One stone two birds: Biosynthesis of 3-hydroxypropionic acid from CO2 and syngas-derived acetic acid in Escherichia coli

In the present paper we describe a new carboxylic acid transporter in Escherichia coli encoded by the gene yaaH. In contrast to what had been described for other YaaH family members, the E. coli transporter is highly specific for acetic acid (a monocarboxylate) and for succinic acid (a dicarboxylate), with affinity constants at pH 6.0 of 1.24±0.13 mM for acetic acid and 1.18±0.10 mM for succinic acid. In glucose-grown cells the ΔyaaH mutant is compromised for the uptake of both labelled acetic and succinic acids. YaaH, together with ActP, described previously as an acetate transporter, affect the use of acetic acid as sole carbon and energy source. Both genes have to be deleted simultaneously to abolish acetate transport. The uptake of acetate and succinate was restored when yaaH was expressed in trans in ΔyaaH ΔactP cells. We also demonstrate the critical role of YaaH amino acid residues Leu131 and Ala164 on the enhanced ability to transport lactate. Owing to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate–Acetate Transporter Protein.

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The ability of Escherichia coli O157:H7 to decrease its intracellular pH and resist the toxicity of acetic acid

Microbiology ◽

10.1099/00221287-143-4-1175 ◽

1997 ◽

Vol 143 (4) ◽

pp. 1175-1180 ◽

Cited By ~ 107

Author(s):

F. Diez-Gonzalez ◽

J. B. Russell

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Intracellular Ph ◽

Escherichia Coli O157

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Mitigating the Antimicrobial Activities of Selected Organic Acids and Commercial Sanitizers with Various Neutralizing Agents

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-447 ◽

2011 ◽

Vol 74 (5) ◽

pp. 820-825 ◽

Cited By ~ 7

Author(s):

YOEN JU PARK ◽

JINRU CHEN

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Lactic Acid ◽

Organic Acids ◽

Shiga Toxin ◽

Room Temperature ◽

Sodium Thiosulfate ◽

Antimicrobial Activities ◽

Phosphate Buffered Saline ◽

Lactic Acids

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.

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Viability of Acid-Adapted Escherichia coli O157:H7 in Ground Beef Treated with Acidic Calcium Sulfate

Journal of Food Protection ◽

10.4315/0362-028x-67.3.591 ◽

2004 ◽

Vol 67 (3) ◽

pp. 591-595 ◽

Cited By ~ 5

Author(s):

LARRY R. BEUCHAT ◽

ALAN J. SCOUTEN

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Calcium Sulfate ◽

Ground Beef ◽

Storage Period ◽

Acid Tolerance ◽

Escherichia Coli O157 ◽

E Coli ◽

Acidic Environments ◽

Subsequent Acid

The effects of lactic acid, acetic acid, and acidic calcium sulfate (ACS) on viability and subsequent acid tolerance of three strains of Escherichia coli O157:H7 were determined. Differences in tolerance to acidic environments were observed among strains, but the level of tolerance was not affected by the acidulant to which cells had been exposed. Cells of E. coli O157:H7 adapted to grow on tryptic soy agar acidified to pH 4.5 with ACS were compared to cells grown at pH 7.2 in the absence of ACS for their ability to survive after inoculation into ground beef treated with ACS, as well as untreated beef. The number of ACS-adapted cells recovered from ACS-treated beef was significantly (α = 0.05) higher than the number of control cells recovered from ACS-treated beef during the first 3 days of a 10-day storage period at 4°C, suggesting that ACS-adapted cells might be initially more tolerant than unadapted cells to reduced pH in ACS-treated beef. Regardless of treatment of ground beef with ACS or adaptation of E. coli O157:H7 to ACS before inoculating ground beef, the pathogen survived in high numbers.

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Production of 3-hydroxypropionic acid from acetate using metabolically-engineered and glucose-grown Escherichia coli

Bioresource Technology ◽

10.1016/j.biortech.2020.124362 ◽

2021 ◽

Vol 320 ◽

pp. 124362

Author(s):

Suman Lama ◽

Yeonhee Kim ◽

Dat Tuan Nguyen ◽

Chae Ho Im ◽

Mugesh Sankaranarayanan ◽

...

Keyword(s):

Escherichia Coli ◽

Hydroxypropionic Acid

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Efficacy of Selected Acidulants in Pureed Green Beans Inoculated with Pathogens (Escherichia coli O157:H7 and Listeria monocytogenes)

Journal of Food Protection ◽

10.4315/0362-028x-69.8.1865 ◽

2006 ◽

Vol 69 (8) ◽

pp. 1865-1869 ◽

Cited By ~ 6

Author(s):

AAKASH KHURANA ◽

GEORGE B. AWUAH ◽

BRADLEY TAYLOR ◽

ELENA ENACHE

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Listeria Monocytogenes ◽

Titratable Acidity ◽

Combined Effect ◽

Escherichia Coli O157 ◽

Green Beans ◽

E Coli ◽

Acid Ph ◽

D Values

Studies were conducted to evaluate the combined effect of selected acidulants (acetic, citric, malic, and phosphoric acid) and heat on foodborne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes) in pureed green beans. To establish a consistent reference point for comparison, the molar concentrations of the acids remained constant while the acid-to-puree ratio, titratable acidity, and undissociated acid were either measured or calculated for a target acidified green beans at a pH of 3.8, 4.2, and 4.6. The D-values at 149°F were used as the criteria for acid efficacy. Generally, acetic acid (puree, pH 3.8 and 4.2) represented the most effective acid with comparatively low D-values irrespective of the target microorganism. A 10-s heating at 149°F inactivated approximately 106 CFU/ml of E. coli O157:H7 in pureed beans at pH 3.8. The efficacy of acetic acid is likely related to the elevated percent titratable acidity, undissociated acid, and acid-to-puree ratio. The effectiveness (which in this study represents the combined effect of acid and heat) of the remaining acids (citric, malic, and phosphoric) at puree pH values of 3.8 and 4.2 were statistically insignificant (α = 0.05). Surprisingly, acetic acid (puree, pH 4.6) appeared to be the least effective as compared to the other acids tested (citric, malic, and phosphoric) especially on E. coli O157:H7 cells, while L. monocytogenes had a similar resistance to all acids at puree pH 4.6. With the exception of citric acid (pH 3.8), acetic acid (pH 4.6), and malic acid (pH 3.8 and 4.6), which were statistically insignificant (P > 0.05), the D-values for L. monocytogenes were statistically different (P ≤ 0.05) and higher than the D-values for E. coli under similar experimental conditions. A conservative process recommendation (referred to as the “safe harbor” process) was found sufficient and applicable to pureed green beans for the pH range studied.

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Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry

Pathogens ◽

10.3390/pathogens9100849 ◽

2020 ◽

Vol 9 (10) ◽

pp. 849

Author(s):

Vinicius Silva Castro ◽

Yhan da Silva Mutz ◽

Denes Kaic Alves Rosario ◽

Adelino Cunha-Neto ◽

Eduardo Eustáquio de Souza Figueiredo ◽

...

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Organic Acids ◽

Sodium Hypochlorite ◽

Bacterial Species ◽

Disk Diffusion ◽

Clinical Strains ◽

Linear Pattern ◽

E Coli ◽

Log Reduction

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

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