CELLULASE FORMATION BY SPECIES OF TRICHODERMA SECT LONGIBRACHIATUM AND OF HYPOCREA SPP WITH ANAMORPHS REFERABLE TO TRICHODERMA SECT LONGIBRACHIATUM

Kubicek, C. P., Bolzlbauer, U.M., Kovacs, W., Mach, R. L., Kuhls, K., Lieckfeldt, E., Borner, T., and Samuels, G. J. 1996. Cellulase formati on by species of Trichoderma sect. Longibrachiatum and of Hypocrea spp , with anamorphs referable to Trichoderma sect. Longibrachiatum, Funga l Genetics and Biology 20, 105-114. The cellulolytic potential of the wild-type strain of Trichoderma reesei was compared to other members o f Trichoderma sect, Longibrachiatum and Hypocrea spp, that have anamor phs referable to that section, There was high diversity even within th e same species (as defined by morphological and macromolecular charact ers). Differences, where notable, were more pronounced for carboxymeth yl-cellulase activity than for filter paper activity. High cellulase a ctivities were observed for several strains of T. longibrachiatum and T. citrinoviride, whereas T. parceramosum formed only low levels of ac tivity, Among the corresponding teleomorphs, most strains of H. schwei nitzii were comparatively poor producers, whereas the highest percenta ge of high producers was found among H. jecorina isolates, and many st rains were even more active than the parent T. reesei QM 6a. Immunoblo t analysis of corresponding culture filtrates of various H. jecorina s trains showed that the three major cellulase proteins (cellobiohydrola se I, cellobiohydrolase II, and endoglucanase I) were present in cultu re filtrates and their M(r) was identical to that of the respective T. reesei proteins, ELISA analysis demonstrated that these enzymes were also present in the same relative proportions in culture filtrates fro m H. jecorina and T. reesei. With the aid of primers, corresponding to conserved sequences in the cellobiohydrolase I-encoding gene cbh1, a fragment of this gene was amplified from selected strains of H. jecori na, T. reesei, T. longibrachiatum, T. citrinoviride, and H. schweinitz ii, The fragments had the same size in all fungi, Cleavage of this fra gment with Hhal produced a RFLP pattern which was identical in H. jeco rina and T. reesei, but different in the other species, In the latter, the RFLP pattern was also species specific, These results provide sup port for a close genetic similarity of T. reesei and H. jecorina cellu lases. In the latter, an ascomycetous model system for cellulase biosy nthesis is now available, The results further indicate that other anam orphs of Trichoderma section Longibrachiatum are promising sources of high cellulase production. (C) 1996 Academic Press, Inc.