glutamicum in C efficiens While the pBL1-based expression vecto

glutamicum in C. efficiens. While the pBL1-based expression vector pEKEx3 [24] did not work in C. efficiens in our hands, the pHM1519-based expression vector pVWEx1 [34] may be used as a tool to extend the genetic repertoire of C. efficiens e.g. for a broader usage of different carbon sources. The biotechnological buy AZD5363 production of lactic acid is observed with special interest due to its use for poly lactic acid production, an alternative to petroleum based plastic. Poly D-lactic acid (PDLA) is more advantageous

than poly L-lactic acid (PLLA) because of its higher melting point [53]. While, poly lactic acid could be synthesized within recombinant E. coli cells [54], poly lactic acid is typically produced in a two step process. After fermentative Bafilomycin A1 chemical structure production of lactic acid, poly lactic acid is synthesized chemically www.selleckchem.com/products/GSK872-GSK2399872A.html by ring-opening polymerisation of lactide, the cyclic diester of lactic acid [53]. Lactic acid fermentation employs lactic acid bacteria, but also S. cerevisiae has been engineered for production of high purity L-lactate [55] or D-lactate [56]. In addition, E. coli has been engineered for lactate production [57–59]. To improve D-lactate production by recombinant E. coli, dld was deleted to avoid re-utilization of the product [60]. As C. glutamicum strains other than ATCC 13032 lack dld, C. glutamicum might be a useful host

for D-lactate production. Indeed, C. glutamcium R, which lacks dld, was engineered for D-lactate production under oxygen limiting conditions employing fermentative NAD-dependent D-lactate dehydrogenase from E. coli [28]. Conclusion Cg1067 encodes quinone-dependent D-lactate dehydrogenase Dld of Corynebacterium glutamicum. Dld is essential for growth with D-lactate as sole carbon source. The genomic region of dld likely has been acquired by horizontal gene transfer. Acknowledgements This work was supported by the research grant strategic project to support the formation of research bases at private universities, Japan.

References 1. Crow VL: Utilization of lactate isomers by Propionibacterium freudenreichii subsp. shermanii : regulatory role for intracellular pyruvate. Appl Environ Microbiol 1986,52(2):352–358.PubMed 2. Duncan SH, Louis P, Flint HJ: Lactate-utilizing bacteria, isolated from human Thymidylate synthase feces, that produce butyrate as a major fermentation product. Appl Environ Microbiol 2004,70(10):5810–5817.PubMedCrossRef 3. Ogata M, Arihara K, Yagi T: D-lactate dehydrogenase of Desulfovibrio vulgaris . J Biochem 1981,89(5):1423–1431.PubMed 4. Vella A, Farrugia G: D-lactic acidosis: pathologic consequence of saprophytism. Mayo Clin Proc 1998,73(5):451–456.PubMedCrossRef 5. Ho C, Pratt EA, Rule GS: Membrane-bound D-lactate dehydrogenase of Escherichia coli : a model for protein interactions in membranes. Biochim Biophys Acta 1989,988(2):173–184.PubMed 6.

Comments are closed.