Abstract
The culture condition and medium composition for the enhanced mycelial growth of Inonotus mikadoi IMSNU 32058 were investigated. The optimal temperature and pH for the mycelial growth were $27^{\circ}C$ and pH 4.5, respectively. Among the complex media tested, the malt extract medium and Phellinus igniarius medium were very good for mycelial growth of I. mikadoi. When Czapek-Dox medium was used as a minimal medium for cultivation of mycelia, xylose, raffinose and carboxymethyl cellulose were very excellent as a carbon and energy source. With respect to carbohydrate, sucrose and glucose were very good carbon sources. In general, organic complex nitrogen sources were better than other inorganic ones. As the organic complex nitrogen sources tested, yeast extract, soytone, proteose peptone and bacto peptone were the best as a source of organic nitrogen. When ammonium sulfate as an inorganic source of nitrogen was used, the enhanced mycelial growth was shown. p-Aminobenzoic acid was proved to be most appropriate source of vitamin. After the mycelia of I. mikadoi was cultivated at $27^{\circ}C$ for 5 days in MEM broth (pH 4.5), the activities of both exomycelial and endo-mycelial enzymes were determined. Among endomycelial enzymes assayed, the specific activity of laccase was much higher than those of other enzymes. When the fungus was grown in MEM broth, exomycelial specific enzyme activity of laccase was comparatively high. However, little or no enzyme activities of protease, chitinase and lipase were found.
Inonotus mikadoi IMSNU 32058의 최적 균사생장을 위한 배양학적 특성 및 세포효소 활성의 최적 조건을 조사하였다. 균사 생장을 위한 최적온도는 $27^{\circ}C$였고, 실험한 pH 범위중pH 4.5에서 최적균사 생장을 나타내었다. 사용된 복합배지 중 malt extract media (MEM)와Phellinus igniarius media (PIM)에서 가장 좋은 균사 생장을 나타내었다. 최소배지로써 Czapek-Dox 한천배지를 사용하여 탄소원으로 단당류, 이당류 및 다항류를 침가하였을 때 xylose, raffinose 및 carboxymethyl cellulose (CMC)에서 가장 좋은 생장을 나타내었다. 일반적으로 유기질소원이 무기질소원보다 생장을 더 촉진하였다. 유기질소원으로는 yeast extract, soytone, proteose peptone 및 bacto peptone을 사용하였을 때 균사생육이 우수하였다. 무기질소원으로는 ammonium sulfate를 사용했을 때 균사생육이 촉진되었으며, 가장 우수한 비타민원은 p-aminobenzoic acid (PABA)이었다. MEM 액체(pH 4.5) 배지를 이용하여 $27^{\circ}C$에서 5일간 배양하였을 때, I. mikadoi의 균사외 분비효소 및 균사내 효소의 활성도를 측정하였다. 균사내 분비 효소중 laccase 의 활성도가 다른 효소에 비해 상대적으로 높았다. 균사외 분비 효소도 균사내 분비효소와 마찬가지로 laccase의 활성도가 다른 효소에 비해 상대적으로 높았으며 protease, chitinase 그리고 lipase의 활성도는 낮거나 없었다.
