title: Identification of Quorum Sensing Signal Molecule of Lactobacillus delbrueckii subsp. bulgaricus.
abstract: Many bacteria in nature use quorum sensing (QS) to regulate gene expression. The quorum sensing system plays critical roles in the adaptation of bacteria to the surrounding environment. Previous studies have shown that during high-density fermentation, the autolysis of lactic acid bacteria was regulated by the QS system, and the two-component system (TCS, LBUL_RS00115/LBUL_RS00110) is involved in the autolysis of Lactobacillus delbrueckii subsp. bulgaricus. However, the QS signal molecule, which regulates this pathway, has not been identified. In this study, we compared the genome of Lactobacillus bulgaricus ATCC BAA-365 with the locus of seven lactobacillus QS systems; the position of the QS signal molecule of Lactobacillus bulgaricus ATCC BAA-365 was predicted by bioinformatics tool. Its function was identified by in vitro experiments. Construction of TCS mutant by gene knockout of LBUL_RS00115 confirmed that the signal molecule regulates the density of the flora by the TCS (LBUL_RS00115/LBUL_RS00110). This study indicated that quorum quenching and inhibition based on the signal molecule might serve as an approach to reduce the rate of autolysis of LAB and increase the number of live bacteria in fermentation.
authors.affiliation: State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy Company Ltd. , Shanghai 200436, People's Republic of China.|Key Laboratory of Agro-Food Processing and Quality Control, Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Science , Beijing 100193, People's Republic of China.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Pang
authors.affiliation: State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy Company Ltd. , Shanghai 200436, People's Republic of China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Liu
authors.affiliation: College of Life Science and Bioengineering, Beijing University of Technology , Beijing 100124, People's Republic of China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Lyu
authors.affiliation: Key Laboratory of Agro-Food Processing and Quality Control, Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Science , Beijing 100193, People's Republic of China.|Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology & Business University (BTBU) , Beijing 100048, People's Republic of China.
authors.forename: Shuwen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Agro-Food Processing and Quality Control, Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Science , Beijing 100193, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory of Agro-Food Processing and Quality Control, Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Science , Beijing 100193, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
authors.affiliation: Beijing Vocational College of Agriculture , Beijing 102442, People's Republic of China.
authors.forename: Changlu
authors.initials: C
authors.lastname: Ma
authors.affiliation: Key Laboratory of Agro-Food Processing and Quality Control, Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Science , Beijing 100193, People's Republic of China.
authors.forename: Jiaping
authors.initials: J
authors.lastname: Lv
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001433:Bacteriolysis; D005285:Fermentation; D007778:Lactobacillus / Q000145:classification / Q000235:genetics / Q000378:metabolism; D048668:Lactobacillus delbrueckii / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D053038:Quorum Sensing
chemical_list: D001426:Bacterial Proteins
keywords: autolysis; quorum sensing; signal molecule; two-component system