Lignocellulose Degrading Capabilities of Sphaerobolus Stellatus in Creeping Bentgrass.

Thatch collapse is a new disease of finely-managed turfgrasses caused by Sphaerobolus stellatus. Symptoms include dark green, circular patches of turf atop degraded organic matter resulting in an indentation of the playing surface. Within a six week period, S. stellatus has been shown to reduce organic matter and thatch depth by 21% and 25%, respectively. To characterize the biochemical process of degradation of organic matter, pure cultures of S. stellatus were grown on creeping bentgrass (Agrostis stolonifera L.) for six weeks.  Utilizing tetramethylammonium hydroxide thermochemolysis to analyze the fate of lignin, we found a significant depolymerization of lignin. To understand the mechanism responsible for lignin degradation, crude enzymes were extracted from S. stellatus turf and mulch isolates and Panaeolina spp. at four times points in three months. Extracts were assayed for manganese independent and dependent peroxidase, laccase, xylanase and cellulose activity. An elevated level of laccase was found within a S. stellatus isolates from turf, and both S. stellatus isolates contained low levels of manganese independent peroxidases. All fungal species contained xylanase activity. Cellulase was not verifiably detected. The presence of laccase in S. stellatus from turfgrass, manganese independent peroxidase in S. stellatus isolates and xylanse in all fungal extracts illustrates a mechanism of organic matter reduction in thatch collapse.