竹粉酶解液发酵产γ-聚谷氨酸研究

为探究以竹子为原料生产γ-PGA的工艺,首先将原料经碱法预处理,然后加入木糖异构酶和纤维素酶等复合酶酶解得出竹子糖液,再经枯草芽孢杆菌发酵生产γ-PGA。结果表明,添加木糖异构酶可提高酶解率,单因素试验得出还原糖含量达到3.086%。通过单因素试验和正交试验得到最佳发酵γ-PGA培养基条件为竹糖80 g/L,有机氮源8 g/L,谷氨酸钠80 g/L,NH4Cl 3 g/L,K2HPO4·3H2O 2 g/L,MgSO4·7H2O 0.25 g/L,接种量为2%,培养条件为pH值7.0~7.2,温度37℃,培养时间48 h,产量可达35.31 g/L,纯度达87.5%。以竹子为原料,γ-PGA的产量和纯度较高,产业前景好,木糖异构酶对酶解效率的提高有促进作用。

Fermentation of Bamboo Powder to Produceγ-polyglutamic Acid

In order to explore the process of producingγ-PGA using bamboo from a wide range of sources,the raw materials were first pretreated by the alkali method,and then mixed with enzymes such as xylose isomerase and cellulase to obtain the sugar solution of bamboo,and then subjected to Bacillus subtilis fermentation producesγ-PGA.The results show that the addition of xylose isomerase can increase the rate of enzymatic hydrolysis,and the reduction sugar content reached 3.086%by single factor experiment.The optimal fermentationγ-PGA medium conditions obtained through single factor and orthogonal ex periments were as follows:bamboo sugar 80 g/L,organic nitrogen source concentration 8 g/L,and sodium glutamate concentration 80 g/L,NH4Cl 3 g/L,K2HPO4·3 H2O 2 g/L,MgSO4·7 H2O 0.25 g/L.The inoculation amount was 2%,and the culture conditions were:pH 7.0~7.2,temperature 37℃,and 48 hours of culture,the yield was 35.31 g/L,and the purity was87.5%.Using bamboo as a raw material,the yield and purity ofγ-PGA is high,and the industry has a good prospect.