농산폐기물을 이용할 목적으로 8점의 시료에서 xylanase생산성이 우수한 두개의 균주를 선발하여 동정하였다 선정된 두 균주에 대해 xylanase의 생산 최적조건효소의 제 특성을 조사하여 다음과 같은 결과를 얻었다. 1. Xylanase생산에 우수한 균주로 Aspergillus niger-1701과 Aspergillus niger-430 두 균주를 선발하였다. 2. 두 균주 모두 배양시 pH $5.0{sim}6.0$에서 배양 2일째에 최고의 효소역가를 나타내었다. 3. Aspergillus niger-1701균주에 대해서는 배양시 첨가한 C.M.C.가 21%, $NH_4H_2PO_4$가 19%, C.S.L.이 20%의 효소생산 증가를 나타냈으며 기타 탄소원, 질소원, 인산염, 생장요소, 무기염류 등은 큰 영향을 미치지 않았다. 4. Aspergillus niger-430균주에 대해서는 배양시 첨가한 탄소원, 질소원, 인산염, 생장요소, 무기염류 등이 효소생산에 큰 영향을 미치지 않았다. 5. 선정된 두 균주가 생산한 xylanase의 효소작용 최적 조건은 다음과 같다. pH:5.0 온도 : $60^{circ}C$, 효소농도 : 33.3%(전용액중), 기질농도 : 2%, 효소작용시간 : 3 hrs. 6. 효소작응 최적조건에서 xylan최고 분해율은 95%였다.
In order to utilize the agricultural waste products for animal feeds, two high xylanase producing mold strains were selected from various sources of samples. The optimum conditions of xylanase production and the characteristics of the mold enzyme were investigated,and summarized as follows. 1. Two Aspergillus niger strains (experimental No. 1701 and 430) showed the high xylanase activity. 2. The highest xylanase production was obtained at pH 5.0-6.0 in two days. 3. Xylanase production in strain 1701 was increase with the addition of carboxy methyl cellulose, $NH_4H_2PO_4$ and corn steep liquor as carbon sources and natural nutrients, as respectively, while the other carbon, nitrogen, phosphate sources, natural nutrients and minerals gave no remarkable effect. In the strain 430, the enzyme procuction was not effected with the above substrate sources. 4. Maximum xylan hydrolysis reaction with the crude enzyme extract (33.3% v/v) was obtained in the 2% substrate concentration at pH 5.0 and $60^{circ}C$ in three hours in both strains. 5. Maximum xylan hydrolysis rate was 95% at the optimum conditions for xylanase activity.
