Recruiting a new strategy to improve levan production in Bacillus amyloliquefaciens

• DOI: 10.1038/srep13814
• Publication Date: 2015-09-08T09:28:31Z
• Authors: Jun Feng; Yanyan Gu; Yufen Quan; Wei Zhang; Mingfeng Cao; Weixia Gao; Cunjiang Song; Chao Yang; Shufang Wang
• Keywords: Bacillus amyloliquefaciens; Bacillus (shape)

Abstract Microbial levan is an important biopolymer with considerable potential in food and medical applications. Bacillus amyloliquefaciens NK-ΔLP strain can produce high-purity, low-molecular-weight levan, but production relatively low. To enhance the of six extracellular protease genes ( bpr , epr mpr vpr nprE aprE ), together tasA gene (encoding major biofilm matrix protein TasA) pgsBCA cluster (responsible for poly-γ-glutamic acid (γ-PGA) synthesis), were intentionally knocked out NK-1 strain. The highest (31.1 g/L) was obtained from NK-Q-7 (Δ Δ nprE, which 103% higher than that ) (15.3 g/L). Furthermore, also showed a 94.1% increase α-amylase compared strain, suggesting positive effect deficient on endogenously secreted proteins. This first report improvement microbes proteases TasA exhibits outstanding characteristics or related product synthesis.