Fig. 6

Relative expression levels of lactate-producing enzyme genes in K. pneumoniae strain harboring CRISPRi system. a Relative expression levels of ldhA, aldA and mgsA genes in K. pneumoniae strain harboring CRISPRi system targeting pmd gene; b Relative expression levels of pmd, aldA and mgsA genes in K. pneumoniae strain harboring CRISPRi system targeting ldhA; c Relative expression levels of pmd, ldhA and mgsA genes in K. pneumoniae strain harboring CRISPRi system targeting aldA; d Relative expression levels of pmd, ldhA and aldA genes in K. pneumoniae strain harboring CRISPRi system targeting mgsA. Kp(ptac-puuC + pdCas9), recombinant K. pneumoniae strain harboring aldehyde dehydrogenase puuC expression vector and dCas9 expression vector; Kp(ptac-puuC + placiL), recombinant K. pneumoniae strain harboring puuC expression vector and CRISPRi vector targeting l-lactate dehydrogenase gene pmb; Kp(ptac-puuC + placiD), recombinant K. pneumoniae strain harboring puuC expression vector and CRISPRi vector targeting d-lactate dehydrogenase gene ldhA; Kp(ptac-puuC + placiA), recombinant K. pneumoniae strain harboring puuC expression vector and CRISPRi vector targeting lactaldehyde dehydrogenase gene aldA; Kp(ptac-puuC + placiM), recombinant K. pneumoniae strain harboring puuC expression vector and CRISPRi vector targeting methylglyoxal synthase gene mgsA. *P < 0.05; **P < 0.01