Reducing Sugar Recovery Research Articles

1-Ethyl-3-methylimidazolium acetate pretreatment for maximizing reducing sugar recovery from mixed cabbage residue.

Vegetable waste, including mixed cabbage residue (MCR), is considered a promising raw material for bioenergy production because of its high lignocellulosic component. In this study, the pretreatment of MCR by ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) was optimized based on response surface methodology. The optimal condition for MCR pretreatment was determined at 55.8°C, with a reaction of 2.65h and liquid-solid ratio of 4.60:1 v/w. Hydrolysis of pretreated MCR from optimal pretreatment conditions generated a maximum glucose yield of 156.65 ± 7.66mg/g MCR. Untreated and pretreated MCRs were successfully characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The pretreated MCR exhibited increased clear pores and incomplete structure. Moreover, compared with untreated biomass, decreased lignin, decreased hemicellulose, increased surface area, and cellulose crystallinity were observed. Thus, [Emim][OAc] pretreatment is a promising alternative approach for higher glucose production from MCR.

Aspergillus awamori MK788209 cellulase: production, statistical optimization, pea peels saccharification and textile applications

BackgroundThe demand for low-cost cellulolytic enzyme synthesis is rising in the enzyme market. This work aims to produce cellulase by utilizing various agricultural wastes and investigating the use of enzyme in saccharification and textile industries.ResultsSolid state fermentation (SSF) was applied to produce industrial enzymes, particularly cellulase, through utilizing Molokhia (Corchorus olitorius) stems by Aspergillus awamori MK788209 isolate. Two stages of statistical factorial designs Plackett-Burman (PB) and Central Composite Design (CCD) were applied to enhance the A. awamori MK788209 cellulase production from Molokhia stems (MS). The fold increase of enzyme production by PB followed by CCD was 2.51 and 4.86, respectively. Additionally, the A. awamori MK788209 culture filtrate was highly effective in saccharifying various agricultural wastes, particularly pea peels (PP) (yielding 98.33 mg reducing sugar/ml), due to its richness in cellulase, laccase, xylanase, pectinase, and amylase. By optimizing the three main variables; pea peel weight, culture filtrate volume added, and saccharification time by CCD, the sugar recovery from PP was enhanced, leading to a 3.44-fold increase in reducing sugar recovery (338 mg reducing sugar /ml). Furthermore, the A. awamori MK788209 culture filtrate showed high efficacy in textile applications, enhancing the roughness, weight loss, white index, and printing capability of treated cotton fabrics.ConclusionsA. Awamori MK788209 produced cellulase which was effective in PP saccharification. The enzyme was also capable of enhancing cotton fabric properties.

Direct enzymatic hydrolysis of alkaline storage pretreated corn stover for lipid production by Rhodosporidium toruloides

Lignocellulosic biomass (LCB) conversion often requires chemical and energy-intensive pretreatment, which produces toxic by-products that impede microbial cell growth and downstream processes. Thus, pretreatment under mild conditions remains to be developed to improve enzymatic digestibility and reduce degradation products. Here, we investigated the direct enzymatic hydrolysis of alkaline storage pretreated corn stover (AS-CS) that was treated with different concentrations of sodium hydroxide (NaOH) under various temperatures for different storage duration. Results revealed that AS-CS was suitable for direct enzymatic hydrolysis for high sugar recovery. The total reducing sugar (TRS) recovery reached 88% for the CS sample treated with 6% NaOH for 60 days at 15 °C, and the corresponding hydrolysates were successfully used by Rhodosporidium toruloides for lipid production at a lipid yield of 0.20 g/g consumed TRS. Storage temperatures ranged from 15 to 35 °C had no differential impacts on enzymatic digestibility, however at 25 °C, the control and those CS samples treated with 2% NaOH were found with relatively high microbial contamination. This method offers an energy-efficient LCB conversion for high TRS recovery and supports microbial lipid technology. Future studies should focus on scalability and techno-economic analysis to validate its applicability on a larger scale.

Effect of Delignification on Reducing Sugar Recovery from Crocodile Gourd for Bioethanol Production

A central composite experimental design was used to optimize the key parameters affecting biomass delignification process of crocodile gourd for maximum reducing sugar recovery. The effects of temperature (70 oC to 90 oC), residence time (2 hrs. to 6 hrs.), concentration of sodium chloride (0.05 g/dm3 to 0.1 g/dm3) and volume of acetic acid (0.50 mL to 3 mL) were studied. The result obtained showed that optimum reducing sugar yield for crocodile gourd was achieved at temperature, time, sodium chloride and acetic acid of 70 oC, 6 hrs. 3 g and 3 mL respectively. The results indicate that X3, X4, X1 2 interactions and X2X4 interaction has linear effect on reducing sugar yield for crocodile gourd. The result of the proximate analysis showed moisture content of 6.50+ 0.50 %, Ash Content 11.00+ 0.28 %, Carbohydrate 64.40+0.62 %, Organic carbon 12.95+0.13 (%), Nitrogen 2.10+ 0.02 (%), Carbon/Nitrogen 6.16+0.08 %, Potassium 14100+23 mg/kg, Sodium 228+ 29 mg/kg, and Fixed carbon 7.4+0.80 %. The result of proximate analysis and compositional analysis revealed that the substrate could be utilized for biofuel production.

Bio-based succinic acid production from durian husk: A rising Southeast Asia agricultural waste

The spiking availability of durian husk in Southeast Asia reveals a promising yet underutilized lignocellulosic biomass. Compositional characterization via National Renewable Energy Laboratories protocols (NREL) showed that durian husk contained 40.96% glucan, 9.51% xylan, and 26.48% of lignin. Enzymatic hydrolysis of durian husk was improved upon dilute sulfuric acid pretreatment. The optimal conditions for particle size and pretreatment duration were determined to be − 80/+ 100 mesh size durian husk exposing to an hour of acid pretreatment, resulting in a maximum reducing sugar recovery of 37.29 and 24.32 g/L for acid and enzyme hydrolysate, respectively. Fermentability tests using Actinobacillus succinogenes 130Z for both acid and enzyme hydrolysates demonstrated succinic acid yields of 49% and 63% (g/g), respectively. A stoichiometry equation describing the formation of substrate and all products was established based on the results obtained from batch fermentation: C6H12O6 + 0.377 C5H10O5 + 0.130NH3 + 0.238CO2 → 0.864 C4H6O4 + 0.224 C2H4O2 + 0.134CH2O2 + 0.292CH2.096O0.111N0.658 + 0.231 H2O. This equation serves as a useful reference for future investigations into succinic acid production reactions. The cost-effectiveness of succinic acid production and its environmental performance were evaluated to highlight the potential of durian husk as feedstock. This study presents the first report on the utilization of durian husk as an alternative and sustainable feedstock for the production of bio-based succinic acid.

Enhancing enzymatic saccharification of sunflower straw through optimal tartaric acid hydrothermal pretreatment

Sunflower straw, a usually neglected and abundant agricultural waste, has great potential for contributing to environmental protection realizing its high-value of valorization if utilizing properly. Because hemicellulose contains amorphous polysaccharide chains, relatively mild organic acid pretreatment can effectively reduce its resistance. Through hydrothermal pretreatment, sunflower straw was pretreated in tartaric acid (1 wt%) at 180 °C for 60 min to enhance its reducing sugar recovery. After tartaric acid-assisted hydrothermal pretreatment, 39.9% of lignin and 90.2% of xylan were eliminated. The reducing sugar recovery increased threefold, while the solution could be effectively reused for four cycles. The properties of more porous surface, improved accessibility, and decreased surface lignin area of sunflower straw were observed through various characterizations, which explained the improved saccharide recovery and provided a basis for the mechanism of tartaric acid-assisted hydrothermal pretreatment. Overall, this tartaric acid hydrothermal pretreatment strategy greatly provided new impetus for the biomass refinery.

Integrated biorefinery of Mucor circinelloides biomass and sugarcane bagasse for application of high-value biopolymers

The replacement of expensive components in microbial growth media with pretreated lignocellulosic waste component to increase the product spectrum and add value to the bioproducts has been encouraged to achieve sustainable and feasible utilization of waste biomass as per the biorefinery approach. This study demonstrates an integrated biorefinery approach towards utilization of sugarcane bagasse and biomass of Mucor circinelloides ZSKP. A maximum reducing sugar recovery of 80.67 g/l was achieved after combining pretreatment with saccharification. A low temperature, glycerol, and ammonium phosphate pretreatment method was established, where glycerol pretreatment conditions were reduced from 250 to 150 °C and from 120 to 45 min. The ammonium phosphate-containing hydrolysate yielded 12.89 g/l of fungal biomass after fermentation to add to 20.8 g lignin from the delignification step. The biomass production was further improved to 17.69 g/l after supplementation with corn steep solids and mineral salts. The fermentation process also yielded 2.36 g/l chitosan and 4.9 g/l of lipids after extraction from the oleaginous fungus. The lignin infused glycerol plasticized chitosan biocomposite plastic had a 100% improvement in thermogravimetric properties with almost 50% more energy needed to increase the temperature of the material when compared to glycerol only plasticized biocomposite. The fungal chitosan showed antimicrobial properties and was effective as a preservative spray for fresh tomatoes and apples extending their shelf life to at least 14 and 18 days, respectively. This study therefore demonstrated that a novel two-step pretreatment process could be environmentally beneficial and yielded multiple products for biotechnological applications.

Production of antifungal iturins from vegetable straw: A combined chemical-bacterial process

A combined chemical-bacterial process was developed to convert vegetable straw waste to high value antifungal iturins. Straws from three widely cultivated vegetable (cucumber, tomato and pepper) were evaluated as feedstocks for iturin production. Microwave assisted hydrolysis with very dilute acid (0.2% w/w H2SO4) achieved efficient reducing sugar recovery. The high glucose concentration in non-detoxified hydrolysate from pepper straw facilitated the optimal growth of Bacillus amyloliquefaciens strain Cas02 and stimulated the production of iturin. The fermentation parameters were optimised to enhance the iturin production efficiency. The obtained fermentation extract was further purified using macroporous adsorption resin, resulting in an iturin-rich extract that exhibited strong antifungal activity against Alternaria alternata with an IC50 of 176.44 μg/mL. Each iturin homologue was identified using NMR. Overall, 1.58 g iturin-rich extract containing 164.06 mg/g iturins was obtained from 100 g pepper straw, illustrating the great potential of valorising pepper straw via this process.

Supercritical Technology-Based Date Sugar Powder Production: Process Modeling and Simulation

Date palm fruits (Phoenix dactylifera) contain high levels of fructose and glucose sugars. These natural sugar forms are healthy, nutritional and easily assimilate into human metabolism. The successful production of soluble date sugar powder from nutritious date fruits would result in a new food product that could replace the commercial refined sugar. In this work, a novel process technology based on the supercritical extraction of sugar components from date pulp was modeled and simulated using Aspen Plus software. The process model consisted of three main steps that were individually simulated for their optimal working conditions as follows: (a) freeze-drying of the date pulp at −42 °C and 0.0001 bar; (b) supercritical extraction of the sugar components using a 6.77 wt.% water mixed CO2 solvent system at a pressure of 308 bar, temperature of 65 °C, and CO2 flow rate of 31,000 kg/h; and (c) spray-drying of the extract using 40 wt.% Gum Arabic as the carrier agent and air as drying medium at 150 °C. The overall production yield of the process showed an extraction efficiency of 99.1% for the recovery of total reducing sugars from the date fruit. The solubility of the as-produced date sugar powder was improved by the process selectivity, elimination of insoluble fiber contents, and the addition of Gum Arabic. The solubility of the final date sugar product was estimated as 0.89 g/g water.

Optimization of oxalic and sulphuric acid pretreatment conditions to produce bio-hydrogen from olive tree biomass

This study investigated the best pretreatment conditions for olive tree biomass (OTB) to produce bio-hydrogen. The pretreatment conditions were optimized with response surface methodology for the dark fermentative hydrogen production to achieve maximum reducing sugar recovery and the independent variables were residence time (30–90min), temperature (100–140 °C), and acid concentration (0.5–3 %w/w for sulfuric and 5–10 %w/w for oxalic acid). Maximum reducing sugar obtained after sulfuric acid pretreatment and oxalic acid pretreatment at optimal pretreatment conditions were 37 g/L and 28 g/L, respectively. An approximately 20-fold increase in sugar concentration was achieved in pretreatment with sulfuric acid compared to the untreated control. The highest hydrogen yield was 0.83 and 0.91 mol H2/mol reducing sugar for oxalic acid pretreatment and sulfuric acid pretreatment, respectively. The results show that OTB has the potential to be used in bioenergy production.

Lactic acid production from food waste using the lactogenic Escherichia coli strain JU15: optimization of reducing sugar recovery

AbstractBACKGROUNDd‐Lactic acid (DLA) has numerous industrial applications, including production of biodegradable polylactic acid, which is one of the most promising biodegradable polymers. Looking for alternative feedstocks is a high priority and recent focus has been on its biological synthesis and biotechnological valorization from food waste (FW) materials. In this study, a response surface methodology (RSM) approach and central composite design (CCD) were performed to hydrolyze FW, obtaining released reducing sugars (RRS) for DLA production using the lactogenic Escherichia coli strain JU15.RESULTSAfter an optimized sulfuric acid‐based pretreatment methodology using RSM and CCD, FW was utilized to obtain the maximum concentration of RRS, obtaining liquors containing glucose (85.59%), fructose (5.48%) and arabinose (8.92%) with an efficiency of ∼98% total sugar conversion from hydrolysis of FW. As the total sugar sources obtained titers of 26.85 ± 1.28 g L−1 (DNS) and DLA production was 22.66 ± 1.01g L−1, the DLA yield was 0.99 g g −1 total sugar. While arabinose was discretely consumed, with a remaining concentration of 0.36 ± 0.02 g L−1 after culture, the production of DLA through bacterial fermentation of the FW hydrolysates by the JU15 strain showed total depletion of glucose and fructose, achieving a maximum DLA production of 22.66 g L−1, with a maximum volumetric productivity of 0.73 g L−1 h−1 at 36 h.CONCLUSIONThis study provides an experimental optimization of a pretreatment to obtain released reducing sugars to lactic acid production from food waste as feedstock using the lactogenic E. coli strain JU15. © 2021 Society of Chemical Industry (SCI).

Fermentative lactic acid production from seaweed hydrolysate using Lactobacillus sp. And Weissella sp

Lactic acid (LA) is an essential commodity chemical, with bio-based LA ruling the market share. Macroalgae are a desirable feedstock for LA fermentation due to their high carbohydrate and low lignin content. Ulva sp., Gracilaria sp., and Sargassum cristaefolium were evaluated as a feedstock for LA fermentation. Mild acid-thermal hydrolysis (sulfuric acid concentrations < 5%) resulted in superior reducing sugar recovery. Gracilaria sp. attained maximum reducing sugar recovery (0.39 g/g biomass) and lactate yield (0.94 g/g). LA fermentation of fucose-rich hydrolysate of Sargassum cristaefolium is demonstrated for the first time, with 0.81 g/g LA yield and 0.36 g/g reducing sugars. Ulva sp. attained 0.21 g/g reducing sugars and 0.85 g/g LA yield. The efficiency of macroalgae for lactate bioconversion was in the order: red macroalgae > green macroalgae > brown macroalgae. L. rhamnosus and L. plantarum could efficaciously utilize seaweed sugars for LA production. Macroalgae can potentially replace lignocellulosic biomass as a feedstock in LA fermentation.

Simple and efficient preparation of high-purity trehalulose from the waste syrup of isomaltulose production using solid-phase extraction followed by hydrophilic interaction chromatography.

A simple and efficient method was developed for the preparation of high-purity trehalulose from the waste syrup of isomaltulose production. The waste syrup was pre-treated with C18 solid-phase extraction, where 98% decolorization and 97% reducing sugar recovery were obtained, followed by hydrophilic interaction liquid chromatography separation on a cysteine-bonded zwitterionic column. Under optimized conditions, trehalulose was separated from isomaltulose isomer and prepared on a semi-preparative scale with >99% purity. The structure of the prepared trehalulose was subsequently confirmed by nuclear magnetic resonance, and three tautomers of trehalulose (α-D-glucosylpyranosyl-1,1-β-D-fructopyranose, α-D-glucosylpyranosyl-1,1-β-D-fructofuranose, and α-D-glucosylpyranosyl-1,1-α-D-fructofuranose) were detected and completely characterized by 13 C NMR spectroscopy for the first time in this study. The tautomerization of α-D and β-D type transition was observed by hydrophilic interaction liquid chromatography on an AdvanceBio Glycan Mapping column, with smaller particle size (2.7 μm). Furthermore, the prepared trehalulose was applied as a standard for trehalulose quantification during the sucrose conversion by Klebsiella sp. LX3. The combination of solid-phase extraction and hydrophilic interaction liquid chromatography offers a new avenue for the preparation of sugar isomers from complex natural or fermentation products.

Fractionation of Oil Palm Fronds (OPF) by Ozonolysis for Enhanced Sugar Production

This study investigates the potential of ozonolysis pretreatment on oil palm frond (OPF) for enhancing total reducing sugar (TRS) recovery. The OPF is pretreated by ozonolysis prior to two-step acid hydrolysis. The effect of ozonolysis pretreatment on the physico-chemical properties of OPF is scrutinized followed by the effect of process parameters on lignin degradation and TRS recovery. The presence of lignin-rich and cellulose-rich fractionates are proven by TGA. The XRD reveals crystallinity after pretreatment is increases while crystal size reduces indicating the removal of amorphous lignin region. The structure of OPF is disrupted during the pretreatment revealing the cellulose rosette structure in treated OPF as shown by FeSEM. Ultimately, TRS recovery increases up to 62.3 % with 90 % lignin degradation. This testifies ozonolysis is pertinent for enhancing sugar yields in acid hydrolysis. Among the process parameters, OPF particle size is the most significant followed by reaction time, moisture content, and ozone flowrate. The findings of this work contribute to new information about the pretreatment of biomass by ozonolysis.

Purification of Sugarcane Juice (Saccharum officinarum L.) Using Chitosan Membrane with Dead-End Flow System

The purification process of sugarcane juice in a sugar factory mostly uses sulphitation process, separating clear juice from dirty juice using a sedimentation system. Impurities on the processing of sugarcane juice will further cause difficulties, the formation of color, an increase in viscosity, and reducing sugar recovery. Membrane purification technology is offered to overcome these problems. This study aims to determine the effect of chitosan and acetic acid on the performance of chitosan membranes in the clearance of sugarcane juice and to find the best concentration of chitosan and acetic acid for the purification process of sugarcane juice. The filtration process was performed by using the chitosan membrane to process a clear sugarcane juice sample from the pretreatment result, which is assumed as clear juice product from sulphitation process in sugar factory. The results showed that (1) the result of pretreatment had the value from TSS (Total Soluble Solids) of 15.4%; turbidity of 82.33 NTU; and the ICUMSA (International Commission for Uniform Methods of Sugar Analysis) colour of 14970.02 IU. (2) After filtration using membrane, better quality of pretreatment clear sugarcane juice is obtained, characterized by increasing chitosan concentration at each acetic acid level, rejection value of TSS, turbidity, and ICUMSA colour. (3) The best treatment result based on Zeleny multiple attribute method is found in chitosan membrane with concentration of 4%, acetic acid concentration of 1.5% to inject TSS until reaching 12.64%, ICUMSA until reaching 9.89%, and rejection of turbidity until reaching 63.61%. Higher chitosan concentration caused small pore size of the membrane.

Valorization of food waste for cost-effective reducing sugar recovery in a two-stage enzymatic hydrolysis platform

The recycling of low-cost resources from waste biomass is a promising strategy towards circular bioeconomy. Food waste is an ideal candidate to produce cost-effective glucose. However several problems such as insolubility of macromolecular substances hindered the valorization of food waste. To recover reducing sugar efficiently, a two-stage enzymatic hydrolysis platform was developed, where the alpha-amylase was used at the first stage and glucoamylase followed. Results showed that the enzymatic hydrolysis was more efficient in comparison with acidic and alkali hydrolysis. The optimum pH and dosage for alpha-amylase and glucoamylase were determined to be 5.5 and 150 U/g total solid (TS), and 4.0 and 150 U/g-TS, respectively. The hybrid hydrolysis was more effective in catalyzing starch, obtaining the highest reducing sugar concentration of 204.2 g/L. Analysis of the physicochemical structures indicated that the solid particles could be broken thoroughly by the two enzymes, resulting in sharp decrease of the particle size and viscosity compared with the control. The mass balance and economic assessment verified the feasibility and profitability of the two stage enzymatic hydrolysis. The features of the two-stage platform widened the door to the further production of value-added biochemicals using the sugars recovered from food wastes.

Effect of gamma irradiation on recovery of total reducing sugars from delignified sugarcane bagasse

The present work investigates the effect of gamma irradiation on the recovery of total reducing sugars from delignified sugarcane bagasse. The bagasse was irradiated with different radiation dose i.e. 25, 100, 250, 400 and 1000 kGy.The effect of different initiators in terms of sugar recovery was also investigated. The total reducing sugars was estimated by Dinitrosalicylic acid (DNS) method and individual sugars were identified and estimated by HPLC.The results revealed that irradiation of delignified sugarcane bagasse increases the yield of total reducing sugar by three fold. The use of 1% Ammonium persulphate (APS) as initiator further increases the yield by four fold. The increase in the yield of total reducing sugar was attributed to the breakage of cellulosic cell walls of sugarcane bagasse by irradiation.

Optimization of protein extraction from Gelidiella acerosa by carbohydrases using response surface methodology

SUMMARYIn this study, application of response surface methodology for enzymic pretreatment optimization of Gelidiella acerosa was investigated in order to improve the extraction of algal proteins using Viscozyme L and Celluclast 1.5L. The total protein, soluble proteins and reducing sugar recovery in the water‐soluble fraction were studied in relation to the hydrolysis time, type and concentration of the enzymes. Enzymatic digestion appeared to be an effective treatment for protein extraction. While enzyme hydrolysis by Celluclast 1.5L was able to facilitate the protein extraction, it was a relatively inefficient way to improve protein extraction yield, in comparison with Viscozyme L. The optimum conditions for protein extraction was found to be hydrolysis by 2.8 μL mL−1 of Viscozyme L for 12 h.

Combination of hydrothermal pretreatment and sodium hydroxide post-treatment applied on wheat straw for enhancing its enzymatic hydrolysis

Wheat straw was respectively pretreated by water, dilute sulfuric acid, and sodium hydroxide solution at elevated temperature. Among the pretreatments, hydrothermal process was carried out with different severities. Hydrothermal pretreated sample and dilute acid pretreated sample were subsequently extracted by sodium hydroxide solution at room temperature which was applied as post-treatment. The pretreated samples were then enzymatically hydrolyzed to evaluate reducing sugar recovery. The result indicated that alkaline pretreatment removed a significant amount of lignin. While hydrothermal pretreatment and dilute acid pretreatment solubilized a significant amount of hemicellulose. And the hydrothermal pretreatment severity affected the solubilization of hemicellulose. The alkaline pretreated sample achieved the highest reducing sugar recovery e.g. 38.5 g sugar/100 g wheat straw. The alkaline post-treatment enhanced the enzymatic hydrolysis of acidic pretreated samples by removing additional hemicellulose and lignin. The best reducing sugar recovery was obtained at 43.6 g sugar/100 g wheat straw which indicated that the combination of hydrothermal pretreatment and alkaline extraction is a promising method in terms of reducing sugar production.

Role of energy irradiation in aiding pretreatment of lignocellulosic biomass for improving reducing sugar recovery

With the depletion of crude oil reserves, the ever-increasing global energy consumption encourages the efforts to find alternative renewable sources for production of biofuels and value-added chemicals. The conversions of lignocellulosic biomass into biofuels and commodity chemicals via the biotechnological pathway have been the recent trend. Specifically, these products can be obtained through fermentation of reducing sugars, which are the main but basic derivatives from the biomass. In order to overcome the recalcitrant structure of the biomass for effective reducing sugar recovery, a pretreatment stage is normally required. Currently, one of the most novel forms of biomass pretreatment is using energy irradiation methods such as electron beam, gamma ray, pulsed electrical field, microwave and ultrasound. In general, these technologies are often used together with other more conventional chemical and/or biological pretreatment techniques for enhancing sugar recovery. Nevertheless, energy irradiation offers significant improvement in terms of possible cost reduction opportunities and reduced toxicity. Hence, this review highlights the recent studies of using energy irradiation for pretreating biomass as well as the industrial applications of reducing sugars in biotechnological, chemical and fuel sectors. In short, more research needs to be done at the scientific, engineering and economic levels to make energy irradiation one of the front runners in the field of biomass pretreatment.