摘要
秸秆生物炼制化学品是解决秸秆资源利用附加值低、减轻秸秆焚烧带来的环境污染的主要方法之一。本研究制备了结冷胶固定化保加利亚乳酸杆菌(Lactobacillus bulgaricus)T15凝胶珠(结冷胶-T15凝胶珠),并对其性质进行表征,建立了结冷胶-T15凝胶珠固定化细胞循环连续发酵产D-乳酸发酵工艺。结冷胶-T15凝胶珠的断裂应力为(91.68±0.11) kPa,较海藻酸钙固定化T15凝胶珠(海藻酸钙-T15凝胶珠)提高了125.12%,表明结冷胶-T15凝胶珠的强度更强。以结冷胶-T15凝胶珠为出发菌株,葡萄糖为发酵基质,10批次循环(720h)发酵,其D-乳酸最高批次产量为(72.90±2.79)g/L,较海藻酸钙-T15凝胶珠提高了33.85%,较游离T15提高了37.70%。将葡萄糖更换为玉米秸秆酶解液,使用结冷胶-T15凝胶珠进行10批次循环(240 h)发酵,D-乳酸生产强度可达(1.74±0.79)g/(L·h),远高于游离菌。10批次循环发酵后结冷胶-T15凝胶珠磨损率小于5%,表明结冷胶是一种细胞固定化的良好载体,可广泛应用于细胞固定化工业发酵领域。本研究为细胞循环发酵产D-乳酸工业化生产提供基础数据,为玉米秸秆生物炼制D-乳酸提供了新途径。
Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads(LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate(D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was(91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads(calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was(72.90±2.79) g/L after fermentation for ten recycles(720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85%higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles(240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached(1.74±0.79) g/(L·h),which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.
作者
郭勇鑫
王刚
李柯欣
韩嘉棋
陈欢
张斯童
李艳丽
陈光
GUO Yongxin;WANG Gang;LI Kexin;HAN Jiaqi;CHEN Huan;ZHANG Sitong;LI Yanli;CHEN Guang(College of life sciences,Jilin Agricultural University,Changchun 130118,Jilin,China;Key Laboratory of Straw Comprehensive Utilization and Black Land Protection of the Ministry of Education,Changchun 130118,Jilin,China)
出处
《生物工程学报》
CAS
CSCD
北大核心
2023年第3期1083-1095,共13页
Chinese Journal of Biotechnology
基金
吉林省重点研发计划(202000402097NC)。
关键词
海藻酸钙
结冷胶
保加利亚乳杆菌
固定化
循环发酵
玉米秸秆
calcium alginate
gellan gum
Lactobacillus delbrueckii
immobilized
cyclic fermentation
corn straw
