Cloning of L-lactate dehydrogenase gene(ldnL) from Rhizopus oryzae and its expression in Escherichia coli

A fragment of L-lactate dehydrogenase gene(ldnL) was cloned from the genomic DNA of Rhizopus oryzae by polymerase chain reaction(PCR) based on the released ldnL sequence.The PCR product was double-digested after T/A clone and the digested fragment was ligated with pET17b,a kind of expression vector in Escherichia coli(E.coli).Then,the recombinant plasmid,pET17b-ldnL,was transformed into the host cell E.coli BL21(DE3).The transformed cell was measured by SDS-PAGE after culturing in the inducing medium and the result showed that the cloned ldnL was expressed in BL21(DE3).