The changes in intracellular enzyme during the mycelial browning of Lentinula edodes (Berkeley) Sing

표고균사 갈변시 세포내 효소의 변화

Sawdust bag cultivation of Shiitake mushroom (Lentinula edodes) is getting increase. The mycelia browning on the substrate surface is important for the stable production. The development of methods for the rapid mycelia browning is quite required. In this study changes in intracellular enzyme during the mycelial browning were investigated to find the rapid mycelia browning. Mycelia of L. edodes was changed into brown color while it grew in agar and liquid media like sawdust substrates. Mycelia of L. edodes was started to change color at 25 days after inoculation and browning was occurred in whole mycelia colony at 30 days and browning was completed at 40 days. The activities of enzymes was evaluated in these periodically color changing mycelia. Laccase activity was highest at 15 days after inoculation on PDB, but it gradually decreased from 15 days. Tyrosinase activity drastically increased in period between 30 days and 40 days while mycelia browning was progressed. The kinds of phosphotase identified by electrophoresis were esterase, acid phosphotase, and alkaline phosphotase. Activities of phosphotase were increased before the initiation of mycelial browning but they were decreased after browning.

표고균사가 액체배지나 한천배지에서 생장하여 숙성되는 동안 갈변되는 현상을 나타낸다. 표고균사는 접종 25일부터 갈변이 시작되어 30일부터 균총 전반에 걸쳐 이루어지기 시작해 접종 40일까지 갈변이 완전히 이루어진다. 이때 균사내의 효소의 활력을 조사한 결과 phenloxidase계통의 효소들은 laccase는 접종 15일에 가장 높았으며 갈변이 되면서 점점 감소되었으나 tyrosinase는 갈변이 이루어지는 30일부터 급격히 증가하였고 peroxidase는 등전점 전기영동에 의하여 조사한 바 갈변이 이루어지는 30일부터 서서히 증가하였다. 등전점전기영동에 의해 조사된 phosphatase효소는 esterase, acid phosphatase, alkaline phosphatase를 조사하였으며 균사의 갈변이 일어나기 시작하는 접종 30일까지는 증가되었으나 그 이후 갈변이 이루어지는 과정에서는 급격히 감소되었다.