汽爆秸秆半纤维素固态发酵柠檬酸的研究

发布时间：2018-06-02 22:27

本文选题：汽爆 + 柠檬酸　；参考：《中国科学院大学(中国科学院过程工程研究所)》2017年硕士论文

【摘要】：面对当今社会的化石能源枯竭及环境恶化问题,木质纤维素基化学品是近年来世界各国生物质工程领域研究的热点。目前大多关注于纤维素和木质素的利用,对半纤维素利用的研究较少。半纤维素是植物纤维原料中含量较多的一类碳水化合物,是地球上含量最丰富、价格最廉价的可再生资源之一,具有巨大的利用潜力和市场价值。半纤维素主要由五碳糖组成,相比纤维素来说,更容易被降解,有效利用这部分天然资源将有利于降低发酵工业的成本。目前半纤维素利用的少量研究主要集中在水解液液态发酵各类化学品,尚无固态发酵的相关研究。因此本论文以柠檬酸为目标产品,主要从以下几个方面对半纤维素的利用进行研究,并取得以下主要研究结果:(1)首先研究了汽爆对秸秆半纤维素解离度、单糖溶出等的影响,进一步通过红外光谱和紫外光谱扫描对其结构基团的变化进行表征,优化出汽爆秸秆半纤维素的操作参数,汽爆压力为1.0 MPa,处理时间为5 min或汽爆压力1.3 MPa,处理时间为3 min时,半纤维素水解糖浓度较高。(2)研究了蠕动强化汽爆秸秆半纤维素在低加酶量下高固半纤维素酶解效果。结果证明在添加0.1 FPU/g底物下,25%高固酶解时间为4 h,与静置酶解相比,酶解时间缩短了 6倍,总糖浓度增加了 23.8%。(3)研究了气相双动态汽爆秸秆半纤维素固态发酵柠檬酸工艺,证实了气相双动态技术是一种有效的强化技术,与传统的静置发酵相比,气相动态发酵技术可使柠檬酸产率提高74%。
[Abstract]:Facing the problems of fossil energy depletion and environmental deterioration, lignocellulos-based chemicals have been a hot topic in the field of biomass engineering all over the world in recent years. At present, much attention is paid to the utilization of cellulose and lignin, but less research has been done on hemicellulose utilization. Hemicellulose is one of the most abundant and cheap renewable resources in the world. It has great utilization potential and market value. Hemicellulose is mainly composed of pentaccharide, which is easier to be degraded than cellulose. The efficient utilization of this natural resource will help to reduce the cost of fermentation industry. At present, a small amount of research on the utilization of hemicellulose is mainly focused on hydrolysate liquid fermentation of all kinds of chemicals, there is no solid state fermentation related research. Therefore, in this paper, citric acid is taken as the target product, the utilization of hemicellulose is studied mainly from the following aspects, and the following main research results are obtained: firstly, the effects of steam explosion on the dissociation degree of hemicellulose and the dissolution of monosaccharide from straw are studied. The changes of the structure groups were characterized by IR and UV spectra, and the operating parameters of the semicellulose were optimized. When the steam explosion pressure was 1.0 MPA, the treatment time was 5 min or the steam explosion pressure was 1.3 MPA, the treatment time was 3 min. The effect of peristaltic enhancement of steam explosion straw hemicellulose on high solid hemicellulase hydrolysis under low enzyme content was studied. The results showed that the hydrolysis time of 25% high solid enzyme was 4 h under 0.1 FPU/g substrate. Compared with static hydrolysis, the enzymatic hydrolysis time was shortened by 6 times, and the total sugar concentration was increased by 23.8%, and the citric acid fermentation process of semi-cellulose solid state fermentation with gas-phase double-dynamic steam explosion straw was studied. Compared with the traditional static fermentation, the gas phase dynamic fermentation technology can increase the citric acid yield by 74%.
【学位授予单位】：中国科学院大学(中国科学院过程工程研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ921.1

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