摘要
考察ε-聚赖氨酸产生菌淀粉酶产色链霉菌(Streptomyces diastatochromogenes)T17,及其经酸性适应性进化得到的3株进化菌株(S.diastatochromogenes AE41、S.diastatochromogenes AE51和S.diastatochromogenes AE56)应对自发酸胁迫的生理响应。比较2个胁迫时间下原始菌株和进化菌株相关生理指标的变化。结果显示,在第0小时(pH 6.5),原始菌株和进化菌株的各生理指标无明显区别;在第48小时(pH 3.2),相较于原始菌株,进化菌株的耐酸能力更强,胞内pH值、ATP含量和H+-ATPase活性均明显提高,胞内天冬氨酸、丙氨酸、谷氨酸、赖氨酸、甘氨酸以及脯氨酸浓度明显增加,细胞膜脂肪酸的不饱和度明显增加从而提高流动性。进化菌株能够实现对自发酸胁迫的制衡。
The physiological responses of theε-poly-L-lysine-producing strain Streptomyces diastatochromogenes T17 and its acid-resistant derivatives,S.diastatochromogenes AE44,S.diastatochromogenes AE51 and S.diastatochromogenes AE56,to spontaneous acid stress were investigated.The changes in relevant physiological indexes of the original and evolutionary strains were compared at two stages of acidic stress.The results showed that at 0 h(pH 6.5),there were no significant differences in the physiological indexes between the original and evolutionary strains.At 48 h(pH 3.2),compared to the original strain,the intracellular pH,ATP concentration and H+-ATPase activity of the evolutionary strains were significantly increased,accompanied by increased levels of intracellular aspartic acid,alanine,glutamic acid,lysine,glycine and proline.The ratio of unsaturated to saturated fatty acids(U/S ratio)in the cell membrane was also increased so that the membrane fluidity was improved.Collectively,we conclude that the evolutionary strains could achieve a balance during spontaneous acid stress.
作者
任喜东
于超
王晨莹
刘新利
REN Xidong;YU Chao;WANG Chenying;LIU Xinli(State Key Laboratory of Biobased Material and Green Papermaking,Qilu University of Technology,Shandong Academy of Sciences,Jinan 250353,China;Shandong Provincial Key Laboratory of Microbial Engineering,Qilu University of Technology,Shandong Academy of Sciences,Jinan 250353,China;School of Food Science and Engineering,Qilu University of Technology,Shandong Academy of Sciences,Jinan 250353,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第12期106-112,共7页
Food Science
基金
国家自然科学基金青年科学基金项目(31701585)。
关键词
Ε-聚赖氨酸
淀粉酶产色链霉菌T17
酸性适应性进化
自发酸胁迫
耐酸生理机制
ε-poly-L-lysine
Streptomyces diastatochromogenes T17
acidic adaptive evolution
spontaneous acid stress
physiological mechanism of acid resistance