Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 10 de 10
Acta sci., Biol. sci ; 43: e51737, 2021. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1460974


Endophytes are growth-promoting agents capable of synthesizing phytohormones, uptaking nutrients, and controlling pathogens. There is a strong potential to exploit them in the agriculture field like biofertilizers and biocontrol agents. In this work, we aimed to evaluate endophytic fungi isolated from Pachystachys lutea for their potential to solubilize phosphate, synthesise indole acetic acid (IAA), antagonize phytopathogens, and promote plant growth under greenhouse conditions. The phosphate solubilization efficiency was assessed on Pikovskaya’s agar medium. For analysis of IAA production, mycelia plugs of endophytes were cultured in Potato Dextrose Broth medium supplemented with L-tryptophan, with Salkowski Reagent, and the absorbance of the culture was measured. The antagonism evaluation of strain Alternaria sp. PL75 against phytopathogens was performed using the paired-culture technique. The promotion of plant growth provided by Alternaria sp. PL75 was evaluated in tomato plants. All strains evaluated were able to solubilize phosphate; however, the strain Alternaria sp. PL75 was the most effective (4.29). Two strains, Nemania sp. PL27 and Alternaria sp. PL75, produced 1.86 and 1.73 & 956;g mL-1 of IAA, respectively. In the antagonism assay, the endophyte Alternaria sp. PL75 and its fungal extract showed the best results against the pathogen Moniliophthora perniciosa. The greenhouse experiment result showed the endophyte Alternaria sp. PL75 increased the plantlets emergency speed index and the percentage of germination from 60 to 81.63%. It was also observed a statistical significance in the shoot length of the treated plants with the endophyte suspension (55.38 cm) compared to the control (41.67 cm).

Endophytes , Phosphates , Lamiales/growth & development , Acetic Acid/analysis
Electron. j. biotechnol ; 47: 29-35, sept. 2020. tab, graf
Article in English | LILACS | ID: biblio-1253015


BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.

Powders/metabolism , Bifidobacterium/growth & development , Bifidobacterium/metabolism , Fatty Acids, Volatile/biosynthesis , Propionates/analysis , Propionates/metabolism , Food Industry , Acetic Acid/analysis , Acetic Acid/metabolism , Lactic Acid/analysis , Lactic Acid/metabolism , Probiotics , Butyric Acid/analysis , Butyric Acid/metabolism , Fatty Acids, Volatile/analysis , Prebiotics , Fermentation , Hydrogen-Ion Concentration
Braz. J. Vet. Res. Anim. Sci. (Online) ; 57(3): e162942, 2020. tab
Article in English | VETINDEX, LILACS | ID: biblio-1122180


This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situdegradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage.(AU)

Foram avaliados os efeitos do aumento dos níveis de quitosana (CHI) sobre o perfil e as perdas fermentativas, a composição química e degradação in situ da silagem de cana-de-açúcar. Os tratamentos foram: 0, 1, 2, 4 e 8 g de CHI / kg de matéria seca (MS). Foram utilizados vinte silos experimentais (tubos de PVC com 28 cm de diâmetro e 25 cm de altura). Areia (2 kg) foi adicionada na porção inferior de cada silo para avaliar as perdas por efluentes e os silos foram pesados 60 dias após a ensilagem para calcular as perdas por gases. Amostras foram coletadas do centro da massa do silo para avaliar a composição química, degradação in situ, perfil fermentativo e a contagem de fungos e leveduras da silagem. Os dados foram analisados como um delineamento inteiramente casualizado e o efeito do tratamento foi decomposto usando regressão polinomial. A CHI aumentou linearmente a concentração de ácido acético e N-NH3, enquanto diminuiu a contagem de leveduras e bolores e a concentração de etanol. Os níveis intermediários de CHI (de 4,47 a 6,34 g/kg MS) mostraram os menores valores de perdas por efluentes, gases e totais. Houve efeito quadrático da CHI sobre o teor de carboidratos não fibrosos, fibra em detergente neutro e ácido e sobre a degradação in situ da MS. Os menores teores de fibras foram observados com níveis de CHI entre 7,01 e 7,47 g/kg MS, enquanto que os maiores teores de carboidratos não fibrosos e degradação in situ da MS foram encontrados com 6,30 e 7,17 g/kg MS de CHI, repectivamente. A CHI aumentou linearmente as concentrações de ácido acético e N-NH3, enquanto reduziu linearmente a concentração de etanol e a contagem de fungos e leveduras. Desta forma, níveis intermediários de CHI, entre 4,47 e 7,47 g / kg de MS, diminuem as perdas fermentativas e melhoram o valor nutricional da silagem de cana-de-açúcar.(AU)

Silage/analysis , Saccharum/chemistry , Chitosan/analysis , Acetic Acid/analysis , Ethanol
Braz. j. microbiol ; 48(3): 592-601, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889150


Abstract The aim of this study was to develop a kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. Saccharomyces cerevisiae, Lactobacillus paracasei, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were the microbial species identified. S. cerevisiae, L. plantarum, A. pasteurianus and A. syzygii were found in smaller quantities at the beginning of the alcoholic fermentation, but were found throughout the alcoholic and acetic fermentation. Kefir grains were able to utilize apple must as substrate to produce ethanol, and acetic acid. Acetate, volatile alcohols and aldehydes in the vinegar-based kefir were also produced. The yield of acetic acid in the kefir vinegars was ∼79%. The acetic acid concentration was ∼41 g L-1, reaching the required standard for the Brazilian legislation accepts it as vinegar (4.0% acetic acid). Kefir vinegar showed good acceptance in the sensory analysis. The technology proposed here is novel by the application of immobilized-cell biomass (kefir grains) providing a mixed inocula and eliminating the use of centrifuge at the end of the fermentative process. This step will save energy demand and investment. This is the first study to produce apple vinegar using kefir grains.

Humans , Alcoholic Beverages/microbiology , Kefir/analysis , Malus/microbiology , Acetic Acid/analysis , Acetic Acid/metabolism , Acetobacter/isolation & purification , Acetobacter/metabolism , Biodiversity , Brazil , Ethanol/analysis , Ethanol/metabolism , Fermentation , Food Handling , Kefir/microbiology , Lactobacillus/isolation & purification , Lactobacillus/metabolism , Malus/metabolism , Saccharomyces cerevisiae/isolation & purification , Saccharomyces cerevisiae/metabolism , Taste
Braz. j. microbiol ; 47(2): 452-460, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780816


Abstract A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25 °C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29 mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12 mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66 mg/L from 5.29 mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

Wine/analysis , Biogenic Amines/analysis , Acetobacter/metabolism , Histamine/metabolism , Rubus/microbiology , Saccharomyces cerevisiae/metabolism , Wine/microbiology , Acetobacter/isolation & purification , Acetobacter/genetics , Histamine/analysis , Acetic Acid/analysis , Acetic Acid/metabolism , Fermentation , Rubus/metabolism , Food Microbiology
Braz. j. microbiol ; 40(2): 387-393, Apr.-June 2009. graf, tab
Article in English | LILACS | ID: lil-520228


This study evaluated the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and acetic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and kill-time assay in nutrient broth, meat broth and in a food model (meat pieces). Acetic acid showed MIC and MFC of 0.6 and 1.25 µL.mL-1, respectively. For O. vulgare essential oil MIC and MBC were 1.25 and 2.5 µL.mL-1, respectively. FIC indexes of the mixture of essential oil and acetic acid at MIC x ½ were £ 1.0, showing an additive effect. No synergy was found at kill-time study. Anti-staphylococcal effect of the antimicrobials alone or in mixture (MIC x ½) was lower in meat than in nutrient and meat broths. The effective combination of essential oils and organic acids could appear as an attractive alternative for the food industry, as the doses to inhibit the microbial growth in foods can be lowered.

Este estudo avaliou a ocorrência de um efeito inibitório potencializado quando da aplicação combinada do óleo essencial de O. vulgare e ácido acético sobre Staphylococcus aureus através da determinação Concentração Inibitória Fracional (FIC) e de ensaios de tempo de morte em caldo nutriente, caldo base carne e em um modelo alimentar (pedaços de carne). O ácido acético mostrou um valor de CIM e CBM de 0,6 e 1,25 µL.mL-1, respectivamente. Estudos prévios encontraram valores de CIM e CBM para o óleo essencial de O. vulgare sobre as cepas teste de S. aureus de 1,25 e 1,5 µL.mL-1, respectivamente. Valores de índices de CIF da mistura do óleo essencial e ácido acético na concentração de CIM x ½ foram £ 1,0 caracterizando uma interação de adição. Nenhum efeito sinérgico foi encontrado nos ensaios de tempo de morte. O efeito anti-estafilocócico dos antimicrobianos isolados ou em combinação (CIM x ½) foi menor quando aplicado em carne em comparação a sua adição em caldo nutriente e caldo carne. A efetiva combinação de óleos essenciais e outros agentes preservativos pode ser reconhecida como uma alternativa promissora para a indústria de alimentos, podendo viabilizando a diminuição de doses de antimicrobianos aplicadas para inibir o crescimento microbiano em alimentos.

Acetic Acid/analysis , Organic Acids/analysis , Oils, Volatile/analysis , Origanum/analysis , Food Samples , Methods , Microbial Sensitivity Tests , Methods
Córdoba; s.n; 2009. 69 p. ilus.
Thesis in Spanish | LILACS | ID: lil-583549


La Inspección Visual con Acido Acético (IVAA) constituye una alternativa frente a la citología Exfoliativa en el examen de detección del cuello de útero en lugares de escasos recursos o como complemento de papanicolaou en zonas de mediano recursos. OBJETIVOS: Examinar la sensibilidad, especiaficidad, valor predictivo positivo y negativo de los tres métodos de pesquisa (inspección visual con acido acético, inspeccion visual con iodo lugol ypapanicolaou), individualmente y asociados entre sí. MATERIALES Y METODOS: Se examinaron 2.230 mujeres que concurrieron en forma espontánea al consultorio de Ginicología del Hospital Nacional de Clínicas Sanagec de la ciudad de Córdoba. Se excluyeron las mujeres con tratamiento previo de lesiones preneoplásicas, embarazadas o con alteraciones graves de la anatomía cervicouterina. En un estudio transversal, médicos residentes debidamente capacitados, tomaron muestras para papanicolaou, y realizaron simultáneamente IVAA, VILI y Colposcopía a cada paciente. Los estudios de tamizaje fueron realizados pro examinador, excepto la colposcopía en la cual intervino un segundo examinador (muestras enmascaradas). Un tercer agente informó los papanicolaou. Se realizó Biopsia en los casos indicados por la colposcopía y en el 10% de colposcoías negativas pero con alguno de los otros métodos positivos. Se usó como prueba de referencia colposcoía mas biopsia, si influencia del sesgo de verificación.

Humans , Female , Acetic Acid/analysis , Colposcopy , Diagnostic Techniques and Procedures , Vaginal Smears/methods , Uterine Cervical Neoplasms/diagnosis , Sensitivity and Specificity , Uterine Cervical Neoplasms
Indian J Med Microbiol ; 2007 Oct; 25(4): 330-5
Article in English | IMSEAR | ID: sea-53837


PURPOSE: The non-sporing anaerobes cause a wide spectrum of infections. They are difficult to culture and their identification is tedious and time-consuming. Rapid identification of anaerobes is highly desirable. Towards this end, the potential of nuclear magnetic resonance (NMR) spectroscopy for providing a fingerprint within the proton spectrum of six genera belonging to anaerobes reflecting their characteristic metabolites has been investigated. METHODS: NMR analysis was carried out using Mercury plus Varian 300 MHz (7.05 T) NMR spectrophotometer on six different anaerobes. These included Bacteroides fragilis, Prevotella melaninogenica, Prevotella denticola, Fusobacterium necrophorum, Peptococcus niger and Peptostreptococcus spp. After the NMR analysis (256/512 scans), the different peaks were noted. The eight pus specimens, which yielded pure culture of anaerobe, also were analysed similarly. RESULTS: The major resonances of multiplex of amino acids/lipid at 0.9 ppm along with lactate/lipid at 1.3 ppm, acetate at 1.92 ppm and multiplex of lysine at 3.0 ppm remained constant to label the organism as an anaerobe. There was a difference found in the MR spectra of different genera and species. A simple algorithm was developed for the identification of the six different anaerobes studied. The MR spectra of the pure culture of the organism matched the MR spectra of pus from which the organism was isolated. CONCLUSIONS: MR-based identification was of value in the identification of anaerobes. However, a larger database of the peaks produced by anaerobes needs to be created for identification of all genera and species. It could then have the potential of diagnosing an anaerobic infection in vivo and thus expedite management of deep-seated abscesses.

Acetic Acid/analysis , Algorithms , Amino Acids/analysis , Bacteria, Anaerobic/chemistry , Bacterial Infections/diagnosis , Diagnosis, Differential , Humans , Lactic Acid/analysis , Lipids/analysis , Magnetic Resonance Spectroscopy/methods , Suppuration/microbiology
Braz. j. microbiol ; 31(2): 107-12, Apr.-Jun. 2000. tab
Article in English | LILACS | ID: lil-297647


The effects of treatment with anaerobic cecal microflora (ACM) and/or lactose and/or acetic acid on systemic and digestive tract of broiler chicks infection with "Salmonella" Typhimurium and "S." Enteritidis were studied. ACM was used without previous bacterial identification. Treatment with ACM contributed to the resistance of broiler chicks to infection with "Salmonella" spp. The infections were more persistent in the cecum, rectum and crops in decreasing order of intensity. The infections were also self-limiting since treated and control lots presented similar infection rates at the end of the experiments. Alone or in combination with lactose, ACM reduced the colonization of the digestive tract of broiler chicks by "S." Typhimurium and "S." Enteritidis. The effect of the combination of ACM with lactose or acetic acid was not potentiated in terms of reduction of fecal excretion of "Salmonella" spp. Treatment with ACM reduced the amount of "S." Typhimurium and "S." Enteritidis in feces. Alone or in combination with lactose, ACM reduced the cecal pH in treated birds. "S." Enteritidis was much more invasive than "S." Typhimurium and the use of ACM alone was more effective on the reduction of systemic infection. An explanation for the process of prevention of intestinal colonization with "Salmonella" spp. probably resides in the interrelationship of physiological, microbiological and immunological phenomena, as well as the variation in cecal pH.

Animals , Acetic Acid/analysis , Lactose/analysis , Salmonella enteritidis/isolation & purification , Salmonella Infections, Animal/diagnosis , Salmonella typhimurium/isolation & purification , Bacterial Infections/diagnosis