin K 2 ) by a menadione-resistant mutant of Bacillus subtilis
Toshiro Sato, Yoko Yamada, Yutaka Ohtani, Nobuo Mitsui, Hisashi Murasawa, S Araki
Journal of Industrial Microbiology & Biotechnology
Abstract
Efficient production of menaquinone (MK) by Bacillus subtilis was achieved. An edible strain of B. subtilis, isolated from the traditional Japanese food natto, was mutated to improve MK productivity. A menadione-resistant mutant producing 30% more MK than its parent strain was obtained. Soybean extract and glycerol were the best nitrogen and carbon sources, respectively, among the sources tested. Addition of yeast extract also increased MK productivity. The maximum concentration of MK reached about 35.0 mg/l after 4 days of culture in a jar fermenter. The pH of the medium decreased to 5.5 after the start of cultivation, then spontaneously increased to 7.7-8.0. This pH change might be important in the production of MK because only small amounts of MK were obtained when pH was controlled at 5.7, 6.0, 7.0, 7.5 or 8.0.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
menaquinone (MK) produced by Bacillus subtilis
“An edible strain of B. subtilis, isolated from the traditional Japanese food natto, was mutated to improve MK productivity. A menadione-resistant mutant producing 30% more MK than its parent strain wa...”
Bacillus subtilis isolated from traditional Japanese food natto
“An edible strain of B. subtilis, isolated from the traditional Japanese food natto, was mutated to improve MK productivity.”
fermentation optimized for MK production
“The maximum concentration of MK reached about 35.0 mg/l after 4 days of culture in a jar fermenter. The pH of the medium decreased to 5.5 after the start of cultivation, then spontaneously increased t...”