A promoter\|signal peptide probe vector of lactic acid bacteria,designated pZLB based on pMG36e has been constructed.The vector contained a reporterd gene encoding for β lactamase,which lacked a promoter and a functional signal sequence.Sau3A restriction fragments (80-400bp) from L.lactis ATCC 7962 total DNA were cloned into Bam HI site of pZLB.A lot of different size framents were selected.These fragments promoted transcription and secretion of β lactamase in L.lac tis. Sequence analysis revealed that inserted fragment in pZLBe7 contained typical promoter,SD sequence and atypical signal sequence.
