文献类型：期刊文献

英文题名：A novel γ-aminobutyric acid biosynthetic pathway in Lentilactobacillus curieae CCTCC M 2011381T

作者：Xie, Xiaoying[1];Ro, Kum-Song[1,3];Wu, Huiling[1];Du, Lei[1];Zhao, Li[1];Xie, Jingli[1,2];Wei, Dongzhi[1,2]

机构：[1]East China Univ Sci & Technol, Dept Food Sci & Engn, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Collaborat Innovat Ctr Biomfg SCICB, Shanghai 200237, Peoples R China;[3]Kim Hyong Jik Univ Educ, Fac Life Sci, Dept Biotechnol, Pyongyang, North Korea

年份：2023

卷号：124

起止页码：160

外文期刊名：PROCESS BIOCHEMISTRY

收录：;EI(收录号：20225113270079);WOS:【SCI-EXPANDED(收录号:WOS:000932896700002)】；

基金：This work is supported by National Key Research and Development Program of China (Nos. 2021YFC2100300 and 2020YFA0907800) P. R. China, and Natural Science Foundation of Shanghai (No. 21ZR1416200) P. R. China.

语种：英文

外文关键词：Lentilactobacillus curieae; Gamma-aminobutyric acid; Biosynthetic pathway; GABA-T

摘要：Gamma-aminobutyric acid (GABA) is an important neurotransmitter for mammals, thus biosynthesized or biotransformed GABA is an important compound for functional foods. In this study, unique biosynthetic pathways of GABA in a novel lactic acid bacteria (LAB) strain, Lentilactobacillus curieae CCTCC M 2011381(T), was discovered. L-glutamate decarboxylase (GAD) which generally catalyzes L-glutamate decarboxylation to form GABA in bacteria, is absent in this strain. Alternatively, transcriptional analysis revealed that L-glutamate played as an amino donor for the step through which succinic semialdehyde (SSA) was converted to GABA catalyzed by GABA transaminase (GABA-T). Then, the deletion and complementation of the GABA-T gene confirmed that GABA-T was the key enzyme responsible for GABA accumulation from SSA. According to residual GABA titer could be detected after the deletion of the GABA-T gene, other decarboxylases among the genome were analyzed by RT-PCR. 5-Oxopent-3-ene-1,2,5-tricarboxylate decarboxylase (HpaG) was verified possessing weaker catalytic capability for the decarboxylation of L-glutamate based on the hetero-expression of the enzyme in E. coli. Thus, GABA is produced mainly through the transamination reaction on SSA catalyzed by GABA-T and L-glutamate as the amino donor, and slightly from the decarboxylation of L-glutamate catalyzed by HpaG in L. curieae, which are distinct pathways in LAB.