Showing papers on "2,3-Butanediol published in 2012"
TL;DR: Production of 1,3-propanediol was positively influenced by stable pH conditions and by the absence of N 2 gas infusions throughout the fermentation, and the presence of glucose as co-substrate seriously enhanced 2, 3-butanediol production.
102 citations
TL;DR: A lactate dehydrogenase-deleted mutant was constructed to improve 2,3-butanediol productivity in Enterobacter aerogenes, and the mutant showed higher carbon source consumption and microbial growth rates in all media.
Abstract: 2,3-Butanediol is an important bio-based chemical product, because it can be converted into several C4 industrial chemicals. In this study, a lactate dehydrogenase-deleted mutant was constructed to improve 2,3-butanediol productivity in Enterobacter aerogenes. To delete the gene encoding lactate dehydrogenase, λ Red recombination method was successfully adapted for E. aerogenes. The resulting strain produced a very small amount of lactate and 16.7% more 2,3-butanediol than that of the wild-type strain in batch fermentation. The mutant and its parental strain were then cultured with six different carbon sources, and the mutant showed higher carbon source consumption and microbial growth rates in all media. The 2,3-butanediol titer reached 69.5 g/l in 54 h during fed-batch fermentation with the mutant, which was 27.4% higher than that with the parental strain. With further optimization of the medium and aeration conditions, 118.05 g/l 2,3-butanediol was produced in 54 h during fed-batch fermentation with the mutant. This is by far the highest titer of 2,3-butanediol with E. aerogenes achieved by metabolic pathway engineering.
97 citations
TL;DR: Adding acetic acid and low dissolved oxygen in the medium are involved in activation of bdhA gene expression from PalsSD promoter in early log phase of growth cycle, which enhanced 2,3-butanediol production by 4-fold in comparison to the control parental strain.
Abstract: Production of 2,3-butanediol by Bacillus subtilis takes place in late-log or stationary phase, depending on the expression of bdhA gene encoding acetoin reductase, which converts acetoin to 2,3-butanediol. The present work focuses on the development of a strain of B. subtilis for enhanced production of 2,3-butanediol in early log phase of growth cycle. For this, the bdhA gene was expressed under the control of PalsSD promoter of AlsSD operon for acetoin fermentation which served the substrate for 2,3-butanediol production. Addition of acetic acid in the medium induced the production of 2,3-butanediol by 2-fold. Two-step aerobic–anaerobic fermentation further enhanced 2,3-butanediol production by 4-fold in comparison to the control parental strain. Thus, addition of acetic acid and low dissolved oxygen in the medium are involved in activation of bdhA gene expression from PalsSD promoter in early log phase. Under the conditions tested in this work, the maximum production of 2,3-butanediol, 2.1 g/l from 10 g/l glucose, was obtained at 24 h. Furthermore, under the optimized microaerophilic condition, the production of 2,3-butanediol improved up to 6.1 g/l and overall productivity increased by 6.7-fold to 0.4 g/l h in the engineered strain compared to that in the parental control.
84 citations
TL;DR: A newly developed Bacillus licheniformis is reported, the first reported high temperature butanediol producer to match the simultaneous saccharification and fermentation conditions and has potential to further lowerbutanediol producing cost with low cost lignocellulosic biomass in the near future.
Abstract: 2,3-Butanediol is an important compound that can be used in many areas, especially as a platform chemical and liquid fuel. But traditional 2,3-butanediol producing microorganisms, such as Klebsiella pneumonia and K. xoytoca, are pathogens and they can only ferment sugars at 37°C. Here, we reported a newly developed Bacillus licheniformis. A protoplast transformation system was developed and optimized for this organism. With this transformation method, a marker-less gene deletion protocol was successfully used to knock out the ldh gene of B. licheniformis BL1 and BL3. BL1 was isolated earlier from soil for lactate production and it was further evolved to BL3 for xylose utilization. Combined with pH and aeration control, ldh mutant BL5 and BL8 can efficiently ferment glucose and xylose to D-(-) 2,3-butanediol at 50°C, pH 5.0. For glucose and xylose, the specific 2,3-butanediol productivities are 29.4 and 26.1 mM/h, respectively. The yield is 0.73 mol/mol for BL8 in xylose and 0.9 mol/mol for BL5 and BL8 in glucose. The D-(-) 2,3-butanediol optical purity is more than 98%. As far as we know, this is the first reported high temperature butanediol producer to match the simultaneous saccharification and fermentation conditions. Therefore, it has potential to further lower butanediol producing cost with low cost lignocellulosic biomass in the near future.
79 citations
TL;DR: The gene encoding 2,3-butanediol dehydrogenase from an Enterobacter cloacae ssp.
67 citations
TL;DR: Evaluated the enzyme activity of meso-SADH and the whole cell conversion yield (meso-2,3-BDO/acetoin) of the E. coli SGSB02, which contains pSB02.
Abstract: meso-2,3-Butanediol (meso-2,3-BDO) is essential for the synthesis of various economically valuable biosynthetic products; however, the production of meso-2,3-BDO from expensive carbon sources is an obstacle for industrial applications. In this study, genes involved in the synthesis of 2,3-BDO in Klebsiella pneumoniae were identified and used to genetically modify Escherichia coli for meso-2,3-BDO production. Two 2,3-BDO biosynthesis genes—budA, encoding acetolactate, and meso-budC, encoding meso-SADH—from K. pneumoniae were cloned into the pUC18 plasmid and introduced into E. coli. In 2 l batch culture, the SGSB03 E. coli strain yielded meso-2,3-BDO at 0.31 g/gglucose (with a maximum of 15.7 g/lculture after 48 h) and 0.21 g/gcrude glycerol (with a maximum of 6.9 g/lculture after 48 h). Batch cultures were grown under optimized conditions (aerobic, 6% carbon source, 37 °C, and initial pH 7). To find the optimal culture conditions for meso-2,3-BDO production, we evaluated the enzyme activity of meso-SADH and the whole cell conversion yield (meso-2,3-BDO/acetoin) of the E. coli SGSB02, which contains pSB02. meso-SADH showed high enzyme activity at 30–37 °C and pH 7 (30.5–41.5 U/mg of protein), and the conversion yield of SGSB02 E. coli was highest at 37–42 °C and a pH of 7 (0.25–0.28 gmeso-2,3-BDO/gacetoin).
67 citations
TL;DR: B batch fermentation shows similar amount of 2,3-BD obtained in lab-scale fermentation, and it is possible to scale up to larger fermentors without major problems.
Abstract: The effects of culture conditions on 2,3-butanediol (2,3-BD) production and its possible scale-up have been studied. A newly isolated Bacillus amyloliquefaciens B10-127, belonged to GRAS microorganisms and showed a remarkable 2,3-BD producing potency, was used for this experiment. Corn steep liquor, soybean meal and ammonium citrate were found to be the key factors in the fermentation according to the results obtained from the Plackett–Burman experimental design. The optimal concentration range of the three factors was examined by the steepest ascent path, and their optimal concentration were further optimized via response surface methodological approach and determined to be 31.9, 22.0 and 5.58 g/l, respectively. The concentration of the obtained 2,3-BD increased significantly with optimized medium (62.7 g/l) when compared with unoptimized medium (45.7 g/l) and the 2,3-BD productivity was about 2.4-fold (The fermentation time was shorten from 72 to 42 h). To observe scale-up effects, batch fermentation was carried out at various working volumes. At a working volume of 20.0 l, the final 2,3-BD concentration and yield were 61.4 and 0.38 g/g at 36 h with a 2,3-BD productivity of 1.71 g/l h. This result shows similar amount of 2,3-BD obtained in lab-scale fermentation, and it is possible to scale up to larger fermentors without major problems.
41 citations
TL;DR: The results of fed-batch fermentation by ZG36 indicated that the glycerol flux and the distribution of metabolites were altered in the K. oxytoca when the 2,3-BD pathway was blocked and the activity of α-acetolactate decarboxylase can not be detected in the fermentation processes.
Abstract: Glycerol metabolism is a typical biological oxidoreductive reaction. 1,3-Propanediol (1,3-PD) is the final product of the reductive branch, while acetate, succinate, lactate, 2,3-butanediol (2,3-BD), and ethanol were produced in the oxidative branch. 2,3-BD, which has similar properties of high boiling point and water solubility with 1,3-PD, not only contests the carbon flow and NADH with 1,3-PD but also serves as an obstacle for obtaining high purity 1,3-PD in downstream processes. In this study, a 2,3-BD pathway-deficient mutant of Klebsiella oxytoca ZG36 was constructed by knocking out the budA gene of the wild-type strain M5al. The results of fed-batch fermentation by ZG36 indicated that the glycerol flux and the distribution of metabolites were altered in the K. oxytoca when the 2,3-BD pathway was blocked. No 2,3-BD was produced, and the activity of α-acetolactate decarboxylase (α-ALDC) can not be detected in the fermentation processes. The indexes of the 1,3-PD titer, the conversion from glycerol to 1,3-PD, and the productivity per cell dry weight (CDW) increased by 42%, 62%, and 46%, respectively, compared with the M5al, and the yield of the byproducts also increased obviously. The assay of the enzyme activities in the oxidative branch and the reductive branch of the glycerol metabolism, as well as the intracellular redox state, exposited the results logically.
30 citations
Patent•
21 Nov 2012
TL;DR: In this paper, a recombinant microorganism engineered for the production of 2,3-butanediol (BDO) was described, wherein said microorganisms overexpresses at least one gene encoding a polypeptide involved in the conversion of pyruvate into 2, 3 butanediol.
Abstract: The present invention is related to a recombinant microorganism engineered for the production of 2,3-butanediol (BDO), wherein said microorganism overexpresses at least one gene encoding a polypeptide involved in the conversion of pyruvate into 2,3- butanediol. The invention is also related to a method of production of 2,3-butanediol comprising the following steps: - providing a recombinant microorganism as described above, - cultivating the recombinant microorganism in a culture medium containing a source of carbon, and - recovering the 2,3-butanediol.
25 citations
01 Jan 2012
TL;DR: In this article, solvent extraction of 2, 3-butanediol produced by Klebsiella pneumoniae fermentation was studied to detect solvent effect on 2,3 butanediol production and determination of efficient volume of solvent.
Abstract: Recovery of metabolites from fermentation broth by solvent extraction can be used to optimize fermentation processes. End-product reutilization, low product concentration, large volumes of fermentation broth and the requirements for large bioreactors, in addition to the high cost largely contributed to the decline in fermentative 2, 3-butanediol production. Extraction can successfully be used for in-situ alcohol recovery in 2, 3-butanediol fermentations to increase the substrate conversion. In the present work organic extraction of 2, 3-butanediol produced by Klebsiella pneumoniae fermentation was studied to detect solvent effect on 2, 3-butanediol production and determination of efficient volume of solvent. The aim of this research was liquid-liquid extractive fermentation systems evaluation as an alternative to overcome the end product effect and to increase of 2, 3-butanediol production by K. pneumoniae because conventional fermentative production of 2, 3-butanediol by K. pneumoniae has the disadvantage of product reutilization by the organism. The highest 2, 3-butanediol production (23.01 g/L) achieved when 20% oleyl alcohol was used.
9 citations
TL;DR: In this paper, solvent extraction of 2, 3-butanediol produced by Klebsiella pneumoniae fermentation was studied to detect solvent effect on 2,3 butanediol production and determination of efficient volume of solvent.
Abstract: Recovery of metabolites from fermentation broth by solvent extraction can be used to optimize fermentation processes. End-product reutilization, low product concentration, large volumes of fermentation broth and the requirements for large bioreactors, in addition to the high cost largely contributed to the decline in fermentative 2, 3-butanediol production. Extraction can successfully be used for in-situ alcohol recovery in 2, 3-butanediol fermentations to increase the substrate conversion. In the present work organic extraction of 2, 3-butanediol produced by Klebsiella pneumoniae fermentation was studied to detect solvent effect on 2, 3-butanediol production and determination of efficient volume of solvent. The aim of this research was liquid-liquid extractive fermentation systems evaluation as an alternative to overcome the end product effect and to increase of 2, 3-butanediol production by K. pneumoniae because conventional fermentative production of 2, 3-butanediol by K. pneumoniae has the disadvantage of product reutilization by the organism. The highest 2, 3-butanediol production (23.01 g/L) achieved when 20% oleyl alcohol was used.
TL;DR: The metabolite profiles showed that 2,3-BDO production favors an acidic environment (pH 5), whereas cell mass favors a neutral environment, and when the pH of the culture fell below 5, both the cell growth and 2, 3- BDO production were inhibited.
Abstract: 2,3-Butanediol (2,3-BDO) is an organic compound with a wide range of industrial applications. Although Escherichia coli is often used for the production of organic compounds, the wild-type E. coli does not contain two essential genes in the 2,3-BDO biosynthesis pathway, and cannot ferment 2,3-BDO. Therefore, a 2,3-BDO biosynthesis mutant strain of Escherichia coli was constructed and cultured. To determine the optimum culture factors for 2,3-BDO production, experiments were conducted under different culture environments ranging from strongly acidic to neutral pH. The extracellular metabolite profiles were obtained using high-performance liquid chromatography (HPLC), and the intracellular metabolite profiles were analyzed by ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry (UPLC/ Q-TOF-MS). Metabolic flux analysis (MFA) was used to integrate these profiles. The metabolite profiles showed that 2,3-BDO production favors an acidic environment (pH 5), whereas cell mass favors a neutral environment. Furthermore, when the pH of the culture fell below 5, both the cell growth and 2,3-BDO production were inhibited.
Patent•
28 Mar 2012
TL;DR: In this article, a method for producing 2, 3-butanediol by using the same on the premise of taking the temperature of 42-55 DEG C and the culture stirring time of 20-60 hours as fermentation conditions and taking glucose as a substrate.
Abstract: The invention discloses bacillus licheniformis 5-2-D and a method for producing 2, 3-butanediol by using the same on the premise of taking the temperature of 42-55 DEG C and the culture stirring time of 20-60 hours as fermentation conditions and taking glucose as a substrate. In the method for producing the 2, 3-butanediol, which is provided by the invention, the advantages of high-temperature fermentation process are fully utilized, the probability of mixed fungi pollution is small, the sterilization is not performed on a fermentation culture medium, and the energy consumption and the loss of nutrient substances are reduced; simultaneously, the highest concentration of the obtained 2, 3-butanediol can achieve 92g/L and the production strength can achieve 2.56g/L/hour.
Patent•
12 Sep 2012
TL;DR: Wang et al. as mentioned in this paper used enterobacter cloacae for stably producing 2,3-butanediol at high yield and a method for compound mutation by using low-temperature plasma and diethyl sulfate.
Abstract: The invention discloses enterobacter cloacae for stably producing 2,3-butanediol at high yield and a method for compound mutation by using low-temperature plasma and diethyl sulfate The enterobacter cloacae is classified and named as Enterobacter cloacae DLM and has the preservation number of CGMCC (China General Microbiological Culture Collection Center) 6053 The mutation method is characterized in that bacterium is suspended into physiological saline and pretreatment of diethyl sulfate and compound mutation of the low-temperature plasma and the diethyl sulfate are sequentially carried out The strain can be used for producing the 2,3-butanediol by fermenting different effectively-utilized carbon sources, wherein the conversion rate of sugar is high and the concentration of the 2,3-butanediol is high; and when glucose or synanthrin is hydrolyzed into a carbon source, the concentrations of the 2,3-butanediol in a 5L fermentation tank respectively reach 1252g/l and 1202g/l The mutation method used in the invention has the characteristics of simpleness and feasibility in operation, short treatment time in mutation and the like and provides a reliable method for mutation breeding of microorganisms
Patent•
01 Aug 2012
TL;DR: In this article, the Geobacillus sp. XT15 was used for 2, 3-butanediol and acetoin production through high-temperature fermentation, which has the advantages of unwanted microbe contamination resistance, high reaction rate, cooling water saving and extensive operation.
Abstract: The invention discloses Geobacillus sp. and application thereof to 2, 3-butanediol and acetoin production through high-temperature fermentation. The strain is Geobacillus sp. XT15 with collector number being CCTCC No.M2011022, is positive through gram staining and generates spores; the cellular morphology is rod-shaped, the length is 0.9-1.8mum and the diameter is 0.4-0.5mum; the strain can grow at 28-65 DEG C and the multiplication speed at 45-55 DEG C is the highest; and the most proper pH value of fermentation media for 2, 3-butanediol and acetoin production is 8.0. By using the strain, and taking glucose as a carbon source, 2, 3-butanediol and acetoin with total concentration being 46.1-57.9g/L can be produced after 48h of shake flask fermentation at 55 DEG C. The method for 2, 3-butanediol and acetoin production through high-temperature fermentation provided by the invention has the advantages of unwanted microbe contamination resistance, high reaction rate, cooling water saving, extensive operation and the like.
Patent•
31 Aug 2012
TL;DR: In this paper, a klebsiella oxytoca M1 (KCCM11177P) strain has a superior production yield of 2,3- butanediol.
Abstract: PURPOSE: A klebsiella oxytoca M1 having a superior production yield of 2,3- butanediol is provided to manufacture 2,3- butanediol in short time at high yield, thereby mass producing 2,3- butanediol. CONSTITUTION: A klebsiella oxytoca M1(KCCM11177P) has a superior production yield of 2,3- butanediol. A manufacturing method of 2,3- butanediol comprises the following steps: cultivating klebsiella oxytoca M1 strain in a culture medium including carbon source klebsiella oxytoca M1; and collecting 2,3-butanediol in the culture medium. The culturing temperature of the cultivation is 25-35 deg. Celsius. The cultivation is enforced under the aerobic condition. The Klebsiella oxytoca M1(KCCM11177P) strain as high yield of acetoin. A manufacturing method of acetoin comprises the following steps: culturing the Klebsiella oxytoca M1 strain under aerobic condition in a culture medium including carbon source; and collecting the acetoin from the culture medium. The culturing temperature of the cultivation step is 34-42 deg.Celsius.
Patent•
12 Oct 2012
TL;DR: In this article, a 2,3-butanediol broth produced by fermentation of microorganisms is distilled by adding an alkaline substance after the nanofiltration membrane treatment and ion exchange treatment step.
Abstract: 2,3-butanediol broth produced by fermentation of microorganisms is distilled by adding an alkaline substance after the nanofiltration membrane treatment and ion exchange treatment step (Step A) (Step B) that is, high purity and coloration degree can be obtained significantly lower 2,3-butanediol BACKGROUND