Fermentative production of L-pipecolic acid from glucose and alternative carbon sources.
Corynebacterium glutamicum is used for the million-ton scale production of amino acids and has recently been engineered for production of the cyclic non-proteinogenic amino acid L-pipecolic acid (L-PA). In this synthetic pathway L-lysine was converted to L-PA by oxidative deamination, dehydration and reduction by L-lysine 6-dehydrogenase (deaminating) from Silicibacter pomeroyi and pyrroline 5-carboxylate reductase from C. glutamicum. However, production of L-PA occurred as by-product of L-lysine production only. Here, the author show that abolishing L-lysine export by the respective gene deletion resulted in production of L-PA as major product without concomitant lysine production while the specific growth rate was reduced due to accumulation of high intracellular lysine concentrations. Increasing expression of the genes encoding L-lysine 6-dehydrogenase and pyrroline 5-carboxylate reductase in C. glutamicum strain PIPE4 increased the L-PA titer to 3.9 g L-1, and allowed faster growth and, thus, a higher volumetric productivity of 0.08 ± 0.00 g L-1h-1respectively. Secondly, expression of heterologous genes for utilization of glycerol, xylose, glucosamine, and starch in strain PIPE4 enabled L-PA production from these alternative carbon sources. Third, in a glucose/sucrose-based fed-batch fermentation with C. glutamicum PIPE4 L-PA was produced to a titer of 14.4 g L-1with a volumetric productivity of 0.21 g L-1h-1and an overall yield of 0.20 g g-1.
Genetics of Prokaryotes, Faculty of Biology & Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
Fernando
F
Pérez-García
Fermentation Technology, Technical Faculty & Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
Joe
J
Max Risse
Fermentation Technology, Technical Faculty & Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
Karl
K
Friehs
Genetics of Prokaryotes, Faculty of Biology & Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
Volker F
VF
Wendisch
D001426:Bacterial Proteins / Q000235:genetics*; D061249:Batch Cell Culture Techniques; D002244:Carbon / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D005285:Fermentation; D017353:Gene Deletion; D005818:Genetic Engineering; D005947:Glucose / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics; D010875:Pipecolic Acids / Q000378:metabolism*; D011762:Pyrroline Carboxylate Reductases / Q000235:genetics
D001426:Bacterial Proteins; D010875:Pipecolic Acids; D002244:Carbon; D010088:Oxidoreductases; D011762:Pyrroline Carboxylate Reductases; C031345:pipecolic acid; D005947:Glucose; D008239:Lysine
Alternative carbon sources; Corynebacterium glutamicum; Fed-batch cultivation; L-pipecolic acid; Lysine dehydrogenase