Effect of pH on the Minimum Inhibitory Concentration of Monolaurin Against Listeria monocytogenes1

1992 ◽  
Vol 55 (6) ◽  
pp. 449-452 ◽  
Author(s):  
DEOG-HWAN OH ◽  
DOUGLAS L. MARSHALL
Keyword(s):  
Listeria Monocytogenes ◽  
Minimum Inhibitory Concentration ◽  
Yeast Extract ◽  
Inhibitory Concentration ◽  
Ph Value ◽  
Potassium Sorbate ◽  
Butylated Hydroxyanisole ◽  
Tertiary Butylhydroquinone ◽  
Effect Of Ph ◽  
Glycerol Monolaurate

The effect of pH on the minimum inhibitory concentration (MIC) of glycerol monolaurate (monolaurin) against four strains of Listeria monocytogenes at 35°C in tryptic soy broth supplemented with 0.6% yeast extract was investigated. Our results demonstrate that the MIC of monolaurin was lower than MIC values reported for other common food antimicrobials such as potassium sorbate, tertiary butylhydroquinone, propyl paraben, and butylated hydroxyanisole. The MIC of monolaurin was reduced by decreasing the pH value of the medium. A 3-fold MIC reduction occurred when the pH decreased from pH 7.0 (10 μg/ml) to pH 5.0 (3 μg/ml).

Inhibition of Staphylococcus aureus by Potassium Sorbate in Combination with Sodium Chloride, Tertiary Butylhydroquinone, Butylated Hydroxanisole or Ethylenediamine Tetraacetic Acid

1980 ◽  
Vol 43 (3) ◽  
pp. 208-211 ◽  
Author(s):  
M. C. ROBACH ◽  
C. L. STATELER
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Potassium Sorbate ◽  
Butylated Hydroxyanisole ◽  
Tetraacetic Acid ◽  
Tertiary Butylhydroquinone ◽  
Synergistic Inhibition ◽  
Ethylenediamine Tetraacetic Acid ◽  
Inhibition Of Growth ◽  
Growth Studies

The effect of potassium sorbate alone and combined with sodium chloride (NaCl), tertiary butylhydroquinone (TBRQ). butylated hydroxyanisole (BHA) or ethylenediamine tetraacetic acid (EDTA) on growth of two strains of Staphylococcus aureus (S-6 and 12600) was studied. The growth studies were made using trypticase soy broth (pH 6.0) at 37 C. Certain combinations of sorbate with NaCl resulted in synergistic inhibition of growth of both strains. The combination of sorbate and TBRQ also resulted in synergistic inhibition of growth of strain 12600, but 25 ppm of TBRQ alone inhibited growth of strain S-6. Certain combinations of sorbate and BHA were synergistic against growth of both strains. Addition of EDTA did not potentiate sorbate's activity against growth of strain S-6 but was synergistic with sorbate against growth of strain 12600.

Antimicrobial Activity-of Sulfur Compounds Derived from Cabbage‡

1997 ◽  
Vol 60 (1) ◽  
pp. 67-71 ◽  
Author(s):  
K. H. KYUNG ◽  
H. P. FLEMING
Keyword(s):  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Minimum Inhibitory Concentration ◽  
Dimethyl Sulfide ◽  
Inhibitory Concentration ◽  
Dimethyl Disulfide ◽  
Allyl Isothiocyanate ◽  
Sulfur Compounds ◽  
Ph Values ◽  
Cysteine Sulfoxide

Selected sulfur compounds found in cabbage and its fermentation product, sauerkraut, were tested for minimum inhibitory concentration (MIC) against growth of 15 species of bacteria and 4 species of yeasts. S-Methyl-l-cysteine sulfoxide, sinigrin, and dimethyl sulfide at 500 ppm were not inhibitory to any of the bacteria and yeasts tested. Dimethyl disulfide at 500 ppm retarded some, but did not prevent growth of any of the test microorganisms. Dimethyl trisulfide had an MIC to bacteria of 200 ppm and to yeast of 20 ppm. Methyl methanethiosulfinate had an MIC between 50 and 200 ppm for all bacteria, and between 6 and 10 ppm for all yeasts tested. Methyl methanethiosulfonate had an MIC between 20 and 100 ppm for bacteria and between 50 and 500 ppm for yeasts. Allyl isothiocyanate had an MIC between 50 and 500 ppm for bacteria and between 1 and 4 ppm for yeasts. Methyl methanethiosulfinate was 10 to 100 times more inhibitory against Listeria monocytogenes at pH values of 5, 6, and 7 and was much less influenced by pH than was sodium benzoate.

Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
E Coli ◽  
Zones Of Inhibition ◽  
In Vitro Antibacterial Activity ◽  
Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

New Groups of Potential Antituberculotics: Bis(1-aryltetrazol-5-yl) Disulfides. Structure Activity Relationship

1994 ◽  
Vol 59 (1) ◽  
pp. 234-238 ◽  
Author(s):  
Karel Waisser ◽  
Jiří Kuneš ◽  
Alexandr Hrabálek ◽  
Želmíra Odlerová
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antimycobacterial Activity ◽  
Activity Relationship ◽  
Active Derivative ◽  
Structure Activity ◽  
Medium Activity ◽  
Substituent Constants ◽  
Atypical Strains

Oxidation of 1-aryltetrazole-5-thiols afforded bis(1-aryltetrazol-5-yl) disulfides. The compounds were tested for antimycobacterial activity against Mycobacterium tuberculosis, M. kansasii, M. avium and M. fortuitum. In the case of M. tuberculosis, the logarithm of minimum inhibitory concentration showed a parabolic dependence on hydrophobic substituent constants. Although the compounds exhibited low to medium activity, the most active derivative, bis(4-chlorophenyltetrazol-5-yl) disulfide (III) was more effective against atypical strains than are the commercial tuberculostatics used as standards.

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