温度对南极衣藻ICE-L(Chlamydomonas sp. ICE-L)谷胱甘肽含量及其相关酶活性的影响

采用分光光度法研究了在不同温度下(包括最适温度、低于或高于最适温度)南极衣藻ICE-L(Chlamydomonassp.ICE-L)谷胱甘肽(GSH)含量、蛋白含量、谷胱甘肽过氧化物酶(GPx)、谷胱甘肽还原酶(GR)和谷胱甘肽硫转移酶(GST)活性,同时分析了已适应高温(16℃)的衣藻重新适应低温(8℃)时这些指标的变化,以期阐明谷胱甘肽系统与南极冰藻低温适应性的关系。结果表明,当温度低于对照组(最适温度8℃)时,蛋白含量降低,而GSH含量、GPx、GST和GR活性上升,已适应高温的衣藻重新适应低温时也出现类似的结果。但当温度高于最适温度时,GSH含量、GST和GPx活性下降,而蛋白含量和GR活力有上升的趋势,GR活力增长幅度比低于最适温度时的变化小。由此可见谷胱甘肽系统在南极衣藻低温适应过程中,GSH、GPx、GR、GST与低温适应呈正相关,同时除GR外其他因子与南极衣藻高温适应呈负相关,GSH及其相关酶在南极冰藻低温适应中具有重要作用。     

Influence of temperature on glutathione level and glutathione-related enzyme activities of Antarctic ice microalgae Chlamydomonas sp.ICE-L

GSH system plays a role in the control of the redox balance state,anti-oxidation and protecting life from injury of ROS(reactive oxygen species).In present paper,the possible GSH system of Chlamydomonas sp.ICE-L has been investigated by evaluating GSH and GSH-related enzymatic responses at different temperatures using spectrophotometer methods.The results showed that the GSH system is correlated positively to low temperature,and other factors but GR are correlated negatively to high temperature.So GSH and GSH-related enzymes play an important role in the adaptation of Antarctic ice microalgae to low temperature.     

南极衣藻（Chlamydomonas sp.ICE-L）谷胱甘肽还原酶基因的原核表达及其条件优化

采用RT-PCR技术克隆南极衣藻GR基因ORF全长cDNA,然后经酶切、连接等步骤构建其原核表达载体;并对其表达的诱导时间、IPTG浓度、温度进行了优化,以期获得较大量的酶蛋白。结果表明,将构建的原核表达载体pET-GR导入大肠杆菌BL21,可以高效表达融合蛋白;且表达的蛋白均以包涵体的形式存在;经SDS-PAGE电泳...     

不同氮源下南极冰藻Chlamydomonas sp.ICE-L的生物量、氮吸收与脂肪酸组成研究

微藻培养过程中氮缺失有利于油脂和生物量的积累,然而不同氮源条件下微藻生长与生物量的研究有限,限制了生物油脂的相关研究。本文研究通过研究南极冰藻Chlamydomonas sp.ICE-L在不同氮源条件下的细胞生长与油脂积累,进一步探究其作为富集油脂微藻的潜力。研究发现：在含有NH₄CL的培养基中,Chlamydomonas sp.ICE-L生长速率最大;在含有NH₄NO₃的条件下,获得了最大干重量0.28 g/L。最高油脂含量0.21 g/g是在缺氮条件下获得,同时得到干重0.24 g/L。在多不饱和脂肪酸的产出方面,NH₄NO₃和NH₄Cl为氮源培养基时要好于缺氮和KNO₃培养基,在NH₄NO₃和NH₄Cl为氮源的培养条件下ICE-L胞内C18：3和C20：5的含量高。比较而言,缺氮和KNO₃培养基时C16：0、C18：1和C18：2的含量要高。     

Effect of high salinity on cell growth and protein production of Antarctic ice microalgae Chlamydomonas sp. ICE-L

Antarctic ice microalgae Chlamydomonas sp. ICE-L can survive and thrive in Antarctic sea ice. In this study, Chlamydomonas sp. ICE-L could survive at the salinity of 132‰ NaCl. SDS-PAGE showed that the density of 2 bands (26 and 36 kD) decreased obviously at the salinity of 99‰ NaCl compared to at the salinity of 33‰ NaCl. The soluble proteins in Chlamydomonas sp. ICE-L grown under salinity of 33‰ and 99% NaCl were compared by 2-D gel electrophoresis. After shocking with high salinity, 8 protein spots were found to disappear, and the density of 28 protein spots decreased. In addition, 19 protein spots were enhanced or induced, including one new peptide (51 kD). The changes of proteins might be correlated with the resistance for Chlamydomonas sp. ICE-L to high salinity.