嗜热菌Geobacillus sp.PZH1产木聚糖酶发酵条件的优化

Optimization of fermentation conditions of xylanase from thermophilic bacterium Geobacillus sp.PZH1

对嗜热菌Geobacillus sp.PZH1发酵产嗜热耐碱木聚糖酶的培养条件进行了优化研究。对碳源、氮源、初始pH、接种量以及发酵温度五个因素进行了单因素实验,在此基础上对碳氮比、初始pH以及接种量进行了正交实验。结果表明,该菌株在发酵培养7d时有最大产酶量,Geobacillus sp.PZH1发酵产木聚糖酶最佳发酵条件为:桦木木聚糖为碳源,牛肉膏为氮源,碳氮比2∶3,初始pH7.0,接种量4%,发酵温度50℃,发酵时间7d。在最佳产酶条件下进行发酵,木聚糖酶活力可达2.56IU/mL,是未优化前酶活的1.44倍。

The culture conditions for alkali-thermo-stable xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 were optimized.Five factors,such as carbon source,nitrogen source,initial pH,inoculum size and fermentation temperature,were researched in single-factor experiment.C/N ratio,initial pH and inoculum size were researched in orthogonal experiment.The results showed that the xylanase yield reached a highest level for 7d culture,and the best combination of fermentation conditions for alkali-thermo-stable xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 was brichwood xylan as carbon source,beef extract as nitrogen source,C N ratio 2∶3,initial pH 7.0,inoculum size 4%,fermentation temperature 50℃ and fermentation time 7d.Under these optimal conditions,the xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 was 2.56IU/mL,1.44 fold higher than that before the optimization.