产耐碱性纤维素酶丝状真菌的筛选及鉴定

The primary study on the screening and characterization of the alkaline-endurable cellulase-producing filamentous fungi

经过初筛和复筛从碱性土样中分离出的 12株丝状真菌中获得 1株能够产耐碱性纤维素酶的丝状真菌SDU3.87,经形态学初步鉴定为哈茨木霉 (Trichodermaharzianum) .生长条件的测定显示该菌生长pH范围较宽 ,在中性偏碱时生长最好 ,在pH 8.0～ 10 .0的碱性条件下长势良好 .粗酶液的性质测定表明 ,该菌所产纤维素酶的pH稳定性较好 ,内切酶活在pH 7.0最高 ,在pH 9.5时仍能保持最高酶活力的 4 0 %以上 .

Twelve filamentous fungi producing cellulases were screened and isolated from alkaline soil. One of them, SDU3.87, was selected for further studies because SDU3.87 and its cellulases were great alkaline tolerance. This strain of SDU3.87 was preliminarily identified as Trichoderma harzianum by morphologic taxonomy. It is revealed by the experiments that SDU3.87 grows in a broad range of pH, while the optimum pH for its growing is pH7.0～8.0, and it also grows well in more alkaline circumstances. It is proved that the crude cellulase from the strain is stable between pH 4.0～9.5 for its activity, and the optimum pH is around pH 7.0 at 50?℃ More than forty percent of the full activity remains at pH9.5.