Fig. 6

d-LA production by introducing lactate dehydrogenase (LDH) gene in JHM80. a The indicated heterologous d form-specific LDH genes from L. jensenii (Lj1.LDH and Lj3.LDH), L. delbrueckii subsp. bulgraricus ATCC 11842 (Ld.LDH), L. mesenteroides subsp. mesenteroides ATCC 8293 (Lm.LDH) were integrated into the genome of JHM80, and LA production levels were detected after growing the cells in NMS medium containing 20% (v/v) methane and 10 μg/mL of kanamycin for 48 h; Wild-type strain integrated with Lm.LDH (JHM14) and JHM80 integrated with Lm.LDH (JHM86) were grown in a 30-mL serum bottle containing 3-mL NMS medium while feeding 20% (v/v) methane every 24 h. Cell growth (b) and LA production (c) were monitored during growth. Error bars indicate standard deviations of two independent experiments