title: A novel vector for lactic acid bacteria that uses a bile salt hydrolase gene as a potential food-grade selection marker.
abstract: A novel vector pM4aB for lactic acid bacterial was developed using a bile salt hydrolase gene from Lactobacillus plantarum as a potential food-grade selection marker. The 3.0-kb pM4aB consisted of the replicon of Lactobacillus plasmid pM4, a multiple cloning site and the bsh gene, which was constructed by elimination of a 5.5-kb non-food-grade DNA fragment from an 8.5-kb intermediate vector pBEmpM4aB. For electroporation into Lactobacillus paracasei X9, a high transformation efficiency of 4.0±1.0×10(4) CFU/μg plasmid DNA was yielded with 0.1% (wt/vol) glycodeoxycholic acid sodium selection. A high segregation stability of the vector was also observed as only 0.1% plasmid was lost after 50 generations of growth without selection pressure. The application potential of pM4aB was further confirmed by expression of a catalase gene from Lactobacillus sakei in L. paracasei. These results revealed that the novel vector pM4aB constructed in this study would be a useful tool for genetic modification of the industrially important LAB.
authors.affiliation: Key Laboratory of Functional Dairy of Ministry of Education of the People's Republic of China & Municipal Government of Beijing, College of Food Science & Nutritional Engineering, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yin
authors.forename: Zhengyuan
authors.initials: Z
authors.lastname: Zhai
authors.forename: Guohong
authors.initials: G
authors.lastname: Wang
authors.forename: Haoran
authors.initials: H
authors.lastname: An
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Luo
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hao
mesh_terms: D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism; D005516:Food Microbiology; D005822:Genetic Vectors / Q000235:genetics*; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics
chemical_list: D000581:Amidohydrolases; C023154:choloylglycine hydrolase