Hemme D, Gaier W, Winters D A, Foucaud C, Vogel R F
Universität Hohenheim, Institut für Lebensmitteltechnologie, Stuttgart, Germany.
Lett Appl Microbiol. 1994 Nov;19(5):345-8. doi: 10.1111/j.1472-765x.1994.tb00471.x.
Lactococcus lactis subsp. lactis CNRZ 1123, a Lac- derivative of CNRZ 1122 was transformed by electroporation with the Lactobacillus casei ATCC 393 plasmid pLZ15, which bears a beta-galactosidase gene. The transformants expressed a constitutive beta-galactosidase activity at a higher level than in Lact. casei, and in the cell-free extract two additional protein bands were detected by SDS-PAGE which could correspond to lactose metabolism enzymes. Both plasmid and beta-gal activity were stable in Lactococcus after 100 generations in glucose-containing medium.
乳酸乳球菌乳酸亚种CNRZ 1123是CNRZ 1122的Lac-衍生物，通过电穿孔法用含有β-半乳糖苷酶基因的干酪乳杆菌ATCC 393质粒pLZ15进行转化。转化子表达的组成型β-半乳糖苷酶活性高于干酪乳杆菌，并且在无细胞提取物中通过SDS-PAGE检测到两条额外的蛋白带，它们可能对应于乳糖代谢酶。在含葡萄糖的培养基中传代100代后，质粒和β-半乳糖苷酶活性在乳酸乳球菌中均保持稳定。
