硫色曲霉SQ-3固态发酵产酶条件的优化

研究了不同培养时间、培养温度、pH值、碳源以及氮源等5个条件对硫色曲霉SQ-3产木聚糖酶、淀粉酶和纤维素酶活性的影响,并检测了不同烘干温度对发酵料中3种酶的活性和孢子存活数的影响。结果表明,在培养温度为28 ℃,初始pH值为7.0,固体发酵料中玉米秸秆粉为25.7%,豆粕为5.8%,麦麸为8.5%,1%的NaNO₃溶液为60%且培养时间为3 d时,硫色曲霉SQ-3的3种酶活性均较高:纤维素酶活性为453.3 U·g^-1,淀粉酶活性达3.9×10³ U·g^-1,而木聚糖酶活性达1.48×10⁵ U·g^-1。在烘干温度为40 ℃时,发酵料中孢子存活数不低于1.1×10⁸ g^-1,木聚糖酶活性保留较好,纤维素酶和淀粉酶也保留大部分活性。结果表明,上述发酵条件适合于硫色曲霉SQ-3低成本且高效的产酶培养。

Optimization of solid fermentation for enzymes produced by Aspergillar sulphureus SQ-3

In this research, effects of different carbon and nitrogen sources, initial pH value, culture temperature and culture time on the activities of cellulase, amylase and xylanase produced by Aspergillar sulphureus SQ-3 were studied. By investigating the influence of different baking temperature on survivability of this fungus and the activities of these enzymes, the results showed that the optimum culture medium for producing enzymes was as follows: 25.7% of corn stalk powder, 5.8% of soybean meal, 8.5% of wheat bran, 28 ℃ as fermentation temperature and initial pH value of 7.0. Under these conditions, higher activities of cellulase, amylase and xylanase were obtained, and they were 453.3 U·g^-1, 3.9×10³ U·g^-1 and 1.48×10⁵ U·g^-1, respectively. The number of viable spores under the baking temperature of 40 ℃ was over 1.1×10⁸ CFU·g^-1 and the activities of xylanase, cellulase and amylase were well preserved. The results indicated that the fermentation conditions listed above were suited to lower-cost and efficient culture for enzymes produced by Aspergillar sulphureus SQ-3.