Abstract

Cultivation condition of yeast on the utilization of fermentable substrate from the cellulosic wastes such as rice hull, rice straw and corn starch cake was investigated. The results obtained were summarized as follows；1. Corn starch cake was respectively added to rice hull and rice straw in order to increase sugar concentration in the hydrolyzate, and then hydrolyzed. As the result, concentration of sugar in hydrolyzed solution of rice hull was 9.12％, in that of rice straw was 7.98％. 2. It was found that calcium carbonate as a neutralizer was the most effective to prepare the culture broth of yeast. 3. An optimal growth of Hansenula subpelliculosa GFY-2 was observed in the medium prepared by adding 0.3％ of ammonium sulfate, 0.4％ of potassium phosphate dibasic, 0.02％ of magnesium sulfate, sodium chloride and calcium chloride to hydrolyaed sugar solution, respectively. 4. Hansenula subpellicuiosa GFY-2 cultured in the substrate solution which of rice hull and rice straw added to corn starch cake was assimilated more than 90％ of sugar in the hydrolyzate within 48 hours. The yeast cells yielded in rice hull was 46.5％, and that of rice straw 45.4％ to utilized sugars.

전분박을 첨가한 왕겨및 볏짚의 산당화액을 이용하여 효모생육조건을 검토하여 다음과 같은 결론을 얻었다. 1. 왕겨와 볏짚에 전분박을 첨가하여 당화시킴으로써 당화액의 당농도가 각각 9.12%, 7.98%까지 증가되었다. 2. 산당화액을 중화할 때 사용한 중화제로서는 CaCO$_3$, Ca(OH)$_2$, NH$_4$OH순으로 효모생육이 좋았다. 3. 당화액을 기질로 하여 무기영양요구성을 검토한 결과 (NH$_4$)$_2$SO$_4$0.3%, $K_2$HPO$_4$0.4%, MgSO$_4$ㆍ7$H_2O$0.02%, NaCl 0.02%, CaCl$_2$0.02%를 가하였을 때 효모의 생육도가 가장 좋았다. 4. 전분박을 첨가한 왕겨와 볏짚의 당화액을 기질로 하여 효모를 배양하였을 때 48시간 이내에 각각 91.2% 90.8%의 당을 소화하였고 당에 대한 수율은 각각 46.5 %, 45.4%이었다.

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