Use Of Acetic Acid Research Articles

Valorization of Winery Spent Yeast Waste Biomass as a New Source for the Production of β-Glucan

In this paper we report the first isolation of yeast β-glucan from a new source, winery spent yeast biomass and its production with an environmental friendly oriented method. β-Glucan has been isolated from brewery wastes and proposed for various applications in food industry but until now the winery solid wastes have not been treated for this purpose. The aim of this study was dual. Firstly, the exploitation of a completely new and alternative source for yeast β-glucan industrial production, winery yeast waste biomass. Secondly, the utilization of winery yeast waste for the production of added value products as a part of an intergraded and sustainable wine industry, targeted to the protection of the environment. β-Glucan isolation from wine lees was performed in a two-step process, yeast autolysis and alkali extraction with NaOH. Autolysis at 55 °C/pH 5.0/48 h with the use of acetic acid from wine must acetic acid bacteria fermentation for the production of yeast extract was optimum. Most purified fraction of β-glucan from red wine lees (28.95 ± 0.50 %) was received with NaOH 2 M/0.5 h/90 °C/1:5 sample to NaOH concentration and from white wine lees (43.37 ± 0.65 %) with NaOH 0.5 M/1.0 h/90 °C/1:5 sample to NaOH concentration. NaOH waste produced during β-glucan isolation process can be further treated for lignin degradation from wood biomass. Winery yeast waste lees can comprise an innovative way for β-glucan production. Further research in extraction methods, immunoactivity and applications of obtained β-glucan from this source, must be investigated. Also, a deeper research for a new β-glucan with wine polyphenols product for incorporation in functional foods and medicines is proposed.

Validation of a predictive model for fed-batch and continuous lipids production processes from acetic acid using the oleaginous yeast Cryptococcus curvatus

This study focuses on the use of acetic acid as carbon source for cell mass and lipid production using an oleaginous yeast, Cryptococcus curvatus. To improve this cell mass and lipid production on acetic acid, a numerical model was built to predict the yeast behavior. The model was first calibrated and validated on a fed-batch culture of the oleaginous yeast grown on acetic acid. After the validation step, this model was used as a predictive tool to search for optimal dilution rate and C/N ratios for continuous culture. A continuous culture was then launched using these culture parameters, revealing that the experimental data fitted the model predictions. At steady-state, cell mass concentration was stabilized at 26.7g/L containing 48–53% of lipid content. A maximal lipid productivity of 0.54gL−1h−1 was obtained, which was superior to those reported in literature. This model could be qualified as a mechanistic one since it allows understanding reactions underlying the lipid production process. The experimental data fitted the model predictions, which confirmed that the use of a model is a powerful and predictive tool which could help the operator to process parameters to improve the culture.

Catalytic activity of magnetic Fe3O4@Diatomite earth and acetic acid for the N-acylation of sulfonamides

The Brønsted and Lewis acidic promoted N-acylation of sulfonamides with acetic anhydride or benzoyl chloride has been achieved using glacial acetic acid and magnetic Fe3O4@Diatomite earth. Use of acetic acid as solvent omits the need for organic bases and permits the isolation of products by filtration and precipitation. Additionally, the magnetic composite Fe3O4@Diatomite acts as a conjugate proton super acid, enabling the acylation of sulfonamide compounds.

Comparing bioapatite carbonate pre-treatments for isotopic measurements: Part 2 — Impact on carbon and oxygen isotope compositions

Carbon and oxygen isotope measurements (δ13C, δ18O) of bioapatite carbonate fractions in archaeological and fossil remains are essential tools to investigate past diets and climates. The reliability of these reconstructions is however dependent on the recovery of the biological signal and the removal of competing sources of carbon and oxygen isotopes, such as remaining organic material and secondary carbonates. Modern, archaeological and fossil bone and tooth specimens have been treated with different chemicals commonly used to pre-treat the samples with the aim of removing these competing sources of isotopes. Results highlight significant shifts in the isotope values of the samples tested, with different isotopic effects according to which pre-treatment was used. This has a clear impact on the data recovered, and may lead to misinterpretations of the results and inferred past diets and climates. The results of this study suggest that both hydrogen peroxide and sodium hypochlorite, the most commonly used oxidising agents employed to remove organic substance, have major problems: hydrogen peroxide is only partially efficient as organic removal agent and causes unwanted bioapatite dissolutions and isotopic shift, while sodium hypochlorite induces the incorporation of exogenous carbonates into the bioapatite, likely from the dissolution of atmospheric CO2 into the test tube. In both cases, there is an impact on the recovered isotope composition. Hydrazine hydrate, a third chemical for organic removal, has the lowest influence on the bioapatite isotopic composition, being also efficient at removing organic matter from bioapatites. The latter is recommended as an organic removal agent if such pre-treatment is deemed necessary. The use of acetic acid also causes isotopic shifts that seem independent on the removal of secondary/diagenetic carbonate, as also occurring in modern samples. Overall, our study clearly shows that any chemical treatment commonly used to remove unwanted contaminants from the bioapatite samples has also unpredictable, often significant effects on the pristine isotopic composition recovered, and corroborates the need for consistency in the pre-treatment of bone and teeth specimens. It also questions the necessity of removing organic matter at all from most skeletal samples prior to isotopic analysis.

SYNTHESIS AND PROPERTIES OF ETHOXYLATED GLYCEROL MONOOLEATE AS PALM OIL BASED NONIONIC SURFACTANTS

Palm oil based nonionic surfactants were synthesized by reacting glycerol monooleate with ethylene oxide at 80 ºC in the prescence of an alkaline catalyst. Purification of the products was conducted by use of acetic acid and black carbon which gave ethoxylated products (EGMO) with a higher level of viscocity and greater solubility in water. Physical and chemical properties of the product such as surface activity, cloud point, acid value, ester value, hydroxyl value, and hydrophilic-lipophilic balance was also determined and results varied depending on the reagent molar ratio. The synthesized EGMO were soluble in water and therefore show potential use as surface active agents in personal care and cosmetic products.Keywords: nonionic surfactant, ethoxylation, glycerol monooleate, palm oil

A simple, economical, and environmentally benign protocol for the synthesis of [1,2,4]triazolo[5,1-b]quinazolin-8(4H)-one and hexahydro[4,5]benzimidazolo[2,1-b]quinazolinone derivatives

An efficient synthesis of [1,2,4]triazolo[5,1-b]quinazolin-8(4H)-one and hexahydro[4,5]benzimidazolo[2,1-b]quinazolinone derivatives with good yields is described. This method involves three-component reaction between aldehydes, dimedone, and 3-amino-1,2,4-triazole or 2-aminobenzimidazole in acetic acid as reaction medium at 60 °C. We have found that the use of acetic acid as reaction medium results in a remarkable beneficial effect on the reaction, allowing it to be performed without the need of incorporating a catalyst, which is the case in other similarly reported methodologies. The notable advantages of this protocol are excellent yields, short reaction time, mild reaction conditions, more readily available and inexpensive materials, more environmentally friendly, no need for column chromatography, and simple work-up procedure.

Acetic acid induces pH-independent cellular energy depletion in Salmonella enterica.

Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (p<0.05) that was apparent for the four Salmonella strains. We suggest that this effect was probably due solely to the action of undissociated acid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56 ± 1.27; p<0.05), where the role of both pH and undissociated acid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH.

Improved rapid and efficient method for Staphylococcus aureus DNA extraction from milk for identification of mastitis pathogens.

A rapid and efficient DNA extraction method was developed for detecting mastitis pathogens in milk. The first critical step involved cell wall disruption by bead-beating, as physical disruption using beads was more effective for DNA extraction from Gram-positive bacteria, such as Staphylococcus aureus, than enzymatic disruption using proteinase K. The second critical step involves the use of acetic acid and ammonium sulfate in the purification process, as these reagents effectively and efficiently remove the lipids and proteins in milk. Using these methods, DNA suitable for loop-mediated isothermal amplification was obtained within 30 min. Also, the rapid and sensitive detection of S. aureus in milk was possible at levels as low as 200 cfu/ml.

Pseudomonas aeruginosa wound infections: a critical appraisal of topical antiseptics

Background: Pseudomonas aeruginosa infection is a serious complication of burns and wounds with a high degree of morbidity and mortality. This paper reviews the literature on the use of topical antiseptics for the treatment of P. aeruginosa wound infections. Methods: Embase and PubMed were searched, yielding 119 results that were reviewed. Inclusion criteria were all papers that assessed patients with confirmed P. aeruginosa wound infection treated with topical antiseptics and reported the eradication of the pathogen. Results: Three papers met the inclusion criteria, with a total sample size of 33. All of the studies analyzed acetic acid for the treatment of P. aeruginosa wound infection. The pooled data demonstrated that 84.8% of confirmed P. aeruginosa wound infections were effectively treated with acetic acid. Conclusions: P. aeruginosa remains a serious infection complicating burn and wound healing. Treatment commonly includes topical antiseptics; however, there is a paucity of clinical based trials to support this. Three small trials demonstrated some evidence for the use of acetic acid as a topical treatment. More evidence is required to demonstrate the efficacy of topical antiseptics as well as recommend specific types of topical treatment for this pathogen.

Post-column sodiation to enhance the detection of polyacetylene glycosides in LC–DAD–MS analyses: an example from Bidens gardneri (Asteraceae)

The use of liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS) in dereplication studies of medicinal plants is a common strategy, but the analyses of polyacetylenes by LC–ESI–MS are little explored and require huge efforts, especially if there are low concentrations in the extracts. A post-column sodiation strategy was successfully applied to enhance the detection of polyacetylene glycosides. Their molecular formulae were proposed by HRESI, whereas the polyacetylene chromophores were determined by UV data. The use of acetic acid in the mobile phase was essential to obtain satisfactory chromatographic resolution, and only the addition of sodium chloride solution allowed good mass spectra, internal calibration and undoubtedly the molar mass determination of polyacetylenes. This new approach has allowed the identification of polyacetylene glycosides from Bidens gardneri extract, guiding the isolation procedures, and two new compounds were obtained. The structures of the isolated polyacetylenes have been confirmed by 1D and 2D NMR, HRMS.

Recovery of volatile fatty acids from fermentation of sewage sludge in municipal wastewater treatment plants

This work investigated the pilot scale production of short chain fatty acids (SCFAs) from sewage sludge through alkaline fermentation and the subsequent membrane filtration. Furthermore, the impact of the fermentation liquid on nutrient bioremoval was examined. The addition of wollastonite in the fermenter to buffer the pH affected the composition of the carbon source produced during fermentation, resulting in higher COD/NH4-N and COD/PO4-P ratios in the liquid phase and higher content of propionic acid. The addition of wollastonite decreased the capillary suction time (CST) and the time to filter (TTF), resulting in favorable dewatering characteristics. The sludge dewatering characteristics and the separation process were adversely affected from the use of caustic soda. When wollastonite was added, the permeate flux increased by 32%, compared to the use of caustic soda. When fermentation liquid was added as carbon source for nutrient removal, higher removal rates were obtained compared to the use of acetic acid.

Selective solvent annealing induced phase separation and dewetting in PMMA/SAN blend ultrathin films

Phase behaviors induced by solvent annealing in poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN) blend ultrathin films have been investigated by atomic force microscopy and grazing incidence small-angle X-ray scattering. Our results indicate that both the phase separation within the blend and the dewetting of the film induced by composition fluctuation take place upon the selective solvent annealing, producing complex structures containing upper droplets (of one phase) and mimic-films (of the other rich-phase). The use of acetic acid (the selective solvent for PMMA) generates PMMA mimic-film and SAN droplets, while the introduction of DMF (exhibiting better solubility for SAN) vapor results in the formation of SAN mimic-film and PMMA droplets. Essentially, the interaction at polymer/substrate interface, resultant wettability of selected component, solubility of PMMA and SAN in adopted solvent dominate not only the phase separation and the dewetting of the whole film but also the synergism of them. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1243–1251

Hybrid films with (trimethoxysilylpropyl) methacrylate (TMSM), poly (methyl methacrylate) PMMA and tetraethoxysilane (TEOS) applied on tinplate

The tetraethoxysilane (TEOS) influences morphological and electrochemical properties of hybrid films by function of concentration. Moreover, the use of acetic acid as a catalyst in the sol enables a more complete hydrolysis of the silane precursors due to the fact that the acetic acid goes through a more complete ionization when in aqueous solution. The aim of this paper is to study the effect of the concentration of tetraethoxysilane (TEOS) on the protective properties of the film on tinplate substrate. The tinplate was coated with a hybrid film obtained from a sol-gel method constituted of the following alkoxide precursors: 3 - (trimetoxisililpropil) methacrylate (TMSM) and poly(methyl methacrylate) PMMA. The effect of tetraethoxysilane (TEOS) concentration has also been evaluated. The films hydrolysis was performed at a pH value of 3. 0 using acetic acid as a catalyst. The films were obtained by dip-coating process, cured for 3 hours at 160 ºC. The film morphology was evaluated by SEM and profilometry. The electrochemical behavior of the films was evaluated by open circuit potential monitoring, potentiodynamic polarization and electrochemical impedance spectroscopy. The film hydrophobicity was determined by contact angle measurements. The studied films have shown good performance as to corrosion resistance on tinplate. The hybrid film which was obtained through the addition of an excessive amount of TEOS (T3A3) showed increased thickness. Nevertheless, due to an intense densification of the film, promoted by the addition of TEOS, a formation of cracks was registered, thereby compromising the corrosion resistance.

Use of external carbon sources derived from biowaste for short-cut nutrient removal from anaerobic effluents.

This work evaluated the use of different external carbon sources to promote the via-nitrite nutrient removal from anaerobic effluents. The carbon sources consisted of fermentation liquid produced from the organic fraction of municipal solid waste (OFMSW FL), drainage liquid produced from OFMSW, fermentation liquid produced from vegetable and fruit waste (VFW FL) and acetic acid. Denitritation and phosphorus uptake via nitrite were evaluated in two sequencing batch reactors, one treating the anaerobic supernatant produced from the co-digestion of OFMSW and activated sludge (highly nitrogenous anaerobic effluent - HNAE), and the other one treating the weakly nitrogenous anaerobic effluent (WNAE) from an upflow anaerobic sludge blanket reactor. The use of OFMSW FL to treat HNAE resulted in high nitrite (27 mgN/(gVSS·h) (VSS - volatile suspended solids) and phosphate uptake (15 mgP/gVSS·h). In the WNAE, nutrient kinetics were much slower. The use of acetic acid and VFW FL performed poorly, while the use of OFMSW FL, which was rich in butyric acid and propionic acid, resulted in significant nutrient removal (7 mgN/gVSS·h and 6 mgP/gVSS·h). The economic evaluation showed that the use of OFMSW FL is a less expensive option than the acetic acid use.

Iridium‐Catalyzed Direct CH Amidation with Weakly Coordinating Carbonyl Directing Groups under Mild Conditions

An iridium-catalyzed direct C-H amidation of weakly coordinating substrates, in particular of those bearing ester and ketone groups, under very mild conditions has been developed. The observed high reaction efficiency was achieved by the combined use of acetic acid and lithium carbonate as additives.

Iridium‐Catalyzed Direct CH Amidation with Weakly Coordinating Carbonyl Directing Groups under Mild Conditions

AbstractAn iridium‐catalyzed direct CH amidation of weakly coordinating substrates, in particular of those bearing ester and ketone groups, under very mild conditions has been developed. The observed high reaction efficiency was achieved by the combined use of acetic acid and lithium carbonate as additives.

Influence of the synthesis process on the features of Y2O3-stabilized ZrO2 powders obtained by the sol–gel method

Y2O3-stabilized ZrO2 (YSZ) powders have been prepared by the sol–gel method using different synthesis parameters. Specifically, zirconium n-propoxide was dissolved in propanol at pH 0.5 or 5 (provided by HNO3), with or without acetic acid in the hydrolysis medium. Subsequently, the YSZ powders obtained by gelation and drying of these solutions was characterized using scanning and transmission electron microscopies, X-ray diffractometry, and N2-adsorption. Compacts made from these YSZ powders which were then sintered were also analyzed. It was found that the pH of the hydrolysis medium has a notable influence on the microstructure, morphology, color, crystallinity, and sintering behavior process of these YSZ sol–gel powders. It was also found that the use of acetic acid also affects the YSZ powder features, and results in compacts with higher residual porosity after sintering. Finally, the compacts prepared from the YSZ powders obtained at pH 5 and without acetic acid exhibit the greatest sinterability.

The Use of Acetic Acid, Sodium Chloride Solutions, and Incubation to Accelerate the Ripening of ‘Mazafati’ Date

This study introduces a method to simultaneously maintain disinfection and accelerated ripening of ‘Mazafati’ date fruit. The method includes immersing of the samples in water, acetic acid, and sodium chloride solutions following incubation. The results revealed that incubation is the main factor responsible for accelerated ripening of date fruit. Dry weight and total soluble solids of samples increased during ripening, whereas total water insoluble solids, textural firmness, and L*a*b* parameters decreased. Overall, the treatments with 0.5% acetic acid solution with incubation at 39°C for 60 and 80 h can be regarded as a suitable method for accelerated ripening of ‘Mazafati’ date fruit.

I-SCAN targeted versus random biopsies in Barrett's oesophagus

The accuracy and effectiveness of targeted oesophageal biopsies in Barrett's oesophagus to detect dysplasia using new magnification techniques are unknown. Aim of this study was to investigate whether the combined use of acetic acid, magnification and electronic filters allows the same accuracy as the four-quadrant random biopsies pattern; pathologist interobserver agreement both in low grade and high grade dysplasia was also assessed. Fifty-four consecutive patients newly diagnosed with Barrett's oesophagus were enrolled in a prospective study from a single endoscopy unit. Biopsies were evaluated by the local pathologist and by an expert pathologist from another pathology unit. Dysplasia detection rate and interobserver agreement for the histologic diagnosis of dysplasia. The use of acetic acid, magnification and electronic filters showed an unacceptably low dysplasia detection rate by the two pathologists (9.2% and 5.5% for targeted biopsies, respectively). The interobserver agreement for low grade dysplasia between pathologists was low (Cohen's K weighted=0.45). In an average setting, the standard four-quadrant method should still be preferred, along with the implementation of a routine second evaluation by an expert pathologist.

SATP (YaaH), a succinate–acetate transporter protein 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.