Bioprospecting of a novel endophytic Bacillus velezensis FZ06 from leaves of Camellia assamica: Production of three groups of lipopeptides and the inhibition against food spoilage microorganisms

• Published in: Journal of biotechnology 2020-11, Vol.323, p.42-53
• Main Authors: Li, Fang-Zhou, Zeng, Ying-Jie, Zong, Min-Hua, Yang, Ji-Guo, Lou, Wen-Yong
• Format: Article
• Language: English
• Subjects: Antimicrobial activity; Bacillus velezensis; Camellia assamica; Endophytic bacteria; Food spoilage microorganism; Lipopeptides
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2020.07.021

[Display omitted] •A novel endophytic B. velezensis FZ06 was isolated from fresh C. assamica leaves.•The FZ06 secondary metabolites synthesis was analyzed by whole-genome technique.•The molecular structures of FZ06 lipopeptides were obtained by UPLC-MS/MS analysis.•The FZ06 and its lipopeptide extracts showed good inhibitory effect on food spoilage microorganisms. Food contamination caused by microorganisms has become a threat to consumers' health. Exploring antagonistic endophytes from plants of food raw-material and applying bioactive metabolites to inhibit the contamination has been an alternative and safer solution. In this study, we isolated and screened potential antagonistic endophytes from fresh Camellia assamica leaves, which were widely used in tea beverage production. We focused on a strain that showed visible inhibitory activity to Gram-positive bacteria, Gram-negative bacteria, and fungi. It was identified as a member of Bacillus velezensis and named FZ06. The results of genome analysis showed the strain FZ06 had 167 single-copy specific genes, much higher than those of most related strains. Also, 11 potential gene clusters of antimicrobial metabolites were found. Three groups of lipopeptides (surfactin, iturin, and fengycin) were identified by UPLC-MS/MS in purified antimicrobial methanol fraction of strain FZ06. The results of minimum inhibitory concentration (MIC) test proved the lipopeptide extract showed significant inhibitory effect on food spoilage bacteria (MIC 512−2048 μg/mL) and toxigenic fungi (MIC 128−256 μg/mL). In conclusion, this study suggests that the endophytic B. velezensis FZ06 and its lipopeptide extract hold great potential applications in the inhibition of food spoilage bacteria and toxic fungi in food industry.