Acetone-butanol-ethanol Fermentation Research Articles

Understanding the dewatering of fermentation-based 1,3-propanediol with acetone before cyclohexanone synthesis

Acetone can be produced by microbial fermentation using Clostridium acetobutylicum (acetone-n-butanol-ethanol fermentation, ABE fermentation), but it provides a mixture of acetone, 1-butanol, and ethanol. N-butanol and ethanol can be used as biofuels, but high-value applications of acetone generally require upgrading. Bio-based 1,3-propanediol is more readily produced by fermentation and separated at higher titers and has been used industrially. Therefore, the coupled upgrading of the two fermentation products can provide another avenue for high-value utilization of acetone. In this paper, salting-out extraction of 1,3-propanediol with acetone was carried out, and 1,3-propanediol and acetone would spontaneously form an organic phase, thus reducing the energy consumption in the 1,3-propanediol separation process. As the double alkylation reaction of acetone with equivalent 1,3-propanediol would generate cyclohexanone, the extraction of 1,3-propanediol with acetone can provide new insight into the process intensification (removing water, salt and water concentrated in the aqueous phase) for the 1,3-propanediol separation and conversion.

Acetone-Butanol-Ethanol (ABE) fermentation with clostridial co-cultures for enhanced biobutanol production

This study has addressed the issue of enhanced biobutanol production through Consolidated Bioprocessing, with the use of clostridial co-cultures combining C. acetobutylicum (Cac) and C. pasteurianum (Cpa). To begin with, the total Acetone-Butanol-Ethanol (ABE) solvent production and butanol selectivity of individual clostridial cultures grown on different carbon sources present in lignocellulosic hydrolysates. Thereafter, statistical optimization of ABE fermentation with co-culture system was carried out using Box-Behnken design. The optimization variables were Cac to Cpa inoculum ratio (X1 in mL mL−1), sodium concentration in the medium (X2 g L−1), and xylose/glucose ratio (X3 g g−1 L L−1), whereas response variables were butanol titre (Y1 in g L−1), biomass growth (Y2 OD600), total ABE titre (Y3 in g L−1). Maximum values of the response variables with the corresponding set of optimization parameters were as follows: Y1, max = 12.1 ± 0.45 (for X1 = 0.30, X2 = 5.90, X3 = 0), Y2, max = 4.15 ± 0.03 (for X1 = 0.3, X2 = 2.42, X3 = 0.14), Y3, max = 23.1 ± 0.55 (for X1 = 0.46, X2 = 6.36, X3 = 0). The study demonstrated a substantial ≈ 22% and 61% increment in butanol titre in co-culture system compared to individual fermentations with Cac and Cpa grown on pure glucose, respectively.

Pilot-scale acetone-butanol-ethanol fermentation from corn stover

Biobutanol is an advanced biofuel that can be produced from excess lignocellulose via acetone-butanol-ethanol (ABE) fermentation. Although significant technological progress has been made in this field, attempts at large-scale lignocellulosic ABE production remain scarce. In this study, 1 m3 scale ABE fermentation was investigated using high inhibitor tolerance Clostridium acetobutylicum ABE-P1201 and steam-exploded corn stover hydrolysate (SECSH). Before expanding the fermentation scale, the detoxification process for SECSH was simplified by process engineering. Results revealed that appropriate pH management during the fed-batch cultivation could largely decrease the inhibition of the toxic components in undetoxified SECSH to the solventogenesis phase of the ABE-P1201 strains, avoiding ‘acid crash’. Therefore, after naturalizing the pH by Ca(OH)2, the undetoxified SECSH, without removal of the solid components, reached 17.68±1.30g/L of ABE production with 0.34±0.01g/g of yield in 1L scale bioreactor. Based on this strategy, the fermentation scale gradually expanded from laboratory-scale apparatus to pilot-scale bioreactors. Finally, 17.05±1.20g/L of ABE titer and 0.32±0.01g/g of ABE yield were realized in 1 m3 bioreactor, corresponding to approximately 145kg of ABE production from 1 t of dry corn stover. The pilot-scale ABE fermentation demonstrated excellent stability during repeated operations. This study provided a simplified ABE fermentation strategy and verified the feasibility of the pilot process, providing tremendous significance and a solid foundation for the future industrialization of second-generation ABE plants.

Decoupling acidogenic cascade via bio-electrogenic induced ABE pathway for enhanced n-butanol synthesis in Clostridium acetobutylicum ATCC-824: Bioenergetics and gene expression analysis

This investigation scrutinized the quantitative aspects of biobutanol production in conventional and bioelectrogenic induced ABE fermentation using Clostridium acetobutylicum ATCC-824. The primary objective of the study was to investigate how alterations in the extracellular redox potential (-0.4 V vs. Ag/AgCl (3.5 M KCl)) affect the hetero-fermentation towards the production of acetone, butanol, and ethanol during the bi-phasic fermentation, utilizing different glucose concentrations from 20 g/L − 60 g/L. The study showed significant results with 68.86 % increased butanol titer (6.67 g/L) compared to conventional fermentation (3.95 g/L butanol). Additionally, the acetone production also increased to 2.34 g/L as compared to conventional fermentation (1.96 g/L). Furthermore, gene expression and network analysis showed that various ABE pathway genes were significantly up or down regulated during the bi-phasic fermentation, indicating a difference between the conventional and EF reactors. The external potential influenced the overexpression of genes like pta, crt, bcd, ask, adh (CA_C1574), and hbd (CA_C3375), while simultaneously downregulation of buk gene, suggesting the acidogenic decoupling and transition from cold channel (butyric acid) towards hot channel pathway (directly from acetyl CoA through butyryl-CoA) for improved butanol production. Moreover, the study also revealed that entropy and enthalpy changes played a significant role in butanol production and ABE fermentation. The EF showed more negative free energy (-3.33 × 104 kJ/mol) when compared with conventional fermentation (-2.8 × 104 kJ/mol) suggesting the mechanism to be more spontaneous and viable. Overall, this study provided evidence of metabolic rerouting with non-genetic approach by regulating electron flow, culminating in an impact on the bi-phasic fermentation towards specific metabolites.

Effects of Temperature, pH, and Agitation on Growth and Butanol Production of Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium saccharoperbutylacetonicum

Abstract Butanol is a promising alternative to fossil-derived fuels. Clostridium genus bacteria are known for their ability to produce butanol as one of the metabolites, however, at the moment this solution is not economically viable. To solve it, the process of butanol production should be optimized. While ABE fermentation has been extensively studied, information about the optimal growth conditions for specific microorganisms often differs from one study to another. Therefore, this study aims to search for optimal growth conditions in sealed serum bottle tests for three widely used strains in ABE fermentation. In this study effects of temperature, pH, and agitation were tested on Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium saccharoperbutylacetonicum. The optimal temperature for C. beijerinckii growth and butanol production was 32 °C, the optimal agitation speed for growth was 0 rpm, but for butanol production, it was 200 rpm. For C. saccharoperbutylacetonicum growth and butanol production pH 7.5, 30 °C temperature and an agitation rate of 100 rpm were optimal, however, this effect was slight. For C. acetobutylicum cultivation optimal temperature, pH, and agitation rate were respectively 37 °C, 6.5, and 200 rpm.

Developing a high-rate ABE fermentation system for rice straw: CSTR with immobilization on granular-activated carbon with ex situ pervaporation

This study assessed the performance of two continuous stirred tank reactors (CSTRs) to immobilize Clostridium acetobutylicum DSM 792 and Clostridium beijerinckii DSM 6422 on granular activated carbon. Dilution rates (D) from 0.05 to 0.60 h−1 were tested using a sugar mixture to mimic rice straw hydrolysate. Immobilization was shown to be a highly effective technique for processing high flows without cell washout. Both CSTRs demonstrated significantly higher butanol productivity than their free-cell counterparts, achieving the remarkable value of 2.29 g L−1 h−1 with C. beijerinckii at D = 0.60 h−1. Rice straw hydrolysate was fed to the high-rate CSTR, reaching a butanol productivity of 2.07 g L−1 h−1 at D = 0.30 h−1. A novel downstream configuration of ex situ gas stripping followed by two pervaporation cycles operated under rough vacuum was explored in discontinuous mode, that reduced the energy demand by 63 % of conventional distillation methods. This configuration holds great promise for the advance of the lignocellulosic biorefinery process.

Waste valorization through acetone-butanol-ethanol (ABE) fermentation

BackgroundBiobutanol, produced through acetone-butanol-ethanol (ABE) fermentation, has been proposed for use as a transportation fuel and for the development of butanol-based materials. However, the economic viability of ABE fermentation is heavily dependent on the cost of raw materials. MethodsThis study assesses various carbon and nitrogen sources for ABE fermentation. Carbon sources examined include local molasses (M1), Thai molasses (M2), Taiwan sugar agricultural molasses (M3), and Taiwan sugar edible molasses (M4). Nitrogen sources considered are corn steep liquor (CSL), acid-hydrolyzed black soldier fly larval meal (IA), and enzyme-hydrolyzed black soldier fly larval meal (IE). Significant findingsOur findings reveal that M2CSL, a combination of Thai molasses and corn steep liquor, serves as a cost-effective and efficient medium for ABE fermentation, resulting in a butanol concentration of 7.4 ± 3.5 g/L. Furthermore, our research identifies variations in molasses and their impact on sucrose consumption inhibition. Notably, this study underscores the potential of insect peptone derived from enzyme-hydrolyzed black soldier fly larval meal (IE) as an alternative nitrogen source, while cautioning against the use of insect peptone obtained from acid-hydrolyzed black soldier fly larval meal (IA) due to its inhibitory properties.

Trifluoroethyl Acrylate-Substituted Polymethylsiloxane—a Promising Membrane Material for Separating an ABE Fermentation Mixture

Trifluoroethyl Acrylate-Substituted Polymethylsiloxane—a Promising Membrane Material for Separating an ABE Fermentation Mixture

Optimising microalgae-derived butanol yield

Rapid global urbanisation emphasises the necessity to explore sustainable energy resources to fulfill escalating energy demands. Biobutanol emerges as a promising biofuel due to heightened energy density and molecular similarity to petrol. Microalgae, rich in carbohydrates, offer a potential glucose source for biobutanol fermentation. The current study shows that varying CO2 concentrations affect carbohydrate content in the biomass of P. kessleri bh-2 and Scenedesmus sp.k-7. The introduction of 1% CO2 significantly improved carbohydrate productivity, reaching 74.5% for P. kessleribh-2 and 71.0% for Scenedesmus sp.k-7. Enzymatic hydrolysis was found to be most effective for ABE fermentation, with optimal results obtained at enzyme loads of 8 mg g−1 cellulase and 2 mg g−1 amylase for both strains. When C. acetobutylicum cells were cultivated with pretreated P. kessleribh-2 biomass, the biobutanol yield amounted to 4.8 gL-1 at a glucose concentration of 5.30 gL-1, demonstrating strain's superior performance compared to Scenedesmus sp.k-7.

Lignocellulosic ethanol and butanol production by Saccharomyces cerevisiae and Clostridium beijerinckii co-culture using non-detoxified corn stover hydrolysate

Considering global economic and environmental –benefits, green renewable biofuels such as ethanol and butanol are considered as sustainable alternatives to fossil fuels. Thus, developing a co-culture strategy for ethanol and butanol production by Saccharomyces cerevisiae and Clostridium beijerinckii has emerged as a promising approach for biofuel production from lignocellulosic biomass. This study developed a co-culture of S. cerevisiae and C. beijerinckii for ethanol and butanol production from non-detoxified corn stover hydrolysate. By firstly inoculating 3 % S. cerevisiae and then 7 % C. beijerinckii with 8–10 h time intervals, the optimized co-culture process gave 24.0 g/L ABE (20.8 g/L ethanol and 2.4 g/L butanol), obtaining ABE yield and productivity of 0.421 g/g and 0.55 g/L/h. The demonstrated co-culture strategy made full use of hexose and pentose in hydrolysate and contributed to total yield and efficiency compared to conventional ethanol or ABE fermentation, indicating its great potential for developing economically feasible and sustainable bioalcohols production.

Trifluoroethylacrylate-Substituted Polymethylsiloxane—Promising Membrane Material for Separating an Abe Fermentation Mixture

This work is aimed at obtaining a membrane material that is resistant to the formation of a precipitate on the surface upon contact with an ABE fermentation mixture and has a good separating ability during the pervaporation isolation of n-butanol from a water–alcohol mixture. In this regard, in this work, for the first time, the creation of pervaporation membranes based on polymethyltrifluoroethylacrylatesiloxane (F3-Acr), as well as a copolymer of polydecylmethylsiloxane and polymethyltrifluoroethylacrylatesiloxane (C10-F3-Acr) is proposed. In comparison with polydecylmethylsiloxane (C10), the structure and sorption properties of the developed membrane materials for n-butanol, ethanol and acetone were studied. It should be noted that the highest sorption of n-butanol is characteristic of C10-F3-Acr (0.46 g/g). Changes in surface properties were assessed by the contact angle and elemental composition of the surface before and after exposure for 1 month in a fermentation medium. The transport and separating properties of the synthesized membrane materials were studied in the vacuum pervaporation mode during the separation of a model ABE fermentation mixture. It was shown that the introduction of a fluorine-containing substituent into the side chain of polysiloxane made it possible to increase the hydrophilicity of the polymer: the water flow for F3-Acr was 0.7 × 10–6 kg m m–2 h–1, which is almost 3 times higher than for C10. It is worth noting the positive effect of the combination of C10 and F3-Acr groups in polysiloxane. Thus, with an increase in the total flow by 60% compared to the C10 membrane, the values of the separation factor for n-butanol, acetone, and ethanol were 40.5, 32.7, and 4.3 and increased by 6, 15, and 12%, respectively, compared to the C10 membrane. For the C10-F3-Acr membrane, the pervaporation separation index for n-butanol, acetone, and ethanol was 136, 109, and 11. Therefore, this membrane is twice as efficient as C10. Taking into account the absence of detectable contamination of the surface of the membrane material with fermentation products, one can note the high potential of the C10-F3-Acr membrane for the task of isolating alcohols from the ABE fermentation mixture.

Effect of metals on simultaneous ABE fermentation and biohydrogen production from fig (Ficus carica) via Plackett-Burman experimental design

Effect of metals on simultaneous ABE fermentation and biohydrogen production from fig (Ficus carica) via Plackett-Burman experimental design

Competitive Adsorption of Butanol from ABE Fermentation Solution by Silicalite-1

Biobutanol is an alternative energy that has been of great interest as a substitute for fossil fuel. It can be obtained from acetone-butanol-ethanol (ABE) fermentation with by-products of acetone and ethanol. In this work, the competitive kinetics of adsorption of butanol from ABE model solution was investigated on Silicalite-1 comparing to commercial ZSM-5. The adsorption was conducted in liquid phase and batch mode at 25°C between 0−90 min with the composition of ABE model solution of 1, 2, 0.33 wt% (acetone, butanol, ethanol) in aqueous solution. The Silicalite-1 shows fast adsorption of butanol from 0.5 min and possesses high adsorption capacity of 0.15 g/g, which is higher than that of the ZSM-5, 0.12 g/g. The Silicalite-1 exhibits high affinity to butanol > acetone > ethanol with selectivity of butanol-to-acetone (SB/A) of 2.6 and butanol-to-ethanol (SB/E) of 13.8. The good performance of Silicalite-1 adsorbent could be related to its hydrophobicity and higher micropore surface area and micropore volume as compared to ZSM-5.

Mathematical modeling of ABE fermentation on glucose substrate with Zn supplementation for enhanced butanol production

Supplementation or limitation of some micronutrients during acetone-butanol-ethanol (ABE) fermentation has led to improvement in butanol yield and productivity. A mechanistic model of ABE fermentation offers insights in understanding these complex interactions and improving productivity through optimal culture conditions. This study proposes a mechanistic kinetic model of ABE fermentation by two Clostridium Acetobutylicum strains, L7 and ATCC 824 using glucose as sole carbon source without zinc and with various zinc doses. The model incorporates enzyme regulation by zinc on several glycolytic, acidogenesis and solventogenesis enzymes. The model was fitted and validated to experimental data collected from the published literature. The simulated results were in compliance with the experimental data, most importantly indicating higher glucose consumption and butanol productivity when supplemented with zinc compared to the control culture. The average squared correlation factor (R2) between the experimental and the simulated results, without and with zinc, were 0.99 and 0.96 for glucose, and 0.89 and 0.95 for butanol, respectively. A sensitivity analysis performed on the fitted and validated model indicated that the glucose consumption and growth parameters most influenced the model outputs. The developed model can be used as a template for modeling ABE fermentation under different combinations of micronutrients that may offer improved butanol yield and productivity.

Biobutanol Production from Acetone–Butanol–Ethanol Fermentation: Developments and Prospects

With global carbon emissions and environmental issues becoming increasingly prominent, there is an increasing focus on the development of clean energy, and biobutanol has gained widespread attention due to its superior performance. Butanol production by fermentation is affected by various factors, such as raw materials, cultivation environment, and butanol toxicity, which results in lower butanol production and restricts its industrial development. This article elaborates on the research progress of butanol fermentation, including butanol-producing microorganisms, butanol synthesis metabolic pathways, raw materials for ABE fermentation, and butanol fermentation technologies. It also looks forward to the prospects of biobutanol, aiming to provide a theoretical basis for the research direction of butanol fermentation.

Solvent-Producing Clostridia Revisited.

The review provides an overview of the current status of the solvent-producing clostridia. The origin and development of industrial clostridial species, as well as the history of the industrial Acetone Butanol Ethanol fermentation process, is reexamined, and the recent resurgence of interest in the production of biobutanol is reviewed. Over 300 fully sequenced genomes for solvent-producing and closely related clostridial species are currently available in public databases. These include 270 genomes sourced from the David Jones culture collection. These genomes were allocated arbitrary DJ codes, and a conversion table to identify the species and strains has now been provided. The expanded genomic database facilitated new comparative genomic and phylogenetic analysis. A synopsis of the common features, molecular taxonomy, and phylogeny of solvent-producing clostridia and the application of comparative phylogenomics are evaluated. A survey and analysis of resident prophages in solvent-producing clostridia are discussed, and the discovery, occurrence, and role of novel R-type tailocins are reported. Prophage genomes with R-type tailocin-like features were detected in all 12 species investigated. The widespread occurrence of tailocins in Gram-negative species is well documented; this survey has indicated that they may also be widespread in clostridia.

Exploring the potential of multiple lignocellulosic biomass as a feedstock for biobutanol production

To improve the cost-effectiveness of biobutanol production, lignocellulosic biomass is used as a cheap and sustainable feedstock. It provides fermentable sugars for microbial fermentation but lacks nitrogen resources and other nutrients. This study investigated the effects of combining multiple types of lignocellulosic biomass with nitrogen-rich wheat bran on ABE fermentation. Depending on the composition and fermentation effects, the optimal mixing ratio of wheat bran added with sugarcane bagasse, corncob and pine was 1:1, 1:4 and 2:3, respectively. The addition of corn steep powder as a nutritional source significantly enhanced sugar consumption and solvent concentration. Integration of pervaporation with ABE fermentation facilitated timely removal of butanol and alleviated product inhibition, resulting in a final total solvents concentration of 14.51 g/L, comparable to fermentation with TYA synthetic medium. This study demonstrates the feasibility of using combined lignocellulosic biomass to reduce feedstock costs and enhance the application of biobutanol production.

Integrated Catalytic Upgrading of Biomass-Derived Alcohols for Advanced Biofuel Production

Sustainable biofuel production is necessary to meet the daunting challenge of “fueling” growing economies with a significantly reduced carbon footprint. Although its higher oxygen content often hinders the direct conversion of lignocellulosic biomass (LCB) into energy-dense biofuels, microbial biofuel production from LCB still has potential. The production of primary alcohols by acetone–butanol–ethanol (ABE) fermentation has been practiced for more than a century to attain near-theoretical maximum. However, ABE produced conventionally by native microorganisms is not equivalent to fossil fuel-based aviation fuels in terms of energy density, volatility, and cost-efficiency. Various strategies have been adapted for the microbial synthesis of advanced fuels from renewable feedstock with the advancements in genetic engineering. Yet, the presence of inhibitors and the inefficiency of microbes to utilize or transport the sugar mixtures from LCB often impede titer and yield. However, ABE mixtures can act as platform chemicals to synthesize high-value biofuels by biocatalytic or chemo-catalytic applications. Chemical catalysts, in particular, are used to produce higher alcohols ranging from 3-carbon to 20-carbon fuels from the ABE fermentation mixture. This article reviews the recent trends in the production of higher biofuels from ABE mixtures using biological and chemical catalysts. Focus is placed on genomic and metabolic engineering strategies implemented to upgrade microbes for higher biofuel production via the fermentation of renewable feedstocks. This paper also summarizes the advancements in the chemical conversion route of an ABE fermentation mixture into higher biofuels. Finally, the review provides insights into future research toward commercializing renewable and sustainable higher biofuels and chemicals.

Screening and Adaptive Evolution of Clostridium for Butanol Synthesis by ABE Fermentation from Cellulosic Biomass: A Review

Screening and Adaptive Evolution of Clostridium for Butanol Synthesis by ABE Fermentation from Cellulosic Biomass: A Review

Understanding the dehydration of acetone, 1-butanol, and ethanol fermentation-based biofuel

ABSTRACT Removing most of the water in the acetone + n-butanol + ethanol (ABE fermentation broth can reduce energy consumption and improve the biobutanol market competitiveness. Understanding the dehydration process of ethanol, acetone, and n-butanol can guide the fermentation process for the subsequent separation, which led to an investigation into the salting-out effects of K2CO3 on aqueous ethanol solution, aqueous acetone solution and n-butanol+water system at various temperatures. Elevating the salt concentration has the potential to decrease the water content of these solutes as well as the content of ethanol or acetone and n-butanol in the salt-free aqueous phase. The distribution and selectivity coefficients of ABE were also enhanced. As a result, the recovery and dehydration ratio of ethanol or acetone, or n-butanol, was also improved. The strong hydrophilicity of acetone and ethanol makes the recovery and dehydration ratio of n-butanol difficult. On the same basis(50% K2CO3), the dehydration ratios of ethanol, acetone, and n-butanol were 91.43%, 96.21%, and 97.52%, respectively. Thus, the dehydration capacity gave the following trend: n-butanol>acetone>ethanol. By raising the temperature，it was possible to increase the amount of ethanol，acetone，or n-butanol in the organic phase while decreasing their amounts in the aqueous phase. The ratio of n-butanol’s recovery and dehydration can be improved by raising the temperature.