南极菌Pseudoalteromonas sp.S-15-13引导糖基转移酶基因表达对环境因子变化的响应  

Effects of environmental factors on the pGTF gene expression of Antarctic bacterium Pseudoalteromonas sp.S-15-13

作　　者：李江[1] 谭姣姣[2] 

机构地区：[1]国家海洋局第一海洋研究所国家海洋局生物活性物质重点试验室,山东青岛266061 [2]青岛科技大学化工学院,山东青岛266042

出　　处：《海洋学报》2012年第5期154-160,共7页

基　　金：国家自然科学基金(40706053);国家863科技计划重点项目(2007AA091905)

摘　　要：为了探讨胞外多糖在南极微生物低温适应性中的作用与机制,克隆了南极菌Pseudoaltero-monas sp.S-15-13的引导糖基转移酶(GTF)核心片段,并采用Real-Time PCR的方法研究了温度、冻融循环、盐浓度、pH等条件对该糖基转移酶基因(gtf)表达的影响。结果表明,低温有利于gtf的表达,短时的低温刺激(2℃)1h后,gtf的表达量即上调为对照的1.5倍;而该菌经4和10℃培养24h后gtf的表达量约为20℃时的8～12倍;经过冻融循环gtf的表达量上调,在第2个冻融循环后gtf的表达量较对照提高了3.667倍;盐浓度对gtf的影响表现为低促高抑,即NaCl含量为6.0%时gtf的表达量是对照(3.0%)的3.59倍,当NaCl含量达9.0%时gtf表达量则显著下调;在一定范围内(pH5.0～8.0),pH的改变会促进gtf的表达,当pH为6.0时gtf表达量约为pH7.0时的2倍。该结果为探讨胞外多糖在南极微生物环境适应性中的作用与机制提供了科学依据。The priming glycosyltransferase gene（gtf） was cloned from the Antarctic bacterium Pseudoalteromonas sp.S-15-13,which was isolated from sea ice（62°00′S,68°30′E） samples,in order to explore the role and mechanism of extracellular polysaccharides on the low temperature adaptation of this strain.The effects of environmental factors（such as temperature,treatment with freeze-thaw cycles,salt concentrations and pH values） on gtf expression were studied with real-time PCR techniques.It was shown that the gtf expression level of S-15-13 stimulation at 2 ℃ was about 1.5 times that grown at 10 ℃ after 1h;and the gtf expression level of S-15-13 grown at 4 and 10 ℃ was about 8～12 times that grown at 20 ℃ after 24 h culture;the expression level of gtf was 3.667 times higher than the untreated sample after two freeze-thaw cycles of Pseudoalteromonas sp.S-15-13;6.0% NaCl could increase the expression level of gtf nearly four times compared to that of 3.0% NaCl,but when the NaCl concentration reached 9.0 %,the expression level of gtf dropped off sharply;pH changes in the range of pH 5.0 ～ 8.0 could promote the expression of gtf： the level of gtf expression at pH 6.0 was 2 times that at pH 7.0.Study on gtf of Pseudoalteromonas sp.S-15-13 may have potential to deepen our understanding of the adaptation mechanism of Antarctic bacteria living in harsh environments.

关 键 词：南极菌Pseudoalteromonas sp.S-15-13 糖基转移酶 REAL-TIME PCR 环境因子 

分 类 号：Q178.53[生物学—水生生物学] Q93-3[生物学—普通生物学]