The generation of fermentation inhibitors during dilute acid hydrolysis of softwood
The generation of fermentation inhibitors during dilute acid hydrolysis of softwood
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DOI：
10.1016/s0141-0229(98)00101-x
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发表时间：
1999-02-01
影响因子：
3.4
通讯作者：
Nilvebrant, NO
中科院分区：
文献类型：
--
作者：
Larsson, S;Palmqvist, E;Nilvebrant, NO
研究了云杉（软木）稀硫酸水解强度对糖产量和酿酒酵母（面包酵母）水解产物发酵能力的影响。发酵能力评估为可发酵糖（甘露糖和葡萄糖）的乙醇产量和平均体积生产率（4小时）。水解条件、停留时间、温度和硫酸浓度被视为单一参数，组合严重性（CS）。当水解条件的CS增加时，可发酵糖的产率增加至甘露糖的CS 2.0-2.7之间的最大值，以及葡萄糖的CS 3.0-3.4之间的最大值，高于此值则下降。单糖产量的下降与糠醛和5-羟甲基糠醛（5HMF）的最大浓度一致。随着CS的进一步增加，糠醛和5-HMF的浓度下降，而甲酸和乙酰丙酸的形成增加。乙醇的产率在CS 3附近下降；在模型发酵中测定了乙酸、甲酸、乙酰丙酸糠醛和5-HMF对发酵能力的影响。乙醇产量和体积生产率随着乙酸、甲酸和乙酰丙酸浓度的增加而降低。糠醛和5-HMF降低了体积生产率，但不影响乙醇的最终产率。当发酵中添加 5-HMF 时，体积生产率的下降更为明显，并且该化合物的消耗速度低于糠醛。在较高 CS 中产生的水解产物中观察到的抑制不能完全用副产物糠醛、5-HMF、乙酸、甲酸和乙酰丙酸的作用来解释。 (C) 1998 爱思唯尔科学公司。
The influence of the severity of dilute sulfuric acid hydrolysis of spruce (softwood) on sugar yield and on the fermentability of the hydrolysate by Saccharomyces cerevisiae (Baker's yeast) was investigated. Fermentability was assessed as the ethanol yield on fermentable sugars (mannose and glucose) and the mean volumetric productivity (4 h). The hydrolysis conditions, residence time, temperature, and sulfuric acid concentration were treated as a single parameter, combined severity (CS). When the CS of the hydrolysis conditions increased, the yield of fermentable sugars increased to a maximum between CS 2.0-2.7 for mannose, and 3.0-3.4 for glucose above which it decreased. The decrease in the yield of monosaccharides coincided with the maximum concentrations of furfural and 5-hydroxymethylfurfural (5HMF). With the further increase in CS, the concentrations of furfural and 5-HMF decreased while the formation of formic acid and levulinic acid increased The yield of ethanol decreased at approximately CS 3; however, the volumetric productivity decreased at lower CS.The effect of acetic acid, formic acid, levulinic acid furfural, and 5-HMF on fermentability was assayed in model fermentations Ethanol yield and volumetric productivity decreased with increasing concentrations of acetic acid, formic acid, and levulinic acid. Furfural and 5-HMF decreased the volumetric productivity but did not influence the final yield of ethanol. The decrease in volumetric productivity was more pronounced when 5-HMF was added to the fermentation, and this compound was depleted at a lower rate than furfural. The inhibition observed in hydrolysates produced in higher CS could not be fully explained by the effect of the by-products furfural, 5-HMF, acetic acid, formic acid: and levulinic acid. (C) 1998 Elsevier Science Inc.