Butanol is a platform chemical that is utilized in a wide range of industrial products and is considered a suitable replacement or additive to liquid fuels. So far, it is mainly produced through petrochemical routes. Alternative production routes, for example through biorefinery, are under investigation but are currently not at a market competitive level. Possible alternatives, such as acetone-butanol-ethanol (ABE) fermentation by solventogenic clostridia are not market-ready to this day either, because of their low butanol titer and the high costs of feedstocks. Here, we analyzed wheat middlings and wheat red dog, two wheat milling byproducts available in large quantities, as substrates for clostridial ABE fermentation. We could identify ten strains that exhibited good butanol yields on wheat red dog. Two of the best ABE producing strains, Clostridium beijerinckii NCIMB 8052 and Clostridium diolis DSM 15410, were used to optimize a laboratory-scale fermentation process. In addition, enzymatic pretreatment of both milling byproducts significantly enhanced ABE production rates of the strains C. beijerinckii NCIMB 8052 and C. diolis DSM 15410. Finally, a profitability analysis was performed for small- to mid-scale ABE fermentation plants that utilize enzymatically pretreated wheat red dog as substrate. The estimations show that such a plant could be commercially successful.Key points• Wheat milling byproducts are suitable substrates for clostridial ABE fermentation.• Enzymatic pretreatment of wheat red dog and middlings increases ABE yield.• ABE fermentation plants using wheat red dog as substrate are economically viable. Graphical abstract.

中文翻译：

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研磨副产物是使用梭菌 ABE 发酵生产丁醇的经济可行的底物。

丁醇是一种平台化学品，广泛用于多种工业产品，被认为是液体燃料的合适替代品或添加剂。迄今为止，主要通过石化途径生产。替代生产路线（例如通过生物精炼）正在研究中，但目前尚未达到市场竞争水平。可能的替代方案，例如通过产溶剂梭状芽胞杆菌发酵丙酮-丁醇-乙醇（ABE），由于其丁醇滴度低且原料成本高，至今尚未准备好投入市场。在这里，我们分析了小麦中粉和小麦红狗，这两种大量可用的小麦加工副产品，作为梭菌 ABE 发酵的底物。我们可以鉴定出十个在小麦红狗上表现出良好丁醇产量的菌株。两种最好的 ABE 生产菌株，拜氏梭菌 NCIMB 8052 和二醇梭菌 DSM 15410，被用来优化实验室规模的发酵过程。此外，对两种研磨副产物进行酶预处理显着提高了菌株 C. beijerinckii NCIMB 8052 和 C. diolis DSM 15410 的 ABE 生产率。最后，对采用酶预处理的中小型 ABE 发酵工厂进行了盈利能力分析小麦红狗作为基质。估计表明，这样的工厂可能会取得商业上的成功。要点• 小麦磨粉副产物是梭菌ABE 发酵的合适底物。• 麦红狗和中粮的酶预处理可提高ABE 产量。• 以麦红狗为底物的ABE 发酵工厂是经济上可行。图形概要。