Induction of mutation in aspergillus niger for conversion of cellulose into glucose (original) (raw)
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Effect of UV irradiation and Colchicine on Cellulase enzyme production by Aspergillus terreus
Development of more efficient cellulases having higher activities and stability to enable the conversion of pretreated biomass to higher yield at lower costs will significantly reduce the process costs. Cellulase are multi-enzymatic complex protein comprising of endo-1,4-beta-D-glucosidase, or endocellulase, carboxy methyl cellulase (CX); Exo-1,4,β-D-glucosidase or beta-glucosidase. The enzymatic saccharification of cellulase has been proposed as a means of producing glucose with the objective of reconstructing cellulase to enhance biomass degradation on an industrial scale. Wild stain of Aspergillus terreus was isolated from agriculture waste and selected to mutagenesis with ultra violet (UV) irradiation and Colchicine. In UV-irradiated Aspergillus terreus (At1) the production of CX increased by 24-folds,β-glucosidase production increased by 55-folds and 84-fold increase in C1 (Cotton Assay) production in 60 minute exposure time. Colchicine treatment 0.1% (W/V) increased the produc...
2014
The need for renewable energy resources has focused attention on the renewable polysaccharide cellulose, which can be enzymatically hydrolyzed to yield sugars. The filamentous fungus Trichoderma reesei is an important host organism for industrial enzyme production producing large amounts of hydrolytic enzymes. The aim of the present study was to improve the cellulase production of T. reesei through a successive mutagenesis step. Trichoderma reesei (PTCC 5142) a cellulolytic microorganism, was subjected to mutagenesis using gama and UV radiation individually as mutagens. Successive mutants showed rapid growth on plates containing MYG medium, clear hydrolysis zone on mandels medium and enhanced cellulase production. The mutant strains of T. reesei were isolated and selected by mandel screening method. Results showed some mutant strains has had higher cellulases activities in comper with parent strain. A mutant strain of Trichoderma reesei (PTCC 5142) with maximum production potential of cellulase was finally selected. The developed mutant from gama mutagenesis way is the best mutant for Ccase, CMCase, Avicellase and Fpase activities. This new method could be applied to obtain potent fungal mutants for more enzymes production.
Development of cellulase hyperproducing mutants derived from the fungus Trichoderma reesei
Background and Aim: Filamentous fungi Trichoderma reesei are considered to be one of the most efficient producers of cellulase capable of degrading cellulose which is the most abundant biopolymer on the Earth. In recent years, cellulases have become industrially important enzymes that are used in a variety of biotechnical applications such as in food, animal feed, pulp and paper, textile and detergent industries and especially in bioethanol technology. In order to make those applications economically feasible, the yields of the cellulolytic enzymes needs to be increased. So investigation on improvement of cellulase productivity is a remarkable object for research. The aim of this study was to enhance extracellular cellulase production of T. reesei using gamma irradiation. Methods: We obtained the T. reesei strain (PTCC 5142) from the Persian Type Culture Collection and maintained it on PDA(Potato-Dextrose-Agar) plates. Mutants were generated by exposing spore suspension of T.reesei ...
Optimization of cellulase production by aspergillus niger NCIM 1207
Applied Biochemistry and Biotechnology, 1991
Aspergillus niger NCIM 1207 produces high levels of extracellular /~-glucosidase and xylanase activities in submerged fermentation. Among the nitrogen sources, ammonium sulfate, ammonium dihydrogen orthophosphate, and corn-steep liquor were the best for the production of cellulolytic enzymes by A. niger. The optimum pH and temperature for cellulase production were 3.0-5.5 and 28~ respectively. The cellulase complex of this strain was found to undergo catabolite repression in the presence of high concentrations of glucose. Glycerol at all concentrations caused catabolite repression of cellulase production. The addition of glucose (up to 1% concentration) enhanced the production of cellulolytic enzymes, but a higher concentration of glucose effected the pronounced repression of enzymes. Generally the growth on glucose-or glycerol-containing medium was accompanied by a sudden drop in the pH of the fermentation medium to 2.0.
γ-Ray induced mutagenesis of Cellulomonas biazotea for improved production of cellulases
Folia Microbiologica, 1998
A rifampin-resistant mutant of Cellulomonas biazotea secreted elevated levels of cellulases in vivo. The cellulase production in the mutant was not inhibited in the presence of 5 % glucose, cellobiose or glycerol in the solid medium. The mutant exhibited approximately two-to three-fold enhanced product yields and productivity of cellular ~glucosidase over the wild parent in shake-flask culture studies when grown on either cellulosic or lignoceUulosic substrates. Extracellular production of filter paper cellulase (FPase) and endo-glucanase (CMCase) were also significantly (p _< 0.05) altered. During growth of the mutant on ~-cellulose, the maximum volumetric productivities for CMCase, FPase and 13-glucosidase were 52, 23.3, and 15.2 IU L -1 h -1, i.e. 118, 121, and 229 % their respective values for the parental strain. Some enzyme properties of the mutant cellulases were altered. Mutant-derived cellulases produced higher yields of glucose arising by degradation of bagasse, wheat straw, and ~-cellulose (1.53-, 1_57-, and 1.75-fold, respectively).
Enhanced cellulase producing mutants developed from heterokaryotic Aspergillus strain
Bioresource Technology, 2014
h i g h l i g h t s Cyclic mutagenesis and rational screening resulted in cellulase hyper-producing mutants. Genome and Proteome based profiling for characterization of developed mutants. Selected mutant strains were evaluated for cellulase production under shake flask and SSF. Saccharification potential of the developed cellulases evaluated using alkali treated rice straw. A sequential approach for production of XOS and ethanol from alkali treated rice straw developed.
Improvement of Fungal Cellulase Production by Mutation and Optimization of Solid State Fermentation
Mycobiology, 2011
Spores of Aspergillus sp. SU14 were treated repeatedly and sequentially with Co 6 0 γ-rays, ultraviolet irradiation, and Nmethyl-N'-nitro-N-nitrosoguanidine. One selected mutant strain, Aspergillus sp. SU14-M15, produced cellulase in a yield 2.2fold exceeding that of the wild type. Optimal conditions for the production of cellulase by the mutant fungal strain using solid-state fermentation were examined. The medium consisted of wheat-bran supplemented with 1% (w/w) urea or NH 4 Cl, 1% (w/w) rice starch, 2.5 mM MgCl 2 , and 0.05% (v/w) Tween 80. Optimal moisture content and initial pH was 50% (v/w) and 3.5, respectively, and optimal aeration area was 3/100 (inoculated wheat bran/container). The medium was inoculated with 25% 48 hr seeding culture and fermented at 35 o C for 3 days. The resulting cellulase yield was 8.5-fold more than that of the wild type strain grown on the basal wheat bran medium.
Cellulase production from Aspergillus niger MS82: effect of temperature and pH
New biotechnology, 2009
Fungal cellulases are well-studied enzymes and are used in various industrial processes. Much of the knowledge of enzymatic depolymerization of cellulosic material has come from Trichoderma cellulase system. Species of Trichoderma can produce substantial amounts of endoglucanase and exoglucanase but very low levels of β-glucosidase. This deficiency necessitates screening of fungi for cellulytic potential. A number of indigenously isolated fungi were screened for cellulytic potential. In the present study, the kinetics of cellulase production from an indigenous strain of Aspergillus niger MS82 is reported. Product formation parameters of endoglucanase and β-glucosidase (Qp + Yp/s) indicate that A. niger MS82 is capable of producing moderate to high levels of both endoglucanase and β-glucosidase when grown on different carbon containing natural substrates, for example, grass, corncob, bagasse along side purified celluloses. Furthermore, it was observed that the production of endoglucanase reaches its maximum during exponential phase of growth, while β-glucosidase during the Stationary phase. Enzyme production by solid-state fermentation was also investigated and found to be promising. Highest production of cellulase was noted at pH 4.0 at 35 °C under submerged conditions. Growth and enzyme production was affected by variations in temperature and pH.