title: Analysis of β-galactosidase production and their genes of two strains of Lactobacillus bulgaricus.
abstract: A bacterial β-galactosidase delivery system is a potential therapy for lactose intolerance. Currently, two Lactobacillus bulgaricus strains with different biological characteristics are under consideration as potential sources. However, differences in these β-galactosidase genes and their resulting production levels are poorly characterized. The β-galactosidase ORF of L. bulgaricus yogurt isolate had high variability and was terminated at site 1924 due to a stop codon. However, the full 114 kDa β-galactosidase band was still resolved by SDS-PAGE, which may indicate that the interrupted ORF was translated into more than one peptide, and they together were folded into the complete enzyme protein that showed much higher β-galactosidase activity (6.2 U/mg protein) than the enzyme generated from L. bulgaricus reference strain (2.5 U/mg protein).
authors.affiliation: Department of Nutrition and Food Hygiene, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China. wendyzhang1982@163.com
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Huang
authors.forename: Qian
authors.initials: Q
authors.lastname: Yu
authors.forename: Heng-Chuan
authors.initials: HC
authors.lastname: Liu
authors.forename: Chao-Wu
authors.initials: CW
authors.lastname: Zhang
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Pei
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Wang
mesh_terms: D001483:Base Sequence; D018388:Codon, Terminator; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D015014:Yogurt / Q000382:microbiology; D001616:beta-Galactosidase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D018388:Codon, Terminator; D001616:beta-Galactosidase