Production of butanol by fermentation in the presence of cocultures of clostridium

Sugars are converted to a mixture of solvents including butanol by a fermentation process employing a coculture of microorganisms of the Clostridium genus, one of said microorganisms favoring the production of butyric acid and the other of which converts the butyric acid so produced to butanol. The use of a coculture substantially increases the yield of butanol over that obtained using a culture employing only one microorganism

Butyric Acid

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142237/1/jpen0443.pd

Enhanced production of butyric acid by solid-state fermentation of rice polishings by a mutant strain of Clostridium tyrobutyricum

Purpose: To enhance butyric acid production by solid-state fermentation with a hyper-producing mutant of Clostridium tyrobutyricum generated by random mutagenesis.Methods: Wild type C. tyrobutyricum was mutagenized with UV irradiation, nitrous acid, and ethidium bromide to obtain a hyper-producing strain. Various physiochemical parameters were optimized to increase the butyric acid yield.Results: The UV-induced mutant (C.TUV) produced significantly higher concentrations of butyric acid than the wild type parent, nitrous acid-induced, and ethidium bromide-induced strains. C.TUV increased butyric acid production 1.4-fold more than the parent strain. Fermentation with C.TUV with 2.5 g of rice polishings (w/w), a 2 % inoculum volume (v/v), and a 48-h incubation period at 37°C under anaerobic conditions produced 11.63 mg/100 g of butyric acid. The addition of 0.6 % corn steep liquor as a nitrogen source increased the butyric acid concentration to 26.09 mg/100 g.Conclusion: These optimized fermentation parameters on a small scale can be used on a commercial scale to mass-produce butyric acid.Keywords: Butyric acid, Mutant, Clostridium tyrobutyricum, Mutagen, Solid-state fermentatio

Exploiting fatty acid metabolic pathway for production of short chain fatty acids in E. coli

Worldwide demand of sustainable fuels and chemicals has encouraged researchers for microbial synthesis of short chain fatty acids (SCFAs), such as such as butyric acid (C4), as they are attractive precursors to replace petroleum-based fuels and chemicals. In this study, we explored the fatty acid metabolism for production of butyric acid in E. coli with the help of three thioesterases, i.e., TesAT from Anaerococcus tetradius, TesBF from Bryantella formatexigens and TesBT from Bacteroides thetaiotaomicron. We found that E. coli strain transformed with gene for TesBT and grown in presence of 8 g/L glucose produced maximum butyric acid titer at 1.46 g/L, followed by that of TesBF at 0.85 g/L and TesAT at 0.12 g/L, showing that these thioesterases were efficiently converting short chain fatty acyl-ACP into corresponding acid. The titer of butyric acid varied significantly depending upon the strain genotype and plasmid copy number. Deletion of genes involved in initiating the fatty acid degradation such as fatty acyl-CoA synthetase and acyl-CoA dehydrogenase and overexpression of FadR, which is a dual transcriptional regulator, exerts negative control over fatty acid degradation pathway, reduced up to 30% of butyric acid titer. This observation suggested that β-oxidation pathway is working synergistically with fatty acid synthesis pathway in production of butyric acid. Moreover, accelerating the fatty acid elongation cycle by overexpressing acetyl-CoA carboxyltransferase (Acc) and 3-hydroxy-acyl-ACP dehydratase (FabZ) or by deleting FabR, the transcription suppressor of elongation, did not improve the butyric acid titer, rather favored the long chain fatty acid production. Use of chemical inhibitor cerulenin, which limits the fatty acid elongation cycle, increased the butyric acid titer by 1.7-fold in case of TesBF, while it had adverse impact in case of TesBT. In vitro enzyme assay showed that cerulenin also inhibited the short chain specific thioesterases, though inhibitory concentration varied according to the type of thioesterase used. Further improvement in butyric acid was achieved by process optimization. Owing to the same pathway for both cell growth and butyric acid production, a balance was achieved between the two by growing the cells under nutrient and oxygen limiting condition. Keeping these factors in mind, a fed-batch cultivation strategy was devised for production of butyric acid in phosphorous and carbon limiting condition. Finally, we obtained 14.3 g/L of butyric acid and 17.5 g/L of total free fatty acid. The strategy used in this study resulted in highest reported titers of butyric acid and free fatty acids in engineered E. coli and could be used to replace the traditional chemical methods for production of butyric acid

effect of butyric acid on the performance and carcass yield of broiler chickens

Short-chain fatty acids such as butyrate are considered potential alternatives to antibiotic growth promoters. The efficacy of butyric acid on performance and carcass characteristics of broiler chickens was tested in two studies. The effect of dietary butyrate on the ability to withstand coccidial oocyte challenge also was investigated. In experiment 1, male broiler chickens were fed diets supplemented with 0 or 11 ppm virginiamycin or 0.2 or 0.4% butyric acid (as mono-, di-, and triglyceride). In experiment 2, broilers were fed bacitracin methylene disalicylate or 0.1 or 0.2% butyric acid. In another trial, birds vaccinated against coccidiosis were challenged with oocytes at 21 d and examined 6 d later. In experiment 1, diet treatments had no effect on body weight gain. Feed intake of the birds fed 0.4% butyric acid was decreased (P < 0.01) compared with birds fed the nonmedicated diet during the starter period, whereas birds fed 0.2% butyric acid had similar feed intake to the control birds. In experiment 2, diet treatments did not affect the performance of broiler chicks while carcass weight and breast meat yield increased (P < 0.01) in birds fed 0.2% butyric acid. With oocyte challenge, birds that had received butyric acid before challenge showed higher growth rate following the challenge compared with birds that received nonmedicated feed. Bacitracin decreased (P < 0.05%) duodenal villi crypt depth, whereas villus length was similar in birds fed butyric acid or the nonmedicated control diet. These results show that 0.2% butyric acid can help to maintain the performance and carcass quality of broilers, especially in vaccinated birds challenged with coccidiosis

Performance of three commercial lipases in a model enzyme modified cheese system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

The effects of Amano 'R' (from Penicillium roqueforti), Palatase (from Mucor miehei) and kid lipase (from kid goat) activity on hydrolysis of triglycerides in a constant enzyme modified cheese (EMC) base have been investigated. The effects of incubation time, temperature, enzyme concentration, pH, water activity (a w ) and salt-in-moisture content on enzyme activity were studied. Under the same conditions (0.15% enzyme, 30°C, 24 h), Palatase and Amano 'R' showed a greater extent of hydrolysis (total free fatty acids) than Kid lipase. The total free fatty acids (FFAs) released by Palatase, Amano 'R' and Kid lipase were 224, 188 and 20.5 mmol FFA. kg EMC. -1 , respectively. The optimum temperature for hydrolysis by Amano 'R', Palatase and Kid lipase was around 30°C, 55°C and 45°C respectively. Amano 'R' was very heat sensitive, compared to the other two enzymes. Hydrolysis increased with increasing initial pH. The optimum pH's determined for Amano 'R', Palatase and Kid lipase were 7.5, 8.0 and 5.5 respectively. Enzyme activity decreased slightly as water activity decreased and salt-in-moisture content increased, for all enzymes. The incubation time and enzyme concentration showed the expected trend. At all process conditions, a high percentage (about 55%) of the fatty acids released by kid lipase was butyric acid. Both Palatase and Amano 'R' were relatively non selective and released large amounts of all fatty acids. Compared to Palatase, Amano 'R' selectively released a higher percentage of butyric acid (about 15% compared to 10%). Generally, the rate of release of butyric acid was greater at lower incubation temperatures for all enzymes. Also, the percentage of butyric acid release decreased with increasing initial pH for Palatase lipase

Optical Resolution and Configuration of Trans-2,3-epoxybutyric Acid

Optical resolution of epoxy derivative of butyric acid with brucine and configuration determination by treatment with ammoni

Effect of pre-germination time on amino acid profile and Gamma Amino Buytric Acid (GABA) contents in different varieties of Malaysian brown rice.

Eighteen varieties of Malaysian brown rice were evaluated for their crude protein, total glutamic acid, and gamma amino butyric acid contents after pre-germination at different times. The crude protein and total glutamic acid content increased significantly in all the varieties after pre-germination. Gamma amino butyric acid content increased dramatically with time during the pre-germination process. A significant (p < 0.05) positive correlation was observed between protein, glutamic acid, and gamma amino butyric acid contents before and after pre-germination. The brown rice varieties containing higher glutamic acid and/or protein content before the pre-germination process provided more gamma amino butyric acid content during pre-germination

Production of butyric acid by different strains of Lactobacillus plantarum (Lactiplantibacillus plantarum)

The butyric acid content produced by three Lactobacillus plantarum (Lactiplantibacillus plantarum) strains (FP37, FP38 and FP48) deposited as probiotic strains was determined. The experimentation was carried out to evaluate whether the production of butyric acid was due to lipolytic activity for the presence of specific lipases or was related to the fermentation of saccharides. Therefore, the three strains were inoculated in different substrates with and without the addition of fat (tributyrin). The free butyric acid contents were determined by gas chromatography after distilling each culture medium. The results showed that butyric acid production occurred mainly in the substrates supplemented with fat and therefore it was linked to the activity of specific L. plantarum lipase. The L. plantarum FP48 strain produced the highest amount of butyric acid in fat substrates and could be a useful strain in the development of dairy products with functional properties

Characterization of Gamma Aminobutyric Acid-producing Lactic Acid Bacteria Isolated from Budu Fish in Padang Pariaman West Sumatra Indonesia and their Potentials as Probiotics

Abstract Background and Objective: Screening of lactic acid bacteria for the production of gamma-amino-butyric acid is important due to its pharmacological functions. In this study, isolation and characterization of lactic acid bacteria from Budu fish, an endemic fish to West Sumatra, Indonesia, have been investigated and their gamma amino butyric acid-producing potentials were identified Material and Methods: The research method was as follows: lactic acid bacteria was isolated from Budu fish bought randomly from a traditional market in West Sumatra, Indonesia. Isolates were characterized morphologically and biochemically. Gram+ isolates were investigated for their capability to produce gamma-amino-butyric acid using thin-layer chromatography. Gamma-amino-butyric acid-positive strains were quantitatively analyzed using spectrometry method. Of the five samples, the highest gamma-amino-butyric acid production was reported in one sample of IB2C isolate. The selected isolates of lactic acid bacteria were molecularly identified using 16S rRNA gene sequencing. Effects of incubation time (20, 40 and 60 h) and monosodium glutamate concentrations (2, 4 and 6%) were investigated on gamma-amino-butyric acid-production strains. Results and Conclusion: Three isolates were selected for the production of gamma-amino-butyric acid in de Mann Rogosa Sharpe broth containing 1% monosodium glutamate. Semiquantitative analysis via pre-staining paper chromatography was carried out to identify the highest gamma amino butyric acid-producing lactic acid bacteria. The highest gamma-amino-butyric acid level of 22.5 mg.ml-1 was achieved using 60 h of incubation and 6% of monosodium glutamate concentration in de Mann Rogosa Sharpe broth. The IB2c isolates were Gram+, catalase-, homofermentative and able to utilize various carbon sources. It inhibited growth of Escherichia coli O157, Staphylococcus aureus and Salmonella enteritidis. The IB2C was further characterized molecularly using 16S rRNA sequencing gene. Results were identified as Lentilactobacillus parabuchneri strain M1-40. A 97.69% similarity of lactic acid bacteria isolated from Budu fish with Lentilactobacillus. parabuchneri indicates probiotic use of the gamma-amino butyric acid-producing lactic acid bacteri