摘要
羟基四氢嘧啶(5-hydroxyectoine,5-HE)是四氢嘧啶(Ectoine)的羟基化衍生物,是一种重要的细胞保护剂。为了研究菌株Halomonas campaniensis XH26在高NaCl浓度培养条件下的生长特性和5-HE合成情况,分别设计了不同NaCl浓度(0%、12%、14%和16%)(质量分数)的嗜盐菌培养基,并利用高效液相色谱(HPLC)对培养后的发酵液中的Ectoine和5-HE产量进行分析。结果显示,随着浓度增加,细菌的生长受到明显抑制,光学显微镜和电镜下观察到菌体长轴明显增加;菌株在12%~18%NaCl条件下培养,5-HE合成量呈现先增加后降低的趋势,5-HE与Ectoine的产量比最高达到0.92,在NaCl浓度为14%时,5-HE的产量最高。此外,优化培养条件得到菌株生长最适温度为33~37℃,最适pH值在5~8之间。菌株Halomonas sp.XH26在高盐胁迫下增加5-HE生物合成的同时细胞形态发生了改变,这为阐明野生菌株的耐盐机制和相容性溶质的合成调控及优化发酵的策略开拓了思路。
5-hydroxyectoine(5-HE),a hydroxylation derivative of ectoine,is a significant cytoprotective agent.This study created four experimental groups with 0%,12%,14%,and 16%NaCl concentrations(mass fraction)to examine the growth characteristics and 5-HE production of strain Halomonas campaniensis XH26 under high NaCl concentration culture conditions.High Performance Liquid Chromatography(HPLC)and culture fermentation were two analytical techniques used to test the samples.The results showed that the bacteria′s electron microscopic morphology altered with salinity increasing.It revealed that the long axis of bacterial body grew longer,the strain′s development was suppressed.When the strains were cultured in the concentration range of 12%to 18%NaCl,the synthesis of 5-HE showed a tendency of increase followed by decrease,the yield ratio of 5-HE/ectoine was increased to 0.92.However,the 5-HE content was the highest at 14%NaCl.Additionally,the optimum temperature for the growth of the strain is 33-37℃and the optimum pH is 5-8.The strain Halomonas sp.XH26 increased 5-HE biosynthesis under high salt stress along with altered cell morphology.This provides new perspectives for elucidating the salt tolerance mechanism,the regulation of compatible solute synthesis in wild strains,and optimizing the strategy of fermentation.
作者
张蔓
林子静
朱德锐
邢江娃
李永臻
ZHANG Man;LIN Zi-jing;ZHU De-rui;XING Jiang-wa;LI Yong-zhen(Res.Ctr.of Basic Med.Sci.,Med.Coll.,Qinghai Uni.,Xining 810016)
出处
《微生物学杂志》
北大核心
2025年第3期30-36,共7页
Journal of Microbiology
基金
国家自然科学基金地区项目(21967018)。
关键词
四氢嘧啶
羟基四氢嘧啶
盐单胞菌
盐胁迫
发酵工程
ectoine
5-hydroxyectoine(5-HE)
Halomonas spp.
salt coercion
fermentation engineering
