Temperature stress improved exopolysaccharide yield from Tetragenococcus halophilus: Structural differences and underlying mechanisms revealed by transcriptomic analysis.
Min Zhang, Mengting Hong, Zihao Wang, Xue Jiao, Chongde Wu
Author Information
Min Zhang: College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China.
Mengting Hong: College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China.
Zihao Wang: College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China.
Xue Jiao: College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China.
Chongde Wu: College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China. Electronic address: cdwu@scu.edu.cn.
This study aimed to enhance exopolysaccharide production by Tetragenococcus halophilus, and results showed that low temperature (20 °C) significantly improved exopolysaccharide production. Based on the analysis of batch fermentation kinetic parameters, a temperature-shift strategy was proposed, and the exopolysaccharide yield was increased by 28 %. Analysis of the structure of exopolysaccharide suggested that low temperature changed the molecular weight and monosaccharide composition. Transcriptomic analysis was performed to reveal mechanisms of low temperature improving exopolysaccharide production. Results suggested that T. halophilus regulated utilization of carbon sources through phosphotransferase system and increased the expression of key genes in exopolysaccharide biosynthesis to improve exopolysaccharide production. Meanwhile, metabolic pathways involved in glycolysis, amino acids synthesis, two-component system and ATP-binding cassette transporters were affected at low temperature. Results presented in this paper provided a theoretical basis for biosynthetic pathway of exopolysaccharide in T. halophilus and aided to strengthen its production and application in many areas.
