以甘油为碳源生产低分子质量β-1,3-葡聚糖的发酵工艺  

Fermentation process for preparation of low-molecular-weightβ-1,3-glucan using glycerol as carbon source

作　　者：李敏[1] 朱莉 詹晓北[1] LI Min;ZHU Li;ZHAN Xiaobei(Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education,School of Biotechnology,Jiangnan University,Wuxi 214122,China;Wuxi Galaxy Biotech Co.Ltd.,Wuxi 214125,China)

机构地区：[1]教育部糖化学与生物技术重点实验室,江南大学生物工程学院,江苏无锡214122 [2]无锡格莱克斯生物科技有限公司,江苏无锡214125

出　　处：《食品与发酵工业》2022年第17期21-28,共8页Food and Fermentation Industries

基　　金：国家重点研发计划项目(2021YFC2101100)。

摘　　要：首次利用Agrobacterium sp.ATCC 31749进行适应性驯化得到1株可单菌发酵生产低分子质量β-1,3-葡聚糖的菌株Agrobacterium sp.WS-8E3T,优化前其利用甘油生产低分子质量β-1,3-葡聚糖的产量为1.648 g/L。针对驯化菌株进行了摇瓶发酵条件的优化,结果表明,甘油初始质量浓度为20 g/L,并在甘油残余量为10 g/L左右时补加20 g/L甘油,最佳复合氮源配比为4 g/L酵母粉以及3 g/L硫酸铵,最佳装液量为75 mL/500 mL,最佳产糖pH为6.30。7 L发酵罐放大验证实验中,菌体生长期最佳pH为7.0,甘油为20 g/L;产糖期pH为6.3,甘油为30 g/L,在此条件下低分子质量β-1,3-葡聚糖产量达到8.03 g/L,相比未优化前提高了386.7%。产品红外光谱分析结果与热凝胶一致,单糖组成为单一葡萄糖,聚合度分布在18~22。研究首次采用单菌发酵策略,显著提高了低分子质量β-1,3-葡聚糖的产量,为进一步低成本、大规模地发酵生产低分子质量β-1,3-葡聚糖提供了理论依据。Agrobacterium sp.WS-8E3T produced low-molecular-weightβ-1,3-glucan was obtained by adaptive domestication of Agrobacterium sp.ATCC 31749.Before optimization,the yield of low-molecular-weightβ-1,3-glucan by the bacterium used glycerol as a carbon source was 1.648 g/L.To obtain high-yield oligosaccharides with lower cost,the fermentation conditions were optimized.The optimal initial glycerol concentration was 20 g/L,after replenished 20 g/L glycerol when the residual glycerol content was about 10 g/L.The optimal initial ratio of compound nitrogen source was 4 g/L of yeast extract and 3 g/L of ammonium sulfate,with a liquid volume of 75 mL/500 mL and pH of 6.3.In 7 L fermenter,during the growth period of the bacteria,the optimal pH was 7.0,and the glycerol was 20 g/L.During the oligosaccharide-producing period,the pH was 6.3,and the glycerol was 30 g/L.The final yield of oligosaccharides reached 8.03 g/L,which was 386.7%higher than that of before optimization.The results of FT-IR analysis and monosaccharide composition was consistent with curdlan,and the degree of polymerization was 18-22.The single-strain fermentation strategy was used to significantly increase the yield of low molecular weightβ-1,3-glucan for the first time,which provide a theoretical basis for further low-cost and large-scale fermentation production of low molecular weightβ-1,3-glucan.

关 键 词：β-1 3-葡聚糖 单菌发酵 甘油 补料 两阶段补料 

分 类 号：TQ929.2[轻工技术与工程—发酵工程]