Increase in the Rate of<scp>L</scp>-Pipecolic Acid Production Usinglat-ExpressingEscherichia colibylysPandyeiEAmplification

Biotransformation of L-lysine (L-Lys) to L-pipecolic acid (L-PA) using lat-expressing Escherichia coli has been reported (Fujii et al., Biosci. Biotechnol. Biochem., 66, 622-627 (2002)). The rate-limiting step of this biotransformation seemes to be the transport of L-Lys into cells. To improve the L-PA production rate, we attempted to increase the rate of L-Lys uptake. E. coli BL21 carrying a plasmid with lat and lysP (pRH125) caused a 5-fold increase in the rate of L-PA production above the level of cells carrying a plasmid with lat (pRH124). Moreover, E. coli BL21 carrying a plasmid with lat, lysP, and yeiE (pRH127) caused a 6.4-fold increase in the rate of L-PA production above the level of cells carrying pRH124. Our results from RT-PCR experiments and the sequence similarity of YeiE to LysR transcriptional regulators suggest the possibility that yeiE expression induces lysP expression. The amplification of lysP, or rather both lysP and yeiE, increases the rate of L-PA production using lat-expressing E. coli.