Hydrolysis Of Rice Straw Research Articles

Expression and characterization of TbCel12A, a thermophilic endoglucanase with potential in biomass hydrolysis

Abstract To increase economic benefit and reduce pollutants, agricultural biomass can be hydrolyzed to monosaccharides, which serve as a feedstock for biorefinery production of fuels and fine chemicals. In a search for new enzymes to apply to this process, Thermobispora bispora TbCel12A endoglucanase was identified by rice straw compost metagenome analysis and expressed in recombinant Escherichia coli. TbCel12A hydrolyzed both soluble and insoluble β-glucan substrates. Its highest hydrolysis rate was observed for cellopentaose compared to other cellooligosaccharides, barley mixed linkage β-glucan, and carboxymethyl cellulose. Low hydrolysis rates were observed for α-cellulose, and avicel. The primary product detected was cellobiose and a smaller amount of glucose. TbCel12A exhibited highest activity at 65 °C and pH 5.0 and retained 86% relative activity after incubation at 60 °C overnight. TbCel12A conserved >80% activity in 10% alcohol and at high salt concentrations. Hydrolysis of pretreated rice straw using commercial cellulase and TbCel12A released slightly more reducing sugars than hydrolysis using only commercial cellulase. Therefore, TbCel12A is a promising enzyme for further development for use in biomass conversion.

Acidogenic mixed consortium isolated from soil of agricultural field: acid production behaviour and growth kinetics under the influence of pretreatment hydrolysate of rice straw (RS)

ABSTRACT The present study was conducted to assess the possibilities of biofuel production through volatile fatty acid (VFA) platform using mixed consortia isolated from a natural source (soil of rice cultivation field). The acid production potential of the isolated acidogenic mixed consortium UACJUChE1, using pretreatment hydrolysate of rice straw as the carbohydrate source, was assessed. Growth kinetic parameters i.e. maximum specific growth rate (μ max) and substrate saturation constant (KS ) of UACJUChE1 have been determined separately for both glucose and hydrolysate in the Reinforced Clostridial Medium (RCM). A summative type growth model has been observed to be valid when the combination of glucose and RS-hydrolysate (RSH) is used as the carbon sources. The summative model has been validated by successful comparison of model predictions with the experimental data. The presence of VFAs in the culture broth of the consortium grown on glucose, RS-hydrolysate and their combination (Glc:RSH: 2:3; 1:4 (w/w)) has been established. The survival and growth of solventogenic Clostridium acetobutylicum in a growth medium amended with the effluent of these batch cultures of UACJUChE1 have been ascertained. This indicates a strong potential of UACJUChE1 in the hybridisation of the VFA platform and conventional sugar platform for the generation of butanol from RS.

Kinetics of producing vanillin and 4-hydroxy benzaldehyde from the hydrolysis residue of rice straw by photocatalysis

Alkali soluble lignin present in rice straw hydrolysis residue (RSHR) is subjected to photocatalytic treatment to study its degradation rates and production of different value-added oxygenated organic compounds. TiO2 and ZnO are used as photocatalysts. ZnO could degrade lignin faster than TiO2 in pseudo-first order photocatalytic degradation. The maximum observed photocatalytic lignin degradation is 83.4% using 2 g/L ZnO dose with pseudo-first order rate constant 0.1386 h−1. Vanillin and 4-hydroxy benzaldehyde are the two important value-added products formed during photocatalysis. Both these compounds, themselves, are susceptible to photocatalytic degradation. Vanillin degradation followed pseudo-first order kinetics and the highest rate constant of 0.1415 h−1 is achieved using 2 g/L ZnO as photocatalyst. While the degradation kinetics of 4-hydroxy benzaldehyde is pseudo-first order with TiO2 and ZnO as a photocatalyst. Higher catalyst doses increased the reaction rate constant. With multiple reactions in operation, the concentration of both vanillin and 4-hydroxy benzaldehyde in the reaction mixture first increased, attained their maxima, and thereafter decreased. With 1 g/L TiO2 as a photocatalyst, the maximum attained vanillin concentration is 22.4 mg/L after 7 h photocatalysis. Maximum attained vanillin concentration, after 8 h photocatalysis, is significantly higher at 51.2 mg/L when 2 g/L ZnO is used as a catalyst. 4-Hydroxy benzaldehyde is produced in lesser amounts. Its maximum observed concentration in the reaction mixture is 20.4 mg/L, obtained with 1.5 g/L TiO2 after 10 h photocatalysis.

Biobutanol production from lignocellulosic biomass using immobilized Clostridium acetobutylicum

Biobutanol produced by acetone-biobutanol-ethanol (ABE) fermentation process has been revisited in the light of its use as “drop in” liquid biofuel to be blended with gasoline. In this study, renewable feedstock like rice straw, sugarcane bagasse and microalgal hydrolysate were used in ABE fermentation via separate hydrolysis and fermentation. Clostridium acetobutylicum ATCC 824 was used as the fermenting organism. Alkali pretreatment followed by enzymatic hydrolysis was used for rice straw and sugarcane bagasse. In batch fermentation, a biobutanol titer and yield of 9.10 g/L and 0.42 mol/mol glucose (0.17 g biobutanol/g glucose), respectively was obtained from rice straw, while sugarcane bagasse achieved a biobutanol titer and yield of 8.40 g/L and 0.40 mol/mol glucose (0.16 g biobutanol/g glucose), respectively. Higher microalgal biomass loading with 3% acid pretreatment severely inhibited fermentation performance. Unhydrolyzed microalgal biomass at a loading of 180 g/L in ABE fermentation resulted in 4.32 g/L biobutanol and 0.09 g biobutanol/g microalgae as yield. C. acetobutylicum was immobilized in polyvinyl alcohol (PVA) for improving the cell loading in fermentation and protect the cells from biobutanol toxicity. With rice straw hydrolysate as a feedstock and in the absence of yeast extract, a biobutanol titer, yield and productivity of 13.80 g/L, 0.90 g/L/h, and 0.58 mol biobutanol/mol glucose (0.23 g biobutanol/g glucose), respectively were obtained. Hence, rice straw is a potential feedstock for biobutanol production for fuel use.

Investigation of Alkaline Hydrogen Peroxide in Aqueous Organic Solvent to Enhance Enzymatic Hydrolysis of Rice Straw

Alkaline hydrogen peroxide (AHP) pretreatment is a promising process for enhancing enzymatic digestibility of lignocellulosic biomass in biorefineries. In the present work, the effects of organic bases (NH4OH and tri-ethylamine) and co-solvents (ethanol, isopropanol, tert-butyl alcohol, water) on AHP pretreatment efficiency of rice straw were studied and compared to the typical aqueous reaction with NaOH. It was found that the glucose recovery from enzymatic hydrolysis of the biomass pretreated by AHP at 35 °C for 24 h using NH4OH in aqueous/tert-butyl alcohol (73.6%) was higher than that achieved using ethanol and isopropanol (31.6–48.6%) and water (71.2%) under the same experimental conditions. Increasing H2O2 concentration from 1 to 10% v/v in the aqueous/tert-butyl alcohol with NH4OH led to enhancing sugar yield to from 349 to 623 mg/g pretreated rice straw, equivalent to the highest glucose recovery of 83.0%. Formation of highly porous structures in pretreated rice straw by removals of hemicelluloses and lignin was revealed by Fourier transform infrared spectroscopy and scanning electron microscopy while the increased crystallinity index was shown by X-ray diffraction. This modified low-temperature AHP pretreatment using organic solvent system is advantageous on recyclability potential of the reagents and potent for further implementation in lignocellulosic biorefineries.

Production of cellulolytic enzymes by Myceliophthora thermophila and their applicability in saccharification of rice straw

Optimization of cellulase production by Myceliophthora thermophila BJTLRMDU3 was studied in solid state fermentation. Sequential use of Plackett-Burman and response surface methodology (RSM) resulted in the production of 98.81, 243.19, and 316.48 U/g dry moldy residue (DMR) of FPase, CMCase, and β-glucosidase, respectively. Statistical optimization has resulted in more than 4.0-fold increase in the production of cellulases. Optimization of saccharification of untreated and pretreated rice straw was carried out by cellulolytic enzymes of thermophilic mold M. thermophila. The liberation of reducing sugars was higher using fungal cellulases in ammonia-pretreated rice straw as compared with untreated biomass. Maximum liberation of reducing sugars was attained at 60 °C (224.24 mg/g substrate) and pH 5.0 (246.33 mg/g substrate) after an incubation time of 24 h (345.61 mg/g substrate) using enzyme dose of 20 U/g in ammonia-pretreated rice straw. Supplementation of xylanase further enhanced the saccharification (488.78 mg/g substrate) of pretreated rice straw. Analysis using high-performance liquid chromatography (HPLC) indicated the presence of various monomeric and oligomeric sugars in the enzymatic hydrolysate of pretreated rice straw. Both, Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) revealed the structural changes in rice straw after ammonia pretreatment.

Microbial lipid production from rice straw hydrolysates and recycled pretreated glycerol

Microbial lipids were produced by both rice straw hydrolysates and recycled pretreated glycerol. First, lipid fermentation of glucose via Cryptococcus curvatus was optimized by response surface methodology. Variables were selected by Plackett–Burman design, and optimized by central composite design, achieving 4.9 g/L total lipid and 0.16 g/g lipid yield, and increased further as glucose increased from 30 to 50 g/L. Secondly, after pretreatment, 72% lignin of rice straw was removed with glucose yield increased by 2.4 times to 74% at 20% substrate and 3 FPU/g. Subsequently, its hydrolysates produced high total lipid (8.8 g/L) and lipid yield (0.17 g/g). Finally, recycled glycerol reached the maximum total lipid of 7.2 g/L and high lipid yield of 0.16 g/g. Based on the calculation, 2.9 g total lipid would be produced from 1 g rice straw and the recycled glycerol, with a similar composition to soybean oil.

Valorization of xylose-rich hydrolysate from rice straw, an agroresidue, through biosurfactant production by the soil bacterium Serratia nematodiphila

Biosurfactants, amphiphilic compounds that reduce interfacial tension in oil-aqueous mixtures, are used in the petroleum, pharmaceutical, food, and agriculture industries. Fermentative production of biosurfactants requires expensive sugar or lipid substrates. Lignocellulosic biomass is a relatively cheap and abundant agricultural residue that can be used as an alternative substrate. Currently, several million tonnes of rice and wheat straw are generated globally as agricultural residues, most of which is disposed by open-field burning thereby leading to severe environmental pollution. This study aimed to produce biosurfactants in xylose-rich hydrolysates generated from rice straw. The hydrolysate is also a byproduct of 2G biofuel processes that often goes underutilized. A soil bacterium capable of growing and producing biosurfactants in rice straw hydrolysates, which typically contain growth-inhibitory compounds such as furfural and hydroxymethyl furfural, was isolated. Interestingly, the organism, identified as Serratia nematodiphila, exhibited higher glycolipid formation (4.5 ± 0.6 gL−1) in xylose-rich hydrolysate than in glucose-rich enzymatic hydrolysate (3.1 ± 0.2 gL−1) despite the higher bacterial cell density observed with the latter. The biosurfactants were thermostable and possessed promising emulsifying property and anti-microbial activity against bacteria and yeast. Further optimization of C:N resulted in a 2.8-fold increase in glycolipid production from xylose-rich hydrolysates. This study demonstrates the production of glycolipid biosurfactants from lignocellulosic biomass, a low-cost substrate and offers a plausible strategy for the management of these residues. Further, it also provides insights into the generation of additional high-value compounds in a bioethanol biorefinery to improve its commercial feasibility.

Acid-base properties of aluminosilicates from rice husk and straw

We obtained aluminosilicates of sodium and potassium from alkaline hydrolysate of rice straw and husk. Chemical, phase composition of the samples was determined, and nature of the functional groups was studied. We presented results of studying acid-base properties of aluminosilicates’ surface by pH-metry and Hammett methods. We built distribution curves of a number of acid-base centers of the samples from pКa indicators. It was found that the surface of the as-prepared aluminosilicates is characterized by a wider spectrum of Bronsted acid centers (pKa + 2.5; + 3.46; + 6.4), presence of Lewis acid centers (pKa + 16.8) and main Bronsted centers (pKa + 9.45). The largest number of Lewis acid centers was recorded on the surface of sodium aluminosilicates with a narrow ratio of Al2O3:SiO2 = 1:2, the smallest—on the surface of potassium aluminosilicate with a wide ratio of Al2O3:SiO2 = 1:5. The maximum number of Bronsted acid centers was present on the surface of sodium aluminosilicates from rice straw, the minimum—on the surface of potassium aluminosilicate with the amount of SiO2 equal to 41%.

Enhancing enzymatic hydrolysis and fermentation efficiency of rice straw by pretreatment of sodium perborate

In this study, we proposed a simple and effective sodium perborate (SPB) pretreatment method to enhance the enzymatic hydrolysis efficiency of rice straw (RS). The lignin removal rate reached 45.76% under the optimum pretreatment conditions of 8% SPB and 80 °C for 4 h, and the enzymatic hydrolysis efficiency of pretreated RS was 84% at a cellulase loading of 20 FPU/g RS. Through simultaneous saccharification and co-fermentation (SScF) of the pretreated RS solid with Saccharomyces cerevisiae SHY07-1, the maximum ethanol concentration was 15.29 g/L at 72 h, with a fermentation efficiency as high as 91.96%. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analyses revealed that the RS structure was destroyed by SPB pretreatment, and lignin was effectively removed. The overall data of this study indicate that SPB pretreatment is a promising method to improve enzymatic hydrolysis and bioethanol production from RS by inoculating Saccharomyces cerevisiae SHY07-1.

Mild alkaline pretreatment can achieve high hydrolytic and fermentation efficiencies for rice straw conversion to bioethanol

Mild alkaline pretreatment was evaluated as a strategy for effective lignin removal and hydrolysis of rice straw. The pretreatment efficiency of different NaOH concentrations (0.5, 1.0, 1.5 or 2.0% w/w) was assessed. Rice straw (RS) pretreated with 1.5% NaOH achieved better sugar yield compared to other concentrations used. A cellulose conversion efficiency of 91% (45.84 mg/ml glucose release) was attained from 1.5% NaOH pretreated rice straw (PRS), whereas 1% NaOH pretreated rice straw yielded 35.10 mg/ml of glucose corresponding to a cellulose conversion efficiency of 73.81%. The ethanol production from 1% and 1.5% NaOH pretreated RS hydrolysates was similar at ∼3.3% (w/v), corresponding to a fermentation efficiency of 86%. The non-detoxified hydrolysate was fermented using the novel yeast strain Saccharomyces cerevisiae RPP-03O without any additional supplementation of nutrients.

Artificial neural network and response surface methodology: a comparative analysis for optimizing rice straw pretreatment and saccharification

The present study demonstrates a comparative analysis between the artificial neural network (ANN) and response surface methodology (RSM) as optimization tools for pretreatment and enzymatic hydrolysis of lignocellulosic rice straw. The efficacy for both the processes, that is, pretreatment and enzymatic hydrolysis was evaluated using correlation coefficient (R2) & mean squared error (MSE). The values of R2 obtained by ANN after training, validation, and testing were 1, 0.9005, and 0.997 for pretreatment and 0.962, 0.923, and 0.9941 for enzymatic saccharification, respectively. On the other hand, the R2 values obtained with RSM were 0.9965 for cellulose recovery and 0.9994 for saccharification efficiency. Thus, ANN and RSM together successfully identify the substantial process conditions for rice straw pretreatment and enzymatic saccharification. The percentage of error for ANN and RSM were 0.009 and 0.01 for cellulose recovery and for 0.004 and 0.005 for saccharification efficiency, respectively, which showed the authority of ANN in exemplifying the non-linear behavior of the system.

Separation of monosaccharides from pretreatment inhibitors by nanofiltration in lignocellulosic hydrolysate: Fouling mitigation by activated carbon adsorption

Lignocellulose pretreatment results in production of hydrolysate consisting of sugars and inhibitors. Previous reports have shown the viability of nanofiltration (NF) of lignocellulosic hydrolysate for simultaneous sugar concentration and inhibitors removal. However, the complexity of real hydrolysate results in severe membrane fouling which greatly hinders the further application of NF in treating biomass hydrolysate. In this investigation, conditioning of real rice straw hydrolysate from dilute acid pretreatment was conducted by three methods (sedimentation, microfiltration (MF) and activated carbon (AC) adsorption) in order to reduce subsequent NF membrane fouling. Results showed that the turbidity, suspended substance (SS) and particle size of SS of the hydrolysate considerably decreased after these three conditioning methods. Only AC adsorption, however, exhibited best performance in terms of increasing the volume reduction ratio (VRR) and decreasing the membrane fouling during NF filtration of rice straw hydrolysate, demonstrating the effectiveness of AC adsorption for hydrolysate conditioning. Further experiments confirmed that removal of phenolics and pigments, the two dominating foulants during NF process, by AC adsorption were most likely responsible for its superior performance compared to sedimentation and MF.

Characterization of magnetic nanoparticle–immobilized cellulases for enzymatic saccharification of rice straw

Cellulases convert lignocellulosic biomass into fermentable sugars which further act as substrate for ethanol production. Our previous research was focused on enzymatic hydrolysis of rice straw by free cellulases for production of fermentable sugars. Immobilization is a powerful tool to increase the stability and reusability of cellulases besides improving the economy of ethanol production process from rice straw. In the present study, cellulase produced from Aspergillus fumigatus was immobilized on magnetic nanoparticles by using glutaraldehyde cross linker with a binding efficiency of 65.55%. The electron microscopy and spectroscopy tools confirmed the enzyme immobilization process on magnetic nanoparticles. The immobilized cellulase exhibited filter paper, carboxymethyl cellulase and cellobiase activities of 11.82, 21.36 and 10.81 IU, respectively. The free and immobilized cellulase exhibited identical pH optima (pH 5.0) while different temperature optima of 50 °C and 60 °C, respectively. The immobilized enzyme retained 56.87% of its maximal activity after 6 h of pre-incubation at 60 °C. Km (Michaelis constant) and Vmax (maximum velocity) of immobilized enzyme were 11.76 mM and 1.17 μmol min−1 ml−1, respectively. The immobilized cellulase hydrolysed pre-treated rice straw with saccharification efficiency of 52.67%. Further, it could be reutilized for up to four saccharification cycles with retention of 50.34% activity. Therefore, the improved properties of magnetic nanoparticle-immobilized cellulase and its reusability benefits offer a promising potential for industrial production of fermentable sugars and ethanol from rice straw.

Enhanced enzymatic hydrolysis of rice straw via pretreatment with deep eutectic solvents-based microemulsions

In this study, four deep eutectic solvents (DESs) were used as cheaper and “greener” alternatives to ionic liquids (ILs) to create novel microemulsions. Compared with 1-ethyl-3-methyl imidazolium acetate ([Emim]Ac), the DESs of lactic acid:glucose:water and lactic acid:fructose:water (molar ratio = 5:1:3) comprising acid hydrogen-bond donor (pKa = 3.86) showed stronger capability to form the microemulsions with Tween 20, methanol and cyclohexane. After the pretreatment of rice straw at 70 °C for 12 h by using the microemulsions (mass ratio of DES, Tween 20/methanol, cyclohexane = 0.1:0.8:0.1), 54.3% of lignin was removed, and the crystalline structure was significantly disrupted. When the content of DES (lactic acid:glucose:water) increased to 50%, the sugar yield of the residues was increased to 88.1%, which was 3 times than that of untreated one. Moreover, the enzymatic hydrolysis of the residues is linearly and positively correlated with the delignification abilities of the DES microemulsion.

Adsorption of ferulic acid from an alkali-pretreated hydrolysate using a new effective adsorbent prepared by a thermal processing method

A new adsorbent (AEPA250) was prepared using the enzymatic hydrolyzed residue of rice straw in an air environment at 250 ℃ by a thermal processing method. Compared to the commercial adsorbent, AEPA250 possessed a larger specific surface area of 277.680 m2 g−1, and the maximum adsorption efficiency of ferulic acid from alkali-pretreated hydrolysate of rice straw achieved 70.33 % at the optimum conditions. Adsorption kinetics and isotherm studies showed that the pseudo second-order (PSO) (0.997 ≤ R2 ≤ 0.999) and Liu models (0.931 ≤ R2 ≤ 0.997) exhibited better fitting results, which indicated that chemical and saturable adsorption existed between ferulic acid and AEPA250. An adsorption thermodynamics study revealed the spontaneous and endothermic adsorption process (ΔHo > 0 and ΔSo< 0). Micropore diffusion was defined as the major adsorption rate-limiting step according to the analysis of Webber-Morris and Bangham’s model. Additionally, π-π*, ion exchange, hydrogen bonding and precipitation were recognized as the four main mechanisms of ferulic acid removal by AEPA250 through SEM/EDX, EDX mapping, XPS, FTIR and XRD analysis. These results indicated that AEPA250 was effective for adsorbing inhibitors in pretreated rice straw hydrolysates, and it has high potential for application in establishing the self-sufficient production process of bioethanol.

Optimizing the production of rice straw hydrolytic cellulase under solid-state fermentation using Aspergillus terreus RS2

Background The enzymatic hydrolysis of lignocelluloses into fermentable sugars is the key step in biorefining, and cellulases are the key enzymes. The low titer of cellulase production and their high cost remain the most significant barriers to their industrial applications. The aim of this study was the economic production of cellulase by an Egyptian fungal isolate under solid-state fermentation by using rice straw as a carbon source. Additionally, the produced enzyme can be applied in the hydrolysis of rice straw and production of free sugars that can be used in several biotechnological industries. Materials and methods The isolated fungus was identified according to its cultural and morphological features followed by 18S rDNA sequencing. Optimization of the enzyme productivity was performed by applying Plackett–Burman and Box–Behnken designs. Finally, the hydrolysis of rice straw for the production of fermentable sugars using the produced enzyme was carried out, confirmed by scanning electron microscope and thin-layer chromatography analysis. Results and conclusion The optimum cellulase activity produced by the isolated fungus Aspergillus terreus RS2 was 124.94 U/g dry substrate. It was achieved at the optimum conditions that were conducted to be as follows: 3.75 g (1.5%w/v) of rice straw moistened with 11.25 ml (1 : 3 biomass to moistening agent) of modified Mandel’s medium [1% (NH4)2SO4 was the only constituent nitrogen source] of pH 7, incubated at 30°C for 8 days. Finally, the activity of the produced enzyme in the degradation of rice straw indicated the release of reducing sugars of 343.98 mg/g dry substrate with a saccharification percentage of 34.4% recorded after 4-h hydrolysis period.

Performance of Burkholderia multivorans CCA53 for ethyl red degradation.

The discharge of industrial dyes and their breakdown products are often environmentally harmful. Here, we describe a biodegradation method using Burkholderia multivorans CCA53, which exhibits a capacity to degrade azo dyes, particularly ethyl red. Under the optimized culture conditions, 100 μM ethyl red was degraded more than 99% after incubation for 8 h. Real-time PCR analysis of azoR1 and azoR2, encoding two azoreductases, revealed that transcription level of these genes is enhanced at early phase under the optimized conditions. For a more practical approach, hydrolysates were prepared from eucalyptus or Japanese cedar chips or rice straw, and rice straw hydrolysate was used as the best medium for ethyl red biodegradation. Under those conditions, ethyl red was also degraded with high efficiency (>91%). We have thus constructed a potentially economical method for the biodegradation of ethyl red.

Process optimization for the production of cellulose nanocrystals from rice straw derived α-cellulose

Nanocrystalline cellulose has emerged out as a substantial nanomaterial in recent years due to its peculiar characteristics such as bio renewability and sustainability while having high mechanical strengths, optical transparency and much more. In this study, we prepared cellulose nanocrystals (CNC) by acid hydrolysis of rice straw derived cellulose. The aim was to maximize the product yield by using RSM (response surface methodology) and also to investigate the interaction between 3 design factors; concentration of acid, temperature of reaction and time period of the reaction to unriddle their effects on yield of the product. A high CNC yield of 90.28% was found when the reactions conditions were kept at temperature 30 °C, acid concentration 75 wt% and time 5 h. Morphological characterization through scanning electron microscopy (SEM) clearly showed the formation of rod shaped CNCs. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) revealed that CNC’s have higher crystallinity (76%) than that of rice straw derived α-cellulose and higher thermal stability respectively. Thus, the isolated CNC may be suitable for use as reinforcing agent in the fabrication of bio-nanocomposites for different applications.

Production of 5-hydroxymethylfurfural (HMF) from rice-straw biomass using a HSO3-ZSM-5 zeolite catalyst under assistance of sonication.

This work studied the application of sulfonated ZSM-5 zeolite, a bi-functional catalyst for conversion of biomass-derived glucose to HMF. Glucose hydrolysate was obtained by enzymatic hydrolysis of rice straw, that was pretreated by sodium hydroxide. Glucose hydrolysate was then subjected to a transformation reaction to achieve HMF using HSO3–ZSM-5 zeolite under the assistance of sonication. The reaction conditions including solvent, temperature, catalyst dosage and reaction time were studied. Suitable conditions, which gave the highest yield of HMF of 54.1% have been found. The HSO3–ZSM-5 zeolite presented a high catalytic efficiency for conversion of glucose to HMF, an important and useful intermediate in the chemical industry.