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1.
Int J Food Microbiol ; 336: 108904, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33129004

RESUMO

The aim of the present study was to determine the effects of organic fruit vinegars (blackberry, pomegranate, rosehip, and grape) used as marination liquids (MLs) on food-borne pathogens inoculated on beef, as well as on the quality characteristics (physical, chemical, microbiological and sensory properties) of beef during marination process at 4 °C for 24 h. In the first part of the study, meat samples separately inoculated with Salmonella Typhimurium, Listeria monocytogenes and Escherichia coli O157:H7 (≅6 log CFU/mL) were marinated in four different MLs and the count of S. Typhimurium, L. monocytogenes and E. coli O157:H7 on samples decreased in the range of 1.040-1.225, 1.420-1.913 and 1.232-1.435 log CFU/g, respectively. Marination with rosehip vinegar (MLR) was determined as the most effective treatment against all pathogens. In the second part of the study, proximate composition, color parameters, cooking yield, marinate absorption, pH, texture profile, aerobic plate count and sensory properties of marinated meat samples were determined. The moisture content of the samples marinated with grape vinegar (MLG) (73.50%) was found lower than of the samples marinated with other formulations (in the range of 75.95-76.65%) (P < 0.05). Marination by various MLs resulted in significant differences between the L*, a* and b* values of meat samples (P < 0.05). The hardness value of the samples was decreased by marination with MLR (P < 0.05) and was determined as 25.70 N. There were no significant differences between the meat samples marinated with the four different MLs in terms of cooking yield, marinate absorption and pH (P > 0.05). Aerobic plate count was reduced in the range of 0.589-0.950 log CFU/g for 24 h marination (P > 0.05). The highest sensory evaluation scores in terms of flavor were determined in meat samples marinated with MLG (P > 0.05). Therefore, different fruit vinegars used as MLs improved the safety and quality of meat at different levels.


Assuntos
Ácido Acético/farmacologia , Culinária/métodos , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Frutas/química , Ácido Acético/química , Animais , Bovinos , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Manipulação de Alimentos/normas , Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Carne Vermelha/normas , Salmonella typhimurium/efeitos dos fármacos , Vitis/química
2.
Sci Rep ; 9(1): 15186, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645575

RESUMO

The current study sought the effective mitigation measure of seawater-induced damage to mung bean plants by exploring the potential roles of acetic acid (AA). Principal component analysis (PCA) revealed that foliar application of AA under control conditions improved mung bean growth, which was interlinked to enhanced levels of photosynthetic rate and pigments, improved water status and increased uptake of K+, in comparison with water-sprayed control. Mung bean plants exposed to salinity exhibited reduced growth and biomass production, which was emphatically correlated with increased accumulations of Na+, reactive oxygen species and malondialdehyde, and impaired photosynthesis, as evidenced by PCA and heatmap clustering. AA supplementation ameliorated the toxic effects of seawater, and improved the growth performance of salinity-exposed mung bean. AA potentiated several physio-biochemical mechanisms that were connected to increased uptake of Ca2+ and Mg2+, reduced accumulation of toxic Na+, improved water use efficiency, enhanced accumulations of proline, total free amino acids and soluble sugars, increased catalase activity, and heightened levels of phenolics and flavonoids. Collectively, our results provided new insights into AA-mediated protective mechanisms against salinity in mung bean, thereby proposing AA as a potential and cost-effective chemical for the management of salt-induced toxicity in mung bean, and perhaps in other cash crops.


Assuntos
Ácido Acético/economia , Ácido Acético/farmacologia , Análise Custo-Benefício , Salinidade , Água do Mar/química , Vigna/fisiologia , Biomassa , Gases/metabolismo , Minerais/metabolismo , Osmose , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Fotossíntese/efeitos dos fármacos , Pigmentos Biológicos/metabolismo , Folhas de Planta/efeitos dos fármacos , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Transpiração Vegetal/efeitos dos fármacos , Potássio/metabolismo , Análise de Componente Principal , Espécies Reativas de Oxigênio/metabolismo , Sódio/metabolismo , Vigna/efeitos dos fármacos , Água
3.
Theriogenology ; 117: 7-15, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29807257

RESUMO

Uterine luminal pH has been demonstrated to be a valid indicator of uterine health in species such as cattle and sheep. However, research regarding uterine luminal pH in equines is lacking. The objectives of this study were to assess uterine luminal pH in mares during the estrous cycle, and evaluate the effect of dilute vinegar lavage on both uterine luminal pH and endometrial health. The study was conducted using a randomized block design in which eight mares (four Thoroughbred and four Standardbred) were aged matched then randomly assigned to two groups. Endometrial biopsies were taken from each mare prior to trial commencement. The treatment group (n = 4; 1 Thoroughbred, 3 Standardbreds) received a uterine lavage of one liter dilute vinegar (20 mL of vinegar in 1 L saline) every second day during each estrus period throughout the trial. Control group mares did not receive a uterine lavage. Uterine luminal pH measurements were recorded in all mares in both groups for a period of up to 10 min immediately prior to lavage (0 h), one hour and 24 h post lavage (same time points in control group mares as if they had been treated). Diestrus uterine luminal pH measurements were recorded once between days 6-10 post-ovulation. Endometrial biopsies were repeated from all mares at trial completion. Mean uterine luminal pH ranged from pH 5.3 to 7.6 and was significantly lower during diestrus compared to estrus (P < 0.001). Regression analysis indicated that this variation in pH was best explained by estrous cycle day, with uterine luminal pH increasing by a mean of 0.03 units each day (P < 0.001) from 6 to 10 days post-ovulation through to ovulation. Uterine lavage with dilute vinegar did not significantly affect uterine luminal pH (P > 0.05). A scoring system to quantify the abundance of cell types in the endometrial biopsies showed that mares in the treatment group had a significant decrease in polymorphonuclear cell abundance between pre- and post-trial biopsies (P = 0.03). Mares in the treatment group also had a significant decrease in lymphocyte, plasma cell and eosinophil cell abundance (P = 0.05). Although dilute vinegar lavage was not associated with a significant change in uterine luminal pH, it was associated with a significant improvement in endometrial biopsy scores. Because the control group did not receive a uterine lavage, further research is required to determine if this significant improvement results from the addition of dilute vinegar, or the uterine lavage itself.


Assuntos
Ácido Acético/farmacologia , Endométrio/fisiologia , Cavalos/fisiologia , Útero/química , Animais , Diestro , Endométrio/química , Endométrio/efeitos dos fármacos , Feminino , Concentração de Íons de Hidrogênio , Irrigação Terapêutica , Útero/efeitos dos fármacos
4.
J Sci Food Agric ; 98(11): 4121-4127, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29393512

RESUMO

BACKGROUND: The aim of this study was to discriminate between commercial apple, rice, balsamic, red-wine, rose, white-wine, grape, and pomegranate vinegars according to their antimicrobial activities, total phenolic contents (TPC), antioxidant activities, and color parameters, and to predict the quality characteristics of vinegars using Fourier transform infrared (FTIR) spectroscopy. RESULTS: Results showed that the highest TPC (3971.43 ± 25.00) was found in balsamic vinegar whereas the lowest TPC was observed in rice vinegar (14.36 ± 0.16). Antioxidant activities of vinegars were correlated with TPC. Grape-based vinegars exhibited higher antimicrobial activity against Staphylococcus aureus (S. aureus), Escherichia coli (E.coli) and Pseudomonas aeruginosa (P.aeruginosa). However, there were no statistically significant differences among vinegars in terms of antimicrobial activities. According to principal component analysis (PCA) and hierarchical cluster analysis (HCA), vinegars were classified into three groups and each group consisted of vinegars from different raw materials. Prediction models were constructed successfully using partial least squares (PLS) considering whole FTIR spectral data. CONCLUSION: The results indicated that FTIR could be used as a rapid method to estimate the antimicrobial activities, TPC, color and antioxidant activities of vinegars. © 2018 Society of Chemical Industry.


Assuntos
Ácido Acético/química , Ácido Acético/farmacologia , Antibacterianos/química , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Ácido Acético/economia , Antibacterianos/economia , Antibacterianos/farmacologia , Malus/química , Oryza/química , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vitis/química
5.
Biotechnol Prog ; 32(4): 971-7, 2016 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-27390294

RESUMO

Mitigating the effect of fermentation inhibitors in bioethanol plants can have a great positive impact on the economy of this industry. Liquid-liquid extraction (LLE) using ethyl acetate is able to remove fermentation inhibitors-chiefly, acetic acid-from an aqueous solution used to produce bioethanol. The fermentation broth resulting from LLE has higher performance for ethanol yield and its production rate. Previous techno-economic analyses focused on second-generation biofuel production did not address the impact of removing the fermentation inhibitors on the economic performance of the biorefinery. A comprehensive analysis of applying a separation system to mitigate the fermentation inhibition effect and to provide an analysis on the economic impact of removal of acetic acid from corn stover hydrolysate on the overall revenue of the biorefinery is necessary. This study examines the pros and cons associated with implementing LLE column along with the solvent recovery system into a commercial scale bioethanol plant. Using details from the NREL-developed model of corn stover biorefinery, the capital costs associated with the equipment and the operating cost for the use of solvent were estimated and the results were compared with the profit gain due to higher ethanol production. Results indicate that the additional capital will add 1% to the total capital and manufacturing cost will increase by 5.9%. The benefit arises from the higher ethanol production rate and yield as a consequence of inhibitor extraction and results in a $0.35 per gallon reduction in the minimum ethanol selling price (MESP). © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:971-977, 2016.


Assuntos
Ácido Acético/isolamento & purificação , Extração Líquido-Líquido/economia , Ácido Acético/química , Ácido Acético/farmacologia , Biocombustíveis , Etanol/química , Etanol/metabolismo , Fermentação/efeitos dos fármacos , Zea mays/química , Zea mays/metabolismo
6.
BMC Neurosci ; 13: 101, 2012 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-22894547

RESUMO

BACKGROUND: Successful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood-brain barrier (BBB) and blood-retinal barrier (BRB), respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB. METHODS: We developed six fluorescent indoline derivatives (IDs) and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7-8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs) on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs. RESULTS: The permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs. CONCLUSIONS: We demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the BBB and BRB. In turn, understanding these mechanisms may lead to the efficient design of compounds targeting the brain and retina.


Assuntos
Barreira Hematoaquosa/fisiologia , Barreira Hematorretiniana/fisiologia , Corantes Fluorescentes/metabolismo , Indóis/metabolismo , Ácido Acético/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Barreira Hematoaquosa/efeitos dos fármacos , Barreira Hematorretiniana/efeitos dos fármacos , Corantes Fluorescentes/administração & dosagem , Corantes Fluorescentes/química , Indóis/administração & dosagem , Indóis/química , Larva , Permeabilidade/efeitos dos fármacos , Reprodutibilidade dos Testes , Peixe-Zebra
7.
Foodborne Pathog Dis ; 9(5): 442-52, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22506696

RESUMO

The purpose of this study was to assess the effect of a commercial peracetic acid-based disinfectant against spores of Bacillus cereus, to identify the most influential factor for the final number of microorganisms after different disinfection procedures, and to evaluate the nature of the inactivation kinetics. The spores of four different strains of B. cereus (DSM 318, 4312, 4313, and 4384) were treated with five different disinfectant concentrations (0.25%, 0.5%, 1.0%, 1.5%, and 2.0% [w/v]) at three different temperatures (10°C, 15°C, and 20°C) with or without protein load. A higher temperature and PES 15/23 concentration resulted in a higher inactivation. Inactivation of B. cereus strain 4312 was around 2 log10 cycles at 10°C and around 7 log10 at 20°C (conc=1% [w/v] PAA; t=60 min; without protein). The protein load at higher concentrations did not significantly reduce the efficacy of the disinfectant (p>0.05). This article indicates the applicability of the Weibull model to fit the B. cereus disinfectant survival curves. A Monte Carlo simulation was used to carry out a sensitivity analysis, which revealed the most influential factors affecting the final number of microorganisms after the disinfection process.


Assuntos
Bacillus cereus/efeitos dos fármacos , Desinfetantes/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Ácido Peracético/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Ácido Acético/farmacologia , Temperatura Baixa , Contagem de Colônia Microbiana , Utensílios de Alimentação e Culinária , Proteínas Alimentares/análise , Desinfecção/métodos , Combinação de Medicamentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Peróxido de Hidrogênio/farmacologia , Cinética , Modelos Biológicos , Método de Monte Carlo , Concentração Osmolar , Soroalbumina Bovina/química , Especificidade da Espécie
8.
Bioresour Technol ; 102(2): 1608-14, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20889336

RESUMO

An assessment of the growth kinetics of acidogenic cells of Clostridium acetobutylicum DSM 792 is reported in the paper. Tests were carried out in a continuous stirred tank reactor under controlled conditions adopting a complex medium supplemented with lactose as carbon source to mimic cheese whey. The effects of acids (acetic and butyric), solvents (acetone, ethanol and butanol) and pH on the growth rate of acidogenic cells were assessed. The conversion process was characterized under steady-state conditions in terms of concentration of lactose, cells, acids, total organic carbon and pH. The growth kinetics was expressed by means of a multiple product inhibition and interacting model including a novel formulation to account for the role of pH. The model has the potential to predict microorganism growth rate under a broad interval of operating conditions, even those typical of solvents production.


Assuntos
Ácidos/metabolismo , Clostridium acetobutylicum/metabolismo , Fermentação/fisiologia , Lactose/metabolismo , Ácido Acético/farmacologia , Ácido Butírico/farmacologia , Clostridium acetobutylicum/efeitos dos fármacos , Clostridium acetobutylicum/crescimento & desenvolvimento , Meios de Cultura/farmacologia , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Cinética , Modelos Biológicos , Solventes/farmacologia
9.
Biosci Biotechnol Biochem ; 74(10): 2158-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20944398

RESUMO

We have reported that acetic acid (AcOH) intake suppresses body fat mass and up-regulates the genes involved in fatty acid oxidation, but it is not clear whether the suppression of body fat mass by AcOH administration is due to an increase in energy expenditure (EE). In this study, we investigated to determine whether a single oral administration of AcOH would increase EE in C57BL/6J mice treated with 1.5% AcOH. The AcOH treatment group had significantly higher oxygen consumption (VO(2)), EE, and fat oxidation (FAT) than the water treatment group. These results suggest that a single administration of AcOH increases EE, resulting in suppression of body fat mass.


Assuntos
Ácido Acético/administração & dosagem , Ácido Acético/farmacologia , Metabolismo Energético/efeitos dos fármacos , Administração Oral , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução/efeitos dos fármacos , Oxigênio/metabolismo
10.
Methods Mol Biol ; 617: 79-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20336415

RESUMO

Pain-depressed behavior can be defined as any behavior that decreases in rate, frequency, duration, or intensity in response to a putative pain state. Common examples include pain-related decreases in feeding, locomotion and expression of positively reinforced operant behavior. In humans, depression of behavior is often accompanied by a comorbid depression of mood. Measurements of pain-depressed behaviors are used to diagnose pain in both human and veterinary medicine, and restoration of pain-depressed behavior is often a priority of treatment. This article describes two strategies for integrating measures of pain-depressed behaviors into preclinical assays of pain and analgesia. Assays of pain-depressed behaviors may contribute both to improved translational efficiency in analgesic drug development and to new insights regarding the mechanisms and determinants of pain and analgesia.


Assuntos
Analgesia/métodos , Analgésicos/uso terapêutico , Comportamento Animal/fisiologia , Medição da Dor , Dor/tratamento farmacológico , Dor/fisiopatologia , Ácido Acético/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Haloperidol/farmacologia , Haloperidol/uso terapêutico , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Morfina/farmacologia , Morfina/uso terapêutico , Antagonistas de Entorpecentes/farmacologia , Antagonistas de Entorpecentes/uso terapêutico , Dor/induzido quimicamente , Medição da Dor/instrumentação , Medição da Dor/métodos , Ratos , Autoestimulação
11.
Br J Nurs ; 17(5): 316-20, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18414294

RESUMO

The sporicidal activity of an odour-free peracetic acid-based disinfectant (Wofasteril) and a widely-used dichloroisocyanurate preparation (Chlor-clean) was assessed against spores of the hyper-virulent strain of Clostridium difficile (ribotype 027), in the presence and absence of organic matter. In environmentally clean conditions, dichloroisocyanurate achieved a >3 log10 reduction in 3 minutes, but a minimum contact time of 9 minutes was required to reduce the viable spore load to below detection levels. Peracetic acid achieved a >3 log10 reduction in 30 minutes and was overall significantly less effective (P<0.05). However, in the presence of organic matter - which reflects the true clinical environment - there was no significant difference between the sporicidal activity of dichloroisocyanurate and peracetic acid over a 60-minute period (P=0.188). Given the greater occupational health hazards generally associated with chlorine-releasing agents, odour-free peracetic acid-based disinfectants may offer a suitable alternative for environmental disinfection.


Assuntos
Ácido Acético/farmacologia , Clostridioides difficile/efeitos dos fármacos , Desinfetantes/farmacologia , Ácido Peracético/farmacologia , Triazinas/farmacologia , Ácido Acético/economia , Clostridioides difficile/genética , DNA Bacteriano/genética , Desinfetantes/efeitos adversos , Desinfetantes/economia , Desinfecção/economia , Desinfecção/métodos , Combinação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Microbiologia Ambiental , Humanos , Testes de Sensibilidade Microbiana , Saúde Ocupacional , Ácido Peracético/economia , Ribotipagem , Esporos Bacterianos/efeitos dos fármacos , Fatores de Tempo , Triazinas/efeitos adversos , Triazinas/economia
12.
Appl Opt ; 46(21): 4834-42, 2007 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-17609734

RESUMO

We aim to investigate the mechanism of acetowhitening upon which the colposcopic diagnosis of cervical cancer is based. The changes in light scattering induced by acetic acid in intact cervical cancer cells and cellular components were studied using elastic light-scattering spectroscopy. After adding acetic acid to intact cancer cell culture samples (cell suspensions and attached monolayer cell cultures), a slight decrease in small-angle forward scattering was observed, while the large-angle scattering increased by a factor of 5-9, indicating that acetowhitening signals are mainly contributed from small-sized intracellular scattering structures. The cellular components of different sizes and masses were isolated to investigate their individual contribution to the changes of light scattering induced by acetic acid. The study provided the evidence that the cellular components of diameter smaller than 0.2 microm in the cytoplasm are the major contributors to the acetowhitening effect in whole cells, while the light scattering from the mitochondria are not sensitive to the acetic acid.


Assuntos
Ácido Acético/farmacologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/fisiopatologia , Análise Espectral/métodos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/patologia , Linhagem Celular Tumoral , Simulação por Computador , Humanos , Modelos Biológicos
13.
Appl Biochem Biotechnol ; 91-93: 117-31, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11963841

RESUMO

In pH-controlled batch fermentations with pure sugar synthetic hardwood hemicellulose (1% [w/v] glucose and 4% xylose) and corn stover hydrolysate (8% glucose and 3.5% xylose) lacking acetic acid, the xylose-utilizing, tetracycline (Tc)-sensitive, genomically integrated variant of Zymomonas mobilis ATCC 39676 (designated strain C25) exhibited growth and fermentation performance that was inferior to National Renewable Energy Laboratory's first-generation, Tc-resistant, plasmid-bearing Zymomonas recombinants. With C25, xylose fermentation following glucose exhaustion was markedly slower, and the ethanol yield (based on sugars consumed) was lower, owing primarily to an increase in lactic acid formation. There was an apparent increased sensitivity to acetic acid inhibition with C25 compared with recombinants 39676:pZB4L, CP4:pZB5, and ZM4:pZB5. However, strain C25 performed well in continuous fermentation with nutrient-rich synthetic corn stover medium over the dilution range 0.03-0.06/h, with a maximum process ethanol yield at D = 0.03/h of 0.46 g/g and a maximum ethanol productivity of 3 g/(L x h). With 0.35% (w/v) acetic acid in the medium, the process yield at D = 0.04/h dropped to 0.32 g/g, and the maximum productivity decreased by 50% to 1.5 g/(L x h). Under the same operating conditions, rec Zm ZM4:pZB5 performed better; however, the medium contained 20 mg/L of Tc to constantly maintain selective pressure. The absence of any need for antibiotics and antibiotic resistance genes makes the chromosomal integrant C25 more compatible with current regulatory specifications for biocatalysts in large-scale commercial operations.


Assuntos
Xilose/metabolismo , Zymomonas/genética , Zymomonas/metabolismo , Ácido Acético/farmacologia , Biomassa , Reatores Biológicos , Etanol/metabolismo , Fermentação , Glucose/farmacologia , Concentração de Íons de Hidrogênio , Hidrólise , Plasmídeos/genética , Recombinação Genética , Zea mays , Zymomonas/efeitos dos fármacos
14.
Cytometry ; 31(4): 307-13, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9551607

RESUMO

Flow cytometry (FCM) was used with different viability dyes to assess changes in cell structure and function induced by acetic acid (AA) in populations of Zygosaccharomyces bailii (AA resistant) and Saccharomyces cerevisiae (AA sensitive). Kinetic changes in esterase activity, intracellular dye processing, and membrane integrity were monitored, and to detect those changes we used three assays involving fluorescein diacetate hydrolysis, FUN-1 processing, and propidium iodide exclusion, respectively. In S. cerevisiae, the decrease in the ability to process FUN-1 preceded the decrease in esterase activity, and there was loss of cell membrane integrity after incubation with AA. In Z. bailii, with higher AA concentrations, there was a similar decrease in the ability to process FUN-1, which also preceded the loss of cell membrane integrity. Changes in esterase activity in this yeast induced by AA treatment could not be monitored because the changes occurred independently of the presence of the acid. For control samples (untreated cells killed with 10% v/v of AA), the percentages of nonaltered cells as estimated by FCM and percentages of viable cells as estimated by colony forming unit (CFU) counts were identical. However, for cell samples treated for short periods with 3% (v/v) or less of AA, none of the dyes produced FCM results comparable to those produced by CFU counts.


Assuntos
Ácido Acético/farmacologia , Citometria de Fluxo/métodos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomycetales/efeitos dos fármacos , Contagem de Colônia Microbiana , Fluoresceínas/metabolismo , Corantes Fluorescentes/metabolismo , Propídio , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/citologia , Saccharomycetales/metabolismo , Coloração e Rotulagem/métodos
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