Cladosporium cladosporioides H1 was found to be the most abundant microbe in Janggyeong Panjeon. C. cladosporioides H1 produced a 20 kDa xylanase, which was generally stable below $60^{circ}C$ and had specialized activity in an acidic condition. Our results may lead to the development of a strategy for preservation of organic cultural heritage environments.