title: Semi-solid-state fermentation of Eicchornia crassipes biomass as lignocellulosic biopolymer for cellulase and 3-glucosidase production by cocultivation of Aspergillus niger RK3 and Trichoderma reesei MTCC164.
abstract: An aquatic weed biomass, Eicchornia crassipes, present in abundance and leading to a threatening level of water pollution was used as substrate for cellulase and beta-glucosidase production using wild-type strain Aspergillus niger RK3 that was isolated from decomposing substrate. Alkali treatment of the biomass (10%) resulted in a 60-66% increase in endoglucanase, exoglucanase, and beta-glucosidase production by the A. niger RK3 strain in semi-solid-state fermentation. Similarly, the alkali-treated biomass led to a 45-54% increase in endo- and exoglucanase and a higher (98%) increase in beta-glucosidase production by Trichoderma reesei MTCC164 under similar conditions. However, the cocultivation of A. niger RK3 and T. reesei MTCC164 at a ratio of 3:1 showed a 20-24% increase in endo- and exoglucanase activities and about a 13% increase in the beta-glucosidase activity over the maximum enzymatic activities observed under single culture conditions. Multistep physical (ultraviolet) and chemical (N-methyl-N'-nitrosoguanidine, sodium azide, colchicine) mutagenesis of the A. niger RK3 strain resulted in a highly cellulolytic mutant, UNSC-442, having an increase of 136, 138, and 96% in endoglucanase, exoglucanase, and beta-glucosidase, activity, respectively. The cocultivation of mutant UNSC-442 along with T. reesei MTCC164 (at a ratio of 3:1) showed a further 10-11% increase in endo- and exoglucanase activities and a 29% increase in beta-glucosidase activity in semi-solid-state fermentation.
authors.affiliation: Department of Biosciences and Biotechnology, University of Roorkee, India.
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: R P
authors.initials: RP
authors.lastname: Singh
mesh_terms: D001234:Aspergillus niger / Q000378:metabolism*; D018533:Biomass; D001704:Biopolymers; D002480:Cellulase / Q000096:biosynthesis / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005285:Fermentation; D043326:Glucan 1,3-beta-Glucosidase; D008031:Lignin / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D016296:Mutagenesis; D010940:Plant Proteins; D014242:Trichoderma / Q000378:metabolism*; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction; D001617:beta-Glucosidase / Q000096:biosynthesis / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D010940:Plant Proteins; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D001617:beta-Glucosidase; D002480:Cellulase; D043326:Glucan 1,3-beta-Glucosidase