Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) co-produced with L-isoleucine in Corynebacterium glutamicum WM001

• Published in: Microbial cell factories 2018-06, Vol.17 (1), p.93-93, Article 93
• Main Authors: Ma, Wenjian, Wang, Jianli, Li, Ye, Yin, Lianghong, Wang, Xiaoyuan
• Format: Article
• Language: English
• Subjects: 3HV fraction; Accumulation; Acyl Coenzyme A - metabolism; Agrobacterium; Alcaligenes; Amino acids; Analysis; Bacillus; Bacteria; Batch culture; Biocompatibility; Biosynthesis; Carbon; Carbon sources; Cell growth; Corynebacterium; Corynebacterium glutamicum; Corynebacterium glutamicum - metabolism; Cupriavidus necator; E coli; Escherichia coli; Fermentation; Gene expression; Gene sequencing; Genes; Genomes; Glucose; Gram-positive bacteria; Hydroxybutyrates - metabolism; Intracellular; Isoleucine; Isoleucine - metabolism; l-Isoleucine; Low level; Mechanical properties; Metabolism; Microorganisms; Nocardia; PHBV; Plasmids; Polyesters; Polyhydroxyalkanoates; Polyhydroxyalkanoic acid; Properties; Propionyl-CoA; Rhodococcus; Salmonella; Seeds; Transcription; Transcription factors
• ISSN: 1475-2859; 1475-2859
• DOI: 10.1186/s12934-018-0942-7

Co-production of polyhydroxyalkanoate (PHA) and amino acids makes bacteria effective microbial cell factories by secreting amino acids outside while accumulating PHA granules inside. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the PHAs with biocompatibility and fine mechanical properties, but its production is limited by the low level of intracellular propionyl-CoA. L-Isoleucine producing Corynebacterium glutamicum strain WM001 were analyzed by genome and transcriptome sequencing. The results showed that the most over-expressed genes in WM001 are relevant not only to L-isoleucine production but also to propionyl-CoA accumulation. Compared to the wild-type C. glutamicum ATCC13869, the transcriptional levels of the genes prpC2, prpD2, and prpB2, which are key genes relevant to propionyl-CoA accumulation, increased 2 , 2 , and 2 -folds in WM001, respectively; and the intracellular level of propionyl-CoA increased 16.9-fold in WM001. When the gene cluster phaCAB for PHA biosynthesis was introduced into WM001, the recombinant strain WM001/pDXW-8-phaCAB produced 15.0 g/L PHBV with high percentage of 3-hydroxyvalerate as well as 29.8 g/L L-isoleucine after fed-batch fermentation. The maximum 3-hydroxyvalerate fraction in PHBV produced by WM001/pDXW-8-phaCAB using glucose as the sole carbon source could reach 72.5%, which is the highest reported so far. Genome and transcriptome analysis showed that C. glutamicum WM001 has potential to accumulate L-isoleucine and propionyl-CoA pool. This was experimentally confirmed by introducing the phaCAB gene cluster into WM001. The recombinant strain WM001/pDXW-8-phaCAB produced high levels of PHBV with high 3-hydroxyvalerate fraction as well as L-isoleucine. Because of its high level of intracellular propionyl-CoA pool, WM001 might be used for producing other propionyl-CoA derivatives.