title: Production in Escherichia coli of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with differing monomer compositions from unrelated carbon sources.
abstract: The industrial production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has been hindered by high cost and a complex control strategy caused by the addition of propionate. In this study, based on analysis of the PHBV biosynthesis process, we developed a PHBV biosynthetic pathway from a single unrelated carbon source via threonine biosynthesis in Escherichia coli. To accomplish this, we (i) overexpressed threonine deaminase, which is the key factor for providing propionyl-coenzyme A (propionyl-CoA), from different host bacteria, (ii) removed the feedback inhibition of threonine by mutating and overexpressing the thrABC operon in E. coli, and (iii) knocked out the competitive pathways of catalytic conversion of propionyl-CoA to 3-hydroxyvaleryl-CoA. Finally, we constructed a series of strains and mutants which were able to produce the PHBV copolymer with differing monomer compositions in a modified M9 medium supplemented with 20 g/liter xylose. The largest 3-hydroxyvalerate fraction obtained in the copolymer was 17.5 mol%.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Guoqing
authors.initials: G
authors.lastname: Wei
authors.forename: Quanfeng
authors.initials: Q
authors.lastname: Liang
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Qi
mesh_terms: D000214:Acyl Coenzyme A / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D055786:Gene Knockout Techniques; D010421:Pentanoic Acids / Q000378:metabolism; D011091:Polyesters / Q000378:metabolism*; D013912:Threonine / Q000096:biosynthesis; D013913:Threonine Dehydratase / Q000096:biosynthesis / Q000235:genetics; D000094122:Polyhydroxybutyrates
chemical_list: D000214:Acyl Coenzyme A; D002244:Carbon; D010421:Pentanoic Acids; D011091:Polyesters; D013912:Threonine; D013913:Threonine Dehydratase; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C013056:beta-hydroxyvaleric acid; C009061:propionyl-coenzyme A