Microbial Electrosynthesis of Bioalcohols through Reduction of High Concentrations of Volatile Fatty Acids

2019 ◽  
Vol 33 (5) ◽  
pp. 4264-4271 ◽  
Author(s):  
José Gavilanes ◽  
C. Nagendranatha Reddy ◽  
Booki Min
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Microbial Electrosynthesis ◽  
High Concentrations

scholarly journals Diurnal variations in the concentrations of volatile fatty acids in the alimentary tracts of wild rabbits

1972 ◽  
Vol 27 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Susan J. Henning ◽  
F. J. R. Hird
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Distal Colon ◽  
Proximal Colon ◽  
Diurnal Variations ◽  
Gut Contents ◽  
Excretion Pattern ◽  
Colon And Rectum ◽  
High Concentrations

1. Wild rabbits were caught during both phases of the excretory cycle and their gut contents were analysed for volatile fatty acids (VFA).2. All rabbits were found to have high concentrations of VFA in the caecum and in the proximal colon. Acetic was the most abundant acid followed by n-butyric, then propionic.3. VFA concentrations in the caecum and in the proximal colon of rabbits caught during the day and during the night were similar. Hard pellets from the distal colon and rectum of rabbits caught during the night had considerably less VFA than did the soft pellets from rabbits caught during the day.4. Owing to the ingestion of soft faeces, the VFA content of stomach material was greater in rabbits caught during the day than in those caught at night.5. The results are discussed in terms of the mechanism of the diurnal excretion pattern and the role of coprophagy in the rabbit.

Sites of organic acid production and absorption in gastrointestinal tract of the pig

1975 ◽  
Vol 228 (2) ◽  
pp. 454-460 ◽  
Author(s):  
RA Argenzio ◽  
M Southworth
Keyword(s):  
Fatty Acids ◽  
Gastric Mucosa ◽  
Organic Acid ◽  
Intestinal Mucosa ◽  
Volatile Fatty Acids ◽  
Control Diet ◽  
Organic Acid Production ◽  
Rumen Epithelium ◽  
High Concentrations ◽  
Digesta Passage

The relationship between diet, pH, and microbial digestion of carbohydrate was examined in 24 pigs fed either a conventional or a low-protein, high-cellulose experimental diet and sacrificed 2, 4, 8, or 12 h after a meal. In animals fed the control diet contents of the cranial half of the stomach demonstrated marked, cyclic fluctuations in pH and high concentrations of organic acids. Contents of the caudal (glandular) half were lower in both pH and organic acid concentration. Despite concentrations of volatile fatty acids (VFAs) as high as 250 meq/liter in the large intestine, the pH remained relatively neutral. The VFA levels remained relatively constant throughout the length of the colon. The VFA transport across isolated gastric and large intestinal mucosa also was examined. All four types of gastric mucosa absorbed and transported VFA at substantial rates. Mucosa of pig cecum and colon transported VFA at much greater rates than gastric mucosa and greater rates than previously determined in equine large intestinal mucosa or even bovine rumen epithelium. Comparison with results of earlier studies in the pony suggested that the higher concentration of VFA in the large intestinal contents of pigs was due to the more rapid rate of digesta passage rather than to less efficient absorption of fatty acids.

Codigestion of manure and industrial organic waste at centralized biogas plants: process imbalances and limitations

2008 ◽  
Vol 58 (7) ◽  
pp. 1521-1528 ◽  
Author(s):  
H. B. Nielsen ◽  
I. Angelidaki
Keyword(s):  
Fatty Acids ◽  
Industrial Waste ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Process Conditions ◽  
Process Data ◽  
Waste Products ◽  
Inadequate Knowledge ◽  
Biogas Plants ◽  
High Concentrations

The present study focuses on process imbalances in Danish centralized biogas plants treating manure in combination with industrial waste. Collection of process data from various full-scale plants along with a number of interviews showed that imbalances occur frequently. High concentrations of ammonia or long chain fatty acids is in most cases expected to be the cause of microbial inhibitions/imbalances while foaming in the prestorage tanks and digesters is the most important practical process problem at the plants. A correlation between increased residual biogas production (suboptimal process conditions) and high fractions of industrial waste in the feedstock was also observed. The process imbalances and suboptimal conditions are mainly allowed to occur due to 1) inadequate knowledge about the waste composition, 2) inadequate knowledge about the waste degradation characteristics, 3) inadequate process surveillance, especially with regard to volatile fatty acids, and 4) insufficient pre-storage capacity causing inexpedient mixing and hindering exact dosing of the different waste products.

scholarly journals Limiting factors for anaerobic digestion of olive mill wastewater blends under mesophilic and thermophilic conditions

2018 ◽  
Vol 49 (2) ◽  
pp. 130-137
Author(s):  
Demetrio Antonio Zema ◽  
Giovanni Zappia ◽  
Souraya Benalia ◽  
Giuseppe Zimbalatti ◽  
Enzo Perri ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Olive Mill Wastewater ◽  
Limiting Factors ◽  
Citrus Peel ◽  
Thermophilic Conditions ◽  
High Concentrations ◽  
Olive Mill

Experimental trials of anaerobic digestion of olive mill wastewater (OMW) blended with other agro-industrial by-products were carried out to evaluate biogas production and sensitivity of the process to inhibiting compounds. Blends containing different percentages of OMW, digested liquid manure, and citrus peel were subjected to a batch anaerobic digestion process under both mesophilic and thermophilic conditions. The results showed that blends with percentages of OMW higher than 20% (v/v) had low methane yields due high concentrations of polyphenols (PPs) and/or volatile fatty acids (concentrations above 0.8 g kg–1 and 2.4 g L–1, respectively). The addition of other substrates such as citrus peel may have induced synergic inhibiting effects of PPs and essential oils (EO) on microbial growth. Thermophilic processes were more sensitive to these inhibiting compounds than mesophilic processes. The results of this study suggest that reducing PPs and EO concentrations in blends subject to anaerobic digestion below the inhibiting concentrations of 0.6 g L–1 and 0.5 g kg–1, respectively, is suitable. Additionally, it is advisable to maintain the volatile fatty acids content below 2 g L–1 to avoid its evident toxic effects on the growth of microorganisms in biochemical processes.

Properties of Oils From Plantain Pseudostem Biotransformed Using Crude Local Enzyme Sources: A Comparison of Poultry Feed Oil

2019 ◽  
Vol 10 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Amadi P. Uchenna ◽  
Ogunka-Nnoka U. Charity ◽  
Abbey Bene
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Radical Scavenging ◽  
Poultry Feed ◽  
Tetradecanoic Acid ◽  
Digestive Juice ◽  
Peroxide Values ◽  
Nitric Oxide Radical ◽  
High Concentrations ◽  
Simultaneous Saccharification

Background: Plantain Pseudostem (PPS) wastes were biotransformed by applying Simultaneous Saccharification and Fermentation (SSF) using excised snail digestive juice and yeast slurry, and their oil properties compared with oils from commercially sold poultry feeds (PF). Patents suggesting the inclusion of certain additives (US20090226558A1), spices (US5741508A), cysteamine (US4711897A), and dextrin (US6326051B1) in animal diets are regarded as expensive, thus, requiring cheaper and readily available sources of growth. Methods: The analysis of their free radical scavenging potentials was carried by spectrophotometry, while fatty acids, volatile fatty acids, essentials oils, and phytosterols were determined by chromatography. Results: After biotransformation, the melting point, specific gravity, acid, and peroxide values of the oils from SSF-PPS were significantly lower than those of PF, and showed elevations of C6:0- C18:1(trans-9) fatty acids, palmitic, stearic, γ-Linolenic, α-linolenic, behenic, and lignoceric acids. Camphene, β-phelandrene, eugenol, β-elemene, bicyclogermacrene, guaiol, tetradecanoic acid, and hexadecanoic acid levels decreased when PPS was biotransformed. Lactic (1575.75 mg/100g), acetic (1234.26 mg/100g), propionic (845.74 mg/100g), and n-butyric (68.56 mg/100g) acids were the predominant Volatile Fatty Acids (VFAs) in the SSF-PPS oils, which were higher than those found in the PF oil while PF oil contained higher campesterol, Stigmasterol, and 5-avesmasterol. The 2,2- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 1,1-diphenyl-2- picrylhydrazyl (DPPH), superoxide, and nitric oxide radical scavenging potentials of PPS oil at high concentrations after biotransformation were equivalent to the standards and the PF oil. Conclusion: his study has shown that biotransformation involving snail digestive juice and yeasts extensively improves the oil qualities of agricultural residues sufficient enough for poultry nutrition.

Mesoporous silica supported CeO2/Cellulose cathode catalyst for efficient bioelectrochemical reduction of inorganic carbon to biofuels

2021 ◽  
Author(s):  
Dayakar Thatikayala ◽  
Deepak Pant ◽  
Booki Min
Keyword(s):  
Fatty Acids ◽  
Mesoporous Silica ◽  
Volatile Fatty Acids ◽  
Inorganic Carbon ◽  
Cathode Catalyst ◽  
Single Chamber ◽  
Microbial Electrosynthesis ◽  
Cathode Electrode

In this study, a novel efficient cathode electrode was fabricated to convert inorganic carbon to volatile fatty acids (VFAs) through microbial electrosynthesis (MES) in a single chamber reactor. The cathode...

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