摘要
研究了盐胁迫对枯草芽孢杆菌主要代谢产物的影响。利用氨基酸自动分析仪和顶空固相微萃取-气质联用技术,检测盐胁迫条件下主要理化指标、氨基酸和挥发性成分的变化情况。高盐胁迫下停滞期结束后,细胞残糖消耗速率最大但菌体生长缓慢,乳酸含量合成和消耗速率最快;天冬氨酸积累量增加而丝氨酸减少,组氨酸和苯丙氨酸浓度基本不变;中间盐浓度刺激下3-羟基-2-丁酮积累量最大,其次为糠醛等小分子风味成分,乙酸乙烯酯、甲氧基异戊酸乙酯等仅在对照盐浓度发酵过程中检测到,存在周期短且含量较低,2,5-二甲基吡嗪和苯甲醛仅在盐胁迫环境中产生。高盐胁迫下基质消耗主要用来进行产物合成,而不是菌体生长,乳酸在细胞抗高渗胁迫过程中起重要作用;高盐胁迫刺激了草酰乙酸为前体的氨基酸代谢途径;渗透胁迫能够刺激枯草芽孢杆菌生成某些特定化合物的代谢途径的增强,从而深入了解高渗胁迫下细胞内代谢方向的变化。
In order to investigate the influence of salt stress on main metabolite of Bacillus subtilis, the changes of amino acid, volatile flavor components and physicochemical indexes including reducing glucose consumption, cell dry weight, lactic acid concentration and amylase activity were measured by automatic analyzer for amino acid and HS- SPME-GC-MS. After cell adaptation period, B. subtilis B15 had the fastest rate of glucose consumption and the lowest rate of cell growth under high salt stress. At the same time, the producing and consumption rate reached highest in cul- ture broth containing 10% NaCl. Along with strengthen of salt stress the increasing Asp, decreasing Ser and unchanged His and Phe were detected. Acetic acid ethenyl ester and methoxyacetic acid, pentyl ester only existed in control medium, whose concentration were lower and existing phase was shorter. The accumulation of 3-hydroxy-2-Butanone increased consciously in middle salt stress. Only in high salt stress we could detect furfural, hexanal, trichloromethane and 1-hexanol. 2,5-dimethyl-pyrazine and benzaldehyde only were found under salt stress. Under high salt stress cell consumed glucose to synthesis products or energy metabolism, not to increase cell dry weight. Lactic acid played an important role in resisting hyper osmosis. High salt stress stimulated amino acid pathway with oxaloacetic acid as metabolic precursor. Hyper osmosis stimulated some metabolic pathways to produce new metabolite which existed in control medium. This study could help us to understand the change of metabolic direction in cell under high osmosis stress.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2015年第7期29-33,共5页
Food and Fermentation Industries
基金
四川省教育厅科技成果重大培育项目(15CZ0029)
四川理工学院研究生创新基金(2013B20306)
国家级大学生创新基金(201310622020
2013106 22002)
四川省学术带头人后备人选基金
