Lactic acid plays a significant role in the food industry as a natural preservative and serves as a platform chemical for the production of biodegradable poly-lactic acid. While its sustainable production through fermentation using cellulosic biomass instead of traditional sugar and starch raw materials shows promise, there remains limited information available on this method. In this study, a xylose-fermenting and lactic acid-tolerant strain (BK01) was engineered for improved cellulosic lactic acid production using the promising energy crop, kenaf. Specifically, was deleted to inhibit lactic acid consumption (BK02), which was further engineered by overexpression to remove the cytotoxic acetate derived from cellulosic biomass (BK03). The BK03 produced 3.25-fold more lactic acid from kenaf pulp hydrolysate than the parental strain (BK01). During pH-controlled fermentation, lactic acid production by BK03 reached a titer of 31 g/L and a productivity of 1.30 g/L-h, the highest value reported so far. This is one of the few studies on yeast-based lactic acid production from lignocellulose.

中文翻译：

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CYB2 缺失和 ACS1 过表达的耦合工程策略提高了酿酒酵母的纤维素乳酸产量


乳酸作为天然防腐剂在食品工业中发挥着重要作用，并作为生产可生物降解聚乳酸的平台化学品。虽然使用纤维素生物质代替传统的糖和淀粉原料进行发酵的可持续生产显示出前景，但有关该方法的可用信息仍然有限。在这项研究中，我们设计了一种木糖发酵且耐乳酸的菌株 (BK01)，以利用有前景的能源作物红麻提高纤维素乳酸的产量。具体而言，删除以抑制乳酸消耗（BK02），通过过度表达进一步改造以去除源自纤维素生物质的细胞毒性乙酸盐（BK03）。 BK03 从红麻果肉水解产物中产生的乳酸是亲本菌株 (BK01) 的 3.25 倍。在 pH 控制发酵过程中，BK03 的乳酸产量达到了 31 g/L 的滴度和 1.30 g/L-h 的生产率，这是迄今为止报道的最高值。这是利用木质纤维素生产酵母乳酸的少数研究之一。