Synthesis Of Butanol Research Articles

Strategies for enhanced acetone-butanol-ethanol production by Clostridium beijerinckii Y10 from glucose and xylose and exploration of its physiological mechanisms

To enhance the production of butanol and its ratio to the total solvent, the impacts of exogenous amino acids supplementation on acetone-butanol-ethanol (ABE) fermentation were studied. With this effort, the highest butanol and total solvent production of 14.18 ± 0.24 g/L and 16.29 ± 0.31 g/L were achieved when 5.0 mg/L of phenylalanine was added at 18 h. Additionally, to explore the physiological reasons for the efficient synthesis of butanol under the optimal condition, the changes of key enzyme activities in the butanol synthesis pathway and the intracellular microenvironment were investigated. The findings show that phenylalanine addition could enhance crude enzyme activities of acetate kinase and butyrate kinase activities, strengthen NADH synthesis and expend more ATP to promote the growth of Clostridium beijerinckii Y10. This study suggests that the method of a tiny amount of amino acid addition was a simple and efficient approach to enhance bio-butanol production, thus providing a new strategy to improve the performance of other similar fermentation.

Glucose tolerance of Clostridium acetobutylicum fermentation in the anaerobic system

Solvent-producing Clostridium acetobutylicum was purified and used in an acetone-butanol-ethanol (ABE) fermentation process. The objective of this study is to design a fermentation medium for the synthesis of butanol and determine the ideal glucose concentration for appropriate microbe ingestion. The fermentation medium was incubated at 37 °C for up to 90 h before inoculation while being sparged with nitrogen gas under anaerobic conditions. Based on the optical density of fermentation media, the growth rate was also monitored. At 60 g/L of glucose, which was the optimum condition for fermentation, the process followed a log phase pattern until the death phase, with the largest growth taking place between 10 h and 50 h after incubation. The C. acetobutylicum steadily consumed the glucose content, reaching its maximal consumption with only around 12 g/L remaining. In contrast to acetone and ethanol, which produced the highest concentrations at 6.4 g/L and 5.2 g/L, respectively, butanol productions were seen appropriately, with the greatest concentration yielding 11.2 g/L of butanol. This shows that C. acetobutylicum expressed its active metabolism for up to 60 g/L and further increase of glucose content will deteriorate the performance of butanol production.

Bacterial metabolic engineering for the production of second-generation (2G) bioethanol and biobutanol; a review.

The second generation (2G) biofuels were introduced to solve the issues associated with first-generation biofuel (dependency on food materials) and fossil fuels such as reservoirs diminution, high demand, price fluctuation, and lethal greenhouse gases emission. Butanol and ethanol are the main 2G biofuels. They are used as a disinfectant, antiseptic, and chemical solvent in pharmaceutical, plastic, textiles, cosmetics, and fuel industries. Currently, their bacterial biological production from lignocellulosic material at the industrial level with primitive microorganisms is under development and not economical and qualitative compatible as compared to that of fossil origin, due to slow growth rate, low titer, recalcitrant nature of lignocellulose, strain intolerance to a higher amount of butanol and ethanol, and strain inability to tolerate inhibitors accumulated during pretreatment of lignocellulosic materials. Therefore, metabolic engineering strategies such as redirection of carbon flux, knocking out competing pathways, enhancing strain robustness and wide range of substrate utilization ability, and overexpression of enzymes involved in their biological synthesis have been applied to bacteria for enhancing their ability for 2G ethanol and butanol production in a highly cost-effective amount from lignocellulosic materials. Herein, we summarized and reviewed the progress in metabolic engineering of bacterial species such as clostridium spp, E. coli, and Z. moibilis for the synthesis of 2G butanol and ethanol, especially from lignocellulosic materials.

ULTRASONIC DISINTEGRATION OF LIGNOCELLULOSE RAW MATERIALS AS A PRE-TREATMENT OF A SUBSTRATE FOR MICROBIOLOGICAL PRODUCTION OF BIOBUTANOL

Aim. The purpose of the study was to investigate the effect of ultrasonic disintegration on the lignocellulosic raw materials (biomass of the non-cereal part of rape) with its subsequent use as a substrate for the production of biobutanol. Methods. Butanol-producing strains and the biomass of the non-cereal part of rape Brassica napus were used in the present study. Ultrasonic disintegration of lignocellulosic raw materials was performed on the specially designed equipment. Results. The effect of ultrasonic disintegration on lignocellulosic raw materials was investigated for further application in biofuel production based on microbiological conversion. The possibility of using the obtained components after the pre-treatment of lignocellulose by ultrasonic disintegration as a substrate for the microbiological synthesis of butanol was shown. The highest accumulation of butanol (2.4 g/l) was obtained with the use of 5% dry matter content in the medium, 5 min treatment and the specific power of ultrasonic disintegration of 0.72 W/ml. Conclusions. The possibility of producer strains of the genus Clostridium to use cellulose in the fermentation process has been shown. When using ultrasonic disintegration for pretreatment of the non-cereal part of the biomass of rape, the accumulation of butanol increased by 3 folds.

Transition metals promoting Mg-Al mixed oxides for conversion of ethanol to butanol and other valuable products: Reaction pathways

This paper is focused on the catalytic synthesis of butanol from ethanol in a microflow reactor at a constant weight hour space velocity (4.5 h−1) and different reaction temperatures (280, 300 and 350 °C). The reaction was catalysed by Mg-Al mixed oxides (i) pure and (ii) with added transition metals such as Co, Ni, Cu, Mn and Cr (synthesis by coprecipitation). The solid materials were deeply characterised. Other products, such as ethylene, 1,1-diethoxyethane, ethyl acetate, 1-hexanol, etc. were also determined and the reaction pathway for their formation was examined. The metals Cr and Mn did not increase the catalyst activity, which was quite low (maximum 19% at 350 °C). However, the metals Co and Ni positively influenced butanol formation, while Cu positively influenced ethyl acetate formation. Moreover, ethanol conversion increased with increasing temperature, but at the same time the selectivity to butanol decreased.

A neutral red mediated electro-fermentation system of Clostridium beijerinckii for effective co-production of butanol and hydrogen

To enhance the co-production of butanol and hydrogen by the acetone-butanol-ethanol (ABE) fermentation of Clostridium beijerinckii, a novel cathodic electro-fermentation (CEF) system was constructed with neutral red (NR) as electron mediator. With the mediation of NR, production of butanol and hydrogen from glucose in the CEF system achieved 5.49 ± 0.28 g/L and 3.74 ± 0.16 L/L, 569.5% and 325.0% higher than that in the open circuit (OC) system, respectively. The butanol and hydrogen yield of 0.30 ± 0.02 g/g and 206.53 ± 8.20 mL/g was 172.7% and 71.4% higher than that in the OC system, respectively. The effective co-production of butanol and hydrogen in the NR-mediated CEF system was attributed to the cooperation of the introduced polarized electrode and the additional NR. With the control of the polarized electrode, a feasible ORP was available for the effective hydrogen production. And the additional NR had induced more carbon source and electrons to the synthesis of butanol.

One-pot production of butyl butyrate from glucose using a cognate \u201cdiamond-shaped\u201d E. coli consortium

Esters are widely used in plastics, textile fibers, and general petrochemicals. Usually, esters are produced via chemical synthesis or enzymatic processes from the corresponding alcohols and acids. However, the fermentative production of esters from alcohols and/or acids has recently also become feasible. Here we report a cognate microbial consortium capable of producing butyl butyrate. This microbial consortium consists of two engineered butyrate- and butanol-producing E. coli strains with nearly identical genetic background. The pathways for the synthesis of butyrate and butanol from butyryl-CoA in the respective E. coli strains, together with a lipase-catalyzed esterification reaction, created a “diamond-shaped” consortium. The concentration of butyrate and butanol in the fermentation vessel could be altered by adjusting the inoculation ratios of each E. coli strain in the consortium. After optimization, the consortium produced 7.2 g/L butyl butyrate with a yield of 0.12 g/g glucose without the exogenous addition of butanol or butyrate. To our best knowledge, this is the highest titer and yield of butyl butyrate produced by E. coli reported to date. This study thus provides a new way for the biotechnological production of esters.

Embedding ruthenium nanoparticles in the shell layer of titanium zirconium oxide hollow spheres to catalyze the degradation of alkali lignin under mild condition

To catalyze the degradation of lignin in refractory wastewater efficiently, a new nanocomposite with Ru nanoparticles embedded on the surface of TiZrO4 hollow spheres was fabricated with three method a “sol-gel + calcination + vacuum-impregnation” template method, and the unique binary composition of TiZrO4/Ru prevented the aggregation of Ru and keep its high activity. During 3-h catalytic-oxidation at 160 °C and 2.0 MPa O2, 98% alkali lignin was degraded and 70% organic carbon was mineralized with the catalysis of TiZrO4/Ru, while the values were only 50% and 25% without analysts. The catalyst increased the catalytic-oxidation rate constant k1 (h−1) of alkali lignin from 0.282 h−1 to 1.175 h−1 because of high-efficiency hydroxyl radical production, as determined by EPR. LC-OCD showed that the catalyst decomposed alkali lignin with molecular weight 1–2 kDa to small molecules. Butyl acetate was the main intermediate product, which should be derived from the auto synthesis of butanol and acetic acid. In addition to high conversion efficiency, the catalyst had good stability with 95% capability after five cycles. In real biogas slurry treatment, an increase of biochemical to COD ratio from 0.28 to 0.51, with obvious decoloration, indicated TiZrO4/Ru enhanced the biodegradability of the refractory wastewater significantly.

Obtaining practically valuable compounds with the use of recombinant yeast Saccharomyces cerevisiae. Part one: synthesis of ethanol, butanol and isobutanol

Obtaining practically valuable compounds with the use of recombinant yeast Saccharomyces cerevisiae. Part one: synthesis of ethanol, butanol and isobutanol

Designer Biosynthetic Pathways for Photosynthetic Biofuels and Bioproducts: Opportunities and Challenges

With synthetic biology, genetically engineered (GE) cyanobacteria are now a potential photosynthetic platform for bioproducts, in that genetic transformation with a series of transgenes can encode for biosynthetic pathways to enable the conversion of CO2, water and sunlight to biofuels (e.g. butanol). This presentation will disclose designer biosynthetic pathways for photosynthetic production of bioproducts such as butanol and/or related higher alcohols from carbon dioxide and water. The designer photosynthetic organisms are created such that the endogenous photobiological regulation mechanism is tamed, and the reducing power (NADPH) and energy (ATP) acquired from the photosynthetic process are used for synthesis of butanol and/or related higher alcohols from carbon dioxide and water. This photosynthetic biofuels‐production method eliminates the problem of recalcitrant lignocellulosics by bypassing it. Furthermore, this approach enables the use of seawater and/or groundwater for photobiological production of higher alcohols (such as 1‐butanol) without requiring freshwater or agricultural soil, since the designer photosynthetic organisms can be created from certain marine algae and/or cyanobacteria that can use seawater and/or certain groundwater. However, there are still significant challenges. For example, it is also important to understand the bio‐risk of such organisms before the synthetic biology approach could be used for commercial application. Recently, using plasmid‐transformed cyanobacteria, we experimentally demonstrated that the horizontal gene transfer from GE cyanobacteria to E. coli could occur as soon as 1–3 days of liquid co‐cultures. On the other hand, there was no detectable transfer event for the integrated transgenes so far. These results suggested that even though GE cyanobacteria carrying integrated transgenes possess a more permanent change in the genomic DNA, the bio‐risk of these GE organisms in the context of gene sharing is less severe than plasmids‐carrying GE cyanobacteria. In any case, biosafety is still a potential challenge that must also be addressed.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Low temperature conversion of syngas to ethanol in liquid phase over Fe modified CuZn catalyst: The promoting effect of Fe

Fe modified CuZn catalysts were prepared and first used for the low temperature ethanol synthesis from syngas in liquid phase. Fe greatly enhanced the CO dissociative adsorption and promoted the formation of C2+ alcohols. The role of Fe was dependent on the catalyst preparation method. The co-precipitation method enhanced the interaction between Fe and other components, which could control the CO dissociative desorption to terminate the carbon chain growth of alcohols at ethanol. The wetness impregnation method benefited the dispersion of iron species and the synthesis of methanol and butanol. As a result, the co-precipitation method prepared Fe modified CuZn catalyst with spinel structure exhibited excellent catalytic performance for the low temperature syngas hydrogenation to ethanol in liquid phase with an ethanol selectivity of 40.9%.

Promoting the Synthesis of Ethanol and Butanol by Salicylic Acid

Multiwalled carbon nanotubes (MWCNTs) were functionalized with salicylic acid (SA). The copper-cobalt catalyst was impregnated on the SA functionalized MWCNTs (SA-MWCNTs). The catalyst copper-cobalt/SA-MWCNTs was used to catalyze the synthesis of alcohols from synthesis gas. Salicylic acid can promote the synthesis of ethanol and butanol from synthesis gas, thus reducing the synthesis of methanol. This work demonstrated that salicylic acid not only can be used to functionalize carbon nanotubes, but also can enhance the production of ethanol and butanol from synthesis gas. On the other hand, the copper-cobalt catalyst supported on MWCNTs of 30 nm in diameter can synthesize more ethanol and butanol than supported on MWCNTs of 15 and 50 nm in diameter, indicating that the diameter of MWCNTs also has an effect on the synthesis of alcohols.

Substrate dependent modulation of butanol to ethanol ratio in non-acetone forming Clostridium sporogenes NCIM 2918

Present study reports a non-acetone producing Clostridium sporogenes strain as a potential producer of liquid biofuels. Alcohol production was positively regulated by sorbitol and instant dry yeast as carbon and nitrogen sources respectively. Media optimization resulted in maximum butanol and ethanol titer (gL−1) of 12.1 and 7.9 respectively. Depending on the combination of carbon sources, the organism was found to manipulate its metabolism towards synthesis of either ethanol or butanol, thereby affecting the total alcohol titer. Among various dual substrate combinations, glucose-glycerol mixture in the ratio of 60:40 resulted in maximum butanol and ethanol titer (gL−1) of 11.9 and 12.1 respectively with total alcohol productivity of 0.59gL−1h−1. In the mixture, when pure glycerol was replaced with crude glycerol, butanol and ethanol titer (gL−1) of 11.2 and 11.7 was achieved. Hence, the strain shows immense potential for biofuels production using crude glycerol as cheap substrate.

USING BY MUTANT STRAINS C. ACETOBUTYLICUM LIGNO-CELLULOSIC MATERIAL AS A SUBSTRATE

Aim. To create a mutant strain with increased accumulation of butanol by chemical mutagenesis (mutating agent N-methyl-N-nitro-N-nitrosoguanidine) cultured on switchgrass biomass mash. Methods. To obtain the mutant strain there were used the method of induced mutagenesis. To determine the production of alcohols there were used gas chromatography. Results. Processing C. acetobutylicum ІMB culture B-7407 (IFBG C6H) via the mutagen N-methyl-N-nitro-N-nitrosoguanidine, led to 99% cell death. There were obtained a mutant resistant strain C. acetobutylicum IFBG C6H 5M which produced 45% more butanol on lignocellulosic materials (switchgrass biomass Panicum virgatum L) compared with the parent strain. It has been shown that the strain does not change its feature to increased synthesis of butanol over 10 passages. The strain of C. acetobutylicum IFBG C6H 5M had a similar morphology to the original strain, but gained the ability to use askulin and trehalose as a substrate. The optimal parameters of the pretreatment of raw materials (crushing ratio, the concentration in the fermentation medium, the temperature and time of cooking) for the cultivation of a mutant strain have been found. It is shown that the optimal concentration of switchgrass biomass in fermentation medium was 60 g/l. It has been shown that the highest concentration of butanol (2.6 g/l and 1.8 g/l to mutant and original strain) accumulated in the culture liquid using raw material pretreated at 2 atm. for 2 hours. Conclusions. Using the methods of induced mutagenesis promising strains can be obtained, which together with optimizations cultivation parameters have an increased yield of the desired product as compared to the parent strain.

Biobutanol as an alternative type of fuel

Butanol is an alternative type of fuel. Amid the depletion of the world’s (accessible) petroleum reserves, butanol is considered to be a potential energy source. Although butanol production was initially associated with microbiological synthesis, on an industrial scale, butanol is produced via chemical synthesis. For its production to become economically viable, strains of microorganisms must have a potential for excessive synthesis of butanol. The pathways of butanol synthesis via microorganisms and their regulation, as well as the most promising producer strains for industrial production and methods for increasing their productivity, are discussed in the survey.

One-pot synthesis of alcohols from olefins catalyzed by rhodium and ruthenium complexes

The one-pot synthesis of butanol and heptanol from propene and 1-hexene, respectively, was performed using Ru 3(PPh 3)Cl 2 and Rh(CO) 2(acac) in the presence of triphenylphosphene. The effects of various reaction parameters, including catalyst concentration, gas partial pressures, and temperature, were investigated. Two methods for performing the one-pot synthesis were developed and are discussed. In the first method, stoichiometric quantities of CO and propene or 1-hexene were fed to the autoclave. It was found that residual carbon monoxide necessary for the hydroformylation poisoned the Ru catalyst used for the hydrogenation. Venting the hydroformylation gases was therefore necessary for hydrogenation of the aldehyde to proceed. In the second method, sub-stoichiometric quantities of CO relative to olefin were fed to the autoclave, and CO conversion was driven to nearly 100%. In this case, the low residual CO concentration allowed the hydrogenation to proceed readily. The optimal temperatures and gas pressures for the hydroformylation were not the optimal temperatures and pressures for the hydrogenation. A strategy is described for maximizing the performance of both steps. Under optimal conditions, 100% conversion of propene to butanol could be achieved with 97% selectivity, and 99% conversion of 1-hexene to hepatanol could be achieved with 98% selectivity. The only byproduct observed in the latter case was a small amount of 2-hexene, which did not undergo hydroformylation. A possible reaction mechanism is proposed for both the hydroformylation of the olefin and the hydrogenation of aldehyde based on spectroscopic evidence.

Pervaporative butanol fermentation using a new bacterial strain

Fermentation processes for the production of butanol had an economic importance in the first part of this century. Today butanol is commercially produced from the Oxo reaction of propylene because relatively low priced propylene during the cracking of petroleum. Efforts have been made during the past decade or two to improve the productivity of butanol fermentation processes. It includes strain improvements, continuous fermentation processes, cell immobilization and simultaneous product separation. This review introduces a new butanol fermentation process using pervaporative product separation and a new bacterial strain producing less amount of organic acids. This review also compares the new process with chemical processes. This kind of new fermentation process may be able to compete with the chemical synthesis of butanol and revitalize the butanol fermentation process.

Sélection de mutants de Clostridium acetobutylicum défectifs dans la production d'acétone

Selection of Clostridium acetobutylicum mutants defective in acetone synthesis The butyrate analogue 2-bromobutyrate is toxic toward Clostridium acetobutylicum. After mutation using nitrosoguanidine, mutants resistant to the suicide co-substrate 2-bromobutyrate were selected. Such mutants no longer produced acetone, whereas the synthesis of butanol and ethanol was unaffected. Enzymatic analysis of a 2-bromobutyrate-resistant mutant showed a low level of coenzyme A transferase and of acetoacetate decarboxylase, the two enzymes implicated in the biosynthesis of acetone, whereas the level of hydrogenase was unaffected.

Acetone-butanol fermentation by mutants selected for resistance to acetate and butyrate halogen analogues

Acetate and butyrate halogen analogues have been used to select mutants resistant to these suicide cosubstrates. Bromoacetate, chloroacetate, fluoroacetate, chlorobutyrate allowed the selection of acidogenic mutants but the strains selected with 2-bromobutyrate failed to produce acetone, whereas the synthesis of ethanol and butanol were unaffected.

Catalytic Dehydro-Condensation Reaction of Ethanol III

In the condensation of ethanol by dehydrogenation with the use of magnesia catalyst, crotonaldehyde as intermediate product is not reduced by hydrogen but by ethanol itself. And this reaction is already proceeded at such a low temperature at which ethanol is singly unreactive. The magnesia catalyst has a property to accelerate aldol condensation of acetaldehyde at such a low tomperature at which ethanol is singly unreactive. Accordingly, the synthesis of butanol is possible by adding acetaldehyde previously into the ethanol as a raw material at such a low temperature at which ethanol is singly unreactive. By extending this consideration, the catalysts gaving no dehydrogenating activity also can be used as the catalysts for condensation of alcohols by the previous addition of acetaldehyde in the raw materials.