Metabolic engineering of Escherichia coli for production of non-natural acetins from glycerol. Issue 22 (23rd September 2020)

• Record Type: Journal Article
• Authors: Zada, Bakht; Joo, Seongjoon; Wang, Chonglong; Tseten, Tenzin; Jeong, Seong-Hee; Seo, Hogyun; Sohn, Jung-Hoon; Kim, Kyung-Jin; Kim, Seon-Won
• Is Part Of: Green chemistry. Volume 22:Issue 22(2020)
• Page Start: 7788
• Page End: 7802
• Publication Date: 2020-09-23
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d0gc02395g
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Development of bioconversion technology for efficient conversion of crude glycerol to non-natural acetins. Abstract : Mono-, di- and triacetin are three glycerol esters which are usually synthesized via costly and environmentally unfriendly chemical synthesis methods. Here, Escherichia coli is metabolically engineered for the production of mono-, di- and triacetin using glycerol as a substrate. First, a novel biosynthetic route of mono- and diacetin is established by overexpression of a native enzyme, maltose O -acetyltransferase (MAA). Next, the biosynthetic pathway is extended to produce a mixture of mono-, di- and triacetin by overexpression of chloramphenicol- O -acetyltransferase (CAT). By successive strategies, including heterologous gene expression, metabolic engineering, and culture optimization, a recombinant E. coli is enabled to produce more than 27 g L −1 of a mixture of mono-, di- and triacetin in shake flask cultures, which is a >650-fold increase over the initial production of 0.04 g L −1 . In vitro studies confirm the acetylation of glycerol to mono- and diacetin by MAA, and the additional acetylation to triacetin by CAT. When crude glycerol is used as a substrate, the engineered strain produced a total of 25.9 g L −1 of the acetin mixture, about the same as that achieved from pure glycerol. To our knowledge, this is the first successful report of microbial production of the artificial chemicals, acetins.