Highly efficient polyhydroxyalkanoate production from lignin using genetically engineered Halomonas sp. Y3. (February 2023)

• Record Type: Journal Article
• Authors: Li, Yuan-Qiu; Wang, Ming-Jun; Luo, Chao-Bing
• Is Part Of: Bioresource technology. Volume 370(2023)
• Publication Date: 2023-02
• Subjects: Polyhydroxyalkanoate -- Lignin -- Laccase -- Engineering -- Halomonas; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.128526
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Halomonas sp. Y3 secreted laccase through Tat and Type I secretion system. Biodesign of a highly efficient laccase secretion apparatus. Heterologous expression of laccase achieved enzyme activity of 184 U/mL. Up to 55 % lignin was degraded by the engineered strain Y3_05. Co-transformation of Y3_05 and Y3_08 produced 740 and 1314 mg/L from lignin and APL. Abstract: Lignin degradation represents a significant challenge in biological valorization, but it is suffering from insufficiency, putting barriers to efficient lignin conversion. Herein, the study first develops a highly efficient laccase secretion apparatus, enabling high enzyme activity of 184 U/mL, complementing the biochemical limits on lignin depolymerization well in Halomonas sp. Y3. Further engineering of PHA biosynthesis produces a significantly high PHA titer of 286, 742, and 868 mg/L from alkaline lignin, catechol, and protocatechuate, respectively. The integration of laccase-secretion and PHA production modules enables a record titer of 693 and 1209 mg/L in converting lignin and lignin-containing stream to PHA, respectively. The titer is improved furtherly to 740 and 1314 mg/L by developing a non-sterilized fermentation. This study advances a cheaper and greener production of valuable chemicals from lignin by constructing a biosynthetic platform for PHA production and provides novel insight into the lignin conversion by extremophilic microbes.