摘要
Simplicillium lanosoniveum(DT06)是一种能够合成特殊胞外多糖的半知菌类真菌。本文以真菌DT06为研究材料,采用BBD设计原则的响应面法优化其胞外多糖的合成工艺条件,并对其发酵动力学参数进行分析。在单因素实验的基础上,以胞外多糖得率为响应值,确定多糖合成的最优条件:初始p H4.87,葡萄糖40.65 g/L,蛋白胨10.38 g/L,温度30℃,转速140 r/min。优化后真菌DT06胞外多糖得率可达0.139 g/g,比优化前提高了32%。在此优化条件下,对DT06的发酵过程进行动力学分析,结果表明:DT06最大比生长速率μmax=0.156 h-1,其多糖合成与菌体生长部分偶联。与其它产多糖的真菌相比,DT06合成多糖的最大比合成速率较高达到0.066 h-1,但总的多糖得率却较低。碳平衡计算发现DT06还产生一种未知的中性含碳产物,其碳得率为0.129 g/g。上述实验为DT06多糖发酵过程的调控及其胞内代谢网络的优化提供了依据。
The optimum synthesis conditions and fermentation kinetic parameters of Simplicillium lanosoniveum DT06 which was a Deuteromycetes fungus being capable of producing unique exopolysaccharide (EPS)was researched.Based on single factor experiment, the optimum culture conditions for EPS yield coefficient were determined applying Box- Behnken design (BBD). Under the optimized conditions (40.65 g/L glucose, 10.38 g/L peptone, pH4.87, temperature 30 ℃ and rotation speed 140 r/min) ,the highest EPS yield coefficient 0.139 g/g was obtained, which increased 32% compared with that before optimization. Kinetics analyses indicate that the maximum specific growth rate(μmax)of DT06 was 0.156 h-1, while its EPS synthesis was semi-growth-associated with a maximum specific production rate 0.066 h -1 ,which was relative higher than those of other EPS-producing Fungi. Nevertheless its average EPS yield coefficient was relative low.Carbon-balance analysis revealed that apart from EPS DT06 also produced a unknown products with a carbon yield coefficient of 0.129 g/g. These results provided essential parameters for controlling DT06' s fermentation process and improving its metabolic network.
出处
《食品工业科技》
CAS
CSCD
北大核心
2016年第18期185-191,共7页
Science and Technology of Food Industry
关键词
胞外多糖
真菌
响应面法
发酵动力学
碳平衡
exopolysaccharide
fungus
RSM
fermentation Kinetic
carbon- balance