77 research outputs found
Response Surface Methodology for the Evaluation and Comparison of Cellulase Production by Aspergillus nidulans SU04 and Aspergillus nidulans MTCC344 Cultivated on Pretreated Sugarcane Bagasse
Get PDFResponse surface methodology (RSM) was used to optimize the conditions for the production of endo β-1,4 glucanase – a component of cellulase by Aspergillus nidulans SU04 and Aspergillus nidulans MTCC344 under solid state fermentation, using pretreated bagasse as chief substrate. A four-factor-five-level central composite design was employed for the experimental design. The endo β-1,4 glucanase produced during the bioconversion of cellulose to glucose by these strains were strongly dependent on the NaOH pretreatment given to bagasse before hydrolysis. Maximum cellulase activity was
32.59 U g–1 and 28.96 U g–1 (CMCase) for A.nidulans SU04 and A. nidulans MTCC344 respectively. The optimum conditions for cellulase production are 15 mm bagasse bed height, 60 % moisture content, pH 5 and temperature 40 °C in the solid state fermenter.
A. nidulans MTCC344 and A. nidulans SU04 were able to hydrolyze pretreated sugarcane bagasse completely after 15 days and 6 days of incubation with significant endo β-1,4 glucanase activities. The results of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) of bagasse showed structural changes through pretreatment, in favor of enzymatic hydrolysis. A. nidulans SU04 was found to be highly efficient compared to A. nidulans MTCC344 in terms of endoglucanase, exoglucanase and β-glucosidase activities
Optimization and Kinetics of Cellulase Immobilization on Modified Chitin Using Response Surface Methodology
No full textThis study was aimed at investigating the immobilization of Aspergillus nidulans cellulase onto modified chitin (MC). The effects of contact time, cellulase concentration, MC dosage, temperature and agitation rate for maximum immobilization percentage and optimum immobilization capacity have been investigated by response surface methodology (RSM) on the basis of a five-level, five-factor central composite design (CCD). The equilibrium nature of the immobilization was described by the Langmuir and Freundlich isotherms. The kinetic data were tested using the first-order and pseudo-second-order kinetic models. The results of thermodynamic investigations indicate spontaneity (ΔG 0 0) and irreversibility (ΔS 0 > 0) for the sorption process. At 120 rpm, 304.6 K, 23.3 min, 1.12 mg of MC immobilized 18.51 mg/g of cellulase from an initial solution concentration of 16.34 mg/mℓ with a retention of 70% of the native cellulase activity up to 10 cycles in batch hydrolysis experiments. Under optimized conditions, immobilized cellulase had a higher K m value (0.83 mM) and a lower V max value (38.2 μmol/min) compared with the free cellulase (0.62 mM and 48.92 μmol/min, respectively), indicating the affinity of cellulase for the MC matrix
Utilization of pretreated coir pith for the optimized bioproduction of cellulase by Aspergillus nidulans
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Preparation and characterization of higher degree-deacetylated chitosan-coated magnetic adsorbent for the removal of chromium(VI) from its aqueous mixture
No full textA Study on the Torrefaction of Rice Husk as an Attempt to Enhance Its Energy Content
Get PDF87-90Torrefaction refers to the thermal and chemical treatment of organic substances (at atmospheric pressure, between 200–300°C, under inert conditions). The objective of this study is to torrefy the rice husk of Ethiopian origin, after a pretreatment with dilute sulfuric acid in order to enhance its energy density. The torrefaction temperature, holding time, and acid concentration investigated in this study were (200, 250, and 300°C), (20, 40, and 60 min) and (0.75, 1.50, and 2.25 g/L), respectively. Box-Behnken experimental Design (BBD) was applied for optimization using Design-Expert ® Version 7 software (Stat-Ease Inc., Minnesota, United States)
Production and Purification of Cellulase from Aspergillus nidulans AJSU04 under Solid-state Fermentation using Coir Pith
Get PDFThe present study deals with the production of cellulase from coir pith accumulated as waste with the aid of Aspergillus nidulans AJSU04 and the subsequent conversion of the residual coir pith into suitable biofertilizer for the increased yield of Solanum lycopersicum. Alkaline pretreatment using NaOH is used to delignify the feed stock material (coir pith). The experiments were carried out under solid state conditions employing coir pith with 60 % moisture content, pH 5, temperature of 40 °C for 11 days. The extract drawn was purified using ammonium sulphate salt precipitation, dialysis, ion exchange chromatography and gel filtration chromatography. Aspergillus nidulans AJSU04 was seen to exhibit endo-β-1,4-glucanase, exo-β-1,4-glucanase and 1,4-β-glucosidase components of cellulase. The residual coir pith was converted into biofertilizer or coir pith waste compost (CWC) using Azobacter chroococcum, Bacillus megaterium, Bacillus mucilaginosus
Lactic acid production from Brewer’s Spent Grain by Lactobacillus plantarum ATCC 8014
Get PDF610-613The objective of this research was to produce lactic acid from Brewery Spent Grain using Lactobacillus plantarum ATCC 8014. The production was carried out in four main stages, including the pretreatment, hydrolysis, fermentation and recovery of lactic acid. Box Behnken Design (BBD) (Design expert® 7 software) was used to investigate the effect of temperature (115–130°C), reaction time (25–35 min) and acid concentration (1.5–2.0 M) during the hydrolysis. Fermentation of the hydrolyzate was performed at 35°C, pH 5.0–5.5 and 200 rpm for 72 h. Optimization results proved the suitability of BSG to be used as a feedstock for the lactic acid production
Optimization and Kinetic Studies of Nickel Treatment in the Electroplating Effluent with Activated Carbon Prepared from Rice Husk
No full textMagnetic hetero-structures as prospective sorbents to aid arsenic elimination from life water streams
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