Batch Simultaneous Saccharification And Fermentation Research Articles

High-Solid Loading Enzymatic Hydrolysis of Waste Office Paper for poly-3-hydroxybutyrate Production Through Simultaneous Saccharification and Fermentation

Waste paper holds great potential as a substrate for the microbial production of bioplastic (Poly-3-hydroxybutyrate (PHB)). This study aimed to produce PHB by utilizing office paper as a substrate using Cupriavidus necator through batch and fed-batch simultaneous saccharification and fermentation (SSF) approach. For the batch experiment, different loadings of shredded office paper (3, 5 and 10%) with two different pretreatments H2O2 (OPH) and H2O2 and Triton X-100 (OPTH) were carried out. For the fed-batch experiment, paper loading started with 3% and two more additions were made at 36 and 84 h. Both experiments were conducted at 30 °C, 200 rpm and pH 7 using 55.5 FPU/g of cellulase and 37.5 CBU/g of β-glucosidase with a fixed amount of nitrogen source. High PHB yield was observed with OPH in all loadings, though the OPHT showed a better hydrolysis. Maximum PHB yield (4.27 g/L) was achieved with 10% OP on the sixth day of fermentation in batch SSF. Whereas, maximum PHB yield (4.19 g/L) was obtained within a shorter time (66 h)with OPH in the fed-batch experiment. The extracted PHB showed well-matched characteristic features to the standard PHB. Finally, this study proves the feasibility of employing the SSF process for PHB production using waste paper as an alternative approach to overcome the shortcoming of the separate hydrolysis and fermentation (SHF) process.

Repeated-batch simultaneous saccharification and fermentation of cassava pulp for ethanol production using amylases and Saccharomyces cerevisiae immobilized on bacterial cellulose

Reusing biocatalysts and repeated-batch process are promising approaches for the reduction of time and costs of a fermentation process. The present study investigated the use of α-amylase, glucoamylase, and cells of Saccharomyces cerevisiae immobilized on bacterial cellulose (BC) in repeated-batch simultaneous saccharification and fermentation (SSF) process for ethanol production from cassava pulp (CP). Ratio between the immobilized α-amylase and glucoamylase, and concentration of CP were optimized to achieve high CP saccharification efficiency, and the immobilized enzymes and cells were reused for four times in five consecutive batches of SSF. The optimum ratio between immobilized α-amylase and glucoamylase, and CP concentration were 75:25 by mass, and 60 g/L, respectively, yielding 0.74 gglucose/gCP (80% hydrolysis efficiency). Repeated-batch SSF gave an overall ethanol yield of 0.28 g/gCP, and an ethanol production rate of 0.27 g/h, whereas a batch SSF gave a yield of 0.3 gethanol/gCP and a production rate of 0.036 gethanol/h. The results reported in this study revealed the applicability of BC as a supporting material for enzymes and cells immobilizations, and the feasibility of the repeated-batch SSF process in ethanol fermentation.

Poly-γ-glutamic acid production by simultaneous saccharification and fermentation using corn straw and its fertilizer synergistic effect evaluation.

Agricultural wastes rich in lignocellulosic biomass have been used in the production of poly-γ-glutamic acid (γ-PGA) through separate hydrolysis and fermentation (SHF), but this process is complicated and generates a lot of wastes. In order to find a simpler and greener way to produce γ-PGA using agricultural wastes, this study attempted to establish simultaneous saccharification and fermentation (SSF) with citric acid-pretreated corn straw. The possibility of Bacillus amyloliquefaciens JX-6 using corn straw as substrate to synthesize γ-PGA was validated, and the results showed that increasing the proportion of glucose in the substrate could improve the γ-PGA yield. Based on these preliminary results, the corn straw was pretreated using citric acid. Then, the liquid fraction (xylan-rich) was used for cultivation of seed culture, and the solid fraction (glucan-rich) was used as the substrate for SSF. In a 10-L fermenter, the maximum cumulative γ-PGA concentration in batch and fed-batch SSF were 5.08 ± 0.78g/L and 10.78 ± 0.32g/L, respectively. Moreover, the product from SSF without γ-PGA extraction was used as a fertilizer synergist, increasing the yield of pepper by 13.46% (P < 0.05). Our study greatly simplified the production steps of γ-PGA, and each step achieved zero emission as far as possible. The SSF process for γ-PGA production provided a simple and green way for lignocellulose biorefinery and sustainable cultivation in agriculture.

Boosting second-generation ethanol titers from green coconut fiber by using high-concentration polyethylene glycol

Efforts have been made to improve and modify lignocellulosic pretreatments, but this step corresponds to a high cost in second-generation ethanol production. Previous studies have shown that high-concentration polyethylene glycol (PEG) is a possible way to dispense chemical and physicochemical pretreatments and increase ethanol production from lignocellulosic material. However, no operational conditions of this strategy were optimized. The present study investigated the effects of operational conditions on simultaneous saccharification and fermentation (SSF) performance using high PEG concentrations and green coconut fiber (GCF) as a substrate. The high-concentration PEG (150 g.L−1) increased ethanol production compared to the PEG-free, 10, and 50 g.L−1 PEG conditions. Using 20 % (w.v−1) solid loading, the batch SSF cultivation with PEG 1500 and without supplementary nutrients reached ethanol production and ethanol yield equal to 22.21 g.L−1 and 64.0 %, respectively. The batch SSF cultivation with 30 % (w.v−1) solid loading presented mass transfer limitations. The addition of salts, yeast extract, or peptone improved ethanol production. Inhibition by ethanol on the Saccharomyces cerevisiae CAT-1 strain was indifferent to the presence of PEG 1500, while the addition of PEG ensured the cellulolytic activity reuse after three fermentation cycles. The fed-batch SSF with PEG facilitated the GCF liquefaction so that it was possible to operate with up to 30 % (w.v−1) solid loading without problems of viscosity and free water. Using 150 g.L−1 PEG 1500 and enzyme loading equal to 13.3 filter paper unit. g−1, the fed-batch SSF reached 35.1 g.L−1 ethanol at 48 h, representing an increase of 70 % compared to the fed-batch SSF without PEG.

Simultaneous saccharification and lactic acid fermentation of the cellulosic fraction of municipal solid waste using Bacillus smithii

ObjectiveA primary drawback to simultaneous saccharification and fermentation (SSF) processes is the incompatibility of the temperature and pH optima for the hydrolysis and fermentation steps—with the former working best at 50–55 °C and pH 4.5–5.5. Here, nine thermophilic Bacillus and Parageobacillus spp. were evaluated for growth and lactic acid fermentation at high temperature and low pH. The most promising candidate was then carried forward to demonstrate SSF using the cellulosic fraction from municipal solid waste (MSW) as a feedstock.ResultsB. smithii SA8Eth was identified as the most promising candidate and in a batch SSF maintained at 55 °C and pH 5.0, using a cellulase dose of 5 FPU/g glucan, it produced 5.1 g/L lactic acid from 2% (w/v) MSW cellulosic pulp in TSB media.ConclusionThis work has both scientific and industrial relevance, as it evaluates a number of previously untrialled bacterial hosts for their compatibility with lignocellulosic SSF for lactic acid production and successfully identifies B. smithii as a potential candidate for such a process.

Different design configurations of simultaneous saccharification and fermentation to enhance ethanol production from cashew apple bagasse pretreated with alkaline hydrogen peroxide applying the biorefinery concept

Different strategies for simultaneous saccharification and fermentation (SSF) process were developed to enhance the productivity of ethanol by Kluyveromyces marxianus ATCC36907 as a part of biorefinery concept using cashew apple bagasse (CAB) as biomass. CAB was pretreated with 4.3% (v/v) alkaline hydrogen peroxide at pH 11.5 (CAB-AHP). Batch SSF conducted at 45 °C using 10% (w/v) CAB-AHP reported the highest concentration and ethanol yield. In the fed-batch SSF, the highest production (7.91 g ethanol/100gCAB) and ethanol yield (84.69%) were achieved using 10% (w/v) CAB-AHP initial solids load, 4% solid feeding at 24 h, and the feeding of enzymes only in the beginning of the process. The recycling of pretreatment inputs decreased 50% of the batch-SSF efficiencies, saving the consumption of water, H2O2, and NaOH in 66.67%, 48.44%, and 66.67%, respectively. Lignin was extracted from the hydrolysate with yield of 39.2%. Thus, the proposed biorefinery concept utilizes CAB to produce ethanol with high efficiency by fed-batch SSF, pretreatment input recycling, and the utilization of the extracted lignin for future applications.

L-lactic acid production by simultaneous saccharification and fermentation of dilute ethylediamine pre-treated rice straw

To effectively produce second-generation L-lactic acid (L-LA), for the first time, rice straw (RS) was pretreated by dilute ethylenediamine (EDA) and followed by fed-batch simultaneous saccharification and fermentation (SSF) under non-sterilized conditions. Specifically, the impact of pretreatment parameters included EDA concentration and pretreatment temperature on sugars and L-LA productions were evaluated. Results indicated that after pretreatment in 6% (w/v) EDA at 200 °C for 1 h and following the enzymatic hydrolysis, 42.25 g L−1 of total monomer sugars was generated. By batch SSF, the maximized 63.5 ± 3.0 g L−1and 296.8 g Kg−1 of L-LA can be obtained from the raw RS using Bacillus coagulans LA-15-2. Fed-batch SSF was further conducted and L-LA concentration of 92.5 g L−1 was obtained in the final fermentation broth. Correspondingly, L-LA productivity and yield reached 2.01 g L−1 h−1 and 578.1 g Kg−1of the pretreated RS, respectively. This study provided a novel environmental-friendly method for L-LA production, which successfully avoided the usage of large amount of inorganic alkali in lignocellulose pretreatment stage.

Optimization of sodium hydroxide pretreatment and enzyme loading for efficient hydrolysis of rice straw to improve succinate production by metabolically engineered Escherichia coli KJ122 under simultaneous saccharification and fermentation

Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95%. With the optimized enzyme loading of 4% cellulase complex + 0.5% xylanase (endo-glucanase 67 CMC-U/g, β-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 ± 0.8% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 ± 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 ± 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 ± 0.4 g/L and 1.37 ± 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale.

Fermentative hydrogen production from Jerusalem artichoke by Clostridium tyrobutyricum expressing exo-inulinase gene

Clostridium tyrobutyricum ATCC25755 has been reported as being able to produce significant quantities of hydrogen. In this study, the exo-inulinase encoding gene cloned from Paenibacillus polymyxa SC-2 was into the expression plasmid pSY6 and expressed in the cells of C. tyrobutyricum. The engineered C. tyrobutyricum strain efficiently fermented the inulin-type carbohydrates from Jerusalem artichoke, without any pretreatment being necessary for the production of hydrogen. A comparatively high hydrogen yield (3.7 mol/mol inulin-type sugar) was achieved after 96 h in a batch process with simultaneous saccharification and fermentation (SSF), with an overall volumetric productivity rate of 620 ± 60 mL/h/L when the initial total sugar concentration of the inulin extract was increased to 100 g/L. Synthesis of inulinase in the batch SSF culture was closely associated with strain growth until the end of the exponential phase, reaching a maximum activity of 28.4 ± 0.26 U/mL. The overall results show that the highly productive and abundant biomass crop Jerusalem artichoke can be a good substrate for hydrogen production, and that the application of batch SSF for its conversion has the potential to become a cost-effective process in the near future.

Fumaric Acid Production from Alkali-Pretreated Corncob by Fed-Batch Simultaneous Saccharification and Fermentation Combined with Separated Hydrolysis and Fermentation at High Solids Loading.

Production of fumaric acid from alkali-pretreated corncob (APC) at high solids loading was investigated using a combination of separated hydrolysis and fermentation (SHF) and fed-batch simultaneous saccharification and fermentation (SSF) by Rhizopus oryzae. Four different fermentation modes were tested to maximize fumaric acid concentration at high solids loading. The highest concentration of 41.32g/L fumaric acid was obtained from 20% (w/v) APC at 38°C in the combined SHF and fed-batch SSF process, compared with 19.13g/L fumaric acid in batch SSF alone. The results indicated that a combination of SHF and fed-batch SSF significantly improved production of fumaric acid from lignocellulose by R. oryzae than that achieved with batch SSF at high solids loading.

Comparison of strategies for the simultaneous saccharification and fermentation of cashew apple bagasse using a thermotolerant Kluyveromyces marxianus to enhance cellulosic ethanol production

Simultaneous saccharification and fermentation (SSF) is a promising process for the bioconversion of lignocellulosic biomass. Furthermore, an efficient approach to reduce the capital costs for the production of bio-based products is the use of high glucan loading. Therefore, in this study, a comparison of SSF strategies were investigated aiming to enhance ethanol production from acidic-alkaline pretreated cashew apple bagasse (CAB-OH) by Kluyveromyces marxianus ATCC36907 at high glucan loading. An ethanol concentration of 58g/L was achieved with 15% CAB-OH using batch SSF, resulting in an 81.2% overall ethanol yield. Prehydrolysis of 12h, prior to SSF, did not significantly increase the overall ethanol yield. Fed-batch SSF, using high loadings of solids, was also investigated. Ethanol concentrations of up to 67g/L could be produced from CAB-OH (20% w/v) by adding fresh substrate every 4h during the first 48h of SSF (10% initial and 2.5% of feeding), achieving an overall ethanol yield of 81%. In the fed-batch mode, the amount of enzyme was lower than used in batch and this process allowed higher ethanol concentrations and similar yield. No major differences in fed-batch performance, considering ethanol concentration and yield, were observed for the different feeding amounts, around 68g/L and 80.7%, respectively.

Kinetic modeling and dynamic analysis of simultaneous saccharification and fermentation of cellulose to bioethanol

Kinetic modeling and dynamic analysis of the simultaneous saccharification and fermentation (SSF) of cellulose to ethanol was carried out in this study to determine the key reaction kinetics parameters and product inhibition features of the process. To obtain the more reliable kinetic parameters which can be applied for a wide range of operating conditions, batch SSF experiments were carried out at three enzyme loadings (10, 15 and 20FPU/g cellulose) and two levels of initial concentrations of fermentable sugars (glucose and mannose). Results indicated that the maximum ethanol yield and concentration were achieved at high level of sugar concentrations with intermediate enzyme loading (15FPU/g cellulose). Dynamic analysis of the acquired experimental results revealed that cellulase inhibition by cellobiose plays the most important role at high level of enzyme loading and low level of initial sugar concentrations. The inhibition of glucose becomes significant when high concentrations of sugars were present in the feedstock. Experimental results of SSF process also reveal that an efficient mixing between the phases helps to improve the ethanol yield significantly.

Integrated bioconversion of pulp and paper primary sludge to second generation bioethanol using Saccharomyces cerevisiae ATCC 26602

Primary sludge, from different pulp and paper mills, was used as feedstock in simultaneous saccharification and fermentation (SSF) processes to produce ethanol. SSF was carried out with Saccharomyces cerevisiae ATCC 26602 yeast and NS 22192 enzymatic extract using 150gL−1 of carbohydrates (CH) from primary sludge. The effect of sterilization, reduction of enzyme dosage and fed-batch vs. batch conditions were studied. The removal of sterilization can be considered since no contamination or atypical by-products were observed, although SSF efficiency slightly decreased. The reduction of the enzyme dosage from 35 to 15FPUgCH−1 was successful. Despite of initial mixing difficulties, batch SSF enabled higher ethanol concentration (41.7gL−1), conversion yield (48.9%) and productivity (0.78gL−1h−1), compared to the fed-batch process at the same conditions of low enzyme dosage of 5FPUgCH−1 and high solids content of 21.7%, rarely found in literature.

High production yield and specific productivity of succinate from cassava starch by metabolically-engineeredEscherichia coliKJ122

BACKGROUND Succinate has been widely used in chemical industries and its microbial production is a desirable option. The feasibility of bio-based succinate production on an industrial scale strongly depends on the utilization of cheaper renewable resources. The use of cassava starch may make the fermentation process of succinate more economically competitive. RESULTS Simultaneous saccharification and fermentation (SSF) of succinate production was performed in minimal salt medium containing a cheap cassava starch. The parameters affecting succinate production from cassava starch by E. coli KJ122 were optimized. A succinate concentration of 70.1 ± 0.1 g Ll−1 was produced with a yield of 1.00 ± 0.01 g g−1 substrate and productivity of 0.97 ± 0.01 g L−1h−1 during batch SSF in a 2 L fermentor under optimized conditions. Further improvements in succinate concentration (82.5 ± 0.7 g L−1), yield (1.03 ± 0.01 g g−1 glucose), and average and specific productivities of 1.15 ± 0.01 g L−1h−1, and 456 mg g CDW−1 h−1, respectively, were observed in fed-batch SSF. CONCLUSION Escherichia coli KJ122 produced a succinate yield of 92% of theoretical maximum and the highest specific productivity ever reported. Succinate production yield and specific productivity from cassava starch in this study are superior to other previously published works. Escherichia coli KJ122 may be used as a biocatalyst for cost-effective succinate production. © 2016 Society of Chemical Industry

Influence of different SSF conditions on ethanol production from corn stover at high solids loadings

AbstractIn this study, three different kinds of simultaneous saccharification and fermentation (SSF) of washed pretreated corn stover with water‐insoluble solids (WIS) content of 20% were investigated to find which one resulted in highest ethanol yield at high‐solids loadings. The different methods were batch SSF, prehydrolysis followed by batch SSF and fed‐batch SSF. Batch‐SSF resulted in an ethanol yield of 75–76% and an ethanol concentration of 53 g/L. Prehydrolysis prior to batch SSF did not improve the ethanol yield compared with batch SSF. Fed‐batch SSF, on the other hand, increased the yield, independent of the feeding conditions used (79–81%, 57–60 g/L). If the initial amount of solids during fed‐batch SSF was lowered, the yield could be improved to some extent. When decreasing the enzyme dosage, the greatest decrease in yield was seen in the fed‐batch mode (75%), while lower or the same yield was seen in batch mode with and without prehydrolysis (73%). This resulted in similar ethanol yields in all methods. However, the residence time to achieve the final ethanol yield was shorter using fed‐batch. This shows that fed‐batch can be a better alternative also at a lower enzyme loading.

Hydrodynamic cavitation as a novel pretreatment approach for bioethanol production from reed

In this study, hydrodynamic cavitation (HC) was employed as a physical means to improve alkaline pretreatment of reed. The HC-assisted alkaline pretreatment was undertaken to evaluate the influence of NaOH concentration (1–5%), solid-to-liquid ratio (5–15%), and reaction time (20–60min) on glucose yield. The optimal condition was found to be 3.0% NaOH at solid-to-liquid (S/L) ratio of 11.8% for 41.1min, which resulted in the maximum glucose yield of 326.5g/kg biomass. Furthermore, simultaneous saccharification and fermentation (SSF) was conducted to assess the ethanol production. An ethanol concentration of 25.9g/L and ethanol yield of 90% were achieved using batch SSF. These results clearly demonstrated HC system can be indeed a promising pretreatment tool for lignocellulosic bioethanol production.

Combined substrate, enzyme and yeast feed in simultaneous saccharification and fermentation allow bioethanol production from pretreated spruce biomass at high solids loadings

BackgroundEconomically feasible cellulosic ethanol production requires that the process can be operated at high solid loadings, which currently imparts technical challenges including inefficient mixing leading to heat and mass transfer limitations and high concentrations of inhibitory compounds hindering microbial activity during simultaneous saccharification and fermentation (SSF) process. Consequently, there is a need to develop cost effective processes overcoming the challenges when working at high solid loadings.ResultsIn this study we have modified the yeast cultivation procedure and designed a SSF process to address some of the challenges at high water insoluble solids (WIS) content. The slurry of non-detoxified pretreated spruce when used in a batch SSF at 19% (w/w) WIS was found to be inhibitory to Saccharomyces cerevisiae Thermosacc that produced 2 g l-1 of ethanol. In order to reduce the inhibitory effect, the non-washed solid fraction containing reduced amount of inhibitors compared to the slurry was used in the SSF. Further, the cells were cultivated in the liquid fraction of pretreated spruce in a continuous culture wherein the outflow of cell suspension was used as cell feed to the SSF reactor in order to maintain the metabolic state of the cell. Enhanced cell viability was observed with cell, enzyme and substrate feed in a SSF producing 40 g l-1 ethanol after 96 h corresponding to 53% of theoretical yield based on available hexose sugars compared to 28 g l-1 ethanol in SSF with enzyme and substrate feed but no cell feed resulting in 37% of theoretical yield at a high solids loading of 20% (w/w) WIS content. The fed-batch SSF also significantly eased the mixing, which is usually challenging in batch SSF at high solids loading.ConclusionsA simple modification of the cell cultivation procedure together with a combination of yeast, enzyme and substrate feed in a fed-batch SSF process, made it possible to operate at high solids loadings in a conventional bioreactor. The proposed process strategy significantly increased the yeast cell viability and overall ethanol yield. It was also possible to obtain 4% (w/v) ethanol concentration, which is a minimum requirement for an economical distillation process.

Ethanol production by repeated-batch simultaneous saccharification and fermentation (SSF) of alkali-treated rice straw using immobilized Saccharomyces cerevisiae cells

Repeated-batch simultaneous saccharification and fermentation (SSF) of alkali-treated rice straw using immobilized yeast was developed to produce ethanol. Saccharomyces cerevisiae cells were immobilized by entrapping in photocrosslinkable resin beads, and we evaluated the possibility of its reuse and ethanol production ability. In batch SSF of 20% (w/w) rice straw, the ethanol yields based on the glucan content of the immobilized cells were slightly low (76.9% of the theoretical yield) compared to free cells (85.2% of the theoretical yield). In repeated-batch SSF of 20% (w/w) rice straw, stable ethanol production of approx. 38gL−1 and an ethanol yield of 84.7% were obtained. The immobilizing carrier could be reused without disintegration or any negative effect on ethanol production ability.

CONCEPTUAL AND MATHEMATICAL MODELS OF BATCH SIMULTANEOUS SACCHARIFICATION AND FERMENTATION: DIMENSIONLESS GROUPS FOR PREDICTING PROCESS DYNAMICS

This paper describes a modeling effort demonstrating that dimensionless groupings of classical process parameters can be used to predicting process dynamics of batch simultaneous saccharification and fermentation (SSF) processes. Michaelis–Menten enzyme kinetics and Monod growth kinetics were employed, and inhibition of enzyme action and inhibition of microbial growth were neglected. The SSF process was characterized by the relative durations of three phases: A microbially-limited phase, a hydrolysis-limited phase, and a monosaccharide-depletion phase. The duration of these three phases were interrelated, and well predicted by the dimensionless magnitude of the monosaccharide peak (MSP). Thus, the MSP could be used as a single-value descriptor of an SSF process. The dimensionless ratio of the initial hydrolysis rate to the initial substrate consumption rate was shown to predict MSP, and an overall system time constant was shown to predict the total run time of a batch SSF process.

Comparison of separate hydrolysis and fermentation and simultaneous saccharification and fermentation processes for ethanol production from wheat straw by recombinant Escherichia coli strain FBR5

Ethanol production by recombinant Escherichia coli strain FBR5 from dilute acid pretreated wheat straw (WS) by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) was studied. The yield of total sugars from dilute acid (0.5% H(2)SO(4)) pretreated (160 °C, 10 min) and enzymatically saccharified (pH 5.0, 45 °C, 72 h) WS (86 g/l) was 50.0 ± 1.4 g/l. The hydrolyzate contained 1,184 ± 19 mg furfural and 161 ± 1 mg hydroxymethyl furfural per liter. The recombinant E. coli FBR5 could not grow at all at pH controlled at 4.5 to 6.5 in the non-abated wheat straw hydrolyzate (WSH) at 35 °C. However, it produced 21.9 ± 0.3 g ethanol from non-abated WSH (total sugars, 44.1 ± 0.4 g/l) in 90 h including the lag time of 24 h at controlled pH 7.0 and 35 °C. The bioabatement of WS was performed by growing Coniochaeta ligniaria NRRL 30616 in the liquid portion of the pretreated WS aerobically at pH 6.5 and 30 °C for 15 h. The bacterium produced 21.6 ± 0.5 g ethanol per liter in 40 h from the bioabated enzymatically saccharified WSH (total sugars, 44.1 ± 0.4 g) at pH 6.0. It produced 24.9 ± 0.3 g ethanol in 96 h and 26.7 ± 0.0 g ethanol in 72 h per liter from bioabated WSH by batch SSF and fed-batch SSF, respectively. SSF offered a distinct advantage over SHF with respect to reducing total time required to produce ethanol from the bioabated WS. Also, fed-batch SSF performed better than the batch SSF with respect to shortening the time requirement and increase in ethanol yield.