Abstract
The culture condition and medium composition for the enhanced mycelial growth of Lepista nuda DGUM 26501 were investigated. The optimal temperature and pH for the mycelial growth were $24^{\circ}C$ and $7.0\~8.0$, respectively. The partial pressure of oxygen for the enhanced mycelial growth was more than $10\%\;O_2$. When Czapek-Dox medium was used as a minimal medium, manitol and xylitol were very good carbon sources. Organic nitrogen sources were better than inorganic ones for mycelial growth. As the nitrogen source tested, com steep liquor, soytone and protease peptone were the best as a source of organic nitrogen sources. When ammonium phosphate as phosphorus sources was used, the enhanced mycelial growth was shown. Nicotinic acid was proved to be the most appropriate source of vitamin. After the mycelia of L. nuda DGUM 26501 was cultivated at $24^{\circ}C$ for 10 days in LNM broth (pH 7.0), the activities of extracellular enzyme were determined. The specific activity of $\alpha-amylase$ was much higher than those of other enzymes. However, little or no enzyme activities of $\beta-glucosidase$, CMCase, laccase and lipase were found.
Lepista nuda DGUM 26501의 균사 생육을 위한 배양조건 및 세포외 분비 효소 활성을 조사하였다. 균사 생육을 위한 최적 온도는 $24^{\circ}C$였고, pH$7.0\~8.0$에서 최적 균사 생육을 나타내었다. 적정 균사생육을 위한 산소분압은 $10\%$이상이었다. 최소배지로 Czapek-Dox 한천배지에 탄소원을 변경하여 첨가시, maltose, sucrose, manitol, xylitol 등이 우수하였다. 유기산으로 gluconate가 가장 우수한 균사 생육을 보여주었다. 전반적으로 유기질소원이 무기질소원보다 균사 생육이 더 우수하였으며, 유기질소원으로 corn steep liquor(CSL), soytone, protease peptone을 사용하였을 때 균사생육이 우수하였다. 사용한 인산원 중 ammonium phosphate, 비타민원으로 pyridoxine, riboflavin, nicotinic acid 첨가시 우수한 균사 생육을 보여주었다. $24^{\circ}C$에서 10일간 배양된 L. nuda DGUM 26501의 균사외 분비효소 중 $\alpha-amylase$의 활성도가 다른 효소에 비해 상대적으로 높았으며, lipase의 활성도는 미미하게 나타났다.
