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Abstract: Decomposition of Picea abies needles and production of extracellular enzymes involved in decomposition of lignin, cellulose, hemicelluloses and other organic compounds were studied in fungal strains of interior needle colonizers isolated from needles in different stages of decomposition (attached to trees, and early and late decomposition stages in the litter horizon). In total, 12 strains of ascomycetes (members of Helotiales, Hypocreales, Dothideales, Diaporthales and Eurotiales) and four basidiomycetes (Polyporales, Agaricales and Russulales) were tested. Significant decomposition of needles was recorded for all fungal isolates. All isolates produced cellobiohydrolase, β-glucosidase, β-xylosidase, N-acetylglucosaminidase, α-glucosidase, phosphatase and arylsulfatase and most fungi also produced endocellulase, endoxylanase and laccase in needle litter. In addition, other hemicellulases were produced by all strains. Mn-peroxidase was only produced by two basidiomycetes. Although enzyme activities varied, fungi associated with needles on fallen trees exhibited enzyme production comparable with later litter colonizers, and there was no significant difference in enzyme production between ascomycete and basidiomycete strains. [Copyright &y& Elsevier]

The article presents a study on the analysis of cellulase hyperproducing mutants derived from the Trichoderma reesei QM9414 fungus. The mutants showed higher filter-paper degrading activity and a lower growth rate than the wild-type QM9414 strain. It suggests that cellulase hyperproduction by the mutants was regulated at the transcriptional levels.

The article highlights the study of the genetic coding for cellobiohydrolase II from the white rot basidiomycete, Irpex lacteus MC-2 and its expression in pichia pastoris. The derived amino acid sequences exposed a significant structure comprised of protein binding domain owning to glycosyl hydrolases family. The primary objective of the study is to help developing effective cellulosic biomass degradation usiing with rot fungi enzymes.

The article discusses the results of a study characterizing the cellobiose dehydrogenase (CDH) enzyme from the white-rot basidiomycete Trametes hirsuta. The molecular weight of the enzyme was 92kDa. The potential of using CDH for the biological treatment of wood chips without negative effects on paper strength is explored.

Investigates cloning, sequencing and heterologous expression of a cellobiohydrolase cDNA from the basidiomycete Corticium rolfsii. Cloning and sequencing of the cellulase gene; Expression of the C. rolfsii CBH1 gene.

An upstream region of cellobiohydrolase I gene promoter was modified from Trichoderma reesei to enhance heterologous gene expression. The base pairs from −677 to −724 were deleted indicating glucose repressor binding sites. Trichoderma reesei is considered an important workplace for homologous/heterologous genes expressions under the modified cbh1 promoter. However, constitutive expression is desirable in some cases over inducible expression that leads to production of undesirable cellulase components as byproduct. Here we report that the reporter β-glucosidase gene (bgl1) from Aspergillus niger BE-2 was cloned and recombined with cbh 1 promoter followed by terminator trpC cloned from fungal expression vector, pUR5750. The expression cassette was ligated to binary vector and transferred into the host strain EU7-22 via Agrobacterium tumefaciens mediated transformation (ATMT) using hygromycin B resistance gene as the screening marker. Four transformants Bgl-1, Bgl-2, Bgl-3 and Bgl-4 were screened. Compared with the host strain EU7-22, the enzyme activities of filter paper (FPA) and β-glucosidase (BG) of transformant Bgl-3 increased by 39% and 47.1% under repression condition respectively. The expression level of Bgl-3 was found 7.9 folds increase over host strain EU7-22. Our results indicate that cbh 1 is a strong promoter and has successfully driven over-expression of bgl1 gene in EU7-22 under repression condition and has surprisingly improved the efficiency of heterologous expression of cellulase genes in EU7-22. [ABSTRACT FROM AUTHOR]