Mayo B, González B, Arca P, Suárez J E
Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Spain.
FEMS Microbiol Lett. 1994 Sep 15;122(1-2):145-51. doi: 10.1111/j.1574-6968.1994.tb07157.x.
The beta-galactosidase (beta-Gal) gene from Lactobacillus plantarum C3.8 was cloned and expressed in Lactococcus lactis and Escherichia coli. Hybridization experiments indicated that the gene is located on a plasmid and is present in other strains of Lactobacillus plantarum. Its sequence is very similar to a Leuconostoc lactis beta-Gal gene. Expression of the gene, both in Lactobacillus plantarum and in Lactococcus lactis, was four-fold higher in cells growth in lactose compared to those grown in glucose. The presence of the beta-Gal gene in Lactococcus lactis allowed this bacterium to be efficient in clotting milk.
从植物乳杆菌C3.8中克隆出β-半乳糖苷酶（β-Gal）基因，并在乳酸乳球菌和大肠杆菌中进行表达。杂交实验表明该基因位于质粒上，并且存在于其他植物乳杆菌菌株中。其序列与乳酸明串珠菌的β-Gal基因非常相似。该基因在植物乳杆菌和乳酸乳球菌中的表达，与在葡萄糖中生长的细胞相比，在乳糖中生长的细胞中的表达高出四倍。乳酸乳球菌中β-Gal基因的存在使该细菌能够有效地凝结牛奶。
