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The Journal of Biological Chemistry Feb 2022The autotrophic acetogen Clostridium ljungdahlii has emerged as a major candidate in the biological conversion of one-carbon gases (CO/CO) to bulk chemicals and fuels....
The autotrophic acetogen Clostridium ljungdahlii has emerged as a major candidate in the biological conversion of one-carbon gases (CO/CO) to bulk chemicals and fuels. Nevertheless, the regulatory pathways and downstream metabolic changes responsible for product formation and distribution in this bacterium remain minimally explored. Protein lysine acetylation (PLA), a prevalent posttranslational modification, controls numerous crucial cellular functions. Herein, we revealed a novel cross-regulatory mechanism that uses both the PLA system and transcription factors to regulate the carbon flow distribution for product formation in C. ljungdahlii. The dominant acetylation/deacetylation system (At2/Dat1) in C. ljungdahlii was found to regulate the ratio of two major products, acetic acid and ethanol. Subsequent genetic and biochemical analyses revealed that the activities of Pta and AdhE1, two crucial enzymes responsible for acetic acid and ethanol synthesis, respectively, were greatly affected by their levels of PLA. We found that the acetylation statuses of Pta and AdhE1 underwent significant dynamic changes during the fermentation process, leading to differential synthesis of acetic acid and ethanol. Furthermore, the crucial redox-sensing protein Rex was shown to be regulated by PLA, which subsequently altered its transcriptional regulation on genes responsible for acetic acid and ethanol formation and distribution. Based on our understanding of this cross-regulatory module, we optimized the ethanol synthetic pathway by modifying the acetylation status (deacetylation-mimicked mutations of crucial lysine residues) of the related key enzyme, achieving significantly increased titer and yield of ethanol, an important chemical and fuel, by C. ljungdahlii in gas fermentation.
Topics: Acetic Acid; Acetylation; Carbon; Clostridium; Ethanol; Fermentation; Gases; Lysine; Polyesters; Protein Processing, Post-Translational
PubMed: 34954142
DOI: 10.1016/j.jbc.2021.101538 -
Nature Communications Jan 2017Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we...
Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we report an iridium-catalysed tyrosinase-like approach to catechols, employing an oxyacetamide-directed C-H hydroxylation on phenols. This method achieves one-step, redox-neutral synthesis of catechols with diverse substituent groups under mild conditions. Mechanistic studies confirm that the directing group (DG) oxyacetamide acts as the oxygen source. This strategy has been applied to the synthesis of different important catechols with fluorescent property and bioactivity from the corresponding phenols. Finally, our method also provides a convenient route to O-labelled catechols using O-labelled acetic acid.
Topics: Acetamides; Acetic Acid; Catalysis; Catechols; Fluorescence; Hydroxylation; Iridium; Oxidation-Reduction; Oxygen; Oxygen Isotopes; Phenols; Staining and Labeling
PubMed: 28128196
DOI: 10.1038/ncomms14227 -
Journal of Food Protection Dec 2022Infection with hepatitis E virus genotype 3 (HEV-3) is an emerging cause of illness in developed countries. In North America and Europe, HEV-3 has been increasingly...
ABSTRACT
Infection with hepatitis E virus genotype 3 (HEV-3) is an emerging cause of illness in developed countries. In North America and Europe, HEV-3 has been increasingly detected in swine, and exposure to pigs and pork products is considered the primary source of infection. We have previously demonstrated the prevalence of the HEV-3 genome in commercial pork products in Canada. In this study, we investigated the application of citric acid and acetic acid to inactivate HEV-3 on food and on food contact surfaces. For this purpose, plastic, stainless steel, and pork pâté surfaces were inoculated with HEV-3 and were treated with acetic acid or citric acid at 1, 3, or 5%. The infectivity of posttreatment viral particles was determined by cell culture. A greater than 2-log reduction in viral infectivity was observed on plastic and stainless steel treated with the organic acids, but the treatment was less effective on HEV infectivity on pork pâté (average reductions of 0.47 log citric acid and 0.63 log acetic acid). Therefore, we conclude that citric acid and acetic acid have potential application to control HEV-3 on food contact surfaces but are not suitable for food.
Topics: Swine; Animals; Hepatitis E virus; Stainless Steel; Plastics; Acetic Acid; Citric Acid
PubMed: 36048964
DOI: 10.4315/JFP-22-164 -
Poultry Science Jul 2021Peroxyacetic acid (PAA) is a widely used antimicrobial during poultry processing that requires to be shipped in a concentrated solution, stored under hazardous...
Peroxyacetic acid (PAA) is a widely used antimicrobial during poultry processing that requires to be shipped in a concentrated solution, stored under hazardous conditions and diluted for use. On-site PAA generation using nonhazardous ingredients can help eliminate transportation and storage issues at the processing plant and reduce the risk of occupational hazards. The objective of the proposed research was to 1) evaluate the efficacy of on-site generated PAA in reducing Salmonella and Campylobacter populations compared to the commercially available PAA stock solutions and 2) to perform color measurements to evaluate any deviations between treatments. PAA solutions at 50 and 100 ppm were used for treating the chicken wings. Fresh chicken wings (0.45 kg) were inoculated with a cocktail of nalidixic acid resistant Salmonella Typhimurium (STNR) and gentamicin resistant Campylobacter coli (CCGR) and immersed in PAA solutions (50 and 100 ppm) adjusted to pH 8.5 and 10.0 or 10.5, for either 10 s or 60 min. Treated chicken wings were rinsed for 1 min in chilled BPW (100 mL), serially diluted and plated on APC Petrifilm for Salmonella, spread plated on Campy-cefex agar supplemented with gentamicin (200 ppm) for Campylobacter enumeration. Immersion of chicken wings in 100 ppm PAA for 60 min irrespective of pH levels and PAA solutions resulted in greater microbial reductions (P < 0.05) of Salmonella by 1.68 and 1.42 log CFU/mL for SaniDate, 1.82 and 1.83 log CFU/mL for OxyFusion (on-site generated). For the same treatments, Campylobacter reductions of 1.59 and 1.36 log CFU/mL for SaniDate, 1.63 and 1.71 log CFU/mL for OxyFusion were achieved. The antimicrobial efficiency of PAA was not affected by pH and type of PAA solution. No significant differences (P > 0.05) in color were observed between treatments and controls. On-site generated PAA provides poultry processors an effective, safer, and less hazardous alternative to commercially available PAA solutions, ensuring poultry workers' health and safety.
Topics: Acetic Acid; Animals; Campylobacter; Chickens; Colony Count, Microbial; Food Handling; Food Microbiology; Meat; Peracetic Acid; Technology
PubMed: 34111613
DOI: 10.1016/j.psj.2021.101206 -
Poultry Science May 2022This study investigated the bactericidal effects of plasma-activated acetic acid (PAAA) on Salmonella Typhimurium and its impact on the physicochemical traits of chicken...
This study investigated the bactericidal effects of plasma-activated acetic acid (PAAA) on Salmonella Typhimurium and its impact on the physicochemical traits of chicken meat. Twenty milliliters of 0.8% (v/v) acetic acid (AA) was treated with plasma (2.2 kHz and 8.4 kVpp) for 30 min. The chicken skins, breasts, and drumsticks, inoculated with S. Typhimurium, were immersed in AA or PAAA and incubated for 10 min. The S. Typhimurium on the breasts and drumsticks were significantly susceptible to treatment with AA and PAAA, compared to the control group (deionized water treatment), and the population of bacterial cells in PAAA-treated chicken breasts and drumsticks decreased by 0.98 and 1.19 log CFU/g, respectively, compared with AA. The values for pH and 2-thiobarbituric acid reactive substances (TBARS) of PAAA-treated samples decreased significantly compared to the control group. The lightness (L*) values of the chicken breasts after AA and PAAA treatments increased compared to the control group, whereas the value for yellowness (b*) decreased. The scanning electron microscopic (SEM) images and the results for volatile compounds in chicken meat revealed similar patterns, with no significant differences between AA and PAAA treatments. In conclusion, we found that PAAA was more effective than AA and synergistic PAAA treatment of chicken caused to the reduction of S. Typhimurium and improve the meat quality. Therefore, PAAA could be utilized as a promising decontaminant for the chicken meat industry.
Topics: Acetic Acid; Animals; Chickens; Colony Count, Microbial; Food Microbiology; Meat; Salmonella typhimurium
PubMed: 35325832
DOI: 10.1016/j.psj.2022.101793 -
Microbiological Research Dec 2023Acetic acid tolerance of Saccharomyces cerevisiae is an important trait in sourdough fermentation processes, where the accumulation of acid by the growth of lactic acid...
Acetic acid tolerance of Saccharomyces cerevisiae is an important trait in sourdough fermentation processes, where the accumulation of acid by the growth of lactic acid bacteria reduces the yeast metabolic activity. In this work, we have carried out adaptive laboratory evolution (ALE) experiments in two sourdough isolates of S. cerevisiae exposed to acetic acid, or alternatively to acetic acid and myriocin, an inhibitor of sphingolipid biosynthesis that sped-up the evolutionary adaptation. Evolution approaches resulted in acetic tolerance, and surprisingly, increased lactic susceptibility. Four evolved clones, one from each parental strain and evolutionary scheme, were selected on the basis of their potential for CO production in sourdough conditions. Among them, two showed phenotypic instability characterized by strong lactic sensitivity after several rounds of growth under unstressed conditions, while two others, displayed increased constitutive acetic tolerance with no loss of growth in lactic medium. Genome sequencing and ploidy level analysis of all strains revealed aneuploidies, which could account for phenotypic heterogeneity. In addition, copy number variations (CNVs), affecting specially to genes involved in ion transport or flocculation, and single nucleotide polymorphisms (SNPs) were identified. Mutations in several genes, ARG82, KEX1, CTK1, SPT20, IRA2, ASG1 or GIS4, were confirmed as involved in acetic and/or lactic tolerance, and new determinants of these phenotypes, MSN5 and PSP2, identified.
Topics: Saccharomyces cerevisiae; Acetic Acid; DNA Copy Number Variations; Saccharomyces cerevisiae Proteins; Fermentation; Phenotype; Karyopherins
PubMed: 37713908
DOI: 10.1016/j.micres.2023.127487 -
Biomolecules Oct 2022We report the discovery of a new abscisic acid (ABA) metabolite, found in the course of a mass spectrometric study of ABA metabolism by the rhizosphere bacterium sp....
We report the discovery of a new abscisic acid (ABA) metabolite, found in the course of a mass spectrometric study of ABA metabolism by the rhizosphere bacterium sp. P1Y. Analogue of (+)-ABA, enriched in tritium in the cyclohexene moiety, was fed in bacterial cells, and extracts containing radioactive metabolites were purified and analyzed to determine their structure. We obtained mass spectral fragmentation patterns and nuclear magnetic resonance spectra of a new metabolite of ABA identified as 1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexene-1-acetic acid, which we named rhodococcal acid (RA) and characterized using several other techniques. This metabolite is the second bacterial ABA degradation product in addition to dehydrovomifoliol that we described earlier. Taken together, these data reveal an unknown ABA catabolic pathway that begins with side chain disassembly, as opposed to the conversion of the cyclohexene moiety in plants. The role of ABA-utilizing bacteria in interactions with other microorganisms and plants is also discussed.
Topics: Abscisic Acid; Acetic Acid; Tritium; Transformation, Bacterial; Plant Extracts
PubMed: 36291718
DOI: 10.3390/biom12101508 -
Poultry Science Aug 2020The cuticle is the outmost layer of the eggshell and may affect the hatchability by modulating eggshell conductance. Three different solutions using acetic acid (AA),...
The cuticle is the outmost layer of the eggshell and may affect the hatchability by modulating eggshell conductance. Three different solutions using acetic acid (AA), vinegar (V), and citric acid (CA) for cuticle removal by egg washing were developed, and the effects of cuticle removal on hatching performance of quail hatching eggs were evaluated. A total of 5,238 fresh quail hatching eggs were randomly divided into 9 treatments as follows: unwashed control, nondipped (CND); washed control, water dipped (CWD); standard control, 0.13% sodium hyperchlorite (CSH); 2% AA (AA2); 4% AA (AA4); 44.4% V (V2); 88.8% V (V4); 2% CA (CA2); and 4% CA (CA4). Overall, AA4, V4, and CA4 treatments significantly improved the hatchability of fertile eggs (95.42%, 94.16% and 95.66%, respectively) (P < 0.05) and the hatchability of CND, CWD, CSH, AA2, V2 and CA2 treatments were 90.98%, 93.00%, 92.27%, 79.44%, 90.37%, and 90.59%, respectively. The eggshell thickness and cuticle quality results showed that all AA, V, and CA solutions can effectively remove the quail eggshell cuticle, and AA4, V4 and CA4 significantly decreased eggshell thickness (P < 0.05). Microbial activity on the eggshell surface in all acid treatments was reduced significantly at day 0 of incubation (P < 0.05) and that significantly decreased than controlled treatments over the incubation period except AA2 treatment. Egg weight loss was lower for all acid treatments than that of the CND treatment (P < 0.05). There was no clear effect of treatments on chick quality. Hatch time in AA4, V4, and CA4 treatments slightly improved compared with controlled treatments (P > 0.05). There were no significant differences between treatments for chick livability and live weight at the first 21 D of life. Results of the present study indicate that cuticle removal with AA4, V4, or CA4 could effectively decrease the microbial activity on the eggshell surface during the incubation period and improve hatchability of quail hatching eggs without negative effects on hatch time and performance of quail chicks.
Topics: Acetic Acid; Animal Husbandry; Animals; Citric Acid; Egg Shell; Female; Microbiota; Quail
PubMed: 32731973
DOI: 10.1016/j.psj.2020.04.018 -
International Journal of Molecular... Feb 2023Ethanol intoxication, although an elemental part of life in many places around the world, still presents several issues associated with excessive consumption. These...
Ethanol intoxication, although an elemental part of life in many places around the world, still presents several issues associated with excessive consumption. These issues range from drunk driving, violence, and antisocial behavior to self-harm, all exerting an increased cost on the society. Monitoring of intoxication levels can help to limit the impact of these issues by preventing the use of automobiles or heavy machinery and personal monitoring. Previous works on noninvasive measurement of ethanol tissue concentration for estimation of blood alcohol concentration (BAC) performed worst during the first hour of intoxication. Gas chromatography research of intoxication shows that levels of acetic acid rise together at a similar rate as those of ethanol after initial imbibement. In this research, short-wave infrared (SWIR) spectroscopy was utilized with the aim of establishing the interaction between ethanol and acetic acid in water and serum mixtures. The most consistent and clear correlation between ethanol and acetic acid was recorded at 2262 and 2302 nm wavelengths. Partial least-squares (PLS) analysis indicates that the most effective region for consideration in measurement of ethanol is the therapeutic window four (IV) due to high variance in vibration of carbon bonds. The behavior of spectra at different concentration ranges was examined and described in detail in relation to the consequence of alcohol measurement. The investigation concluded that ethanol shows distinctive regions of absorbance at wavelengths of 2262 and 2302 nm, with variations arising from increasing concentrations of acetic acid, whilst also showing that therapeutic window four is amongst the most influential regions of the spectrum for SWIR.
Topics: Humans; Ethanol; Blood Alcohol Content; Acetic Acid; Water; Spectrophotometry, Infrared
PubMed: 36769307
DOI: 10.3390/ijms24032980 -
Journal of Physiology and Pharmacology... Aug 2022Gastroesophageal reflux disease (GERD) is a condition characterized by persistent symptoms and complications resulting from reflux of gastric contents into the...
Gastroesophageal reflux disease (GERD) is a condition characterized by persistent symptoms and complications resulting from reflux of gastric contents into the esophagus. Short-chain fatty acids (SCFAs) are fermentation products of dietary fibres by the gut microbiota and are often studied for their anti-inflammatory and anticancer effects. The presence of SCFAs in the upper gastrointestinal tract, including in patients with GERD, has not been previously studied. The aim of this study was to investigate the relationship between the concentrations of SCFAs in the saliva of different age groups of patients with GERD. The study included 86 patients diagnosed with GERD, divided into two groups according to age: under and over 60 years of age, treated in the Gastroenterology and Hepatology Outpatient Clinic of the University Hospital in Cracow and 39 patients without gastrointestinal tract diseases. After clinical examination, blood was drawn to determine complete blood count, haemoglobin, and CRP. The oral cavity was examined, and unstimulated mixed saliva was collected. The SCFAs analysis was made by liquid chromatography-tandem mass spectrometry after facile derivatization coupled with liquid-liquid extraction. Of the six SCAFs studied, the highest median concentrations of acetic acid and propionic acid were observed in the saliva of patients with GERD and in the control group, in both the younger and older groups of patients. The concentrations of acetic acid and propionic acid were also higher compared with the four other fatty acids in the saliva of patients with GERD and in the control subjects. There were no correlations between salivary SCFAs levels and selected clinical and endoscopic parameters, including chronic inflammatory changes of the esophagus and stomach. In conclusions: SCFAs are present in the saliva of patients with GERD and in the control healthy persons. With the exception of valeric and isovaleric acids, salivary levels of SCFAs were significantly higher in patients with GERD compared to the control group. The highest concentrations of acetic acid and propionic acid were observed in patients with GERD and in both the younger and older patient groups. There were no differences in the concentrations of SCFAs in the saliva of female and male groups. We found no correlations between salivary SCFAs levels and selected clinical, laboratory and endoscopic changes of the oesophagus and stomach.
Topics: Humans; Male; Female; Middle Aged; Aged; Propionates; Saliva; Fatty Acids, Volatile; Gastroesophageal Reflux; Acetic Acid
PubMed: 36696242
DOI: 10.26402/jpp.2022.4.05