Kluyveromyces fragilis No. 351 was used to study the optimum conditions for inulase production. In order to maximize the production of inulase, the composition of the medium containing Jerusalem artichoke tuber extract were studied. The optimum concentration of Jerusalem artichoke tuber was 3.5% (dry weight) and bactocasitone was better than yeast extract. The optimum concentration of bactocasitone was 2.0% and the optimum temperature & pH of the production of inulase were 30℃ and pH 5.5 respectively. The addition of $NH_4H_2PO_4$ (0.5%) increased the production of inulase, and the effect of various metal salt was also studied. The requirement of metal salt was KCl (40 ppm), $MgSO_4.7H_2O$ (20 ppm), $FeSO_4.7H_2O$ (20 ppm), NaCl (20 ppm), $CoCl_2.6H_2O$ (30 ppm). Inulase synthesis was growth - associated (intracellular) and the production of inulase was increased as the concentration of dissolved oxygen concentration was increasing. The addition of Tween 85 increased extracellular inulase but antifoam decreased. Maximum production of inulase was 3.3unit/ml (Total inulase). A high quantity of industrial grade inulase was prepared by autolysis of the yeast cells, ultrafiltration of supernatant and ethanol fractionation. The recovery was 72%.
Kluyveromyces fragilis No. 351 을 이용하여 이눌라아제 생산을 최대로 할수있는 배지조성 및 배양조건을 조사하였다. 탄소원으로 돼지감자 추출액을 이용 하였으며 건체 중량 3.5% 가 가장 적합하였다. 일반적으로 많이 이용되는 유기 질소원인 yeast extract 보다 bactocasitone 이 더 좋았고 2.0% 에서 효소 생성이 최대로 되었다.
초기 pH 5.5 가 알맞은 배양조건 이었으며 $NH_4H_2PO_4$ 0.5% 첨가로 효소 생성이 증가 되었다. 금속염 으로는 KCl 40 ppm, $MgSO_4\cdot67H_2O$, 20 ppm, $FeSO_4 \cdot7H_2O$ 20 ppm, NaCl 20 ppm, $CoCl_2\cdot6H_2o$ 30 ppm이 좋은 결과를 보였다. 이눌라아제의 생성은 통기를 높여감에 따라 더욱 많이 생성되었고 화학적 거품 제거제 (antifoam) 의 처리는 효소생성을 저해한 반면 surfactant 의 처리는extracellular enzyme 의 생성을 증가시켰다. Surfactant 로는 Tween 85 0.2% 가 적합하였다. intracellular inulase 의 생성은 균체 증식에 비례하여 증가 되었으며 extracellular와 intracellular 를 합한 total inulase 의 생성은 3.3 unit/ml이었다. Ultrafiltration 과 에탄올 침전법을 이용한 효소의 회수는 72% 였다.
