草酸青霉的植物多糖降解酶基因表达调控的研究进展

Gene expression and regulation of plant-polysaccharide-degrading enzymes in Penicillium oxalicum

植物生物质是地球上最丰富的可再生资源,对其生物炼制可生产高附加值的生物基产品。生物炼制需要使用植物多糖降解酶(plant-polysaccharide-degrading enzymes,PPDEs),如纤维素酶、木聚糖酶和生淀粉酶。丝状真菌草酸青霉(Penicillium oxalicum)能分泌完整的具有高活力的植物多糖降解酶,但其产量低限制了大规模生产及应用。草酸青霉中植物多糖降解酶的生物合成受到多种调控因子包括转录因子的严格调控。本文主要介绍在以植物生物质甘蔗渣和木薯生淀粉为原料的生物炼制中,涉及的一些关键微生物方面的问题,如从高产植物多糖降解酶的真菌菌株的筛选、育种,到草酸青霉植物多糖降解酶合成及其基因表达的调控基因的鉴定,以及酶产量提高的工程菌株的构建等,为丝状真菌资源的开发与利用提供理论指导。

Plant biomass is the most abundant renewable bioresource on earth. Many high-value added bio-based products can be produced by biomass biorefinery which needs to use plant-polysacchari-dedegrading enzymes(PPDEs), such as cellulase, xylanase and raw-starch-degrading enzymes.Filamentous fungus Penicillium oxalicum can secrete complete PPDEs with high activity, but low yields of PPDEs limit their large-scale production and application. The biosynthesis of PPDEs in P. oxalicum is strictly regulated by many regulators such as transcription factors. In this review, in the biorefinery of sugarcane bagasse and raw cassava starch as feedstocks, some aspects concerning microorganisms were introduced, including the screening and breeding of fungal strains with high production of PPDEs, identification of regulatory genes regulating the biosynthesis of PPDEs and their gene expression in P. oxalicum, and construction of the engineered P. oxalicum strains with improved PPDE production, which would provide theoretical guidance for the exploration and utilization of fungal resources.