Butyric Acid Addition Research Articles

Optimization of hydrogen and butanol production from agave guishe juice using Clostridium acetobutylicum ATCC824

Substrate selection is crucial to achieve cost feasibility in acetone-butanol-ethanol (ABE) fermentation. Therefore, the aim of this study was the optimization of hydrogen and butanol production by Clostridium acetobutylicum ATCC824 using Agave lechuguilla juice as low-cost substrate. Effects of C/N ratio, temperature and butyric acid addition were first evaluated conventionally (one factor at a time). Butyric acid addition showed an adverse effect in the process. In optimization studies, C/N ratio, temperature and guishe juice concentration were investigated using response surface methodology with a Box-Behnken design. Results revealed that temperature and juice concentration had significant influence, whether C/N ratio have no significant effect. Under optimum conditions, 5.96 g/L butanol and 4.37 L/L were produced. This study demonstrates the potential of guishe juice as a low-cost feedstock for hydrogen and butanol production, indicating a promising approach for further research into the full valorization of Agave lechuguilla through a biorefinery conceptualization.

Effect of Fructose and Butyric Acid Addition during Electricity Production in Single Chamber Microbial Fuel Cell

The substrate is an important factor for efficient electricity production in Microbial Fuel Cell systems. The substrate is an organic compound that promotes the growth of active microbes. The goal of this study was to investigate the effect of substrate type and concentration on the bioelectricity produced by a single-chamber MFC. Fructose and butyric acid were used as substrates and carbon felt used as an electrode. Types and variations in substrate concentration were applied to the soil media used in the MFC. After 3 weeks of incubation, the optimum power density value achieved by MFC with 90 g/L fructose substrate was 20.5 mW/m2. Whereas, MFC treated with 800 mg/L butyric acid produced a maximum power density of 19.7 mW/m2.Keywords: Substrate, Fructose, Butyric acid, Power density, Microbial Fuel Cell.

A non-solventogenic Clostridium beijerinckii strain lacking acetoacetate decarboxylase assimilates acetate and accumulates butyrate

Clostridium beijerinckii is a remarkable biocatalyst that can perform Acetone-Butanol-Ethanol (ABE) fermentation. Nevertheless, some C. beijerinckii strains lose the capacity to produce butanol. Here, we compare xylose fermentation in the presence of acetic acid and butyric acid by two C. beijerinckii strains: Br21 and ATCC 35702. The former strain is non-solventogenic (it lacks the adc gene for acetoacetate decarboxylase), whereas the latter is a known solventogenic strain capable of ABE fermentation. Fermentation of xylose alone and with acetic acid, butyric acid, or acetic and butyric acid supplementation revealed differences between strains Br21 and ATCC 35702 in terms of product profile. Strain Br21 consumed six times more acetic acid than strain ATCC 35702. External butyric acid addition helped strain ATCC 35702 to enhance butanol generation. However, butyric acid supplementation did not affect strain Br21, which was not able to reassimilate butyric acid to produce butanol. Expression of acidogenic enzymes revealed that acetoacetyl-CoA-acetate/butyrate-CoA-transferase was a key enzyme for butyric acid evolution by strain Br21. Besides xylose fermentation, strain Br21 was able to use acetic acid, a biomass hydrolysis derivative, to form butyric acid as the only fermentation product. Although C. beijerinckii Br21 was unable to form butanol, it is a promising biocatalyst for obtaining butyric acid through an unconventional pathway involving xylose fermentation and acetate assimilation.

Increased Selectivity for Butanol in Clostridium Pasteurianum Fermentations via Butyric Acid Addition or Dual Feedstock Strategy

Volatility of the petroleum market has renewed research into butanol as an alternate fuel. In order to increase the selectivity for butanol during glycerol fermentation with Clostridium pasteurianum, butyric acid can be added to the medium. In this manuscript, different methods of extracellular butyric acid addition are explored, as well as self-generation of butyric acid fermented from sugars in a co-substrate strategy. Molasses was used as an inexpensive sugar substrate, and the optimal molasses to glycerol ratio was found to allow the butyric acid to be taken back up into the cells and increase the productivity of butanol from all carbon sources. When butyric acid is added directly into the media, there was no significant difference between chemically pure butyric acid, or butyric acid rich supernatant from a separate fermentation. When low concentrations of butyric acid (1 or 2 g/L) are added to the initial media, an inhibitory effect is observed, with no influence on the butanol selectivity. However, when added later to the fermentation, over 1 g/L butyric acid is taken into the cells and increased the relative carbon yield from 0.449 to 0.519 mols carbon in product/mols carbon in substrate. An optimized dual substrate fermentation strategy in a pH-controlled reactor resulted in the relative carbon yield rising from 0.439 when grown on solely glycerol, to 0.480 mols C product/mols C substrate with the dual substrate strategy. An additional benefit is the utilization of a novel source of sugars to produce butanol from C. pasteurianum. The addition of butyric acid, regardless of how it is generated, under the proper conditions can allow for increased selectivity for butanol from all substrates.

Kinetic modeling of butyric acid effects on butanol fermentation by Clostridium saccharoperbutylacetonicum

A kinetic model of acetone-butanol-ethanol (ABE) fermentation taking into account butyric acid effects was developed and implemented in COPASI. The model was validated by comparing the simulation results with experimental data in batch cultures of Clostridium saccharoperbutylacetonicum under various concentrations of initial glucose (97.1 to 152.6 mM) and butyric acid (90.7 to 153.2 mM). The modeling results suggested that increasing the conversion rates from butyryl-CoA (BCoA) to butanol, from butyrate to BCoA, or from pyruvate to lactate would increase butanol synthesis. Similarly, reducing glucose uptake rate or the reaction rates from pyruvate to acetyl CoA (ACoA), from acetoacetyl CoA (AACoA) to BCoA, or from BCoA to butyrate would improve butanol production. Overall, the kinetic model developed can accurately predict the dynamic behavior of metabolites in ABE fermentation with butyric acid addition, which may subsequently be used to identify genetic manipulation strategies for higher bio-butanol production.

Acceleration of Echinacea purpurea (L.) Moench Shoot Growth by Benzyl Adenine and Indole Butyric Acid Addition

Echinacea (Echinacea purpurea (L.) Moench) is a medicinal plant known to boost the immune system. Propagation is necessary to increase production. One of the methods of propagation in tissue culture. This research was conducted to understand the most suitable concentration of plant growth regulators. The treatment was given a combination of Benzyl Adenine (BA) and Indole Butyric Acid (IBA) with BA concentration of 1 ppm, 2 ppm, 3 ppm and 4 ppm while the IBA concentration used was 1 ppm and 2 ppm. The next step was subculture by using the combination among IBA 0 ppm, 0.5 ppm, 0.75 ppm and BAP 0 ppm, 0.5 ppm, 0.75 ppm of BAP. The result showed that the most shoots produced by the combination treatment of BA 2 ppm and IBA 1 ppm while the highest shoot and leaf number is best produced in treatment BA 1 ppm and IBA 2 ppm. The largest number of shoots was shown by treatment BA 2 ppm and IBA 1 ppm. This study can be concluded that BA 1 ppm and IBA 2 ppm, and BA 2 ppm and IBA 1 ppm gave the best treatment for shoot growth and control for root induction.

Biogas Production on Demand Regulated by Butyric Acid Addition

Investigating effects of volatile fatty acids on the biogas process it was observed that butyric acid can be used for transient stimulation of the methane production in biogas plants operating with low energy substrates like cattle manure. Upon addition of butyrate the methane output of the reactors doubled within 24 h and reached almost 3-times higher methane yields within 3-4 days. Butyrate was quantitatively eliminated and the reactors returned to the original productivity state within 3 days when application of butyrate was stopped. The opportunity to use butyrate feeding for increased biogas production on demand is discussed.

Enhanced butanol production by optimization of medium parameters using Clostridium acetobutylicum YM1.

A new isolate of the solvent-producing Clostridium acetobutylicum YM1 was used to produce butanol in batch culture fermentation. The effects of glucose concentration, butyric acid addition and C/N ratio were studied conventionally (one-factor-at-a-time). Moreover, the interactions between glucose concentration, butyric acid addition and C/N ratio were further investigated to optimize butanol production using response surface methodology (RSM). A central composite design was applied, and a polynomial regression model with a quadratic term was used to analyze the experimental data using analysis of variance (ANOVA). ANOVA revealed that the model was highly significant (p < 0.0001) and the effects of the glucose and butyric acid concentrations on butanol production were significant. The model validation experiment showed 13.82 g/L butanol was produced under optimum conditions. Scale up fermentation in optimized medium resulted in 17 g/L of butanol and 21.71 g/L of ABE. The experimental data of scale up in 5 L bioreactor and flask scale were fitted to kinetic mathematical models published in the literature to estimate the kinetic parameters of the fermentation. The models used gave the best fit for butanol production, biomass and glucose consumption for both flask scale and bioreactor scale up.

Improved n-butanol production by a non-acetone producing Clostridium pasteurianum DSMZ 525 in mixed substrate fermentation

The kinetics of growth, acid and solvent production in batch culture of Clostridium pasteurianum DSMZ 525 were examined in mixed or mono-substrate fermentations. In pH-uncontrolled batch cultures, the addition of butyric acid or glucose significantly enhanced n-butanol production and the ratio of butanol/1,3-propanediol. In pH-controlled batch culture at pH = 6, butyric acid addition had a negative effect on growth and did not lead to a higher n-butanol productivity. On the other hand, mixed substrate fermentation using glucose and glycerol enhanced the growth and acid production significantly. Glucose limitation in the mixed substrate fermentation led to the reduction or inhibition of the glycerol consumption by the growing bacteria. Therefore, for the optimal growth and n-butanol production by C. pasteurianum, a limitation of either substrate should be avoided. Under optimized batch conditions, n-butanol concentration and maximum productivity achieved were 21 g/L, and 0.96 g/L × h, respectively. In comparison, mixed substrate fermentation using biomass hydrolysate and glycerol gave a n-butanol concentration of 17 g/L with a maximum productivity of 1.1 g/L × h. In terms of productivity and final n-butanol concentration, the results demonstrated that C. pasteurianum DSMZ 525 is well suitable for n-butanol production from mixed substrates of biomass hydrolysate and glycerol and represents an alternative promising production strain.

Enhancement of Biobutanol Production by Butyric Acid Addition Using Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564)

Enhancement of Biobutanol Production by Butyric Acid Addition Using Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564)

The Effect of Initial Butyric Acid Addition on ABE Fermentation by C. acetobutylicum NCIMB 619

The addition of organic acids to the growth medium has been shown to stimulate solvent production and protect against the degeneration of ABE-producing clostridia. The objective of this study is to demonstrate the effect of introduction of butyric acid in the fermentation media on the solvent production by C. acetobutylicum NCIMB 619. In this study, batch cultures were carried out in Reinforced Clostridial Media (RCM) containing 0.0015, 2.0 and 5.0 g/l of butyric acid, simultaneously with a control media (without addition of butyric acid) at 37°C for 72 hours. Samples were periodically withdrawn for analysis purposes. It was found that the presence of butyric acid during the early stage of the fermentation process favor the solvent yield to glucose utilization and productivity up to 139%. By adding butyric acid, the concentration of acetone, butanol and ethanol generated was improved significantly. In the case of 5.0 g/l butyric acid addition, acetone, butanol and ethanol production was increased approximately 92, 8 and 2 folds, respectively compared to control culture. The result obtained in this study showed that the addition of butyric acid has successfully enhanced the cell growth and subsequently promoted solvent production by C. acetobutylicum NCIMB 619.

Stimulation of monoclonal antibody production of hybridoma cells by butyrate: evaluation of a feeding strategy and characterization of cell behaviour.

Experiments, earlier performed in our laboratory, showedthe stimulating effect of butyric acid on monoclonalantibody production by hybridoma cells. Itssimulaneous inhibitory effect on cell growth canhowever compensate for this, so that no increase ofmonoclonal antibody titer might be obtained. We showin this article an experiment with addition of butyricacid in the middle of the growth phase of a batchculture, as a strategy to take real profit of such anaddition by a significant increase of final monoclonalantibody concentration. Indeed, in this way asignificant cell density could be obtained before theaddition of butyric acid, while the remaining culturetime was still sufficiently long for its action,resulting in a two fold increase of final monoclonalantibody titer. The experiment was carried out in a 2 L bioreactor, showing the real practical interest ofsuch an addition for the large scale production ofproteins. Furthermore, analysis of the produced IgG bySDS-PAGE and Western blot did not reveal structuralchanges after stimulation by butyric acid. An originalpoint of our study is the characterization of the cellbehaviour, by flow cytometry and other relatedtechniques, leading to a better insight in the effectof the butyric acid addition on cell growth andmonoclonal antibody production. Although there existsa lot of knowledge about the effects of butyrate oncells in the field of molecular biology, our article isat our knowledge one of the first to show some of itseffects on cell behaviour in bioreactor culture,carried out under perfectly defined and controlledconditions, and with the aim to stimulate monoclonalantibody production.

Influence of acetic and butyric acid addition on polysaccharide formation byClostridium acetobutylicum

The production of granulose (an intracellular reserve polygranule), capsule and exopolysaccharide was investigated in a synthetic medium in which the oxido-reduction level was modified by the addition of acetic or butyric acid. After addition of the acids, granulose synthesis increased from 150 to 300 mg glucose equivalents ·1−1 and capsular synthesis decreased by 25%. Exopolysaccharide production was unchanged under these conditions. A hypothesis that attributes a role to the polymer in the oxido-reduction sequences is discussed.

Preliminary characterization of a small intestinal binding component for retinol and fatty acids in the rat

A component which can bind retinol and fatty acids was detected in the rat's intestinal cell cytosol following intestinal perfusion in vivo with 3H-all-trans retinol. Following Sephadex G-100 filtration of the cytosol, the void volume concentrate was treated with 2-mercaptoethanol and SDS. Sephadex G-100 filtration of the concentrate disclosed the presence of a cytosol binder of an approximate molecular weight of 12,000–17,000. The binder contained most of the 3H-retinol eluted off the column. In vitro incubation experiments disclosed that 3H-retinol could be displaced from its bindinf cytosol fraction by the addition of nonradioactive retinol, retinyl acetate, and the fatty acids octanoic, linoleic, and linolenic. Butyric acid addition did not displace 3H-retinol from its binding fraction. The intestinal cytosol binding fraction may be involved in the trans-cytosol transport of lipid compounds from the lipid cell membrane to the intracellular organelles.