Enzymatic Hydrolysis and Fermentation of Pretreated Cashew Apple Bagasse with Alkali and Diluted Sulfuric Acid for Bioethanol Production

The aim of this work was to optimize the enzymatic hydrolysis of the cellulose fraction of cashew apple bagasse (CAB) after diluted acid (CAB-H) and alkali pretreatment (CAB-OH), and to evaluate its fermentation to ethanol using Saccharomyces cerevisiae. Glucose conversion of 82?±?2 mg/g CAB-H and 730?±?20 mg/g CAB-OH was obtained when 2% (w/v) of solid and 30 FPU/g bagasse was used during hydrolysis at 45 °C, 2-fold higher than when using 15 FPU/g bagasse, 44?±?2 mg/g CAB-H, and 450?±?50 mg/g CAB-OH, respectively. Ethanol concentration and productivity, achieved after 6 h of fermentation, were 20.0?±?0.2 g L^?1 and 3.33 g L^?1 h^?1, respectively, when using CAB-OH hydrolyzate (initial glucose concentration of 52.4 g L^?1). For CAB-H hydrolyzate (initial glucose concentration of 17.4 g L^?1), ethanol concentration and productivity were 8.2?±?0.1 g L^?1 and 2.7 g L^?1 h^?1 in 3 h, respectively. Hydrolyzates fermentation resulted in an ethanol yield of 0.38 and 0.47 g/g glucose with pretreated CAB-OH and CAB-H, respectively. Ethanol concentration and productivity, obtained using CAB-OH hydrolyzate, were close to the values obtained in the conventional ethanol fermentation of cashew apple juice or sugar cane juice.     

Biotechnological Utilization of Biodiesel-Derived Glycerol for the Production of Ribonucleotides and Microbial Biomass

Ten yeast strains were evaluated concerning their capabilities to assimilate biodiesel-derived glycerol in batch cultivation. The influence of glycerol concentration, temperature, pH and yeast extract concentration on biomass production was studied for the yeast selected. Further, the effect of agitation on glycerol utilization by the yeast Hansenula anomala was also studied. The yeast H. anomala CCT 2648 showed the highest biomass yield (0.30?g?g^?1) and productivity (0.19?g?L^?1?h^?1). Citric acid, succinic acid, acetic acid and ethanol were found as the main metabolites produced. The increase of yeast extract concentration from 1 to 3?g?L^?1 resulted in high biomass production. The highest biomass concentration (21?g?L^?1), yield (0.45?g?g^?1) and productivity (0.31?g?L^?1?h^?1), as well as ribonucleotide production (13.13?mg?g^?1), were observed at 700?rpm and 0.5?vvm. These results demonstrated that glycerol from biodiesel production process showed to be a feasible substrate for producing biomass and ribonucleotides by yeast species.     

Single-cell Protein and Xylitol Production by a Novel Yeast Strain <Emphasis Type="Italic">Candida intermedia</Emphasis> FL023 from Lignocellulosic Hydrolysates and Xylose

Yeasts are good candidates to utilize the hydrolysates of lignocellulose, the most abundant bioresource, for bioproducts. This study aimed to evaluate the efficiencies of single-cell protein (SCP) and xylitol production by a novel yeast strain, Candida intermedia FL023, from lignocellulosic hydrolysates and xylose. This strain efficiently assimilated hexose, pentose, and cellubiose for cell mass production with the crude protein content of 484.2 g kg^?1 dry cell mass. SCP was produced by strain FL023 using corncob hydrolysate and urea as the carbon and nitrogen sources with the dry cell mass productivity 0.86 g L^?1 h^?1 and the yield of 0.40 g g^?1 sugar. SCP was also produced using NaOH-pretreated Miscanthus sinensis straw and corn steep liquor as the carbon and nitrogen sources through simultaneous saccharification and fermentation with the dry cell productivity of 0.23 g L^?1 h^?1 and yield of 0.17 g g^?1 straw. C. intermedia FL023 was tolerant to 0.5 g L^?1 furfural, acetic acid, and syringaldehyde in xylitol fermentation and produced 45.7 g L^?1 xylitol from xylose with the productivity of 0.38 g L^?1 h^?1 and the yield of 0.57 g g^?1 xylose. This study provides feasible methods for feed and food additive production from the abundant lignocellulosic bioresources.     

Ethanol Production from Sugarcane Bagasse Hydrolysate Using Pichia stipitis

The objective of this study was to evaluate the ethanol production from the sugars contained in the sugarcane bagasse hemicellulosic hydrolysate with the yeast Pichia stipitis DSM 3651. The fermentations were carried out in 250-mL Erlenmeyers with 100 mL of medium incubated at 200 rpm and 30 °C for 120 h. The medium was composed by raw (non-detoxified) hydrolysate or by hydrolysates detoxified by pH alteration followed by active charcoal adsorption or by adsorption into ion-exchange resins, all of them supplemented with yeast extract (3 g/L), malt extract (3 g/L), and peptone (5 g/L). The initial concentration of cells was 3 g/L. According to the results, the detoxification procedures removed inhibitory compounds from the hemicellulosic hydrolysate and, thus, improved the bioconversion of the sugars into ethanol. The fermentation using the non-detoxified hydrolysate led to 4.9 g/L ethanol in 120 h, with a yield of 0.20 g/g and a productivity of 0.04 g L^?1 h^?1. The detoxification by pH alteration and active charcoal adsorption led to 6.1 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.13 g L^?1 h^?1. The detoxification by adsorption into ion-exchange resins, in turn, provided 7.5 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.16 g L^?1 h^?1.     

Improving the Performance of a Continuous Process for the Production of Ethanol from Starch

In a previous work, a continuous simultaneous saccharification and fermentation process to produce ethanol from cassava starch was studied, using a set of fixed-bed reactors. The biocatalyst consisted of glucoamylase immobilized in silica particles and co-immobilized with S. cerevisiae in pectin gel. Using 3.8 U mL^?1 _reactor and 0.05 g_{wet yeast} mL^?1 _reactor at start-up, starch hydrolysis was the rate-limiting step. Maximum ethanol productivity was 5.8 g_ethanol L^?1 h^?1, with 94.0% conversion of total reducing sugars (TRS) and 83.0% of the ethanol theoretical yield. In this work, the molar mass of the substrate and the biocatalyst particle size were reduced in an attempt to improve the bioreactor performance. The diameters of silica and pectin gel particles were reduced from 100 μm and 3–4 mm, respectively, to 60 μm and 1–1.5 mm, and the degree of substrate prehydrolysis by α-amylase was increased. The bioreactor performance was assessed for different loads of immobilized glucoamylase (2.1, 2.8, and 3.8 U mL^?1 _reactor), for the same initial cell concentration (0.05 g_{wet yeast.}mL^?1 _reactor). Feeding with 154.0 g L^?1 of TRS and using 3.8 U mL^?1 _reactor, fermentation became the rate-limiting step. Productivity reached 11.7 g L^?1 h^?1, with 97.0% of TRS conversion and 92.0% of the ethanol theoretical yield. The reactor was operated during 275 h without any indication of destabilization.     

Evaluation and Optimization of Organic Acid Pretreatment of Cotton Gin Waste for Enzymatic Hydrolysis and Bioethanol Production

This paper investigates the efficiency of the organic acids on the pretreatment of an industrially generated cotton gin waste for the removal of lignin, thereby releasing cellulose and hemicellulose as fermentable sugar components. Cotton gin waste was pretreated with various organic acids namely lactic acid, oxalic acid, citric acid, and maleic acid. Among these, maleic acid was found to be the most efficient producing maximum xylose sugar (126.05?±?0.74 g/g) at the optimum pretreatment condition of 150 °C, 500 mM, and 45 min. The pretreatment efficiency was comparable to the conventional dilute sulfuric acid pretreatment. A lignin removal of 88% was achieved by treating maleic acid pretreated biomass in a mixture of sodium sulfite and sodium chlorite. The pretreated biomass was further evaluated for the release of sugar by enzymatic hydrolysis and subsequently bioethanol production from hydrolysates. The maximum 686.13 g/g saccharification yield was achieved with maleic acid pretreated biomass which was slightly higher than the sulfuric acid (675.26 g/g) pretreated waste. The fermentation of mixed hydrolysates(41.75 g/l) produced 18.74 g/l bioethanol concentration with 2.25 g/l/h ethanol productivity and 0.48 g/g ethanol yield using sequential use of Saccharomyces cerevisiae and Pichia stipitis yeast strains. The production of bioethanol was higher than the ethanol produced using co-culture in comparison to sequential culture. Thus, it has been demonstrated that the maleic acid pretreatment and fermentation using sequential use of yeast strains are efficient for bioethanol production from cotton gin waste.     

Kinetics and Thermodynamics of Ethanol Production by Saccharomyces cerevisiae MLD10 Using Molasses

In this study, we have used ultraviolet (UV) and γ-ray induction to get a catabolite repression resistant and thermotolerant mutant with enhanced ethanol production along with optimization of sugar concentration and temperature of fermentation. Classical mutagenesis in two consecutive cycles of UV- and γ-ray-induced mutations evolved one best catabolite-resistant and thermotolerant mutant Saccharomyces cerevisiae MLD10 which showed improved ethanol yield (0.48?±?0.02 g g^?1), theoretical yield (93?±?3 %), and extracellular invertase productivity (1,430?±?50 IU l^?1 h^?1), respectively, when fermenting 180 g sugars l^?1 in molasses medium at 43 °C in 300 m³ working volume fermenter. Ethanol production was highly dependent on invertase production. Enthalpy (ΔH*) (32.27 kJ M^?1) and entropy (ΔS*) (?202.88 J M^?1 K^?1) values at 43 °C by the mutant MLD10 were significantly lower than those of β-glucosidase production by a thermophilic mutant derivative of Thermomyces lanuginosus. These results confirmed the enhanced production of ethanol and invertase by this mutant derivative. These studies proved that mutant was significantly improved for ethanol production and was thermostable in nature. Lower fermentation time for ethanol production and maintenance of ethanol production rates (3.1 g l^?1 h^?1) at higher temperature (43 °C) by this mutant could decrease the overall cost of fermentation process and increase the quality of ethanol production.     

Ethanol Production by Fermentation Using Immobilized Cells of Saccharomyces cerevisiae in Cashew Apple Bagasse

In this work, cashew apple bagasse (CAB) was used for Saccharomyces cerevisiae immobilization. The support was prepared through a treatment with a solution of 3% HCl, and delignification with 2% NaOH was also conducted. Optical micrographs showed that high populations of yeast cells adhered to pre-treated CAB surface. Ten consecutive fermentations of cashew apple juice for ethanol production were carried out using immobilized yeasts. High ethanol productivity was observed from the third fermentation assay until the tenth fermentation. Ethanol concentrations (about 19.82–37.83 g L^?1 in average value) and ethanol productivities (about 3.30–6.31 g L^?1 h^?1) were high and stable, and residual sugar concentrations were low in almost all fermentations (around 3.00 g L^?1) with conversions ranging from 44.80% to 96.50%, showing efficiency (85.30–98.52%) and operational stability of the biocatalyst for ethanol fermentation. Results showed that cashew apple bagasse is an efficient support for cell immobilization aiming at ethanol production.     

Biodiesel Residual Glycerol Metabolism by Klebsiella pneumoniae: Pool of Metabolites Under Anaerobiosis and Oxygen Limitation as a Function of Feeding Rates

The metabolism of residual glycerol from biodiesel synthesis by Klebsiella pneumoniae BLh-1 was investigated in this study. Batch and fed-batch cultivations were performed in bioreactors under anaerobic and oxygen limitation conditions. Results of batch cultivations showed that the main product was 1,3-propanediol (1,3-PD) in both conditions, although the higher yields and productivities (0.46 mol mol^?1 glycerol and 1.22 g?L^?1?h^?1, respectively) were obtained under anaerobic condition. Large amounts of ethanol were also produced under batch anaerobic condition, peaking at 12.30 g?L^?1. Batch cultivations under oxygen limitation were characterized by faster growth kinetics, with higher biomass production but lower conversions of glycerol into 1,3-PD, with yields and productivities of 0.33 mol mol^?1 glycerol and 0.99 g?L^?1?h^?1, respectively. The fed-batch cultivations were carried out in order to investigate the effects of feeding of raw glycerol on cells. Fed-batch under anaerobiosis showed that 1,3-PD and ethanol concentrations increased with the feeding rate, with maximal productions of 26.12 and 19.2 g?L^?1, respectively. The oxygen limitation conditions diverted the bacterium metabolism to an elevated lactic acid formation, reaching 59 g?L^?1 in higher feeding rates of glycerol, but lowering the production of ethanol.     

Microbial Fed-batch Production of 1,3-Propanediol Using Raw Glycerol with Suspended and Immobilized Klebsiella pneumoniae

The production of 1,3-propanediol (1,3-PD) was investigated with Klebsiella pneumoniae DSM 4799 using raw glycerol without purification obtained from a biodiesel production process. Fed-batch cultures with suspended cells revealed that 1,3-PD production was more effective when utilizing raw glycerol than pure glycerol (productivity after 47 h of fermentation, 0.84 g?L^?1?h^?1 versus 1.51 g?L^?1?h^?1 with pure and raw glycerol, respectively). In addition, more than 80 g/L of 1,3-PD was produced using raw glycerol; this is the highest 1,3-PD concentration reported thus far for K. pneumoniae using raw glycerol. Repeated fed-batch fermentation with cell immobilization in a fixed-bed reactor was performed to enhance 1,3-PD production. Production of 1,3-PD increased with the cycle number (1.06 g?L^?1?h^?1 versus 1.61 g?L^?1?h^?1 at the first and fourth cycle, respectively) due to successful cell immobilization. During 46 cycles of fed-batch fermentation taking place over 1,460 h, a stable and reproducible 1,3-PD production performance was observed with both pure and raw glycerol. Based on our results, repeated fed batch with immobilized cells is an efficient fermentor configuration, and raw glycerol can be utilized to produce 1,3-PD without inhibitory effects caused by accumulated impurities.     

Ethanol Production from Starch Hydrolyzates using <Emphasis Type="Italic">Zymomonas mobilis</Emphasis> and Glucoamylase Entrapped in Polyvinylalcohol Hydrogel

The glucoamylase from Aspergillus niger, immobilized into poly(vinylalcohol) hydrogel lens-shaped capsules LentiKats®, was used for simultaneous saccharification and fermentation (SSF) with Zymomonas mobilis in free form. This system was stable in both the repeated batch and continuous mode of SSF. The microorganism was found to adsorb on the capsules with immobilized enzyme. This increased the ethanol productivity of the repeated batch system with 5% w/v of immobilized glucoamylase almost 2.1 times (7.2 g l^?1 h^?1) compared to free enzyme–free microorganism system (3.5 g l^?1 h^?1). The continuous SSF with the immobilized glucoamylase (11.5% w/v) tested for 15 days had productivity 10 g l^?1 h^?1, which is comparable to continuous experiments on semi-defined glucose medium (10 g l^?1 h^?1). These two systems were stable in both glucoamylase activity and microorganism productivity.     

Alcoholic Fermentation with Flocculant Saccharomyces cerevisiae in Fed-Batch Process

Studies have been conducted on selecting yeast strains for use in fermentation for ethanol production to improve the performance of industrial plants and decrease production costs. In this paper, we study alcoholic fermentation in a fed-batch process using a Saccharomyces cerevisiae yeast strain with flocculant characteristics. Central composite design (CCD) was used to determine the optimal combination of the variables involved, with the sucrose concentration of 170 g/L, a cellular concentration in the inoculum of 40 % (v/v), and a filling time of 6 h, which resulted in a 92.20 % yield relative to the theoretical maximum yield, a productivity of 6.01 g/L h and a residual sucrose concentration of 44.33 g/L. With some changes in the process such as recirculation of medium during the fermentation process and increase in cellular concentration in the inoculum after use of the CCD was possible to reduce the residual sucrose concentration to 2.8 g/L in 9 h of fermentation and increase yield and productivity for 92.75 % and 9.26 g/L h, respectively. A model was developed to describe the inhibition of alcoholic fermentation kinetics by the substrate and the product. The maximum specific growth rate was 0.103 h^?1, with K _I and K _s values of 109.86 and 30.24 g/L, respectively. The experimental results from the fed-batch reactor show a good fit with the proposed model, resulting in a maximum growth rate of 0.080 h^?1.     

Improvement of Bioethanol Productivity of Immobilized Saccharomyces Bayanus with Using Sodium Alginate-Graft-Poly(N-Vinyl-2-Pyrrolidone) Matrix

In this study, immobilization conditions and bioethanol production characteristics of immobilized Saccharomyces bayanus were investigated into sodium alginate-graft-poly(N-vinyl-2-pyrrolidone; NaAlg-g-PVP) matrix. The matrix that crosslinked with calcium clorid was used for immobilization of S. bayanus. Bioethanol productivity of the NaAlg-g-PVP matrix was found to increase from 4.21 to 4.84?gL^?1?h^?1 when compared with the convential sodium alginate matrix. The production of bioethanol was affected by initial glucose concentration and percentage of immobilized cell beads in fermentation medium. Bioethanol productivity was increased from 3.62 to 4.84?gL^?1?h^?1 while the glucose concentration increasing from 50 to 100?gL^?1. Due to the increase in percentage from 10 to 20?% of immobilized cell beads in the fermentation medium, bioethanol productivity was increased from 4.84 to 8.68?gL^?1?h^?1. The cell immobilized NaAlg-g-PVP beads were protected 92?% of initial activity after six repeated fermentation.     

Effect of Agitation Rate on Ethanol Production from Sugar Maple Hemicellulosic Hydrolysate by Pichia stipitis

Concentrated dilute acid hydrolysate was obtained from hot water extracts of Acer saccharum (sugar maple) and was fermented to ethanol by Pichia stipitis in a 1.3-L-benchtop bioreactor. The conditions under which the highest ethanol yield was achieved were when the air flow rate was set to 100?cm³ and the agitation rate was set to 150?rpm resulting in an overall mass transfer coefficient (K _L a) of 0.108?min^?1. A maximum ethanol concentration of 29.7?g/L was achieved after 120?h of fermentation; however, after 90?h of fermentation, the ethanol concentration was only slightly lower at 29.1?g/L with a yield of 0.39?g ethanol per gram of sugar consumed. Using the same air flow rate and adjusting the agitation rate resulted in lower ethanol yields of 0.25?g/g at 50?rpm and 0.30?g/g at 300?rpm. The time it takes to reach the maximum ethanol concentration was also affected by the agitation rate. The ethanol concentration continued to increase even after 130?h of fermentation when the agitation rate was set at 50?rpm, whereas the maximum ethanol concentration was reached after only 68.5?h at 300?rpm.     

A Comparison Between Shaker and Bioreactor Performance Based on the Kinetic Parameters of Xanthan Gum Production

Xanthan gum production was studied using sugarcane broth as the raw material and batch fermentation by Xanthomonas campestris pv. campestris NRRL B-1459. The purpose of this study was to optimize the variables of sucrose, yeast extract, and ammonium nitrate concentrations and to determine the kinetic parameters of this bioreaction under optimized conditions. The effects of yeast extract and ammonium nitrate concentrations for a given sucrose concentration (12.1–37.8 g L^?1) were evaluated by central composite design to maximize the conversion efficiency. In a bioreactor, the maximum conversion efficiency was achieved using 27.0 g L^?1 sucrose, 2.7 g L^?1 yeast extract, and 0.9 g L^?1 NH₄NO₃. This point was assayed in a shaker and in a bioreactor to compare bioreaction parameters. These parameters were estimated by the unstructured kinetic model of Weiss and Ollis (Biotechnol Bioeng 22:859–873, 1980) to determinate the yields (Y _P/S), the maximum growth specific rate (μ _max), and the saturation cellular concentration (X*). The parameters of the model (μ _max, X*, m, λ, α, and β) were obtained by nonlinear regression. For production of xanthan gum in a shaker, the values of μ _max and Y _P/S obtained were 0.119 h^?1 and 0.34 g g^?1, respectively, while in a bioreactor, they were 0.411 h^?1 and 0.63 g g^?1, respectively.     

Effect of Nutrients on Fermentation of Pretreated Wheat Straw at very High Dry Matter Content by Saccharomyces cerevisiae

Wheat straw hydrolysate produced by enzymatic hydrolysis of hydrothermal pretreated wheat straw at a very high solids concentration of 30% dry matter (w/w) was used for testing the effect of nutrients on their ability to improve fermentation performance of Saccharomyces cerevisiae. The nutrients tested were MgSO₄ and nitrogen sources; (NH₄)₂SO₄, urea, yeast extract, peptone and corn steep liquor. The fermentation was tested in a separate hydrolysis and fermentation process using a low amount of inoculum (0.33 g kg^?1) and a non-adapted baker’s yeast strain. A factorial screening design revealed that yeast extract, peptone, corn steep liquor and MgSO₄ were the most significant factors in obtaining a high fermentation rate, high ethanol yield and low glycerol formation. The highest volumetric ethanol productivity was 1.16 g kg^?1 h^?1 and with an ethanol yield close to maximum theoretical. The use of urea or (NH₄)₂SO₄ separately, together or in combination with MgSO₄ or vitamins did not improve fermentation rate and resulted in increased glycerol formation compared to the use of yeast extract. Yeast extract was the single best component in improving fermentation performance and a concentration of 3.5 g kg^?1 resulted in high ethanol yield and a volumetric productivity of 0.6 g kg^?1 h^?1.     

Diminished Respirative Growth and Enhanced Assimilative Sugar Uptake Result in Higher Specific Fermentation Rates by the MutantPichia stipitis FPL-061

A mutant strain ofPichia stipitis, FPL-061, was obtained by selecting for growth on L-xylose in the presence of respiratory inhibitors. The specific fermentation rate of FPL-061, was higher than that of the parent,Pichia stipitis CBS 6054, because of its lower cell yield and growth rate and higher specific substrate uptake rate. With a mixture of glucose and xylose, the mutant strain FPL-061 produced 29.4 g ethanol/L with a yield of 0.42 g ethanol/g sugar consumed. By comparison, CBS 6054 produced 25.7 g ethanol/L with a yield of 0.35 gJg. The fermentation was most efficient at an aeration rate of 9.2 mmoles O₂ L^-1 h^-1. At high aeration rates (22 mmoles O₂ L^-1 h^-1), the mutant cell yield was less than that of the parent. At low aeration rates, (1.1 to 2.5 O₂ L^-1 h^-1), cell yields were similar, the ethanol formation rates were low, and xylitol accumulation was observed in both the strains. Both strains respired the ethanol once sugar was exhausted. We infer from the results that the mutant, P.stipitis FPL-061, diverts a larger fraction of its metabolic energy from cell growth into ethanol production.     

Characteristics of an Immobilized Yeast Cell System Using Very High Gravity for the Fermentation of Ethanol

The characteristics of ethanol production by immobilized yeast cells were investigated for both repeated batch fermentation and continuous fermentation. With an initial sugar concentration of 280?g/L during the repeated batch fermentation, more than 98% of total sugar was consumed in 65?h with an average ethanol concentration and ethanol yield of 130.12?g/L and 0.477?g ethanol/g consumed sugar, respectively. The immobilized yeast cell system was reliable for at least 10 batches and for a period of 28?days without accompanying the regeneration of Saccharomyces cerevisiae inside the carriers. The multistage continuous fermentation was carried out in a five-stage column bioreactor with a total working volume of 3.75?L. The bioreactor was operated for 26?days at a dilution rate of 0.015?h^?1. The ethanol concentration of the effluent reached 130.77?g/L ethanol while an average 8.18?g/L residual sugar remained. Due to the high osmotic pressure and toxic ethanol, considerable yeast cells died without regeneration, especially in the last two stages, which led to the breakdown of the whole system of multistage continuous fermentation.     

Ethanol Production from Sugarcane Bagasse by Zymomonas mobilis Using Simultaneous Saccharification and Fermentation (SSF) Process

Considerable efforts have been made to utilize agricultural and forest residues as biomass feedstock for the production of second-generation bioethanol as an alternative fuel. Fermentation utilizing strains of Zymomonas mobilis and the use of simultaneous saccharification and fermentation (SSF) process has been proposed. Statistical experimental design was used to optimize the conditions of SSF, evaluating solid content, enzymatic load, and cell concentration. The optimum conditions were found to be solid content (30%), enzymatic load (25 filter paper units/g), and cell concentration (4 g/L), resulting in a maximum ethanol concentration of 60 g/L and a volumetric productivity of 1.5 g L^?1?h^?1.     

Bioethanol Production from Ipomoea Carnea Biomass Using a Potential Hybrid Yeast Strain

The paper deals with the exploitation of Ipomoea carnea as a feedstock for the production of bioethanol. Dilute acid pretreatment under optimum conditions (3 %H₂SO₄, 120 °C for 45 min) produced 17.68 g L^?1 sugars along with 1.02 g L^?1 phenolics and 1.13 g L^?1 furans. A combination of overliming and activated charcoal adsorption facilitated the removal of 91.9 % furans and 94.7 % phenolics from acid hydrolysate. The pretreated biomass was further treated with a mixture of sodium sulphite and sodium chlorite and, a maximum lignin removal of 81.6 % was achieved. The enzymatic saccharification of delignified biomass resulted in 79.4 % saccharification with a corresponding sugar yield of 753.21 mg g^?1. Equal volume of enzymatic hydrolysate and acid hydrolysate were mixed and used for fermentation with a hybrid yeast strain RPRT90. Fermentation of mixed detoxified hydrolysate at 30 °C for 28 h produced ethanol with a yield of 0.461 g g^?1. A comparable ethanol yield (0.414 g g^?1) was achieved using a mixture of enzymatic hydrolysate and undetoxified acid hydrolysate. Thus, I. carnea biomass has been demonstrated to be a potential feedstock for bioethanol production, and the use of hybrid yeast may pave the way to produce bioethanol from this biomass.