Pleurotus ostreatus BP连续开放预处理玉米秸秆的研究

Continuous Pretreatments of Corn Stalk with Pleurotus ostreatus BP under Non-sterile Condition

通过筛选开放性菌株以及对开放状态下玉米秸秆糖化率随预处理时间变化规律的研究,建立了菌株Pleurotus ostreatus BP连续开放预处理玉米秸秆体系,并进一步对该体系的稳定性进行了评价。从14株自腐菌中筛选出5株在秸秆上萌发时间短、生长速率快的菌株,其中只有P.ostreatus BP能在玉米秸秆上开放培养,预处理15 d时糖化率最高。由此建立了P.ostreatus BP开放预处理玉米秸秆15 d的连续体系并预处理5批。结果表明,前3批的预处理效果较稳定,糖化率均比对照提高了20%以上。在连续的第4、5批次中,糖化率提高很少,这主要是由于开放体系中的杂菌数量急剧增多造成的。

A continuous and non-sterile pretreatment system was constructed by screening for an anti-contaminated white-rot fungus and determining the saccharification rate of corn stalk after pretreatment with the fungus for different time length, and the stability of this system was farther evaluated. 5 strains were screened from 14 white-rot fungi by comparing the germination time and growth speed, and strain Pleurotus ostreatus BP was repeated screened for its ability of fast growth on corn stalk under non-sterile condition. Further study suggested that the saccharification rate was the highest after pretreatment with P. ostreatus BP for 15 days. Therefore, a continuous system of non-sterile pretreatment with P. ostreatus BP for 15 days was constructed and five batches of pretreatment were carried out. The pretreatment effect of the first three batches was stable and the saccharification rates were enhanced by more than 20 % than that of the untreated corn stalk. However, the improvements of saccharification rates of the fourth and fifth pretreated batches was less noticeable, which could be caused mainly by the speeded increase of contaminated bacteria, yeast and molds under non-sterile condition.