嗜热厌氧杆菌SCUT27(Thermoanaerobacterium aotearoense SCUT27,SCUT27)能同时利用木糖和葡萄糖,是发酵廉价木质纤维素获得乙醇及乳酸的优势菌株.为了提高该菌株对木糖和葡萄糖的利用效率,对其在葡萄糖、木糖和混合糖下不同时间点转录组数据分析的基础上,敲除pro-sigmaK抑制因子BofA(pro-sigmak processing inhibitor BofA,BofA)基因,获得基因工程菌 ΔbofA.摇瓶发酵结果显示,与出发菌相比,当以木糖为唯一碳源时,突变株 ΔbofA对木糖的代谢速率提高51.43%,乳酸产率提高23.53%;以混合糖(葡萄糖:木糖为=1:1)为碳源时,ΔbofA对木糖的代谢速率提高44.44%,乳酸和乙醇的产率分别提高43.75%和20.00%.由此可见,pro-sigmaK抑制因子BofA是木糖利用的负调控因子,其功能有待进一步研究.%Thermoanaerobacterium aotearoense SCUT27 which can utilize both glucose and xylose is a promising candidate for ethanol and lactic acid production from lignocellulose feedstocks. In order to improve sugar (glucose and xylose) co-utilization efficiency, transcriptome data of SCUT27 using glucose, xylose and mixed sugar as carbon sources at different time points was acquired, and bofA gene encoding pro-sigmak processing inhibitor BofA was knocked out to obtain mutant ΔbofA. Shake flask fermentation results show that when xylose is used as sole carbon source, the xylose metabolic rate of ΔbofA and the productivity of lactic acid are increased by 51.43% and 23.53%, respectively (compared with the parent strain). When glucose and xylose (glucose:xylose=1:1) are used as carbon source, xylose metabolic rate of ΔbofA and the productivity of lactic acid and ethanol are 44.44%, 43.75% and 20% higher than those of the parent strain, respectively. Therefore, pro-sigmak processing inhibitor BofA is a negative regulator for xylose utilization and its function needs further exploration.
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