Abstract
The optimal conditions for cellulase and xylanase production by Trichoderma reesei 28217 were studied for enzymatic deinking of old newspaper. The amounts of cellulase and xylanase from the strain was varied by initial medium pH, Tween 80, inoculum size of spore suspension, and carbon and nitrogen sources. The optimal conditions for cellulase production were pH 5.0-6.5, 0.02% of Tween 80, 0.5-1.0% of inoculum size of spore suspension ($1{\times}10^{7}$/ml). cottonseed meal as nitrogen source, and corn flour as carbon source. On the other hand, the optimal conditions for xylanase production were pH 6.5, 0.01% of Tween 80, corn steep liquor as nitrogen source, and disintegrated old newspaper as carbon source. The inoculum size for xylanase production was the same as for cellulase production. The concomitant production of cellulase and xylanase in shake flask culture was efficiently induced in the medium containing 0.5% cottonseed meal as nitrogen source and 1.0% old newspaper and 2.0% corn flour as carbon sources. In this case the activities of cellulase and xylanase produced were 6.11-7.22 IU/mJ and 97.7 IU/ml. respectively. However, the cellulase production in $5{\ell}$ fermentor scale was slightly decreased compared with that in flask scale. Moreover, xylanase production was severely reduced in a fermentor scale. The study for the reason of decreased enzyme production in fermentor is further needed.
효모탈묵용 cellulase와 xylanase 생산을 위한 조건을 조사한 결과 배지초기 pH, Tween 80, 포자접종량, 질소원의 종류 및 탄소원의 종류에 따라 효소 생산량이 크게 변하였다. Cellulase 생산을 위한 최적조건으로는 pH5.0-6.5, Tween 80 0.02 , 포자현탄액($1{\times}10^{7}$/ml) 접종량 0.5-1.0 , 질소원으로 면실박, 탄소원으로 옥분을 사용하였을 때 가장 효과적 이었다. 또한, xylanase 생산을 위한 최적조건으로는 pH6.5, Tween 80 0.01% , 질소원으로 corn steep liquor, 탄소원으로는 신문고지를 사용하였을 때 효과적이었으며, 이때 포자현탁액의 접종량은 cellulase 생산의 경우와 동일하였다.한편, cellulasedhk xylanase의 동시생산을 위해서는 플라스크 규모에서 질소원으로 면실박 0.5%, 탄소원으로 신문고지 1.0%와 옥분 2.0%를 첨가하였을 때 효과적이었으며, 이때 생상된 배양약의 cellulase의활성은 6.11~7.22IU/ml, xylanase의 활성은 97.7IU/ml이었다. 그러나 fermentor 규모에서는 동일 배지조성에서 효소생산이 다소 감소하였으며, 특히 xylanase 경우 배양액의 효소활성이 낮아서 이에 대한 보완이 요구된다.
