Isolation and Identification of Bacillus amyloliquefaciens BY01 with High Productivity of Menaquinone for Cheonggukjang Production

Abstract

To develop a cheonggukjang with high content of menaquinone (MK), bacterial strains were isolated from good quality cheonggukjang, and MK productivities of isolated strains were determined by high-performance liquid chromatography. After sensory evaluation and MK determination, a potential probiotics, BY01, with acceptable sensory quality and high productivity of MK was isolated. Fermentation under aerobic condition produced more MK than that obtained under anaerobic condition, and the synthesized MK mainly remained in the form of endocellular deposit. To identify species of strain BY01, biochemical tests and gyrase B gene (gyrB) sequence analysis were carried out, and strain BY01 was identified as Bacillus amyloliquefaciens. The content of MK in cheonggukjang fermented with B. amyloliquefaciens BY01 reached 7.54 μg/g, 2fold higher than that of commercial cheonggukjang products. This is the first report on the isolation of B. amyloliquefaciens as a superior MK producer in cheonggukjang fermentation.

Menaquinone-7 production from maize meal hydrolysate by Bacillus isolates with diphenylamine and analogue resistance

“…This result was in contrast with the previous reports that the majority of MK-7 production was during the logarithmic growth phase of B. subtilis natto (Berenjian et al, 2011). Wu and Ahn (2011) have reported that the amount of the intracellular MK-7 is larger than that of extracellular MK-7. However, the intracellular MK-7 can be released into the extracellular fraction by forming an intracellular complex with protein during the culture process (Armougom et al, 2009).…”

Isolation and characterisation of Bacillus spp. antagonistic to Vibrio parahaemolyticus for use as probiotics in aquaculture

“…3). Two strains with a sequence identity of greater than 99 % should be classified as the same species according to Wu and Ahn (2011). It is difficult for B. pumilus and B. mojavensis, having a B. subtilis-like phenotype, to be distinguished from B. subtilis.…”

Enhancing menaquinone-7 production in recombinant Bacillus amyloliquefaciens by metabolic pathway engineering

“…Many microorganisms can be used to biosynthesize MK-7, such as Escherichia coli, 7 Sphingobacterium multivorum, 8 Bacillus amyloliquefaciens 9,10 and Bacillus subtilis. [11][12][13] However, commercial production of MK-7 is mainly done through extraction from natto, a type of food, rather than via microbial fermentation.…”

“…14 This is because the fermentative production of MK-7 is too low. 9,[11][12][13] Fortunately, the biosynthetic pathway of MK-7 has been claried at present (Fig. 1).…”