Integration of engineering microbial consortium and boosting extracellular amylase of B. amyloliquefaciens for intensifying bioconversion of food waste into lipopeptides

• Published in: Journal of environmental chemical engineering 2024-08, Vol.12 (4), p.113161, Article 113161
• Main Authors: He, Jia-Xuan, Hou, Zheng-Jie, Qiao, Bin, Ding, Ming-Zhu, Cao, Chun-Yang, Zhang, Yu-Miao, Xu, Qiu-Man, Cheng, Jing-Sheng
• Format: Article
• Language: English
• Subjects: Artificial consortium; Bacillus amyloliquefaciens; Bioconversion; Food waste; Lipopeptides
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.113161

Lipopeptides possess significant antifungal activity and serve as eco-friendly biopesticides. However, their widespread application is limited by exorbitant production costs and low yields. Food waste emerges as a promising substrate for lipopeptide production. To efficiently harness the starch in food waste during bioconversion it into lipopeptides, the engineered Bacillus amyloliquefaciens HM618, constructed by knocking out multiple extracellular proteolytic enzyme genes (aprE, nprE, vpr, and epr) and overexpressing gene amyA with Phag promoter, capable of producing both high-level extracellular amylase and lipopeptides. It was found that the recombinant B. amyloliquefaciens HM3–5 in the pure culture containing starch exhibited notable amylase activity about 17046.37 U/mL, a total of 2530.72 mg/L lipopeptides, and 80.02 % degradation rate of starch. Considering the crucial roles of fatty acids and amino acids precursors in lipopeptide synthesis, these engineered B. amyloliquefaciens producing higher-level extracellular amylase, Yarrowia lipolytica producing fatty acids, and Corynebacterium glutamicum releasing proline and serine were integrated to construct an artificial consortium for efficiently bio-converting food waste into lipopeptides. After optimized inoculation times and ratios of these engineered strains, the levels of surfactin, fengycin, and iturin A in the four-strains artificial consortium during food waste bioconversion reached 8690.67, 635.83, and 74.19 mg/L, respectively. The total lipopeptides in the four-strain artificial consortium reached 9400.69 mg/L, 2.38-fold increase compared to that in the pure culture of strain HM3–5. Furthermore, the degradation efficiencies of starch and oil in food waste were 96.41 % and 98.35 %, respectively. This work provides a new strategy for efficiently bio-transforming food waste into lipopeptides. [Display omitted] •Knock-out gene vpr and overexpressing amyA increased amylase activity.•Enhancing amylase elevated lipopeptide level during starch bioconversion.•Artificial consortia intensified bioconversion of FW into lipopeptides.•Artificial consortia boost degradation efficiencies of starch and oil in FW.