Biosynthesis and characterization of poly(d‐lactate‐co‐glycolate‐co‐4‐hydroxybutyrate). Issue 7 (21st April 2020)

• Record Type: Journal Article
• Authors: Choi, So Young; Chae, Tong Un; Shin, Jihoon; Im, Jung Ae; Lee, Sang Yup
• Is Part Of: Biotechnology and bioengineering. Volume 117:Issue 7(2020)
• Page Start: 2187
• Page End: 2197
• Publication Date: 2020-04-21
• Subjects: 4‐hydroxybutyrate -- glycolate -- lactate -- metabolic engineering -- poly(d‐lactate‐co‐glycolate‐co‐4‐hydroxybutyrate) -- polyhydroxyalkanoate; Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.27354
• Languages: English
• ISSNs: 0006-3592

Abstract

Abstract: Poly(d ‐lactate‐ co ‐glycolate‐ co ‐4‐hydroxybutyrate) [poly(d ‐LA‐ co ‐GA‐ co ‐4HB)] and poly(d ‐lactate‐ co ‐glycolate‐ co ‐4‐hydroxybutyrate‐ co ‐d ‐2‐hydroxybutyrate) [poly(d ‐LA‐ co ‐GA‐ co ‐4HB‐ co ‐d ‐2HB)] are of interest for their potential applications as new biomedical polymers. Here we report their enhanced production by metabolically engineered Escherichia coli . To examine the polymer properties, poly(d ‐LA‐ co ‐GA‐ co ‐4HB) polymers having various monomer compositions (3.4–41.0mol% of 4HB) were produced by culturing the engineered E. coli strain expressing xylBC from Caulobacter crescentus, evolved phaC1 from Pseudomonas sp. MBEL 6‐19 ( phaC1437 ), and evolved pct from Clostridium propionicum ( pct540 ) in a medium supplemented with sodium 4HB at various concentrations. To produce these polymers without 4HB feeding, the 4HB biosynthetic pathway was additionally constructed by expressing Clostridium kluyveri sucD and 4hbD . The engineered E. coli expressing xylBC, phaC1437, pct540, sucD, and 4hbD successfully produced poly(d ‐LA‐ co ‐GA‐ co ‐4HB‐ co ‐d ‐2HB) and poly(d ‐LA‐ co ‐GA‐ co ‐4HB) from glucose and xylose. Through modulating the expression levels of the heterologous genes and performing fed‐batch cultures, the polymer content and titer could be increased to 65.76wt% and 6.19g/L, respectively, while the monomer fractions in the polymers could be altered as desired. The polymers produced, in particular, the 4HB‐rich polymers showed viscous and sticky properties suggesting that they might be used as medical adhesives. Abstract : The authors reported enhanced production of poly(d ‐lactate‐ co ‐glycolate‐ co ‐4‐hydroxybutyrate) [poly(d ‐LA‐ co ‐GA‐ co ‐4HB)] by metabolically engineered Escherichia coli using glucose and xylose as carbon sources. Through modulating the expression levels of the heterologous genes and performing fed‐batch cultures, the polymer content and titer could be increased while the monomer fractions in the polymers could be altered as desired. Poly(d ‐LA‐ co ‐GA‐ co ‐4HB) having various monomer compositions produced in this study will be useful for applications such as medical materials and adhesives.