sodium-acetate--anhydrous and hexanoic-acid

Caproic acid is the precursor of ethyl caproate, the main representative flavor substance of strong-flavor baijiu (SFB). Caproic acid-producing bacteria are considered to be the most important type of acid-producing microorganisms in the pit mud of the SFB ecosystem. In this study, the Rummeliibacillus suwonensis 3B-1 with a high yield of caproic acid (4.064 g/L) was screened from SFB pit mud. The genome of the R. suwonensis 3B-1 was sequenced, the total size was found to be 4117,671 bp and a calculated GC content of 35.86%. The caproic acid biosynthesis pathway was identified and analyzed, and it showed that 3B-1 could not only use ethanol, but it could also use glucose and other carbon sources as substrates to produce caproic acid. According to the genome analysis and with an optimized medium, the optimal conditions for caproic acid production were yeast powder at 3 g/L, sodium acetate at 15 g/L, and 1% biotin at 8 mL/100 mL. The yield of caproic acid reached 4.627 g/L, an increase of 13.9%, which was higher than that of general caproic acid bacteria. This is the first report of the synthesis of caproic acid by R. suwonensis. This strain could be used to produce caproic acid, an artificial pit mud preparation, and/or an enhanced inoculum in the production of SFB.

Topics: Alcoholic Beverages; Bacteria; Biotin; Caproates; Carbon; Ecosystem; Ethanol; Fermentation; Glucose; Planococcaceae; Powders; Sodium Acetate

In a study screening anaerobic microbes utilizing D: -galactitol as a fermentable carbon source, four bacterial strains were isolated from an enrichment culture producing H₂, ethanol, butanol, acetic acid, butyric acid, and hexanoic acid. Among these isolates, strain BS-1 produced hexanoic acid as a major metabolic product of anaerobic fermentation with D: -galactitol. Strain BS-1 belonged to the genus Clostridium based on phylogenetic analysis using 16S rRNA gene sequences, and the most closely related strain was Clostridium sporosphaeroides DSM 1294(T), with 94.4% 16S rRNA gene similarity. In batch cultures, Clostridium sp. BS-1 produced 550 ± 31 mL L⁻¹ of H₂, 0.36 ± 0.01 g L⁻¹ of acetic acid, 0.44 ± 0.01 g L⁻¹ of butyric acid, and 0.98 ± 0.03 g L⁻¹ of hexanoic acid in a 4-day cultivation. The production of hexanoic acid increased to 1.22 and 1.73 g L⁻¹ with the addition of 1.5 g L⁻¹ of sodium acetate and 100 mM 2-(N-morpholino)ethanesulfonic acid (MES), respectively. Especially when 1.5 g L⁻¹ of sodium acetate and 100 mM MES were added simultaneously, the production of hexanoic acid increased up to 2.99 g L⁻¹. Without adding sodium acetate, 2.75 g L⁻¹ of hexanoic acid production from D-galactitol was achieved using a coculture of Clostridium sp. BS-1 and one of the isolates, Clostridium sp. BS-7, in the presence of 100 mM MES. In addition, volatile fatty acid (VFA) production by Clostridium sp. BS-1 from D-galactitol and D: -glucose was enhanced when a more reduced culture redox potential (CRP) was applied via addition of Na₂S·9H₂O.

Topics: Acetic Acid; Anaerobiosis; Base Sequence; Biofuels; Butyric Acid; Caproates; Clostridium; Fermentation; Galactitol; Genes, rRNA; Oxidation-Reduction; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Sewage; Sodium Acetate; Water Microbiology

We evaluated the potential of sodium [1-(11)C]hexanoate (11C-HA) as a radiopharmaceutical with which to assess oxidative metabolism of the brain by PET. 11C-HA, sodium [1-(14)C]acetate and [3H]deoxyglucose were simultaneously injected into mice under control, hypoxic and starving conditions. In the control, the brain uptake of 11C was maximal at 3 min (% ID/g = 2.2-2.5), being twice as high as that of 14C, followed by a gradual clearance. The time-radioactivity curve of 11C was similar to that of 14C. Hypoxia enhanced the brain uptake of 3H, but not of either 11C or 14C. Starvation enhanced the brain uptake of 3H and 11C. The clearance rate of 11C was not significantly affected by either condition. In the control brain at 3 min postinjection of HA, 65% of the total radioactivity was detected as labeled glutamate and glutamine, which was gradually decreased by 47% at 30 min. The brain to blood ratios of 11C-HA at 3 min were significantly reduced by butyrate, hexanoate and octanoate loading but not by that with other monocarboxylic acids or ketone bodies.

Topics: Animals; Brain; Caproates; Carbon Radioisotopes; Deoxyglucose; Hypoxia, Brain; Injections, Intravenous; Male; Mice; Mice, Inbred Strains; Sodium Acetate; Tomography, Emission-Computed; Tritium