scholarly journals Effects of Black Pepper (Piper nigrum L.) Chloroform Extract on the Enzymatic Activity and Metabolism of Escherichia coli and Staphylococcus aureus

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Wenxue Chen ◽  
Lan Zou ◽  
Weijun Chen ◽  
Yueying Hu ◽  
Haiming Chen

The chemical composition and antimicrobial mechanism of action of black pepper chloroform extract (BPCE) were investigated, as well as the potential antibacterial activities of BPCE against Escherichia coli and Staphylococcus aureus. The results showed that 1H-Cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene-, [1ar-(1aα,4aα,7β,7a,β,7bα.)]- (8.39%) and 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (6.92%) were identified as the two primary components of BPCE. The release of intracellular transaminases from bacteria after being incubated with BPCE revealed that the bacterial cell walls and membranes were degraded and that protein synthesis was inhibited to some extent. The inhibition of bacterial Na+/K+-ATPase activity upon the addition of BPCE also indicated an enhanced permeability of bacterial cell membranes. Moreover, an analysis of hexokinase and pyruvate kinase activities showed that BPCE affected the metabolic rate of glycolysis and disrupted the normal metabolism of bacteria. This phenomenon was supported by an observed accumulation of lactic acid (LA) in the treated bacterial cells. Overall, our results indicated that BPCE damaged bacterial cell walls and membranes, which was followed by a disruption of bacterial cell respiration.

1981 ◽  
Vol 59 (1) ◽  
pp. 76-83 ◽  
Author(s):  
M. Ivan

Twelve sheep, each prepared with a rumen fistula, were divided into three groups of four and fed three dietary levels of manganese (22, 300, and 3000 μg/g dry matter) for 11 weeks. The sheep were then dosed with radioactive manganese and samples of rumen contents were taken via the rumen fistula at 1, 7, and 13 h after dosing. The sheep were immediately killed after the last sampling and total rumen contents were mixed and sampled. Rumen fluid was separated from all samples and fractionated by centrifugation into protozoa plus plant particles, bacteria, and cell-free fraction. The bacterial cells were disrupted and fractionated into cell walls and cytoplasm. The cytoplasmic protein was precipitated with trichloroacetic acid.Although the concentration of radiomanganese in rumen fluid decreased with time after dosing from 14.4–17.8 to 6.1–9.3% of dose/L the protozoal and bacterial uptakes of radiomanganese were not significantly different and ranged from 26.5 to 40.6% and 18.9 to 31.7% of total in the rumen fluid, respectively. There was also no effect of dietary concentration of manganese on the uptake and distribution of radiomanganese in the rumen fluid fractions. However, on the average more radiomanganese was found in the bacterial cell walls (48.1–75.3% of total in bacteria) and less in the cytoplasm (51.9–24.7% of total in bacteria) with increasing dietary manganese. Very little radioactivity was found in the trichloroacetic acid precipitated cytoplasm (1.79–0.78% of total in cytoplasm). Concentrations of manganese in the bacteria and bacterial cell walls were higher than, and closely related with, those in the diet. Specific activities of radiomanganese decreased in all fractions with increasing dietary manganese. Approximately 15–17% of the total radiomanganese in the rumen contents at 13 h after dosing was found in the protozoal fraction and 10–15% was found in the bacterial fraction; only approximately 21% of the radiomanganese remained in cell-free fraction of the rumen fluid in each dietary treatment.


2019 ◽  
pp. 67-70

EFECTO DE LA RADIACIÓN GAMMA SOBRE LAS CARACTERÍSTICAS MICROBIOLÓGICAS, FíSICO-QUÍMICAS y EVALUACIÓN SENSORIAL EN PIMIENTA NEGRA MOLIDA (Piper nigrum) EFFECT OF GAmmA RADIATION ON THE mICROBIOLOGIGAL, PHySICO-CHEmICAL CHARACTERISTICS AND SENSORy ANALySIS OF BLACK PEPPER POWDER (Piper nigrum) Johnny Vargas, Marco Linares A, Flor de María Quispe M Instituto Peruano de Energía Nuclear, Av. Canadá 1470, Lima 41, Perú Probuysa EIRL, Jr. Libertad 455, Lima 17 DOI: https://doi.org/10.33017/RevECIPeru2010.0010/ RESUMEN La pimienta es la más famosa de las especias, se utiliza para dar sabor a los alimentos. Es una de las especias con mayor población microbiana, por lo que es causante de enfermedades y de descomposición de los alimentos principalmente procesados. El objetivo del presente trabajo es dar a conocer el efecto de la radiación gamma sobre la población microbiana, las características físico-químicas y la evaluación sensorial en pimienta negra molida, tratada con diferentes dosis alternativas, con la finalidad de obtener la dosis mínima óptima que reduzca la carga microbiana a las especificaciones recomendadas, sin alterar significativamente las características físico-químicas y sensoriales. Muestras de 500 g fueron irradiadas en el equipo Gammacell 220 (0; 4; 6 y 8 kGy). La tasa de dosis inicial fue de 5.82 kGy/h. Se realizaron los siguientes análisis: microbiológico (Aerobios mesófilos, anaerobios, enterobacterias, Salmonella/ Shigella, Coliformes totales, Escherichia coli, Staphylococcus aureus, Estreptococos grupo D Lancefield, Bacillus cereus, Clostridium sulfito reductor, mohos y levaduras). Físico-químico (cenizas totales, cenizas insolubles en HCl, solubles en HCl, extracto alcohólico, extracto etéreo y fibra cruda). La evaluación sensorial (color, olor y sabor mediante test descriptivo. Los métodos fueron los recomendados por la FDA, APHA, AOAC y las NTP. A las diferentes dosis ensayadas, no se encontraron diferencias en los análisis físico-químicos y sensoriales. La dosis mínima seleccionada fue de 8 kGy que redujo la población de microorganismos aerobios mesófilos en 5 ciclos logarítmicos de 9,8 x 106 a 4,0 x 10 UFC/g. Dosis de 4 kGy fue suficiente para reducir la población de hongos en 3 ciclos logarítmicos de 1,7 x 103 a <10 UFC/g, cumpliendo con las especificaciones requeridas. Palabras clave: Radiación gamma, pimienta, población microbiana, dosis. ABSTRACT Pepper is the most famous of spices used to flavor foods. It is one of the crops with the highest microbial population, and it is causing disease and decay of mostly processed foods. The aim of this study was to determine the effect of gamma radiation on microbial population, the physicalchemical and sensory evaluation in ground black pepper, treated with different doses alternatives, in order to obtain the optimal minimal dose that reduces microbial load to the recommended specifications, without significantly altering the physical-chemical and sensory. 500 g samples were irradiated in the Gammacell 220 (0, 4, 6 and 8 kGy). The initial dose rate was 5.82 kGy/h. Were performed the following analysis: microbiological (aerobic mesophiles, anaerobes, Enterobacteriaceae, Salmonella / Shigella, total coliforms, Escherichia coli, Staphylococcus aureus, Lancefield group D streptococci, Bacillus cereus, Clostridium sulfite reducer, molds and yeasts). Physico-chemical (total ash, ash insoluble in HCl, HCl-soluble extract, alcohol, ether extract and crude fiber. Sensory evaluation (color, odor and flavor by descriptive test). The methods were those recommended by the FDA, APHA, AOAC and NTP. At different doses tested, there were no differences in physical-chemical analysis and sensory. The minimum dose of 8 kGy was selected that reduced the population of aerobic plate in 5 log units of 9,8 x 106 to 4.0 x 10 UFC/g, dose of 4 kGy was sufficient to reduce the fungal population by 3 log units of 1,7 x 103 to <10 UFC/g , according to the specifications. Keywords: Gamma radiation, pepper, microbial population, dose.


Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010


1968 ◽  
Vol 243 (11) ◽  
pp. 3169-3179 ◽  
Author(s):  
D J Tipper ◽  
J L Strominger

1981 ◽  
Vol 256 (17) ◽  
pp. 9229-9234
Author(s):  
E Benedetti ◽  
B Di Blasio ◽  
V Pavone ◽  
C Pedone ◽  
C Toniolo ◽  
...  

1970 ◽  
Vol 245 (14) ◽  
pp. 3675-3682
Author(s):  
Roland Plapp ◽  
Jack L. Strominger

1966 ◽  
Vol 116 ◽  
pp. 487-515 ◽  
Author(s):  
John S. Anderson ◽  
Pauline M. Meadow ◽  
Mary A. Haskin ◽  
Jack L. Strominger

Sign in / Sign up

Export Citation Format

Share Document