Wecker Patricia, Klockow Christine, Ellrott Andreas, Quast Christian, Langhammer Philipp, Harder Jens, Glöckner Frank Oliver
Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Microbial Genomics Group, Celsiusstr. 1, Bremen 28359, Germany.
BMC Genomics. 2009 Sep 2;10:410. doi: 10.1186/1471-2164-10-410.
The marine model organism Rhodopirellula baltica SH1(T) was the first Planctomycete to have its genome completely sequenced. The genome analysis predicted a complex lifestyle and a variety of genetic opportunities to adapt to the marine environment. Its adaptation to environmental stressors was studied by transcriptional profiling using a whole genome microarray.
Stress responses to salinity and temperature shifts were monitored in time series experiments. Chemostat cultures grown in mineral medium at 28 degrees C were compared to cultures that were shifted to either elevated (37 degrees C) or reduced (6 degrees C) temperatures as well as high salinity (59.5 per thousand) and observed over 300 min. Heat shock showed the induction of several known chaperone genes. Cold shock altered the expression of genes in lipid metabolism and stress proteins. High salinity resulted in the modulation of genes coding for compatible solutes, ion transporters and morphology. In summary, over 3000 of the 7325 genes were affected by temperature and/or salinity changes.
Transcriptional profiling confirmed that R. baltica is highly responsive to its environment. The distinct responses identified here have provided new insights into the complex adaptation machinery of this environmentally relevant marine bacterium. Our transcriptome study and previous proteome data suggest a set of genes of unknown functions that are most probably involved in the global stress response. This work lays the foundation for further bioinformatic and genetic studies which will lead to a comprehensive understanding of the biology of a marine Planctomycete.
海洋模式生物波罗的海玫瑰单胞菌SH1(T)是首个完成全基因组测序的浮霉菌门细菌。基因组分析预测其具有复杂的生活方式以及多种适应海洋环境的遗传机会。通过使用全基因组微阵列进行转录谱分析，研究了其对环境应激源的适应性。
在时间序列实验中监测了对盐度和温度变化的应激反应。将在28摄氏度的矿物培养基中培养的恒化器培养物与转移至较高温度（37摄氏度）或较低温度（6摄氏度）以及高盐度（59.5‰）的培养物进行比较，并观察300分钟以上。热休克显示出几种已知伴侣基因的诱导。冷休克改变了脂质代谢和应激蛋白相关基因的表达。高盐度导致编码相容性溶质、离子转运蛋白和形态相关基因的调控。总之，7325个基因中的3000多个受到温度和/或盐度变化的影响。
转录谱分析证实波罗的海玫瑰单胞菌对其环境高度敏感。此处确定的不同反应为这种与环境相关的海洋细菌的复杂适应机制提供了新的见解。我们的转录组研究和先前的蛋白质组数据表明，一组功能未知的基因很可能参与了全局应激反应。这项工作为进一步的生物信息学和遗传学研究奠定了基础，这些研究将有助于全面了解海洋浮霉菌门细菌的生物学特性。
