降解玉米秸秆混合菌系的筛选及发酵工艺优化1

摘要

Aimed at studying the impact of mixed strains on the degradation of corn straw in the way of liquid fermentation and optimizing its fermentation conditions, the paper selected one primary and two alternative strains from 8 strains in 3 species of cellulose degrading microorganisms, then mixed them together and got the best mixed strains. In response to a value of reducing sugar content, the paper designed a three factors (fermentation temperature, time and the total amount of inoculation) and three levels of response surface design experiment. The results showed that the corn stalks’ optimal parameters of fermentation at 30℃for 5 days and the total amount of the mixed inoculum strains of 8 mL, the resulting reduction sugar content 260.661mol by the mixed strains of Bacillus subtilis S3 and Trichoderma reesei by 1:1, which suggested that mixed strains can improve the degradation of corn stalks through.%研究了几种微生物混合液态发酵对玉米秸秆降解的影响，并对其最佳发酵条件进行了优化。先进行了单因素试验，对3类菌种共8株菌进行了单菌种发酵，从中筛选出1株发酵效果最佳的菌株作为混和菌系的主菌种，与其他2类菌株进行混合发酵，进而确定了最优混合菌系。然后采用响应面法对发酵温度、发酵时间和接种总量三个因素进行了研究设计，考察其对玉米秸秆纤维素降解的影响。结果表明，最佳混合菌系为枯草芽孢杆菌S3和里氏木霉（1∶1），混合菌系发酵的最优参数是发酵温度30℃、发酵时间5 d 及混合菌系总接种量为8 mL ，玉米秸秆经降解后的还原糖含量260.661mol。由此可见，玉米秸秆经过混合微生物液态发酵后可以有效提高其降解效果。