Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
BMC Genomics. 2011 Feb 2;12:93. doi: 10.1186/1471-2164-12-93.
Clostridium acetobutylicum, a gram-positive and spore-forming anaerobe, is a major strain for the fermentative production of acetone, butanol and ethanol. But a previously isolated hyper-butanol producing strain C. acetobutylicum EA 2018 does not produce spores and has greater capability of solvent production, especially for butanol, than the type strain C. acetobutylicum ATCC 824.
Complete genome of C. acetobutylicum EA 2018 was sequenced using Roche 454 pyrosequencing. Genomic comparison with ATCC 824 identified many variations which may contribute to the hyper-butanol producing characteristics in the EA 2018 strain, including a total of 46 deletion sites and 26 insertion sites. In addition, transcriptomic profiling of gene expression in EA 2018 relative to that of ATCC824 revealed expression-level changes of several key genes related to solvent formation. For example, spo0A and adhEII have higher expression level, and most of the acid formation related genes have lower expression level in EA 2018. Interestingly, the results also showed that the variation in CEA_G2622 (CAC2613 in ATCC 824), a putative transcriptional regulator involved in xylose utilization, might accelerate utilization of substrate xylose.
Comparative analysis of C. acetobutylicum hyper-butanol producing strain EA 2018 and type strain ATCC 824 at both genomic and transcriptomic levels, for the first time, provides molecular-level understanding of non-sporulation, higher solvent production and enhanced xylose utilization in the mutant EA 2018. The information could be valuable for further genetic modification of C. acetobutylicum for more effective butanol production.
梭菌属（Clostridium）是一种革兰氏阳性、产芽孢的厌氧菌，是丙酮丁醇乙醇发酵生产的主要菌株。但是，之前分离到的一株高产丁醇的梭菌（C. acetobutylicum）EA 2018 菌株不产芽孢，且与模式菌株 C. acetobutylicum ATCC 824 相比，具有更强的溶剂生产能力，尤其是丁醇。
采用 Roche 454 焦磷酸测序法对 C. acetobutylicum EA 2018 的全基因组进行测序。与 ATCC 824 的基因组比较鉴定出许多可能导致 EA 2018 菌株高产丁醇的特征的变异，包括总共 46 个缺失位点和 26 个插入位点。此外，与 ATCC824 相比，EA 2018 中基因表达的转录组谱分析显示，与溶剂形成相关的几个关键基因的表达水平发生了变化。例如，spo0A 和 adhEII 的表达水平更高，而 EA 2018 中大多数酸形成相关基因的表达水平较低。有趣的是，结果还表明，参与木糖利用的假定转录调节因子 CEA_G2622（ATCC 824 中的 CAC2613）的变异可能加速了底物木糖的利用。
首次在基因组和转录组水平上对产丁醇梭菌（C. acetobutylicum）高产丁醇突变株 EA 2018 和模式菌株 ATCC 824 进行比较分析，从分子水平上了解了突变株 EA 2018 不产芽孢、更高的溶剂生产能力和增强的木糖利用能力。这些信息对于进一步遗传修饰 C. acetobutylicum 以提高丁醇生产效率可能具有重要价值。
