稻草粉基混合菌发酵产纤维素酶研究

以稻草粉为主要原料,对白腐菌(White-rot fungi)NS75和黑曲霉(Aspergillus niger)NS83进行固态混合发酵产纤维素酶进行研究。混合菌固态发酵与单菌固态发酵实验结果比较表明,混合菌发酵产生的纤维素酶总体酶活明显高于单菌种发酵,其β-葡萄糖苷酶(β-G)酶活较白腐菌NS75单菌发酵提高了120.9%;葡聚糖内切酶(CMC)酶活比黑曲霉NS83单菌发酵提高了140.8%。单因素实验和正交实验结果表明,当稻草粉麸皮质量比为9∶1,料水比为1∶2,白腐菌NS75与黑曲霉NS83的接种比例为1∶1(v∶v)时,培养第3d开始搅拌,每天搅拌一次,于30℃,培养5d,稻草粉基混合菌发酵产纤维素酶中CMC酶活达到16650U/g,β-G酶活为16108U/g、滤纸酶活(FPA)酶活为3164U/g。

Cellulases produced by mixed strains fermentation in straw powder

Straw powder was used as the raw material,the solid fermentation conditions of cellulases production by mixed strains of White-rot fungi NS75 and Aspergillus niger NS83 had been investigated. The results of comparative experiments between single strain solid-state fermentation and mixed strains solid-state fermentation showed that,the cellulose enzyme activity produced by mixed strains had increased obviously than that produced in single strain solid-state fermentation,in which,the β-G enzyme activity had increased 120.9% than that produced by White-rot fungi NS75 single fermentation,and the CMC enzyme activity had increased 140.8% than that produce by Aspergillus niger NS83 single fermentation. According to the single factor and orthogonal experiment results the optimum fermentation conditions were determined as follows:ratio between straw powder and bran powder 9∶1,feed-water ratio 1∶2,inoculation volume ratio of White-rot fungi NS75 and Aspergillus niger NS83 1∶1(v∶v),start stirring on the third day and once a day,30℃ culture 5d. Under this conditions,the enzyme activity of CMC enzyme,β-G enzyme,FPA enzyme produced had reached respectively 16650,16108 and 3164U/g.