사과푸른곰팡이병균 Penicillium expansum의 benomyl 저항성균주(抵抗性菌株) 중(中) 병원성이 약화된 균주를 선발하여 pectin질(質) 분해효소(分解酵素)의 활성과 병원성(病原性)간의 관계를 알아보았다. 인공배지에서는 병원성이 높은 $S_2$균주와 병원성이 낮은 $R_2$균주가 endo-polymethylgalacturonase, endo-polygalacturonase, pectin methyl-trans-eliminase, polygalacturonate-trans-eliminase를 생산하였으며 두균주간의 효소활성에 있어서 현저한 차이는 없었다. 사과배지에서는 위의 4개의 효소가 모두 생산되었으나 endo-polymethylgalacturonsae, endo-polygalacturonase의 활성은 병원성이 높은 $S_1$균주가 병원성이 낮은 $R_2$균주보다 6배 이상 높은 활성을 보였으나 pectin methyl-trans-eliminase와 polygalacturonate-trans-eliminase의 활성은 큰 차이가 없었다. Ammonium sulfate로 염석시켜 얻어진 조효소액(粗酵素液) 중(中) $80{sim}90%$ fraction에서 endo-PMG와 endo-PG의 활성이 가장 높았으며 이 조효소액(粗酵素液)의 첨가(添加)에 따른 저항성균주(抵抗性菌株)의 병원성이 대조구에 비하여 증가하였다.
Isolates of Penicillium expansum with reduced pathogenicity were arbitrarily selected among benomyl-resistant isolates in order to investigate relationship of their pectolytic enzyme acitivity with pathogenicity. In artificial medium, strongly pathogenic isolate $S_1$ and weakly pathogenic isolate $R_2$ produced considerable amonts of endo-polymethylgalacturonase, endo-polygalacturonase, pectin methyl-trans-eliminase, and polygalacturonate-trans-eliminase. No marked difference in enzyme activities was observed between two isolates. In apple medium, the activities of endo-polymethylgalacturonase and endo-polygalacturonase of isolate $S_1$ were over 6 times higher than those of isolate $R_2$. But pectin methyl-trans-eliminase and polygalacturonate-trans-eliminase did not show a great difference. Activities of endo-polymethylgalacturonase and endopolygalacturonase precipitated at 80-95% saturation of ammonium sulfate were highest, and addition of these enzyme solutions increased pathogenicity of weakly pathogenic isolates $R_{1-4}$.
