Substrate For Saccharification Research Articles

Biotechnological Potential of the Stress Response and Plant Cell Death Regulators Proteins in the Biofuel Industry.

Production of biofuel from lignocellulosic biomass is relatively low due to the limited knowledge about natural cell wall loosening and cellulolytic processes in plants. Industrial separation of cellulose fiber mass from lignin, its saccharification and alcoholic fermentation is still cost-ineffective and environmentally unfriendly. Assuming that the green transformation is inevitable and that new sources of raw materials for biofuels are needed, we decided to study cell death-a natural process occurring in plants in the context of reducing the recalcitrance of lignocellulose for the production of second-generation bioethanol. "Members of the enzyme families responsible for lysigenous aerenchyma formation were identified during the root hypoxia stress in Arabidopsis thaliana cell death mutants. The cell death regulatory genes, LESION SIMULATING DISEASE 1 (LSD1), PHYTOALEXIN DEFICIENT 4 (PAD4) and ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) conditionally regulate the cell wall when suppressed in transgenic aspen. During four years of growth in the field, the following effects were observed: lignin content was reduced, the cellulose fiber polymerization degree increased and the growth itself was unaffected. The wood of transgenic trees was more efficient as a substrate for saccharification, alcoholic fermentation and bioethanol production. The presented results may trigger the development of novel biotechnologies in the biofuel industry.

Bioethanol production from urban cellulosic waste employing Alcaligenes faecalis HI-1 isolated from gut of termite Heterotermes indicola

This study assessed the potential of termite gut inhabiting bacteria towards bioconversion of cellulosic waste into biofuel. Total seven bacterial isolates from the gut of Heterotermes indicola were isolated. Among all the isolates, HI-1 produced the largest zone upon primary screening. Untreated paper had more cellulose content (73.03%) than acid (0.5%) treated paper that was used as a lignocellulosic substrate for saccharification. Among all the isolates tested, glucose yield (1.08mg/mL) was high for HI-1 isolate. Several factors were considered for optimizing augmented glucose yield (8.57mg/mL) and growth (8.07×108cfu/mL), such as temperature 37°C, pH 4.5, 5% (w/v) substrate concentration, 6 % bacterial inoculum size, agitation 150 rpm with PEG 0.25 % and Ca2+ ions 0.002 g/L. Overall 8-fold increase in glucose yield was achieved. Enzyme activity of HI-1 showed higher endoglucanase 0.29 ± 0.01 (U/mL/min) and exoglucanase 0.15±0.01 (U/mL/min) activity under optimum conditions, mentioned above. temperature 37°C, pH 4.5, substrate concentration 5%, inoculum size 6%, surfactants PEG 0.01%, ions Ca2+(0.002g/L) and agitation (120 rpm). Simultaneous saccharification and fermentation (SSF) of hydrolyzed office paper yielded 5.43mg/mL bioethanol. According to 16S rRNA sequence homology, the bacterial isolate H1 was identified as Alcaligenes faecalis. Bioethanol production from office paper untreated waste proved an effective strategy. Bacteria having natural tendency towards cellulosic waste consumption are promising for bioconversion of cellulosic waste to valuable products.

Selection of Microorganisms Possessing Thermostable Lignocellulolytic Enzymes and Application of the Enzymes for Saccharification of Pretreated Palm Oil Mill Wastes

This study attempted to find potential effective thermotolerant microorganisms producing complex enzymes for use in the hydrolyzing empty fruit bunch (EFB) to reduce cost of enzyme and enhance the efficiency of saccharification. The enrichment process at 45 °C was employed as a strategy to obtain four effective thermotolerant microorganisms. Streptomyces thermocarboxydus ME742, Bacillus subtilis ME751 and Bacillus amyloliquefaciens ASB/TRE produced the highest activity of xylanase (226.2 U/mL), CMCase (3.84 U/mL) and FPase (69.55 U/mL), respectively, while Aspergillus fumigatus A4112 exhibited the highest specific activity of xylanase (637.9 U/mg), CMCase (5.55 U/mg) and FPase (21.58 U/mg). Xylanase of isolated ME742 and A4112, CMCase of isolated ASB/TRE, FPase of isolated ME742, ME751 and ASB/TRE possessed thermostability with 80% remaining activity at 60 °C after 1 h incubation. These four strains were capable to reduce 49–78% (w/w) lignin in raw EFB with simultaneous enzyme production. The EFB residue was reused as substrate for saccharification with the highest amount of reducing sugar using the crude enzymes from S. thermocarboxydus ME742 (9.24 mg/g EFB). The sugar was 3.76 and 3.61 fold higher than that obtained from saccharification of acid- and alkaline-pretreated EFB, respectively. Moreover, the crude enzymes from A. fumigatus A4112 and B. amyloliquefaciens ASB/TRE hydrolyzed palm oil mill effluent (POME) to generate high yield of reducing sugar (61.01–64.63 mg/g TS-POME). Therefore, these selected strains were considered as the potent biological tool applicable in the bioconversion of oil palm biomass to fermentable reducing sugars.

Jackfruit outer rind: A sustainable feedstock for fermentable sugar production using recombinant endoglucanase from Bacillus subtilis MU S1

Abstract In the present scenario, two main issues that the world is facing are energy crisis and environmental pollution. Utilization of lignocellulosic biomass is a two in one remedy to address these issues. Hence, bioconversion of biomass, particularly agro-wastes into biofuels and value-added products, is gaining considerable attention. In the current study, the potential of five agro-wastes (pepper waste, banana peduncle, arecanut husk, tamarind husk and jackfruit outer rind) as a substrate for saccharification using recombinant endoglucanase from Bacillus subtilis MU S1 was investigated. Initially, the substrates were pretreated with steam explosion, and saccharification was carried out at 50 °C for five days. Saccharification percentage was determined at 24 h intervals. Among the different agro-wastes, highest saccharification of 33.4 % was observed in the case of jackfruit outer rind. In all cases, the highest saccharification was attained at 96 h of incubation. On optimization studies, the saccharification percentage of jackfruit outer rind increased by 1.23 fold. The highest saccharification was obtained at a temperature 50 °C, pH 5.0 with 15 mg/ml substrate and 18 U of recombinant endoglucanase. The study indicates the economic utilization of agro-wastes for sugar production and also the potential of the recombinant enzyme in saccharification of lignocellulosic agro-wastes.

Saccharification and hydrolytic enzyme production of alkali pre-treated wheat bran by Trichoderma virens under solid state fermentation.

BackgroundIn continuation of our previously interest in the saccharification of agriculture wastes by Bacillus megatherium in solid state fermentation (SSF), we wish to report an investigation and comparative evaluation among Trichoderma sp. for the saccharification of four alkali-pretreated agricultural residues and production of hydrolytic enzymes, carboxymethyl cellulase (CMCase), filter paperase (FPase), pectinase (PGase) and xylanase (Xylase) in SSF. The optimization of the physiological conditions of production of hydrolytic enzymes and saccharification content from Trichoderma virens using alkali-pretreated wheat bran was the last goal.MethodsThe physico-chemical parameters of SSF include incubation time, incubation temperature, moisture content of the substrate, incubation pH, supplementation with carbon and nitrogen sources were optimized.ResultsSaccharification of different solid state fermentation sources wheat bran, date's seeds, grass and palm leaves, were tested for the production of fermentable sugar by Trichoderma sp. The maximum production of hydrolytic enzymes CMCase, FPase, PGase and Xylase and saccharification content were obtained on wheat bran. Time course, moisture content, optimum temperature, optimum pH, supplementation with carbon and nitrogen sources were optimized to achieve the maximum production of the hydrolytic enzymes, protein and total carbohydrate of T. virens using alkali pre-treated wheat bran. The maximum production of CMCase, FPase, PGase, Xylase, protein and carbohydrate content was recorded at 72 h of incubation, 50-70 % moisture, temperature 25-35 °C and pH 5. The influence of supplementary carbon and nitrogen sources was studied. While lactose and sucrose enhanced the activity of PGase from 79.2 to 582.9 and 632.6 U/g, starch inhibited all other enzymes. This was confirmed by maximum saccharification content. Among the nitrogen sources, yeast extract and urea enhanced the saccharification content and CMCase, PGase and Xylase.ConclusionsThe results of this study indicated that alkali pre-treated wheat bran was a better substrate for saccharification and production of hydrolytic enzymes CMCase, FPase, PGase and xylase by T. virens compared to other alkali-pretreated agricultural residues tested.

Mustard stalk and straw: A new source for production of lignocellulolytic enzymes by the fungus Termitomyces clypeatus and as a substrate for saccharification

Agro residue of mustard obtained as mustard stalk and straw (MSS) was investigated for the first time for production of lignocellulolytic enzymes by Termitomyces clypeatus and also for use as substrate for saccharification. MSS with high cellulose and hemicellulose content was utilized as sole source of carbon by the fungus for productions of enzymes such as (CMcase, β-glucosidase, xylanase and β-xylosidase) in submerged fermentation. Production of enzymes were further increased by 2–10 folds on supplementation with common agro-residues such as wheat bran and rice straw (MWR) in 1:1:1 ratio and by using alkali treated MSS (TMSS). The enzymes obtained from MWR and TMSS media could saccharify 10% (w/v) wheat bran up to 53% and 58% in 24h, and xylan up to 52% and 81% in 12h, respectively. MSS was used for saccharification by enzymes of T. clypeatus grown in cellulose media after pretreatment with hot water and NaCl respectively, where extent of saccharification was doubled to 80% by salt treatment as compared to that with hot water. The results indicated that MSS can be used as a potential and cheap renewable raw material from India for production of bio-ethanol.