title: Cellulolytic and xylanolytic potential of high β-glucosidase-producing Trichoderma from decaying biomass.
abstract: Availability, cost, and efficiency of microbial enzymes for lignocellulose bioconversion are central to sustainable biomass ethanol technology. Fungi enriched from decaying biomass and surface soil mixture displayed an array of strong cellulolytic and xylanolytic activities. Strains SG2 and SG4 produced a promising array of cellulolytic and xylanolytic enzymes including β-glucosidase, usually low in cultures of Trichoderma species. Nucleotide sequence analysis of internal transcribed spacer 2 (ITS2) region of rRNA gene revealed that strains SG2 and SG4 are closely related to Trichoderma inhamatum, Trichoderma piluliferum, and Trichoderma aureoviride. Trichoderma sp. SG2 crude culture supernatant correspondingly displayed as much as 9.84 ± 1.12, 48.02 ± 2.53, and 30.10 ± 1.11 units mL(-1) of cellulase, xylanase, and β-glucosidase in 30 min assay. Ten times dilution of culture supernatant of strain SG2 revealed that total activities were about 5.34, 8.45, and 2.05 orders of magnitude higher than observed in crude culture filtrate for cellulase, xylanase, and β-glucosidase, respectively, indicating that more enzymes are present to contact with substrates in biomass saccharification. In parallel experiments, Trichoderma species SG2 and SG4 produced more β-glucosidase than the industrial strain Trichoderma reesei RUT-C30. Results indicate that strains SG2 and SG4 have potential for low cost in-house production of primary lignocellulose-hydrolyzing enzymes for production of biomass saccharides and biofuel in the field.
authors.affiliation: Department of Biology, Bioprocessing and Biofuel Research Laboratory, Auburn University at Montgomery, P.O. Box 244023, Montgomery, AL, 36124-4023, USA. bokeke@aum.edu.
authors.forename: Benedict C
authors.initials: BC
authors.lastname: Okeke
mesh_terms: D056804:Biofuels; D018533:Biomass; D005656:Fungal Proteins / Q000096:biosynthesis*; D005966:Glucuronidase / Q000096:biosynthesis*; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors; D014242:Trichoderma / Q000201:enzymology / Q000254:growth & development; D014995:Xylosidases / Q000096:biosynthesis*
chemical_list: D056804:Biofuels; D005656:Fungal Proteins; C036909:lignocellulose; D008031:Lignin; D014995:Xylosidases; D005966:Glucuronidase; C026579:exo-1,4-beta-D-xylosidase