Microbiology Unit, Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar, 751002, Odisha, India.
Mol Biol Rep. 2014 Mar;41(3):1639-44. doi: 10.1007/s11033-013-3011-7. Epub 2014 Jan 8.
Thermophiles exhibit various kinds of molecular mechanisms to survive in extreme environment, but their behavioral responses to long duration stress is poorly understood until date. In the present study, we have prospected for the genes differentially expressed in response to long duration heat stress in thermophilic bacteria. A cDNA library was constructed from Geobacillus thermoglucosidasius grown with a temperature upshift of 10 °C from optimum growth temperature of 45 °C for 16 h. A total of 451 clones from the library were sequenced with accurate base calling that generated 257 high quality sequences with an average read length of 350 bp. We queried our collection of single pass sequences against the NCBI non-redundant database using the BLASTX algorithm and obtained sequences that showed significant similarity (>60%) with heat shock proteins, metabolic proteins and hypothetical proteins. The expressed sequence tags (ESTs) expressed in response to heat stress were annotated that further commuted a strong interaction network among one another. The ESTs based on the best hits were validated by RT-PCR. Di- and tri-nucleotide repeat motifs were also found to be associated with 17 genes involved in heat shock response, metabolism, transport and transcriptional regulation. The present results provide the novel identification of the putative genes responsible for imparting tolerance to bacteria under heat stress and unveil their role for survival of life in environmental extremes.
嗜热菌表现出各种分子机制以在极端环境中生存，但直到目前为止，它们对长时间应激的行为反应还了解甚少。在本研究中，我们预测了在嗜热细菌中对长时间热应激有反应的差异表达基因。从生长温度从最适生长温度 45°C 升高 10°C 并持续 16 小时的嗜热葡萄糖苷酶的 Geobacillus thermoglucosidasius 中构建了 cDNA 文库。从文库中总共测序了 451 个克隆，碱基准确调用，生成了 257 个高质量序列，平均读长为 350bp。我们使用 BLASTX 算法将我们的单通序列集合与 NCBI 非冗余数据库进行了查询，并获得了与热休克蛋白、代谢蛋白和假设蛋白具有显著相似性（>60%）的序列。对响应热应激表达的表达序列标签（EST）进行了注释，进一步相互之间建立了强大的相互作用网络。基于最佳命中的 EST 通过 RT-PCR 进行了验证。二核苷酸和三核苷酸重复基序也与参与热休克反应、代谢、运输和转录调节的 17 个基因相关联。这些结果为赋予细菌在热应激下的耐受性的可能基因提供了新的鉴定，并揭示了它们在极端环境中生存的作用。
