Chen Chen, Huang Ke, Li Xiaohong, Tian Huaixiang, Yu Haiyan, Huang Juan, Yuan Haibin, Zhao Shanshan, Shao Li
School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai, People's Republic of China.
Shanghai Customs P. R. China Technical Center For Animal, Plant And Food Inspection And Quarantine, Shanghai, People's Republic of China.
Appl Microbiol Biotechnol. 2021 May;105(9):3691-3704. doi: 10.1007/s00253-021-11276-0. Epub 2021 Apr 14.
Lactiplantibacillus plantarum is frequently exposed to salt stress during industrial applications. Catabolite control protein (CcpA) controls the transcription of many genes, but its role in the response to salt stress remains unclear. In this study, we used transcriptome analyses to investigate differences in the logarithmic growth phases of Lactiplantibacillus plantarum ST-III and its ccpA-knockout mutant when grown with or without salt and glycine betaine (GB). The deletion of ccpA significantly affected bacterial growth under different conditions. Among the comparisons, the highest proportion of differentially expressed genes (64%) was observed in the comparison between the wild-type and ccpA mutant grown with NaCl, whereas the lowest proportion (6%) was observed in the comparison between the ccpA mutant strain cultures grown with NaCl alone or with GB together. Transcriptomic analyses showed that CcpA could regulate GB uptake, activate iron uptake, produce acetyl-CoA, and affect fatty acid composition to maintain membrane lipid homeostasis in the adaptation of high-salinity conditions. Conclusively, these results demonstrate the importance of CcpA as a master regulator of these processes in response to salt stress, and provide new insights into the complex regulatory network of lactic acid bacteria. KEY POINTS: • The absence of CcpA significantly affected growth of L. plantarum and its response to salt stress. • CcpA regulates compatible solutes absorption and ions transport to resist salt stress. • CcpA alters fatty acids composition to maintain membrane lipid homeostasis towards salt stress.
植物乳杆菌在工业应用过程中经常会受到盐胁迫。分解代谢物控制蛋白（CcpA）可调控许多基因的转录，但其在应对盐胁迫中的作用仍不清楚。在本研究中，我们利用转录组分析来探究植物乳杆菌ST-III及其ccpA基因敲除突变体在有盐和无盐以及有或无甘氨酸甜菜碱（GB）存在的情况下对数生长期的差异。ccpA基因的缺失在不同条件下显著影响细菌生长。在各项比较中，野生型与在NaCl存在下生长的ccpA突变体之间差异表达基因的比例最高（64%），而在单独添加NaCl或同时添加GB的ccpA突变体菌株培养物之间的比较中比例最低（6%）。转录组分析表明，CcpA可调节GB摄取、激活铁摄取、产生乙酰辅酶A并影响脂肪酸组成，以在适应高盐条件下维持膜脂稳态。总之，这些结果证明了CcpA作为这些过程应对盐胁迫的主要调节因子的重要性，并为乳酸菌复杂的调控网络提供了新的见解。要点：• CcpA的缺失显著影响植物乳杆菌的生长及其对盐胁迫的反应。• CcpA调节相容性溶质吸收和离子转运以抵抗盐胁迫。• CcpA改变脂肪酸组成以维持膜脂对盐胁迫的稳态。
