RNA Production from the Hydrolyzate of Sliced and Dried Sweet Potatoes.

절간고구마를 이용한 RNA 생산에 관한 연구

During an extensive screening tests of yeasts for their RNA formation, it was found that Cryptococcus laurentii had especially high RNA content and high dry cell weight, when hydrolyzate of sliced and dried sweet potatoes was used as a carbon source. Growth conditions of this strain were examined, and the most desirable results were obtained at 48 hours of cultivation on a reciprocal shaker at 3$0^{\circ}C$ with initial pH 6.0. Under the above conditions, the RNA content and yield of dry cells were investigated using various media compositions. Ammonium sulfate 0.40%, peptone 0.6 ％, and yeast extract 0.4% were appeared to be favorable as a nitrogen sources. The optimum concentrations of K $H_2$P $O_4$, M $n^{++}$, C $O^{++}$ were 0.05 ％, 0.1 ％, and 0.001 ％, respectively. Ca-pantothenate, 400$\mu\textrm{g}$/$m\ell$, showed relatively favorable effects as a growth factor. The maximum RNA content obtained in this study was 16.8 ％ of the total dry cell weight.t.t.

절간고구마 당화액을 탄소원으로하여 RNA를 다량 축적하는 효모를 선정한 결과 Cryptococcus laurentii가 가장 높은 균체량 및 RNA량을 나타내었다. 이 선정 균주에 대한 배양조건을 검사한 결과 최적 PH 6.0, 3$0^{\circ}C$, 48시간 통기 진탕배양하였을 때 가장 좋은 결과를 얻었다. 이러한 조건 하에서 배지조성을 변화시켜 RNA 함량과 균체증식량을 검토한 결과 (N $H_4$)$_2$S $O_4$ 0.4%, Peptone 0.6%. yeast extract 0.4%가 질소원으로 좋은 결과를 보였으며 K $H_2$P $O_4$의 최적농도는 0.5 %, M $n^{++}$ 은 0.1 %, $Co^{++}$은 0.001 %를 나타내었다. 또 비타민 요구성 실험에서 Ca-pantothenate를 400$\mu\textrm{g}$/$\ell$ 첨가하였을 때 가장 좋은 효과를 얻었으며 기본배지의 배양조건을 검토하여 얻은 최종배지를 비교해 본 결과 효모 균체당 RNA 함량이 12.9%~16.8%로 증가하였다.