Optimization of pretreatment parameters and nanoparticle based enzyme immobilization for lignocellulosic biomass saccharification
dc.contributor.advisor | Verma, A.K. | |
dc.contributor.author | Singh, Archana | |
dc.date.accessioned | 2019-03-26T09:27:19Z | |
dc.date.available | 2019-03-26T09:27:19Z | |
dc.date.issued | 2018-09 | |
dc.description.abstract | Pretreatment is a prerequisite technology to facilitate the recovery of fermentable sugars from lignocellulosic biomass. Various lignocellulosic biomass viz. sugarcane leaves, rice straw, wheat straw, orange peel and pomegranate peel were used for pretreatment with ionic liquid EmimAc (1-ethyl-3-methylimidazolium acetate), aqueous ammonia and a combination of both followed by saccharification with immobilized cellulase and β-glucosidase (BGL) on magnetic nanoparticles. Magnetic nanoparticles (Fe3O4) and cellulase/BGL immobilized nanoparticles were characterized by TEM, SEM, FTIR and Zeta potential. Immobilization efficiency of cellulase and BGL were found to be 86.36% and 87.73%, immobilization yield were 83.38 and 85.18% respectively. The immobilized cellulase had optimum pH 5.0 and optimum temperature 50°C. The immobilized cellulase retained 90% of initial activity after 60 min incubation at 50°C while free cellulase had only 49% of its initial activity. Km value for free and immobilized cellulase was found to be 0.625 mM and 0.714 mM and the Vmax was 35.71 and 38.16 μmole/min/mg respectively. Immobilized cellulase retained up to 97% of residual activity on 6th day when stored at 4°C and 45% at 25°C whereas free cellulase had 86% of residual activity at 4°C and 20% at 25°C. Immobilized cellulase retained about 87% of residual activity after 10 cycle of reuse. The immobilized BGL had optimum pH 5.0 and optimum temperature 50°C. The immobilized BGL retained 91% of initial activity after 60 min incubation at 50°C while free BGL had only 51% of its initial activity. Km value for free and immobilized BGL was found to be 0.555 mM and 0.779 mM and the Vmax was 38.46 and 43.47 μmole/min/mg. Immobilized BGL retained up to 95% of residual activity on 6th day when stored at 4°C and 42% at 25°C whereas free BGL had 87% of residual activity at 4°C and 18% at 25°C. Immobilized BGL retained about 85% of residual activity after 10 cycle of reuse. The combined use of EmimAc and aqueous ammonia in 1:1 for pretreatment at 6 hrs with <2 mm size of biomass followed by saccharification with 3.2 U of immobilized cellulase showed a synergistic effect on biomass with release of 93% glucose. Combined pretreated biomass were analysed for saccharification by addition of 3.2 U BGL with 3.2 U cellulase and 97% of glucose released. Furthermore, EmimAc and immobilized cellulase were recycled for 6 times with 89% of efficiency; EmimAc, immobilized cellulase and immobilized BGL were recycled for 6 times with 90% of efficiency. Thus, compared to the other pretreatment method, this combine method is more efficient and cost effective. To identify the cheapest source for enzymes biogas slurry was analysed for different enzymes. These were cellulase (0.41), BGL (0.30), Xylanase (0.31), α-amylase (0.06), β-amylase (0.20), Dehydrogenase (0.37), and Protease (0.29) U/mL. Saccharification was done with crude enzyme isolated from biogas slurry and found 69% of glucose release in combined pretreated biomass. | en_US |
dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810099456 | |
dc.keywords | optimization, pretreatment, nanoparticles, enzymes, immobilization, lignocellulose, biomass, saccharification | en_US |
dc.language.iso | en | en_US |
dc.pages | 187 | en_US |
dc.publisher | G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand) | en_US |
dc.research.problem | Saccharification | en_US |
dc.sub | Biochemistry | en_US |
dc.subject | null | en_US |
dc.theme | Biomass | en_US |
dc.these.type | Ph.D | en_US |
dc.title | Optimization of pretreatment parameters and nanoparticle based enzyme immobilization for lignocellulosic biomass saccharification | en_US |
dc.type | Thesis | en_US |