Synthesis of polyhydroxyalkanoates from glucose that contain medium-chain-length monomers via the reversed fatty acid β-oxidation cycle in Escherichia coli.
Polyhydroxyalkanoates that contain the medium-chain-length monomers (mcl-PHAs) have a wide range of applications owing to their superior physical and mechanical properties. A challenge to synthesize such mcl-PHAs from unrelated and renewable sources is exploiting the efficient metabolic pathways that lead to the formation of precursor (R)-3-hydroxyacyl-CoA. Here, by engineering the reversed fatty acid β-oxidation cycle, we were able to synthesize mcl-PHAs in Escherichia coli directly from glucose. After deletion of the major thioesterases, the engineered E. coli produced 6.62wt% of cell dry weight mcl-PHA heteropolymers. Furthermore, when a low-substrate-specificity PHA synthase from Pseudomonas stutzeri 1317 was employed, recombinant E. coli synthesized 12.10wt% of cell dry weight scl-mcl PHA copolymers, of which 21.18mol% was 3-hydroxybutyrate and 78.82mol% was medium-chain-length monomers. The reversed fatty acid β-oxidation cycle offered an efficient metabolic pathway for mcl-PHA biosynthesis in E. coli and can be further optimized.
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China.
Qianqian
Q
Zhuang
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China.
Qian
Q
Wang
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China.
Quanfeng
Q
Liang
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China. Electronic address: qiqingsheng@sdu.edu.cn.
Qingsheng
Q
Qi
D020155:3-Hydroxybutyric Acid / Q000235:genetics / Q000378:metabolism; D000214:Acyl Coenzyme A; D000217:Acyltransferases / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism*; D010084:Oxidation-Reduction; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*; D044223:Pseudomonas stutzeri / Q000201:enzymology / Q000235:genetics
D000214:Acyl Coenzyme A; D001426:Bacterial Proteins; D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase; D005947:Glucose; D020155:3-Hydroxybutyric Acid
Escherichia coli; Metabolic engineering; Polyhydroxyalkanoates; Reversed fatty acid β-oxidation cycle