Institute of Natural Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, People's Republic of China.
College of Landscape Architecture, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, People's Republic of China.
Appl Microbiol Biotechnol. 2018 Dec;102(24):10439-10456. doi: 10.1007/s00253-018-9425-3. Epub 2018 Oct 10.
Bioconversion of lignocellulosic biomass to high-value bioproducts by fermentative microorganisms has drawn extensive attentions worldwide. Lignocellulosic biomass cannot be efficiently utilized by microorganisms, such as Saccharomyces cerevisiae, but has to be pretreated prior to fermentation. Aldehyde compounds, as the by-products generated in the pretreatment process of lignocellulosic biomass, are considered as the most important toxic inhibitors to S. cerevisiae cells for their growth and fermentation. Aldehyde group in the aldehyde inhibitors, including furan aldehydes, aliphatic aldehydes, and phenolic aldehydes, is identified as the toxic factor. It has been demonstrated that S. cerevisiae has the ability to in situ detoxify aldehydes to their corresponding less or non-toxic alcohols. This reductive reaction is catalyzed by the NAD(P)H-dependent aldehyde reductases. In recent years, detoxification of aldehyde inhibitors by S. cerevisiae has been extensively studied and a huge progress has been made. This mini-review summarizes the classifications and structural features of the characterized aldehyde reductases from S. cerevisiae, their catalytic abilities to exogenous and endogenous aldehydes and effects of metal ions, chemical protective additives, and salts on enzyme activities, subcellular localization of the aldehyde reductases and their possible roles in protection of the subcellular organelles, and transcriptional regulation of the aldehyde reductase genes by the key stress-response transcription factors. Cofactor preference of the aldehyde reductases and their molecular mechanisms and efficient supply pathways of cofactors, as well as biotechnological applications of the aldehyde reductases in the detoxification of aldehyde inhibitors derived from pretreatment of lignocellulosic biomass, are also included or supplemented in this mini-review.
利用发酵微生物将木质纤维素生物质转化为高价值的生物制品已引起全球广泛关注。木质纤维素生物质不能被微生物（如酿酒酵母）有效利用，在发酵前必须进行预处理。醛类化合物是木质纤维素生物质预处理过程中的副产物，被认为是对酿酒酵母细胞生长和发酵的最重要的毒性抑制剂。醛抑制剂中的醛基，包括糠醛、脂肪醛和酚醛，被认为是毒性因子。已经证明，酿酒酵母具有将醛原位还原为相应的低毒或无毒醇的能力。这种还原反应由 NAD(P)H 依赖的醛还原酶催化。近年来，酿酒酵母对醛抑制剂的解毒作用已得到广泛研究，并取得了巨大进展。本综述总结了酿酒酵母中已鉴定的醛还原酶的分类和结构特征，它们对外源和内源性醛的催化能力，以及金属离子、化学保护添加剂和盐对酶活性的影响、醛还原酶的亚细胞定位及其在保护亚细胞器官中的可能作用，以及关键应激反应转录因子对醛还原酶基因的转录调控。还包括或补充了醛还原酶的辅酶偏好及其分子机制和辅酶的有效供应途径，以及醛还原酶在木质纤维素生物质预处理衍生的醛抑制剂解毒中的生物技术应用。
