Ethanol Production In Fermentation Research Articles

A novel integrated process of high cell-density culture combined with simultaneous saccharification and fermentation for ethanol production

A novel process integration occupying high cell-density culture (HCDC) and simultaneous saccharification and fermentation (SSF) in one bioreactor achieved an efficient ethanol production in this study. The effect of inoculum sizes of S. cerevisiae for ethanol production in SSF was investigated. High ethanol production was obtained with high inoculums size of cells from 4 to 30 kg﹒m−3. The process integration including HCDC and SSF in one reactor was achieved. A production of 35.2 kg﹒m−3 cells was obtained with HCDC in aerobic conditions. Cellulase and pretreated corn stover were added into the fermentation broth in the same bioreactor, and the SSF procedure was initiated in anaerobic conditions. The highest ethanol titer of 17.08kg﹒m−3 corresponding to 101.50% theoretical yield was obtained, and the peak value time was 24 h with β-glucosidase addition in the HCDC-SSF system. The highest ethanol titer of 11.01 kg﹒m−3, corresponding 65.41% theoretical yield, was obtained at 72 h with regular SSF.

Valorization of Sugar-Ethanol Industry Waste Vinasse for Increased Second-Generation Ethanol Production Using Spathaspora passalidarum Yeast Strains

In this study, sugarcane bagasse hydrolysate supplemented with different proportions of sugar-ethanol industrial waste (vinasse) was used to optimize fermentative ethanol production using two Spathaspora passalidarum yeast strains isolated from decaying wood in Amazonian biome. The bagasse samples were pretreated chemically and enzymatically before using a binary factorial experimental design. The factorial design was carried out in two stages; in the first, a 24 factorial design was done to assess the effects of pretreated sugarcane bagasse hydrolysate and vinasse, ammonium sulfate concentration, yeast biomass concentration, and two different strains of yeast, S. passalidarum; in the second stage, a 23 factorial design was done to provide a more detailed analysis of the effects of vinasse supplementation on the fermentation process—this time, by modifying the ratio of sugarcane bagasse hydrolysate and vinasse and, more significantly, the same factor—biomass concentration. The results showed that the most significant factors for increasing bioethanol production in the 24 factorial design proved to be the following: inoculum and hydrolyzed bagasse supplementation with vinasse (the optimal being 75:25), followed by yeast concentration (optimal at 14% w/v cell wet weight) and then the type of strain used (S. passalidarum UFMG-HMD-14.1). The use of only hydrolyzed bagasse without vinasse (23 factorial design) had no significant influence on the results, nor did varying the concentration of nitrogen. This increase in ethanol production, which allows the same amount of ethanol productivity through a reduction in the carbon source, suggests it can lead to an improved final use for vinasse.

Fermentative ethanol production from Madhuca indica flowers using immobilized yeast cells coupled with solar driven direct contact membrane distillation with commercial hydrophobic membranes

The objective of the present investigation is to develop and evaluate economic production of biofuels (ethanol) using immobilized yeast cells (Saccharomyces cerevisiae NCIM 3095) from renewable carbon source Madhuca indica (Mahua flowers). The entrapment of yeast cells in calcium alginate-polyvinyl alcohol (CA-PVA) film were found most suitable immobilizing matrix as a protective carrier to increase the stability and tolerance limit during continuous fermentation. Under similar fermentation conditions, immobilized yeast cells produced higher ethanol yield (∼0.48 g/g) and productivity (∼28 g/L/h) as compared to traditional suspended free cells system in continuous fermentation with dilution rate of 0.4/h. Further, the fermenter was coupled with solar driven membrane distillation (SDMD) process for separation and concentration of ethanol after fermentation. The new system does not require centrifugation/microfiltration for separation and/or recycle of biomass as the cells were immobilized and could be easily separated by simple filtration. The SDMD with cross flow module in rectangular shape and counter-current flow of streams (hot and cold) ensured higher ethanol flux (23 kg EtOH/m2/24 h) in comparison to existing literature. The new process design is compact yet flexible, eco-friendly, energy intensive and sustainable process for the development of economic biofuel production.

The substratostat - an automated near-infrared spectroscopy-based variable-feed system for the continuous alcoholic fed-batch fermentation of high gravity grape must at static sugar concentrations

Aim: High sugar concentrations in musts cause a hyperosmotic stress response in Saccharomyces cerevisiae increasing the risk of sluggish and stuck alcoholic fermentations and/or causing high acetic acid levels. Applying a fed-batch technique where sugar levels are kept at a constant, low rate throughout fermentations reduces this stress but requires in-situ quantification of sugars and process automation for practicability. The aim of this work was to develop and validate a near-infrared (NIR) spectroscopy method allowing for the continuous in-situ quantification of total fermentable sugars in fully turbid alcoholic fermentations of grape musts. Calibration models for glucose, fructose and the fermentation product ethanol were also established.Methods and results: A research Fourier-transform NIR spectrophotometer equipped with a transflectance probe was used to acquire spectra from 240 natural and semisynthetic standards from fermentations conducted using varying concentrations of yeast and yeast nutrients. Using chemometric software, calibration models for total sugars, glucose, fructose and ethanol demonstrated R2 values >0.93 and prediction error (RMSEP) values of 11.6 g l-1, 12.3 g l-1, 10.2 g l-1, and 0.328 % v/v, respectively. The method was integrated with modern process automation technology and was able to maintain sugar concentrations within 5 g l-1 of the 45 g l-1 setpoint adjusted during alcoholic fermentations.Conclusions: The NIR calibration models generated allow prediction of total sugar levels accurately enough to conduct fully automated fed-batch grape must fermentations at constant substrate concentrations. Application of a transflectance probe measuring a high proportion of back-scattered radiation proved useful and necessary considering the high degree of turbidity during fermentations. Placement of the measurement probe in a recirculation loop decreased interference from biomass sedimentation and adherence of CO2 bubbles.Significance and impact of the study: This study presents a fully automated system to carry out fed-batch fermentations which allow circumventing the hyperosmotic stress response of S. cerevisiae during alcoholic fermentations. Calibrated for other substrates, the system may be used in other food and non-food fermentations, too.

Fermentative Production of Ethanol Using Pinus patula as Raw Material: Economic and Energy Assessment

The production of cellulosic ethanol has been gaining attention in the industry sector because of the high availability of lignocellulosic biomass from agricultural and forestry activities. Pinus patula is one of the most typical softwood species in Colombia. The aim of this work is to evaluate the production of ethanol using Pinus patula as raw material using dilute acid pretreatment and enzymatic hydrolysis to produce sugars able to be used as substrate for the strain Saccharomyces cerevisiae. Three fermentation configurations were selected to evaluate the performance of the microorganism: configurations 1 and 2 used glucose in a percentage of 80%w/v and 70%w/v, respectively, as substrate to establish the adaptation requirements of the microorganism. The configuration 3 considered the use of concentrated P. patula hydrolysate. An experimental yield of 0.364 ± 0.009 g ethanol/g sugar (73% of the theoretical) was obtained. Additionally, the economic and energetic comparison between the biochemical (ethanol production through fermentation) and thermochemical (synthesis gas through gasification) pathways to produce bioenergy was performed through simulation approaches. As main results, a higher ethanol production cost (1.53 USD/L) was obtained in comparison to the market price (0.77 USD/L) and a low energy efficiency (20%). Different alternatives such as waste integration and energy incentives must be considered in order to produce ethanol in a feasible way.

Gut Dysbiosis With Bacilli Dominance and Accumulation of Fermentation Products Precedes Late-onset Sepsis in Preterm Infants.

Gut dysbiosis has been suggested as a major risk factor for the development of late-onset sepsis (LOS), a main cause of mortality and morbidity in preterm infants. We aimed to assess specific signatures of the gut microbiome, including metabolic profiles, in preterm infants <34 weeks of gestation preceding LOS. In a single-center cohort, fecal samples from preterm infants were prospectively collected during the period of highest vulnerability for LOS (days 7, 14, and 21 of life). Following 16S rRNA gene profiling, we assessed microbial community function using microbial metabolic network modeling. Data were adjusted for gestational age and use of probiotics. We studied stool samples from 71 preterm infants with LOS and 164 unaffected controls (no LOS/necrotizing enterocolitis). In most cases, the bacteria isolated in diagnostic blood culture corresponded to the genera in the gut microbiome. LOS cases had a decelerated development of microbial diversity. Before onset of disease, LOS cases had specific gut microbiome signatures with higher abundance of Bacilli (specifically coagulase-negative Staphylococci) and a lack of anaerobic bacteria. In silico modeling of bacterial community metabolism suggested accumulation of the fermentation products ethanol and formic acid in LOS cases before the onset of disease. Intestinal dysbiosis preceding LOS is characterized by an accumulation of Bacilli and their fermentation products and a paucity of anaerobic bacteria. Early microbiome and metabolic patterns may become a valuable biomarker to guide individualized prevention strategies of LOS in highly vulnerable populations.

Development of a multi-criteria decision making model for evaluating the energy potential of Miscanthus germplasms for bioenergy production

Biomass is the bioenergy carrier and can be converted to solid, liquid and gaseous fuels. Miscanthus, a plant type with high biomass yield potential, is a promising feedstock source for bioenergy production. However, the current expansion of miscanthus (Miscanthus spp.) production is constrained by a shortage of commercial varieties, especially those suitable for different energy usages and cultivation under adverse environmental conditions. Therefore, breeding or selecting high-biomass-yielding, high quality and stress tolerant miscanthus varieties is essential for the extension of miscanthus for bioenergy production. To effectively select elite germplasms and breed new varieties of miscanthus, it is necessary to establish a scientific evaluation method for analysing their energy potential. In this study, a multi-criteria decision making (MCDM) model was designed to evaluate the potential of miscanthus germplasms as feedstock in four energy usages including combustion for power generation (CPG), pyrolysis for bio-oil production (PBP), fermentation for ethanol production (FEP) and fermentation for biogas production (FBP). The MCDM model was constructed based on 11 sub-criteria indices, which were grouped into agronomic-related and quality-related criteria indices. The agronomic-related criteria indices include dry matter yield, canopy height, stem diameter, tiller number and base diameter/canopy diameter ratio. The quality-related criteria indices include the leaf/stem ratio, moisture content, ash content, cellulose content, hemicellulose content and lignin content. Thirty-eight representative germplasms of miscanthus were evaluated. The MCDM analysis results showed that Miscanthus lutarioriparius (especially the XiangNanDi no. 1 variety) and Miscanthus floridulus (especially A0521) are the best species for CPG/PBP and FEP/FBP, respectively. These results are superior to those calculated by the traditional energy potential assessment method, which showed that Miscanthus floridulus was the most suitable species for CPG, FEP and FBP, especially A0521 and D0624. Moreover, the analysis also indicated that D0505 (M. floridulus) can be used as a suitable parent together with XiangNanDi no. 1 to breed new varieties for CPG and PBP; XiangNanDi no. 1 can be used as an alternative parent for breeding to improve A0521 for use in FEP and FBP.

Detoxification and concentration of corn stover hydrolysate and its fermentation for ethanol production

Environmental and energy concerns have increased interest in renewable energy sources, particularly biofuels. Thus the fermentation of glucose from sulfuric acid-hydrolyzed corn stover for the production of bioethanol has been explored using a combined acid retardation and continuous-effect membrane distillation treatment process. This process resulted in the separation of the sugars and acids from the acid-catalyzed hydrolysate, the removal of most of the fermentation inhibitors from the hydrolysate and the concentration of the detoxified hydrolysate. The recovery rate of glucose from the sugar-acid mixture using acid retardation was greater than 99.12% and the sulfuric acid was completely recovered from the hydrolysate. When the treated corn stover hydrolysate, containing 100 g/L glucose, was used as a carbon source, 43.06 g/L of ethanol was produced with a productivity of 1.79 g/(L∙h) and a yield of 86.31%. In the control experiment, where glucose was used as the carbon source these values were 1.97 g/(L∙h) and 93.10% respectively. Thus the integration of acid retardation and a continuous-effect membrane distillation process are effective for the production of fuel ethanol from corn stover.

Potential of Saccharine Substrates for Ethanol Production

Brazil, which has a great territorial extension, with fertile soils and availability of water and, in this way, can produce a diversity of vegetal products with bioenergetics potential. Thus, this study aims to evaluate the technological characteristics of saccharine substrates of direct fermentation for ethanol production as well as to analyze the fermentative profile of FT-858 yeast in different culture conditions. For this, a bibliographic survey was carried out comparing the technological qualities of the analyzed biomasses. To evaluate the fermentative capacity, the saccharine substrates were used at concentrations of 18 and 32°Brix at 30 °C for 24 hours in test tubes containing Durhan tubes. For the analysis of the fermentation profile the yeasts were grown in 2% YPD medium and the biomass obtained was used in the saccharine substrates of direct fermentation for 50 hours. The saccharine substrates presented potential for ethanol production: sugar cane and saccharine sorghum. The yeast FT-858 presented fermentation capacity in the different substrates in the concentrations of Brix analyzed, presenting a better fermentative performance in sugarcane broth and the highest concentrations of ethanol occurring in the times of 10 and 15 hours of fermentation for both substrates. DOI: http://dx.doi.org/10.17807/orbital.v10i1.1013

Effect of Moisture Content and Inoculum Size on Cell Wall Composition and Ethanol Yield from Switchgrass after Solid-State Pleurotus ostreatus Treatment

Abstract. The white-rot fungus is capable of selectively degrading lignin over polymeric sugars. Solid-state cultivation and subsequent simultaneous saccharification and fermentation for ethanol production were performed. Effects of moisture content (MC) and fungus inoculum on biomass degradation, ligninolytic enzyme, and ethanol production were evaluated. First, fungal pretreatment was performed with varied MC and inoculum levels and sampled every 20 days. The highest xylose yield observed was 15.6% for samples with 75% MC and 5 mL inoculum at fungal pretreatment of 40 days. The highest lignin degradation of 52% and highest ethanol yield of 31% (based on the glucan present in the raw switchgrass) were achieved for 80-day fungal-treated samples with 75% MC and 5 mL inoculum. Keywords: KLywords. Bioenergy, Fungal pretreatment, Oyster mushroom, Perennial grass.

Fermentative energy conversion: Renewable carbon source to biofuels (ethanol) using Saccharomyces cerevisiae and downstream purification through solar driven membrane distillation and nanofiltration

Experimental studies on fermentative production of ethanol from renewable sugarcane juice as carbon source were carried out in a bench scale fermenter integrated with microfiltration, nanofiltration and membrane distillation units (MF-NF-MD) for downstream purification and concentration enrichment of ethanol. This new design is flexible, compact, eco-friendly, and modular and, operated in a cross flow module that ensures almost fouling-free membrane separation while overcoming the product inhibition of traditional batch fermenters. The system is blessed with steady and continuous ethanol production from sugarcane juice with comparatively high productivity 9.2gL−1h−1, yield 0.47gg−1 and concentration 54.3gL−1 using Saccharomyces cerevisiae (NCIM 3205) vis-à-vis the existing technologies. The new system enables continuous product withdrawal, separation and recycle of the biomass as well as residual carbon source back to the fermenter under high cell density without product inhibition. Membrane distillation in the final stage, increases product purity and results in significant concentration enrichment. The study culminates in development of a green and sustainable process for a biofuel production.

Two-step size reduction and post-washing of steam exploded corn stover improving simultaneous saccharification and fermentation for ethanol production

The simultaneous saccharification and fermentation (SSF) of corn stover biomass for ethanol production was performed by integrating steam explosion (SE) pretreatment, hydrolysis and fermentation. Higher SE pretreatment severity and two-step size reduction increased the specific surface area, swollen volume and water holding capacity of steam exploded corn stover (SECS) and hence facilitated the efficiency of hydrolysis and fermentation. The ethanol production and yield in SSF increased with the decrease of particle size and post-washing of SECS prior to fermentation to remove the inhibitors. Under the SE conditions of 1.5MPa and 9min using 2.0cm particle size, glucan recovery and conversion to glucose by enzymes were 86.2% and 87.2%, respectively. The ethanol concentration and yield were 45.0g/L and 85.6%, respectively. With this two-step size reduction and post-washing strategy, the water utilization efficiency, sugar recovery and conversion, and ethanol concentration and yield by the SSF process were improved.

Fed-batch Saccharomyces cerevisiae fermentation of hydrolysate sugars: A dynamic model-based approach for high yield ethanol production

The efficient fermentation of hydrolyzed sugars from lignocellulosic biomass feedstock to ethanol remains a complex multi-parametric problem. Thus, in the present study, an advanced structured dynamic model for the simulation of the fermentative ethanol production from hydrolysate sugars is developed. The model is combined with a statistical experimental design to determine an optimal operating strategy that maximizes ethanol production and serves for the systematic evaluation of critical process variables. In particular, the effects of various operating conditions and feeding strategies on the dynamic behavior of batch and fed-batch fermentation processes are explored. The deviation from the desired product or the metabolic inhibition of ethanol production are related with the applied environmental conditions and substrate and product inhibition phenomena. The operating strategy, designed with the assistance of the mathematical tools proposed in this study, includes an exponential addition policy of substrate. This strategy is experimentally proved to enhance the final product concentration, raising the ethanol productivity to 2.27 g L−1 h−1 and the ethanol yield to 53.5% of the maximum theoretical value. Moreover, the simulated strategies were in excellent agreement with the experimental results obtained from the real process using low and high glucose initial concentration, under batch and fed-batch conditions, in both flask- and bioreactor-scale cultivations, proving the model's predictive and optimization capabilities. Further improvement of process performance is expected when combining the proposed dynamic model with advanced optimization algorithms to derive the optimal bioprocess operating strategy.

Utilization of unripe banana peel waste as feedstock for ethanol production

AbstractBanana is second largest produced fruit of total world’s fruits. Cooking banana or plantains processing industry is generating enormous amount of waste in the form of unripe banana peel at one place, thus important to study waste management and utilization. Therefore, unripe banana peel was investigated for ethanol production. This study involved chemical characterization, optimization of acid hydrolysis, selection of yeast strain and optimization of fermentative production of ethanol from dried unripe banana peel powder (DUBPP). Ethanol concentration was determined using gas chromatography flame ionization detector (GC-FID). Characterization of DUBPP revealed notably amount of starch (41% w/w), cellulose (9.3% w/w) and protein (8.4% w/w). 49.2% w/w of reducing sugar was produced by acid hydrolysis of DUBPP at optimized conditions. Three yeast strains of Saccharomyces cerevisiae were screened for ethanol conversion efficiency, osmotolerance, ethanol tolerance, thermotolerance, fermentation ability at high temperature and sedimentation rate. Further, fermentation conditions were optimized for maximum ethanol production from acid hydrolysate of DUBPP. At optimized fermentation conditions, 35.5 g/l ethanol was produced using selected strain of Saccharomyces cerevisiae NCIM 3095. Hence, unripe banana peel waste can be good feedstock for ethanol production.

Production of low or non-alcoholic beer in microbial fuel cell

Microbial fuel cells (MFC) are bioreactors that are used to generate electricity on the expense of organic substrate oxidation. The MFC's operation-mechanism offers the possibility to use the fuel cell in the beer production technologies to make low or non-alcoholic beers. In this study the effect of MFC anode surface area and riboflavin as an electron shuttle on electric current and on ethanol production in fermentation of wort is demonstrated. The enlargement of anode surface induces an increase of electricity generation (from 4 to 12.5mA/m2) while the ethanol production decreases. Adding riboflavin to the wort in the MFC results significant increase in electricity production, furthermore it decreases the ethanol synthesis. Addition of 50μM riboflavin enhances the current output to 51mA/m2 with a 1.5V/V% decrease of ethanol production, while 100μM results 86mA/m2 and 2V/V% decrease of ethanol production. These results show the potentiality to brew low or non-alcoholic beer in MFC.

Enzymatic saccharification and fermentation of rice processing residue for ethanol production at constant temperature

The aim was to investigate the enzymatic saccharification and fermentation for ethanol production. The rice bran, inoculum, corn steep liquor, soybean bran, amylase, cellulase concentrations and time of inoculum addition were evaluated using a Plackett-Burman (PB) experimental design. Furthermore, a central composite rotational design (CCRD) for three independent variables was carried out to optimise the ethanol production. Inoculum was added after 18 h of enzymatic hydrolysis and all the process was carried out at 35 °C during 48 h. Maximum ethanol production was 175 ± 5.8 g kg−1 obtained at 15% (m/m) concentration of inoculum, 150 g l−1 of rice bran and 3% (m/m) of cellulase. Rice bran is therefore a promising raw material for ethanol production.

Enhancing the Feasibility of Microcystis aeruginosa as a Feedstock for Bioethanol Production under the Influence of Various Factors.

Microcystis aeruginosa, a freshwater microalga, is capable of producing and accumulating different types of sugars in its biomass which make it a good feedstock for bioethanol production. Present study aims to investigate the effect of different factors increasing growth rate and carbohydrates productivity of M. aeruginosa. MF media (modified BG11 media) and additional ingredients such as aminolevulinic acid (2 mM), lysine (2.28 mM), alanine (1 mM), and Naphthalene acetic acid (1 mM) as cytokine promoted M. aeruginosa growth and sugar contents. Salmonella showed growth-assisting effect on M. aeruginosa. Enhanced growth rate and carbohydrates contents were observed in M. aeruginosa culture grown at 25°C under red LED light of 90 μmolm−2s−1 intensity. More greenish and carbohydrates rich M. aeruginosa biomass was prepared (final OD660 nm = 2.21 and sugar contents 10.39 mM/mL) as compared to control (maximum OD660 nm = 1.4 and sugar contents 3 mM/mL). The final algae biomass was converted to algae juice through a specific pretreatment method. The resulted algae Juice was used as a substrate in fermentation process. Highest yield of bioethanol (50 mM/mL) was detected when Brettanomyces custersainus, Saccharomyces cerevisiae, and Pichia stipitis were used in combinations for fermentation process as compared to their individual fermentation. The results indicated the influence of different factors on the growth rate and carbohydrates productivity of M. aeruginosa and its feasibility as a feedstock for fermentative ethanol production.

Selection of yeast strains for bioethanol production from UK seaweeds.

Macroalgae (seaweeds) are a promising feedstock for the production of third generation bioethanol, since they have high carbohydrate contents, contain little or no lignin and are available in abundance. However, seaweeds typically contain a more diverse array of monomeric sugars than are commonly present in feedstocks derived from lignocellulosic material which are currently used for bioethanol production. Hence, identification of a suitable fermentative microorganism that can utilise the principal sugars released from the hydrolysis of macroalgae remains a major objective. The present study used a phenotypic microarray technique to screen 24 different yeast strains for their ability to metabolise individual monosaccharides commonly found in seaweeds, as well as hydrolysates following an acid pre-treatment of five native UK seaweed species (Laminaria digitata, Fucus serratus, Chondrus crispus, Palmaria palmata and Ulva lactuca). Five strains of yeast (three Saccharomyces spp, one Pichia sp and one Candida sp) were selected and subsequently evaluated for bioethanol production during fermentation of the hydrolysates. Four out of the five selected strains converted these monomeric sugars into bioethanol, with the highest ethanol yield (13 g L−1) resulting from a fermentation using C. crispus hydrolysate with Saccharomyces cerevisiae YPS128. This study demonstrated the novel application of a phenotypic microarray technique to screen for yeast capable of metabolising sugars present in seaweed hydrolysates; however, metabolic activity did not always imply fermentative production of ethanol.

Optimizing Semisimultaneous Saccharification and Fermentation for Ethanol Production from Chinese Distiller's Spent Grains

Spent grains are a main byproduct for Chinese liquor production. In this study, the semisimultaneous saccharification and fermentation (S-SSF) for ethanol production based on multi-enzyme degradation of the spent grains was investigated. After optimization with orthogonal design experiments, an enzyme combination composed of cellulase NS22086 at 0.30 mL/g, β-glucosidase NS22118 at 0.20 mL/g, xylanase NS22083 at 0.08 mL/g, complex enzyme NS22119 at 0.08 mL/g, complex enzyme NS22002 at 0.02 mL/g, and glucoamylase NS22035 at 0.01 mL/g was obtained. With 14% of the substrate concentration and the optimal enzyme combination, reducing sugar, glucose, and xylose at 109.97, 60.02, and 16.05 g./L, respectively, were attained in the saccharified solution, which are approximately fourfold of those obtained before optimizing and are among the highest values reported for different lignocellulosic materials. Experiments of batch and fed-batch S-SSF for ethanol production from the spent grains were then performed, and higher efficiency of saccharification and ethanol formation was observed in the fed-batch S-SSF, where an ethanol concentration of over 30 g/L was attained. Kinetic models satisfactorily describing the processes of S-SSF were developed and analyzed. This study contributes to the utilization of Chinese distiller's spent grains and other similar materials.

Influence of Eastern redcedar oil on enzymatic hydrolysis of microcrystalline cellulose and Saccharomyces cerevisiae fermentations

Abstract Essential oils from plants are known to be inhibitory to yeast and amylase activity. This study investigated the effects of oil in Eastern redcedar ( Juniperus virginiana L .) on enzymatic cellulose hydrolysis and yeast fermentation for ethanol production from redcedar. Enzymatic hydrolysis was conducted with 2% and 4% (w/w) cellulose loadings, 25 FPU/g cellulose and 50 FPU/g cellulose enzyme loadings (Accelerase ® 1500) and 0%, 0.5% and 1% (w/w) redcedar oil loadings. The presence of 0.5% and 1% (w/w) redcedar oil inhibited cellulose-to-glucose yields by 26% and 33% and inhibited cell growth and ethanol production by Saccharomyces cerevisiae during the first 9 h. Similar ethanol concentrations of up to 22 g/l (92% of theoretical yield) were produced with all treatments within 12 h. The results of this study suggest that redcedar oil be removed prior to enzymatic hydrolysis and fermentation for efficient ethanol production using redcedars.