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Improvement of iturin A production in Bacillus subtilis ZK 0 by overexpression of the comA and sigA genes
Author(s) -
Zhang Z.,
Ding Z.T.,
Zhong J.,
Zhou J.Y.,
Shu D.,
Luo D.,
Yang J.,
Tan H.
Publication year - 2017
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12739
Subject(s) - bacillus subtilis , bacillales , microbiology and biotechnology , gene , bacillaceae , biology , bacteria , production (economics) , chemistry , biochemistry , genetics , macroeconomics , economics
Bacillus subtilis ZK 0, which was isolated from cotton, produces a type of lipopeptide antibiotic iturin A that inhibits the growth of pathogenic fungi on agricultural crops. However, the low level of iturin A production by B. subtilis ZK 0 does not support its large‐scale application. In this study, B. subtilis ZK 0 was subjected to genetic manipulation to improve iturin A production. By the independent or simultaneous overexpression of two regulatory genes ( comA and sigA ), iturin A production by B. subtilis ZK 0 was significantly increased. When both genes were simultaneously overexpressed under optimal conditions, iturin A production increased up to 215 mg l −1 (an approximate 43‐fold increase compared with B. subtilis ZK 0). Moreover, overexpression of both genes was unexpectedly found to inhibit biofilm formation by B. subtilis ZK 0, indicating that the phenomenon of ‘stuck fermentation’ would be avoided during B. subtilis ZK 0 fermentation. In conclusion, a genetic manipulation method that improves iturin A production and inhibits biofilm formation in B. subtilis ZK 0 is reported for the first time and this method has the potential to be widely applied in B. subtilis ZK 0 commercial fermentation. Significance and Impact of the Study This study provides new perspectives on improving iturin A production by Bacillus subtilis . Our newly engineered strains could be applied to commercial fermentation by enhancing yields of iturin A and reducing the rate of ‘stuck fermentation’. Increased production would facilitate more widespread application of this powerful antibiotic.