Isolation of Lecythophora sp. YP363, a secretor of various thermostable plant cell wall-degrading enzymes with high activity

摘要

A fungal strain that produces high activities of various plant cell wall degrading enzymes such as CMCase, filter paperase, β-glucosidase, avicelase, xylanase and pectinase with high activities was isolated from soil surrounding rotten wood. The strain was identified asLecythophora?sp. YP363 based on its ITS, 18S and 26S sequences. The specific activities of the various plant cell wall-degrading enzymes of?Lecythophora?sp. YP363 were, depending on the enzyme, identical to or much higher than those of?Trichoderma reesei?Rut C-30. Notably, the specific activities of the β-glucosidase, xylanase and pectinase of?Lecythophora?sp. YP363 were 4.6, 1.9 and 3.2 times higher, respectively, than those of?T. reesei?Rut C-30. The residual activities of CMCase, FPase and avicelase of?Lecythophora?sp. YP363 after the heat treatment at 60°C for 1 h were 100% or close to 100%, whereas the enzymes of?T. reesei?Rut C-30 are not resistant to heat treatment, that is, the residual activities of all the?T. reesei?Rut C-30 enzymes were only 36.9 ~ 41.9%. This result indicated that the enzymes of?Lecythophora?sp. YP363 were quite stable to heat treatment. Therefore,?Lecythophora?sp. YP363 has a potential as an alternative fungal strain to?T. reesei?in the lignocellulosic biomass-based industry.