FIBROLYTIC ACTIVITY OF PODAXIS PISTILLARIS FUNGUS IN SUBMERGED CULTURE

Podaxis pistillaris is a fungus commonly found in most desert areas worldwide. The oval shaped peridium, the rigid woody stipe, plus a 10-15 μm spore size stand out among its morphological features. Even though this fungus is used for human consumption and for several traditional remedies, a lack of knowledge regarding its fibrolytic enzymatic system still prevails. This fungus was collected from the central region of the Sonoran desert (29° 07.23´ 97” LN and 110° 53.58´ 02” LW, 238 masl). In order to study its enzymatic system on common fibers, P. pistillaris was grown in a specific submerged culture in order to determine total cellulases, xylanases and laccases. The maximum cellulolytic (501.7 U·mg-1), as well as xylanolytic (157.8 U·mg-1) activities, were detected after 18 cultivation days, whereas the highest laccase specific activity (179.6 U·mg-1) was registered after 15 days at 40° C. The thermostability of total cellulases, xylanases and laccases was found within temperatures ranging from 40 to 60° C. The present study represents the first report of P. pistillaris fibrolytic activity in submerged culture.