162,336 research outputs found
Enzymatic Hydrolysis of Porang by Streptomyces Violascens BF 3.10 Mannanase for the Production of Mannooligosaccharides
Porang (Amorphophallus muelleri Blume) is an indigenous Indonesian plant containing high hemicellulose as a source of glucomannan. An alternative way to produce a good quality of mannooligosaccharides was through hydrolysis of glucomannan by endo-β mannnase from actynomicetes. Based on 16S rRNA analysis, BF 3.10 isolate, isolated from Bukit Duabelas National Park soil, Jambi was identified as Streptomyces violascens BF 3.10. Reducing sugar was analyzed by dinitrosalicylic acid methods. The highest reducing sugar was achieved at the 72 hours of incubation. Mannanase of isolate BF 3.10 had the highest activity at pH 6 and temperature of 70 °C with enzyme activity of 16.38 U/mL and was stable at 4 °C for 48 h. During 5-hour of hydrolysis with substrate concentration of 0.25%, 0.5%, and 1% porang glucomannan dissolved in 10 mL enzyme, mannooligosaccharides were produced with the degree of polymerization of 2-3. Visualization of the products by using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) methods showed that mannooligosaccharides produced comprised of glucose, mannobiose, mannotriose, and mannotetraose. The degree of polymerization and the simple sugars produced indicated that mannanase produced by S. violascens actively catalyzed the hydrolysis of 1.4-β-D-mannoside linkage from β-1.4-mannan backbone, that eventually produced simple sugars of mannooligosaccharides
Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis
Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW) and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%
High pressure pre-treatments promote higher rate and degree of enzymatic hydrolysis of cellulose
The effect of high pressure (HP) pre-treatments on the subsequent enzymatic hydrolysis of cellulose from bleached kraft Eucalyptus globulus pulp by cellulase from Tricoderma viride was evaluated. Pressure pre-treatments of 300 and 400 MPa during 5–45 min, lead to both an increased rate and degree of hydrolysis, reaching values ranging from 1.5- to 1.9-fold, quantified by the formation of reducing sugars. Both the pressure and time under pressure influenced the enzymatic hydrosability of the cellulosic pulps, with the former being more important. The results indicate that the pressure pre-treatments promoted an increased accessibility of cellulose towards cellulase in the cell wall. The results obtained open promising possibilities, to contribute to overcome conventional limitations of enzymatic cellulose hydrolysis for the production of fermentable glucose, for the production of second generation bioethanol and chemicals by enhancement of both rate and yield of hydrolysis. The results are also of interest for the preparation of “pressure engineered” celullose with incremented tailored hydrolysis patterns
Impacts of microalgae pre-treatments for improved anaerobic digestion: Thermal treatment, thermal hydrolysis, ultrasound and enzymatic hydrolysis
Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This work investigated the effect of four pre-treatments on three microalgae species, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. The analysis of the composition of the soluble COD released and of the TEM images of the cells showed two main degradation actions associated with the processes: (1) cell wall damage with the release of intracellular AOM (thermal, thermal hydrolysis and ultrasound) and (2) degradation of the cell wall constituents with the release of intracellular AOM and the solubilisation of the cell wall biopolymers (enzymatic hydrolysis). As a result of this, enzymatic hydrolysis showed the greatest biogas yield increments (>270%) followed by thermal hydrolysis (60–100%) and ultrasounds (30–60%)
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CELF significantly reduces milling requirements and improves soaking effectiveness for maximum sugar recovery of Alamo switchgrass over dilute sulfuric acid pretreatment
BackgroundPretreatment is effective in reducing the natural recalcitrance of plant biomass so polysaccharides in cell walls can be accessed for conversion to sugars. Furthermore, lignocellulosic biomass must typically be reduced in size to increase the pretreatment effectiveness and realize high sugar yields. However, biomass size reduction is a very energy-intensive operation and contributes significantly to the overall capital cost.ResultsIn this study, the effect of particle size reduction and biomass presoaking on the deconstruction of Alamo switchgrass was examined prior to pretreatment by dilute sulfuric acid (DSA) and Co-solvent Enhanced Lignocellulosic Fractionation (CELF) at pretreatment conditions optimized for maximum sugar release by each pretreatment coupled with subsequent enzymatic hydrolysis. Sugar yields by enzymatic hydrolysis were measured over a range of enzyme loadings. In general, DSA successfully solubilized hemicellulose, while CELF removed nearly 80% of Klason lignin from switchgrass in addition to the majority of hemicellulose. Presoaking and particle size reduction did not have a significant impact on biomass compositions after pretreatment for both DSA and CELF. However, presoaking for 4 h slightly increased sugar yields by enzymatic hydrolysis of DSA-pretreated switchgrass compared to unsoaked samples, whereas sugar yields from enzymatic hydrolysis of CELF solids continued to increase substantially for up to 18 h of presoaking time. Of particular importance, DSA required particle size reduction by knife milling to < 2 mm in order to achieve adequate sugar yields by subsequent enzymatic hydrolysis. CELF solids, on the other hand, realized nearly identical sugar yields from unmilled and milled switchgrass even at very low enzyme loadings.ConclusionsCELF was capable of achieving nearly theoretical sugar yields from enzymatic hydrolysis of pretreated switchgrass solids without size reduction, unlike DSA. These results indicate that CELF may be able to eliminate particle size reduction prior to pretreatment and thereby reduce overall costs of biological processing of biomass to fuels. In addition, presoaking proved much more effective for CELF than for DSA, particularly at low enzyme loadings
Enzymatic hydrolysis of kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside), the key bitter compound of rapeseed (Brassica napus L.) protein isolate
BACKGROUND: The use of rapeseed protein for human nutrition is primarily limited by its strong bitterness, which is why the key bitter compound, kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside), is enzymatically degraded. RESULTS: Mass spectrometry analyses of an extract from an untreated rapeseed protein isolate gave three signals for m/z 815 [M-H]. The predominant compound among the three compounds was confirmed as kaempferol-3-O-(2‴-O-sinapoyl-β-sophoroside). Enzymatic hydrolysis of this key bitter compound was achieved using a sinapyl ester cleaving side activity of a ferulic acid esterase (FAE) from the basidiomycete Schizophyllum commune (ScoFAE). Recombinant ferulic acid esterases from Streptomyces werraensis (SwFAE) and from Pleurotus eryngii (PeFAE) possessed better cleavage activity towards methyl sinapate but did not hydrolyze the sinapyl ester linkage of the bitter kaempferol sophoroside. CONCLUSION: Kaempferol-3-O-(2‴-O-sinapoyl-β-sophoroside) was successfully degraded by enzymatic treatment with ScoFAE, which may provide a means to move the status of rapeseed protein from feed additive to food ingredient. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry
The Effect of Enzymatic Hydrolysis on the Properties of Protein Hydrolysate From Paddy Mushroom
Protein hydrolysate was prepared from Paddy (Volvariella volvaceae) mushroom. Hydrolysis uses commercially protease available Protamex ™ with enzyme concentration of 0.1% (w/w). Hydrolysis was performed at three different temperatures (room temperature, 40 °C, and 50 °C) with different incubation periods (60, 90, and 120 minutes). Enzyme inactivation was done in 90 °C for 3 minutes. Yield and degree of hydrolysis ranged from 94.76% to 99.55% and 19.06% to 24.59%. Protein solubility was about 89–11,8%. The longer time of hydrolysis, the darker the color of protein hydrolysate. Protein hydrolysate which has hydrolysis at 50 °C for 120 minutes has the highest protein yield and the best sensory properties: 4.76 (taste liking), 3.68 (aroma liking), and 4.56 (overall liking). However, this protein hydrolysate has the potential for application as an ingredient in formulated diets
Optimization of enzymatic hydrolysis conditions of Caspian kutum (Rutilusfrisiikutum) by-product for production of bioactive Peptides with antioxidative properties
The enzymatic hydrolysis was performed by Alcalase to recover the fish protein hydrolysate from Caspian kutum by-product (CB). The degree of hydrolysis (DH) was applied for monitoring the hydrolysis reaction of CB. The response surface methodology was applied based on a D-optimal design to perform the optimization process for obtaining the high yield of CB protein hydrolysate. The effect of four independent variables including pH (7.5–8.5), temperature (45–55 °C), time (1–3 h), and enzyme concentration (0.5–1.5% w/w) on DH was studied. The results indicated that the predicted and actual values of the optimum condition had no significant difference. The optimum enzymatic hydrolysis conditions were achieved at pH 8.5, temperature of 55 °C, enzyme concentration of 1.5% w/w, and time of 3 h, which resulted in the maximum value of DH (19.08%). Antioxidant assays including DPPH scavenging and metal chelating activities showed that Caspian kutum protein hydrolysates had antioxidant properties
Kinetics of the hydrolysis of polysaccharide galacturonic acid and neutral sugars chains from flaxseed mucilage
Different hydrolysis procedures of flaxseed polysaccharides (chemical and enzymatic) were carried out with H2SO4, HCl and TFA at different acid concentrations (0.2, 1 and 2 M) and temperatures (80 and 100°C). Enzymatic and combined chemical and enzymatic hydrolyses of polysaccharide from flaxseed mucilage were also studied. Acid hydrolysis conditions (2 M H2SO4, 4 h, 100°C) are required to quantify total monosaccharide content of flaxseed mucilage. The enzymatic pathway (Pectinex™ Ultra SP) limits sugar destruction during hydrolysis, but it is also insufficient for complete depolymerization. The combination of the two treatments, i.e. moderate chemical hydrolysis (0.2 M H2SO4, 80°C, 48 h) combined with enzymatic hydrolysis is not more effective compared to chemical hydrolysis in drastic conditions (2 M H2SO4 at 100°C). The strong interaction between the neutral and acid fractions of flaxseed mucilage may hinder total release of sugar residues. Physical treatment prior to the hydrolysis could be necessary to achieve complete depolymerisation of flaxseed mucilage
The effects of mixing on the enzymatic hydrolysis of lignocellulosic biomass
Biorefining of lignocellulosic biomass into biofuels and chemicals can help replace fossil resources and decrease anthropogenic greenhouse gas emissions. This thesis is focused on the effects of mixing on the enzymatic hydrolysis of pretreated biomass. Two different types of biomass were studied: softwood (Norway spruce and Scots pine), and the energy grass giant reed. Before enzymatic hydrolysis, the biomass was pretreated by either steam or sulfite pretreatment. The first part of the work concerns the connection between particle morphology and rheology of pretreated biomass, how such properties change during the course of enzymatic hydrolysis, and how the changes are influenced by reactor mixing. The second part examines the effects of mixing in stirred tank reactors on the enzymatic hydrolysis of different pretreated materials, and also attempts to explain the mechanisms behind the observed phenomena.The particle size reduction during enzymatic hydrolysis of steam pretreated spruce was primarily driven by reactor agitation. In the case of steam pretreated giant reed the particle size was mainly reduced by enzymatic hydrolysis. The rapid reduction in particle size of giant reed coincided with a rapid liquefaction. For steam pretreated softwood, the viscosity in fact increased at the beginning of enzymatic hydrolysis, followed by a gradual decrease during the remainder of the hydrolysis. This interesting phenomenon was in part linked to the type of pretreatment used on the softwood biomass. In contrast to steam pretreated softwood, the viscosity of sulfite pretreated spruce decreased rapidly during enzymatic hydrolysis. Efficient viscosity reduction in sulfite pretreated spruce was also achieved with very low doses of pure endoglucanase enzymes (0.1 mg protein per g glucan) without significant glucose release.The effect of mixing on the enzymatic hydrolysis was in part determined by the viscosity of the pretreated biomass. For steam pretreated spruce at low solid loading, decreasing the agitation rate had little effect on the the enzymatic hydrolysis. However, if the viscosity was increased by the addition of a thickening agent, the effect of agitation was much larger. For a substrate that underwent rapid initial viscosity reduction, such as steam pretreated giant reed, the enzymatic hydrolysis was almost independent of agitation rate. Another important factor determining the effect of mixing on the enzymatic hydrolysis was the level of product inhibition. If the glucose and cellobiose concentrations were high, as during high solid hydrolysis of steam pretreated spruce, low agitation rate had a large negative effect on the enzymatic hydrolysis. However, if the product concentration was kept low, as during SSF, the effect of agitation was much weaker. Overall, the results indicate that the decrease in hydrolysis rate occurred due to increased local product inhibition, caused by mass transfer limitations in the stagnant zones, formed in the reactor volume when under low intensity mixing. The rate of enzymatic hydrolysis appeared to be determined by flow regime, i.e. Reynolds number, rather than specific mixing power input. This implies that the negative effects of low agitation rate will be less of a problem in larger reactors
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