Improvement of Aspergillus sulphureus endo-beta-1,4-xylanase expression in Pichia pastoris by codon optimization and analysis of the enzymic characterization

High-level secretory production of leghemoglobin in Pichia pastoris through enhanced globin expression and heme biosynthesis

Soy leghemoglobin is a key food additive that imparts meaty flavor and color to meat analogs. Here, a Pichia pastoris strain capable of high-yield secretory production of functional leghemoglobin was developed through gene dosage optimization and heme pathway consolidation. First, multi-copy integration of LegH expression cassette was achieved via both post-transformational vector amplification and CRISPR/Cas9 mediated genome editing methods. A combination of inducible expression and constitutive expression resulted in the highest production of leghemoglobin. Then, heme biosynthetic pathway was engineered to address challenges in heme depletion and leghemoglobin secretion. Finally, the disruption of ku70 was complemented in engineered P. pastoris strain to enable high-density fermentation in a 10-L bioreactor. These engineering strategies increased the secretion of leghemoglobin by more than 83-fold, whose maximal leghemoglobin titer and heme binding ratio reached as high as 3.5 g/L and 93 %, respectively. This represents the highest secretory production of heme-containing proteins ever reported.

Optimization of Pichia pastoris Expression System for High-Level Production of Margatoxin

Margatoxin (MgTx) is a high-affinity blocker of voltage-gated potassium (Kv) channels. It inhibits Kv1.1–Kv1.3 ion channels in picomolar concentrations. This toxin is widely used to study physiological function of Kv ion channels in various cell types, including immune cells. Isolation of native MgTx in large quantities from scorpion venom is not affordable. Chemical synthesis and recombinant production in Escherichia coli need in vitro oxidative refolding for proper disulfide bond formation, resulting in a very low yield of peptide production. The Pichia pastoris expression system offers an economical approach to overcome all these limitations and gives a higher yield of correctly refolded recombinant peptides. In this study, improved heterologous expression of recombinant MgTx (rMgTx) in P. pastoris was obtained by using preferential codons, selecting the hyper-resistant clone against Zeocin, and optimizing the culturing conditions. About 36 ± 4 mg/L of >98% pure His-tagged rMgTx (TrMgTx) was produced, which is a threefold higher yield than has been previously reported. Proteolytic digestion of TrMgTx with factor Xa generated untagged rMgTx (UrMgTx). Both TrMgTx and UrMgTx blocked the Kv1.2 and Kv1.3 currents (patch-clamp) (K_d for Kv1.2 were 64 and 14 pM, and for Kv1.3, 86 and 50 pM, respectively) with comparable potency to the native MgTx. The analysis of the binding kinetics showed that TrMgTx had a lower association rate than UrMgTx for both Kv1.2 and Kv1.3. The dissociation rate of both the analogues was the same for Kv1.3. However, in the case of Kv1.2, TrMgTx showed a much higher dissociation rate with full recovery of the block than UrMgTx. Moreover, in a biological functional assay, both peptides significantly downregulated the expression of early activation markers IL2R and CD40L in activated CD4⁺ T_EM lymphocytes whose activation was Kv1.3 dependent. In conclusion, the authors report that the Pichia expression system is a powerful method to produce disulfide-rich peptides, the overexpression of which could be enhanced noticeably through optimization strategies, making it more cost-effective. Since the presence of the His-tag on rMgTx only mildly altered the block equilibrium and binding kinetics, recombinant toxins could be used in ion channel research without removing the tag and could thus reduce the cost and time demand for toxin production.

Purification, Identification, and Characterization of a Glycoside Hydrolase Family 11-Xylanase with High Activity from Aspergillus niger VTCC 017

Xylanases (EC 3.2.1.8) have been considered as a potential green solution for the sustainable development of a wide range of industries including pulp and paper, food and beverages, animal feed, pharmaceuticals, and biofuels because they are the key enzymes that degrade the xylosidic linkages of xylan, the major component of the second most abundant raw material worldwide. Therefore, there is a critical need for the industrialized xylanases which must have high specific activity, be tolerant to organic solvent or detergent and be active during a wide range of conditions, such as high temperature and pH. In this study, an extracellular xylanase was purified from the culture broth of Aspergillus niger VTCC 017 for primary structure determination and properties characterization. The successive steps of purification comprised centrifugation, Sephadex G-100 filtration, and DEAE-Sephadex chromatography. The purified xylanase (specific activity reached 6596.79 UI/mg protein) was a monomer with a molecular weight of 37 kDa estimating from SDS electrophoresis. The results of LC/MS suggested that the purified protein is indeed an endo-1,4-β-D-xylanase. The purified xylanase showed the optimal temperature of 55 °C, and pH 6.5 with a stable xylanolytic activity within the temperature range of 45-50 °C, and within the pH range of 5.0-8.0. Most divalent metal cations including Zn²⁺, Fe²⁺, Mg²⁺, Cu²⁺, Mn²⁺ showed some inhibition of xylanase activity while the monovalent metal cations such as K⁺ and Ag⁺ exhibited slight stimulating effects on the enzyme activity. The introduction of 10-30% different organic solvents (n-butanol, acetone, isopropanol) and several detergents (Triton X-100, Tween 20, and SDS) slightly reduced the enzyme activity. Moreover, the purified xylanase seemed to be tolerant to methanol and ethanol and was even stimulated by Tween 80. Overall, with these distinctive properties, the putative xylanase could be a successful candidate for numerous industrial uses.

Enhanced Secretory Expression and Surface Display Level of Bombyx mori Acetylcholinesterase 2 by Pichia pastoris Based on Codon Optimization Strategy for Pesticides Setection

The cholinesterase-based spectrophotometric assay, also called enzyme inhibition method, is a good choice for rapid detection of organophosphate pesticides (OPs) and carbamate pesticides (CPs). Obviously, the cholinesterase is the core reagent in enzyme inhibition method. In our previous work, a recombinant acetylcholinesterase 2 from Bombyx mori (rBmAChE2) was expressed in yeast successfully and exhibited great sensitivity. However, the yield of rBmAChE2 is not desirable. In this study, a codon optimization strategy was employed to enhance the yield of rBmAChE2 in Pichia pastoris GS115. Results showed that by replacing 6 key rare codons and increasing the percentage of bases G and C up to 46.85%, codon adaptation index (CAI) of Bombyx mori acetylcholinesterase 2 (bmace2) gene was improved from 0.70 to 0.81. After being transformed into Pichia pastoris GS115 via electroporation, the expression transformant can produce 139.7 U/mL secretory codon-optimized rBmAChE2 (opt-rBmAChE2) in the culture supernatant, 3.62 times higher than that of strain bearing the wild-type bmace2 gene. Meanwhile, opt-rBmAChE2 displayed on the yeast surface was up to 2280.02 U/g, 2.8 times higher than wild-type displayed rBmAChE2. In addition, either secretory or surface-displayed opt-rBmAChE2 maintained the similar sensitivities to the wild-type rBmAChE2 for tested inhibitors. Furthermore, the detection limits of the opt-rBmAChE2-based enzyme inhibition method for 10 kinds of OPs or CPs (0.01-2.69 mg/kg) were lower than most of the indexes present in current standard method (GB/T 5009.199-2003) or the maximum residue limits (GB 2763-2019) in China. The results might contribute to the utilization of rBmAChE2 for pesticide residue screening detection in practice.

Increase in the Production of Endo-1,4-β-Xylanase from Paenibacillus brasilensis in Pichia pastoris

A Pichia pastoris yeast strain producing endo-l,4-β-xylanase from Paenibacillus brasilensis with an activity of 54,400 U/mL after 140 h of fermentation in a laboratory fermenter has been obtained. A number of approaches were used to increase the level of the xylanase production in this strain: optimization of the target gene codon composition, multiple integration of the expression cassette into the recipient strain chromosome using the Cre-lox recombination system, and also improving the heterologous protein folding via the overexpression of the HAC1i gene from Pichia pastoris. xylanase, xylan, Cre-lox system, HAC1p transcriptional activator, multicopy strain, Paenibacillus brasilensis, Pichia pastoris The work was performed with the financial support of the Ministry of Education and Science of Russia (Unique Project Identifier RFMEFI60717X0180) using the Multipurpose Scientific Installation of «All-Russian Collection of Industrial Microorganisms» National Bio-Resource Center, NRC «Kurchatov Institute» - GosNIIgenetika.

Trends in recombinant protein use in animal production

Recombinant technologies have made possible the production of a broad catalogue of proteins of interest, including those used for animal production. The most widely studied proteins for the animal sector are those with an important role in reproduction, feed efficiency, and health. Nowadays, mammalian cells and fungi are the preferred choice for recombinant production of hormones for reproductive purposes and fibrolytic enzymes to enhance animal performance, respectively. However, the development of low-cost products is a priority, particularly in livestock. The study of cell factories such as yeast and bacteria has notably increased in the last decades to make the new developed reproductive hormones and fibrolytic enzymes a real alternative to the marketed ones. Important efforts have also been invested to developing new recombinant strategies for prevention and therapy, including passive immunization and modulation of the immune system. This offers the possibility to reduce the use of antibiotics by controlling physiological processes and improve the efficacy of preventing infections. Thus, nowadays different recombinant fibrolytic enzymes, hormones, and therapeutic molecules with optimized properties have been successfully produced through cost-effective processes using microbial cell factories. However, despite the important achievements for reducing protein production expenses, alternative strategies to further reduce these costs are still required. In this context, it is necessary to make a giant leap towards the use of novel strategies, such as nanotechnology, that combined with recombinant technology would make recombinant molecules affordable for animal industry.

High-level expression of improved thermo-stable alkaline xylanase variant in Pichia Pastoris through codon optimization, multiple gene insertion and high-density fermentation

In paper industry, xylanases are used to increase the pulp properties in bleaching process as its eco-friendly nature. The xylanases activity is hindered by high temperature and alkaline conditions with high enzyme production cost in the paper industry. Here, XynHB, an alkaline stable xylanase from Bacillus pumilus HBP8 was mutated at N188A to XynHBN188A. Expressed mutant in E. coli showed 1.5-fold higher xylanase activity than XynHB at 60 °C. The mutant expressed in Pichia pastoris was glycosylated, remained stable for 30 min at 60 °C. XynHBN188A optimized based on codon usage bias for P. pastoris (xynHBN188As) showed an increase of 39.5% enzyme activity. The strain Y16 forming the largest hydrolysis halo in the xylan plate was used in shake flask experiments produced an enzyme activity of 6,403 U/ml. The Y16 strain had 9 copies of the recombinant xynHBN188As gene in the genome revealed by qPCR. The enzymatic activity increased to 48,241 U/ml in a 5 L fermentor. Supplement of 15 U/g xylanase enhanced the brightness of paper products by 2% in bleaching experiment, and thereby improved the tensile strength and burst factor by 13% and 6.5%, respectively. XynHBN188As has a great potential in paper industries.

Lignocellulose degrading extremozymes produced by Pichia pastoris: current status and future prospects

In this review article, extremophilic lignocellulosic enzymes with special interest on xylanases, β-mannanases, laccases and finally cellulases, namely, endoglucanases, exoglucanases and β-glucosidases produced by Pichia pastoris are reviewed for the first time. Recombinant lignocellulosic extremozymes are discussed from the perspectives of their potential application areas; characteristics of recombinant and native enzymes; the effects of P. pastoris expression system on recombinant extremozymes; and their expression levels and applied strategies to increase the enzyme expression yield. Further, effects of enzyme domains on activity and stability, protein engineering via molecular dynamics simulation and computational prediction, and site-directed mutagenesis and amino acid modifications done are also focused. Superior enzyme characteristics and improved stability due to the proper post-translational modifications and better protein folding performed by P. pastoris make this host favourable for extremozyme production. Especially, glycosylation contributes to the structure, function and stability of enzymes, as generally glycosylated enzymes produced by P. pastoris exhibit better thermostability than non-glycosylated enzymes. However, there has been limited study on enzyme engineering to improve catalytic efficiency and stability of lignocellulosic enzymes. Thus, in the future, studies should focus on protein engineering to improve stability and catalytic efficiency via computational modelling, mutations, domain replacements and fusion enzyme technology. Also metagenomic data need to be used more extensively to produce novel enzymes with extreme characteristics and stability.

Extracellular expression and antiviral activity of a bovine interferon-alpha through codon optimization in Pichia pastoris

Interferons (IFNs) are the primary line of defense against infectious agents. In particular, IFN-α is an important antiviral cytokine and has a wide range of immune-modulating functions. Porcine and human IFN-α have been successfully prepared and play important roles in the prevention and therapy of viral diseases. To date, there has been limited applied research on bovine IFN-α. To achieve high-level expression of recombinant bovine IFN-α (bIFN-α) in Pichia pastoris for large-scale application, the bIFN-α gene was optimized and synthesized on the basis of codon bias of P. pastoris. Optimized bIFN-α (opti-bIFN-α) was successfully expressed in P. pastoris and directly secreted into the culture supernatant. The amount of extracellular soluble opti-bIFN-α was observed to be 200μg/mL in a shake flask. Expression efficiency of opti-bIFN-α was found to be about three times that of wild-type bIFN-α when the expression yield was compared at the same copies of the targeted gene. In addition, both the original cultural supernatant and purified opti-bIFN-α showed strong antiviral activity in MDBK cells (2×10(6)AU/mL and 1×10(7)AU/mg, respectively) and IBRS-2 cells (3×10(5)AU/mL and 1.5×10(6)AU/mg, respectively) against a recombinant vesicular stomatitis virus expressing the green fluorescence protein. In this study, we demonstrated high-level extracellular expression of opti-bIFN-α by P. pastoris. To the best of our knowledge, the opti-bIFN-α yield observed in this study is the highest to be reported to date. Our results demonstrated that the extracellular opti-bIFN-α with strong antiviral activity could be easily prepared and purified at a low cost and that it may be a potential biological therapeutic drug against bovine viral infections.

Improved Production of Aspergillus usamii endo-β-1,4-Xylanase in Pichia pastoris via Combined Strategies

A series of strategies were applied to improve expression level of recombinant endo-β-1,4-xylanase from Aspergillus usamii (A. usamii) in Pichia pastoris (P. pastoris). Firstly, the endo-β-1,4-xylanase (xynB) gene from A. usamii was optimized for P. pastoris and expressed in P. pastoris. The maximum xylanase activity of optimized (xynB-opt) gene was 33500 U/mL after methanol induction for 144 h in 50 L bioreactor, which was 59% higher than that by wild-type (xynB) gene. To further increase the expression of xynB-opt, the Vitreoscilla hemoglobin (VHb) gene was transformed to the recombinant strain containing xynB-opt. The results showed that recombinant strain harboring the xynB-opt and VHb (named X33/xynB-opt-VHb) displayed higher biomass, cell viability, and xylanase activity. The maximum xylanase activity of X33/xynB-opt-VHb in 50 L bioreactor was 45225 U/mL, which was 35% and 115% higher than that by optimized (xynB-opt) gene and wild-type (xynB) gene. Finally, the induction temperature of X33/xynB-opt-VHb was optimized in 50 L bioreactor. The maximum xylanase activity of X33/xynB-opt-VHb reached 58792 U/mL when the induction temperature was 22°C. The results presented here will greatly contribute to improving the production of recombinant proteins in P. pastoris.

Codon Optimization Significantly Improves the Expression Level of α -Amylase Gene from Bacillus licheniformis in Pichia pastoris

α-Amylase as an important industrial enzyme has been widely used in starch processing, detergent, and paper industries. To improve expression efficiency of recombinant α-amylase from Bacillus licheniformis (B. licheniformis), the α-amylase gene from B. licheniformis was optimized according to the codon usage of Pichia pastoris (P. pastoris) and expressed in P. pastoris. Totally, the codons encoding 305 amino acids were optimized in which a total of 328 nucleotides were changed and the G+C content was increased from 47.6 to 49.2%. The recombinants were cultured in 96-deep-well microplates and screened by a new plate assay method. Compared with the wild-type gene, the optimized gene is expressed at a significantly higher level in P. pastoris after methanol induction for 168 h in 5- and 50-L bioreactor with the maximum activity of 8100 and 11000 U/mL, which was 2.31- and 2.62-fold higher than that by wild-type gene. The improved expression level makes the enzyme a good candidate for α-amylase production in industrial use.

Biotechnical paving of recombinant enterocin A as the candidate of anti-Listeria agent

Background

Enterocin A is a classic IIa bacteriocin isolated firstly from Enterococcus faecium CTC492 with selective antimicrobial activity against Listeria strains. However, the application of enterocin A as an anti-Listeria agent has been limited due to its very low native yield. The present work describes high production of enterocin A through codon optimization strategy and its character study.

Results

The gene sequence of enterocin A was optimized based on preferential codon usage in Pichia pastoris to increase its expression efficiency. The highest anti-Listeria activity reached 51,200 AU/ml from 180 mg/l of total protein after 24 h of induction in a 5-L fermenter. Recombinant enterocin A (rEntA), purified by gel filtration chromatography, showed very strong activity against Listeria ivanovii ATCC 19119 with a low MIC of 20 ng/ml. In addition, the rEntA killed over 99% of tested L. ivanovii ATCC19119 within 4 h when exposed to 4 × MIC (80 ng/ml). Moreover, it showed high stability under a wide pH range (2–10) and maintained full activity after 1 h of treatment at 80°C within a pH range of 2–8. Its antimicrobial activity was enhanced at 25 and 50 mM NaCl, while 100–400 mM NaCl had little effect on the bactericidal ability of rEntA.

Conclusion

The EntA was successfully expressed in P. pastoris, and this feasible system could pave the pre-industrial technological path of rEntA as a competent candidate as an anti-Listeria agent. Furthermore, it showed high stability under wide ranges of conditions, which could be potential as the new candidate of anti-Listeria agent.

Codon modification for the DNA sequence of a single-chain Fv antibody against clenbuterol and expression in Pichia pastoris

The expression efficiency was improved for the recombinant single-chain variable fragment (scFv) against clenbuterol (CBL) obtained from mouse and expressed in the methylotrophic yeast Pichia pastoris GS115, by redesigning and synthesizing the DNA sequence encoding for CBL-scFv based on the codon bias of P. pastoris. The codons encoding 124 amino acids were optimized, in which a total of 156 nucleotides were changed, and the G+C ratio was simultaneously decreased from 53 to 47.2 %. Under the optimized expression conditions, the yield of the recombinant CBL-scFv (41 kDa) antibodies was 0.223 g L⁻¹ in shake culture. Compared to the non-optimized control, the expression level of the optimized recombinant CBL-scFv based on preferred codons in P. pastoris demonstrated a 2.35-fold higher yield. Furthermore, the recombinant CBL-scFv was purified by Ni-NTA column chromatography, and the purity was 95 %. The purified CBL-scFv showed good CBL recognition by a competitive indirect enzyme-linked immunoassay. The average concentration required for 50 % inhibition of binding and the limit of detection for the assay were 5.82 and 0.77 ng mL⁻¹, respectively.

Codon optimisation improves the expression of Trichoderma viride sp. endochitinase in Pichia pastoris

The mature cDNA of endochitinase from Trichoderma viride sp. was optimised based on the codon bias of Pichia pastoris GS115 and synthesised by successive PCR; the sequence was then transformed into P. pastoris GS115 via electroporation. The transformant with the fastest growth rate on YPD plates containing 4 mg/mL G418 was screened and identified. This transformant produced 23.09 U/mL of the recombinant endochitinase, a 35% increase compared to the original strain bearing the wild-type endochitinase cDNA. The recombinant endochitinase was sequentially purified by ammonia sulphate precipitation, DE-52 anion-exchange chromatography and Sephadex G-100 size-exclusion chromatography. Thin-layer chromatography indicated that the purified endochitinase could hydrolyse chito-oligomers or colloidal chitin to generate diacetyl-chitobiose (GlcNAc)₂ as the main product. This study demonstrates (1) a means for high expression of Trichoderma viride sp. endochitinase in P. pastoris using codon optimisation and (2) the preparation of chito-oligomers using endochitinase.

Identification and characterization of P GCW14 : a novel, strong constitutive promoter of Pichia pastoris

The available promoters in the Pichia pastoris expression platform are still limited. We selected and identified a novel strong constitutive promoter, P GCW14 , and tested its promoter activity using enhanced green fluorescent protein (EGFP) as a reporter. Potential promoter regions of P GCW14 were cloned upstream of the EGFP gene and promoter activity was analyzed by measuring fluorescence intensity. P GCW14 exhibited significantly stronger promoter activity than the classic strong constitutive promoters P TEF1 and P GAP under various carbon sources, suggesting that P GCW14 is a strong and constitutive promoter. Hence, P GCW14 can be used as a promoter for high-level expression of heterologous proteins.

Expression, purification, and immunogenic characterization of Epstein-Barr virus recombinant EBNA1 protein in Pichia pastoris

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus associated with the development of both lymphoid and epithelial tumors. EBNA1 is the only viral protein expressed in all EBV-associated malignancies and plays important roles in EBV latency. Thus, EBNA1 is thought to be a promising antigen for immunotherapy of all EBV-associated malignancies. This study was undertaken to produce recombinant EBNA1 protein in Pichia pastoris and evaluate its immunogenicity. The truncated EBNA1 (E1ΔGA, codons 390-641) was expressed as a secretory protein with an N-terminal histidine tag in the methylotrophic yeast P. pastoris and purified by Ni-NTA affinity chromatography. The purified proteins were then used as antigens to immunize BALB/c mice for production of polyclonal antibodies. Western blot analysis showed that the polyclonal antibodies specifically recognized the EBNA1 protein in B95-8 cell lysates. The recombinant E1ΔGA also induced strong lymphoproliferative and Th1 cytokine responses in mice. Furthermore, mice immunized with E1ΔGA developed CD4+ and CD8+ T cell responses. These findings showed that the yeast-expressed E1ΔGA retained good immunogenicity and might be a promising vaccine candidate against EBV-associated malignancies.

Development of an industrial medium and a novel fed-batch strategy for high-level expression of recombinant β-mananase by Pichia pastoris

An industrial medium, Corn Steep Liquor Powder Dextrose (CSD medium) was developed for constitutive expression of recombinant β-mananase by Pichia pastoris. The β-mananase activity (513 U/mL) with CSD medium was 1.64- and 2.5-fold higher than with YPD and BSM in shaken flasks. The β-mananase productivity with CSD medium was 61.0 U/mL h, which was 1.7- and 2.5-fold higher than with YPD and BSM in a 5-L fermenter based on a novel fed-batch strategy combining the real-time exponential feed mode with the DO-stat feed mode. The β-mananase activity, dry cell weight and the recombinant enzyme reached up to 5132 U/mL, 110.0 g/L and 4.50 g/L after 50 h cultivation in a 50-L fermenter. The high efficient expression of recombinant β-mananase by P. pastoris indicated that CSD medium and the novel fed-batch strategy have great potential for the production of recombinant β-mananase in industrial fermentation.

GH11 xylanases: Structure/function/properties relationships and applications

For technical, environmental and economical reasons, industrial demands for process-fitted enzymes have evolved drastically in the last decade. Therefore, continuous efforts are made in order to get insights into enzyme structure/function relationships to create improved biocatalysts. Xylanases are hemicellulolytic enzymes, which are responsible for the degradation of the heteroxylans constituting the lignocellulosic plant cell wall. Due to their variety, xylanases have been classified in glycoside hydrolase families GH5, GH8, GH10, GH11, GH30 and GH43 in the CAZy database. In this review, we focus on GH11 family, which is one of the best characterized GH families with bacterial and fungal members considered as true xylanases compared to the other families because of their high substrate specificity. Based on an exhaustive analysis of the sequences and 3D structures available so far, in relation with biochemical properties, we assess biochemical aspects of GH11 xylanases: structure, catalytic machinery, focus on their "thumb" loop of major importance in catalytic efficiency and substrate selectivity, inhibition, stability to pH and temperature. GH11 xylanases have for a long time been used as biotechnological tools in various industrial applications and represent in addition promising candidates for future other uses.

Direct ethanol production from hemicellulosic materials of rice straw by use of an engineered yeast strain codisplaying three types of hemicellulolytic enzymes on the surface of xylose-utilizing Saccharomyces cerevisiae cells

The cost of the lignocellulose-hydrolyzing enzymes used in the saccharification process of ethanol production from biomass accounts for a relatively high proportion of total processing costs. Cell surface engineering technology has facilitated a reduction in these costs by integrating saccharification and fermentation processes into a recombinant microbe strain expressing heterologous enzymes on the cell surface. We constructed a recombinant Saccharomyces cerevisiae that not only hydrolyzed hemicelluloses by codisplaying endoxylanase from Trichoderma reesei, β-xylosidase from Aspergillus oryzae, and β-glucosidase from Aspergillus aculeatus but that also assimilated xylose through the expression of xylose reductase and xylitol dehydrogenase from Pichia stipitis and xylulokinase from S. cerevisiae. The recombinant strain successfully produced ethanol from rice straw hydrolysate consisting of hemicellulosic material containing xylan, xylooligosaccharides, and cellooligosaccharides without requiring the addition of sugar-hydrolyzing enzymes or detoxication. The ethanol titer of the strain was 8.2g/l after 72h fermentation, which was approximately 2.5-fold higher than that of the control strain. The yield (grams of ethanol per gram of total sugars in rice straw hydrolysate consumed) was 0.41g/g, which corresponded to 82% of the theoretical yield. The cell surface-engineered strain was thus highly effective for consolidating the process of ethanol production from hemicellulosic materials.