National Engineering Laboratory of Rice and By-Product Deep Processing, Central South University of Forestry and Technology, Shaoshan Nan Road No. 498, Changsha, 410004, People's Republic of China.
College of Food Science and Technology, Central South University of Forestry and Technology, Shaoshan Nan Road No. 498, Changsha, 410004, People's Republic of China.
Microb Cell Fact. 2018 Mar 3;17(1):35. doi: 10.1186/s12934-018-0884-0.
Phenolic compounds generated in hydrolysis of lignocellulosic materials are major limiting factors for biological production of solvents by Clostridia, but it lacks the attention on the study of adaptation or resistance mechanisms in response to phenolic compounds.
Gene Cbei_3304, encoding a hypothetical membrane transport protein, was analyzed by bioinformatic method. After insertional inactivation of the functionally uncertain gene Cbei_3304 in Clostridium beijerinckii NCIMB 8052, resulted in enhanced phenolic compounds tolerance. Compared to the parent strain C. beijerinckii NCIMB 8052, evaluation of toxicity showed the recombination stain C. beijerinckii 3304::int had a higher level of tolerance to four model phenolic compounds of lignocellulose-derived microbial inhibitory compounds. A comparative transcriptome analysis showed that the genes were involved in membrane transport proteins (ABC and MFS family) and were up-regulated expression after disrupting gene Cbei_3304. Additionally, the adaptation of C. beijerinckii NCIMB 8052 in response to non-detoxified hemicellulosic hydrolysate was improved by disrupting gene Cbei_3304.
Toxicity evaluation of lignocellulose-derived phenolic compounds shows that Cbei_3304 plays a significant role in regulating toxicities tolerance for ABE fermentation by C. beijerinckii, and the adaptation of non-detoxified hemicellulosic hydrolysate is significantly improved after inactivation of Cbei_3304 in wild-type strain C. beijerinckii NCIMB 8052. It provided a potential strategy for generating high inhibitor tolerance strains for using lignocellulosic materials to produce solvents by clostridia in this study.
木质纤维素水解产生的酚类化合物是梭菌生物生产溶剂的主要限制因素，但缺乏对适应或抵抗酚类化合物的机制的研究。
通过生物信息学方法分析了编码假定膜转运蛋白的基因 Cbei_3304。在 Clostridium beijerinckii NCIMB 8052 中功能不确定基因 Cbei_3304 插入失活后，增强了对酚类化合物的耐受性。与亲本菌株 C. beijerinckii NCIMB 8052 相比，毒性评估表明重组菌株 C. beijerinckii 3304::int 对四种木质纤维素衍生的微生物抑制化合物的模型酚类化合物具有更高的耐受性。比较转录组分析表明，这些基因参与膜转运蛋白（ABC 和 MFS 家族），并且在破坏基因 Cbei_3304 后上调表达。此外，通过破坏基因 Cbei_3304，C. beijerinckii NCIMB 8052 对未经解毒的半纤维素水解物的适应能力得到了提高。
木质纤维素衍生酚类化合物的毒性评估表明，Cbei_3304 在调节 C. beijerinckii 对 ABE 发酵的毒性耐受性方面起着重要作用，并且在野生型菌株 C. beijerinckii NCIMB 8052 中失活 Cbei_3304 后，对未经解毒的半纤维素水解物的适应能力得到了显著提高。该研究为利用木质纤维素材料生产溶剂的梭菌产生高抑制剂耐受性菌株提供了一种潜在策略。
