The Study Using Genetic Engineering Technolog Screening High-yield Lysine Bacillus

Bacillus subtilis producing lysine is the most important product of the metabolic pathway of homoserine, its metabolic genes encoding key enzymes is hom, if knock out that gene in the metabolic pathway, can cause the metabolism of stream flow to the synthesis of lysine, lysine production increases. So this experiment is to use genetic engineering breeding of Bacillus subtilis YB83 homoserine dehydrogenase (hom) missing strains, study hom gene deletion strains on the effect of lysine production.Template with Bacillus subtilis YB83 genomic DNA, PCR amplification get hom genes connected to the carrier pMD19-T, in E coliDH5a transformation, screening of recombinant plasmid pMD19-T-hom.Then plasmid pET-28 for a template, PCR amplification for km genes, and connect the km after using BssH2 enzyme gene recombinant plasmid pMD19-T-hom, in E coliDH5a transformation, in the plasmid vector is obtained by the kanamycin resistance screening pMD19-T-hom::km. Through shock process pMD19-T-hom::km in Bacillus subtilis YB83 transformation, validated by PCR success knockout Bacillus subtilis YB83 hom gene locus on a chromosome.Obtained by selection of Bacillus subtilis YB83 homoserine dehydrogenase lack strains lysine yield increased 2.07 times, missing Bacillus subtilis YB83 strain after 24 h of fermentation production of 0.375 g/L lysine, while Bacillus subtilis YB83 strains after 24 h of lysine production is 0.181 g/L.