Inhibition and Inactivation of Listeria monocytogenes by Sorbic Acid

1988 ◽  
Vol 51 (11) ◽  
pp. 842-847 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Incubation Period ◽  
Sorbic Acid ◽  
Gradual Decrease ◽  
The Other ◽  
Complete Inhibition ◽  
Potassium Sorbate ◽  
Limited Growth ◽  
Complete Inactivation ◽  
Slight Growth

Inhibition and inactivation of Listeria monocytogenes by sorbic acid were studied using tryptose broth supplemented with 0, 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3% potassium sorbate; adjusted to pH 5.6 or 5.0; and incubated at 4, 13, 21 or 35°C. The bacterium grew in sorbate-free controls under all conditions except at 4°C and pH 5.0. At pH 5.6 and 4°C, the bacterium was inactivated by 0.25 or 0.3% of potassium sorbate after 66 and 60 d. Other concentrations permitted slight growth followed by decreases in populations. At 4°C and pH 5.0, concentrations of 0.15 to 0.3% potassium sorbate completely inactivated the pathogen in 60 to 36 d, whereas the other concentrations caused a gradual decrease in populations during the incubation period. At 13°C and pH 5.6, L. monocytogenes grew at all test concentrations of potassium sorbate, but the maximum populations were directly related to the concentration of potassium sorbate added to the medium - the higher the concentration, the lower the ultimate maximum population. At 13°C and pH 5.0, concentrations of 0.2, 0.25 or 0.3% potassium sorbate completely inhibited growth and caused complete inactivation of the pathogen, whereas presence of 0.15% or less potassium sorbate allowed growth of the pathogen. At 21 and 35°C and pH 5.6, appreciable growth of L. monocytogenes occurred at all test concentrations of sorbate. Reducing the pH to 5.0 allowed limited growth of the pathogen at 21 and 35°C when the medium contained 0.05, 0.1 or 0.15% potassium sorbate. Higher concentrations caused either complete inhibition or inhibition plus partial or complete inactivation of L. monocytogenes.

Sodium Benzoate Inhibits Growth of or Inactivates Listeria monocytogenes

1988 ◽  
Vol 51 (7) ◽  
pp. 525-530 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Incubation Period ◽  
Sodium Benzoate ◽  
The Other ◽  
Complete Inhibition ◽  
Initial Population ◽  
Limited Growth ◽  
Complete Inactivation ◽  
Low Concentrations ◽  
Slight Growth

The ability of Listeria monocytogenes to grow or survive was determined using tryptose broth at pH 5.6 or 5.0, supplemented with 0, 0.05. 0.1, 0.15. 0.2. 0.25 or 0.3% sodium benzoate, and incubated at 4,13,21 or 35°C. The bacterium grew in benzoate-free controls under all conditions except at 4°C and pH 5.0. At pH 5.6 and 4°C, after 60 d, L. monocytogenes (initial population ca. 103/ml) was inactivated by 0.2, 0.25 and 0.3% sodium benzoate. Other concentrations of benzoate permitted slight growth during the first 36 d of incubation followed by a decrease in populations of the pathogen. At pH 5.0 and 4°C, from 0.15 to 0.3% benzoate completely inactivated the pathogen in 24 to 30 d, whereas the other concentrations caused a gradual decrease in the population during the 66-d incubation period. At 13°C and pH 5.6, L. monocytogenes grew (more at lower than higher concentrations of benzoate) in the presence of all concentrations of benzoate except 0.25 or 0.3%, which prohibited growth throughout a 264-h incubation period. Reducing the pH to 5.0 minimized growth at the two low concentrations of benzoate and caused slight decreases in population at the other concentrations of benzoate. At 21 and 35°C and pH 5.6, appreciable growth of L. monocytogenes occurred in the presence of 0.2% or less sodium benzoate, whereas higher concentrations were inhibitory, permitting little if any growth by the pathogen. Reducing the pH to 5.0 allowed limited growth of the pathogen at 21 and 35°C when the medium contained 0.05 or 0.1% sodium benzoate. Higher concentrations caused either complete inhibition or inhibition plus partial or complete inactivation of the pathogen during incubations of 117 h at 21°C or 78 h at 35°C.

Growth and Synthesis of Aflatoxin by Aspergillus parasiticus in the Presence of Sorbic Acid

1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Incubation Period ◽  
Aspergillus Parasiticus ◽  
Sorbic Acid ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Early Stages ◽  
Cumulative Data ◽  
The Media ◽  
Growth Ph

Two media [basal (M1) and enriched (M2)] containing potassium sorbate (0–300 ppm as sorbic acid) were inoculated with spores (104 – 106/flask) of Aspergillus parasiticus and incubated for 5 days at 28 C. The greater the amount of sorbate added, the higher was the pH of the media after incubation and the smaller was the yield of mold mycelium. Intermediate amounts of sorbate sometimes resulted in greater accumulation of aflatoxin than when media were free of sorbate. Sorbate more effectively inhibited mold growth and aflatoxin production in medium M2 than M1 and when the small rather than the large inoculum was used. A second trial was done with 106 or 105 spores/flask of M2 (ca. 27 ml) and 105 spores/flask of M2 (ca. 27 ml) containing sorbate (200 ppm of sorbic acid). Cumulative data for mold growth. pH and content of aflatoxin in the medium showed that relative effects of different treatments changed during the incubation period. An index to measure the capacity of molds to synthesize aflatoxins was developed. Application of the index indicates that sorbate delayed mold growth but did not inhibit biosynthesis of aflatoxin. The ability to synthesize aflatoxin was greatest in the early stages of mold growth and then decreased linearly as mold growth progressed.

Growth of Listeria monocytogenes in the Presence of Pseudomonas fluorescens at 7 or 13°C in Skim Milk

1989 ◽  
Vol 52 (12) ◽  
pp. 852-855 ◽  
Author(s):  
SEHAM A. FARRAG ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Pseudomonas Fluorescens ◽  
Incubation Period ◽  
Skim Milk

Autoclaved samples of skim milk were inoculated with Listeria monocytogenes (strain Scott A, California or V7), Pseudomonas fluorescens (strain P26 or B52), or a combination of L. monocytogenes plus P. fluorescens, and incubated at 7 or 13°C for 8 weeks. McBride Listeria Agar was used to determine populations of L. monocytogenes (at 0, 7, 14, 28, 42, or 56 d), and Pseudomonas isolation agar to enumerate P. fluorescens. Growth of L. monocytogenes was somewhat enhanced after 7 d of incubation at 7 but not at 13°C in the presence of pseudomonads. However, after 14 d and until the end of the incubation period (56 d), slight inactivation of L. monocytogenes in the presence of P. fluorescens was observed. L. monocytogenes did not affect growth or survival of P. fluorescens; also, no marked changes in pH of the milk were caused either by L. monocytogenes alone or by L. monocytogenes plus P. fluorescens.

scholarly journals Effect of Gaseous Ozone on Listeria monocytogenes Planktonic Cells and Biofilm: An In Vitro Study

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1484
Author(s):  
Felice Panebianco ◽  
Selene Rubiola ◽  
Francesco Chiesa ◽  
Tiziana Civera ◽  
Pierluigi Aldo Di Ciccio
Keyword(s):  
Listeria Monocytogenes ◽  
In Vitro Study ◽  
Planktonic Cells ◽  
Free Living ◽  
Biofilm Inhibition ◽  
Additional Tool ◽  
Complete Inactivation ◽  
Gaseous Ozone ◽  
Food Borne

Among food-borne pathogens, Listeria monocytogenes continues to pose concerns to food business operators due to its capacity to form biofilm in processing environments. Ozone may be an eco-friendly technology to control microbial contaminations, but data concerning its effect on Listeria monocytogenes biofilm are still limited. In this study, the effect of gaseous ozone at 50 ppm on planktonic cells and biofilm of reference and food-related Listeria monocytogenes strains was evaluated. Ozone caused a reduction in microbial loads of 3.7 ± 0.4 and 3.9 ± 0.4 Log10 CFU/mL after 10 and 30 min, respectively. A complete inactivation of planktonic cells after 6 h of treatment was observed. Biofilm inhibition and eradication treatments (50 ppm, 6 h) resulted in a significant decrease of the biofilm biomass for 59% of the strains tested, whilst a slight dampening of live cell loads in the biofilm state was observed. In conclusion, gaseous ozone is not sufficient to completely counteract Listeria monocytogenes biofilm, but it may be useful as an additional tool to contrast Listeria monocytogenes free-living cells and to improve the existing sanitization procedures in food processing environments.

Allergic contact dermatitis from potassium sorbate and sorbic acid in topical pharmaceuticals and medical devices

2021 ◽  
Author(s):  
Ella Dendooven ◽  
Stefan Kerre ◽  
Kenn Foubert ◽  
Luc Pieters ◽  
Julien Lambert ◽  
...  
Keyword(s):  
Contact Dermatitis ◽  
Allergic Contact Dermatitis ◽  
Medical Devices ◽  
Sorbic Acid ◽  
Potassium Sorbate ◽  
Allergic Contact

On the incubation period in neurolues

1927 ◽  
Vol 23 (10) ◽  
pp. 1046-1050
Author(s):  
E. V. Sukhova
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Incubation Period ◽  
The Other ◽  
Other Hand ◽  
General Number ◽  
The Central Nervous System

Speaking about syphilis lesions of the central nervous system, it is impossible not to note that these lesions are among the most severe diseases of the latter. But, on the other hand, their severity is redeemed to some extent by the specific means of combating them which we have in our hands. In this case, the fight against neurolues is reduced not so much to its treatment as to its prevention. Hence the interest with which the question of the influence of various conditions on the occurrence of syphilitic lesions of the central nervous system has recently begun to be comprehensively discussed and the exact causes which, from the general number of syphilitics, distinguish the group subsequently condemned to neurolues have been sought to be elucidated.

scholarly journals Acrylic resin disinfection by peracetic acid and microwave energy

2015 ◽  
Vol 63 (3) ◽  
pp. 315-318 ◽  
Author(s):  
Carmen Beatriz Borges FORTES ◽  
Vicente Castelo Branco LEITUNE ◽  
Fabrício Mezzomo COLLARES ◽  
Nélio Bairros DORNELLES JUNIOR ◽  
Stéfani Becker RODRIGUES ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Microwave Irradiation ◽  
Incubation Period ◽  
Peracetic Acid ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
The Other ◽  
Disinfection Methods ◽  
Acrylic Resins ◽  
Irradiation Power

Objective: The objective of this study was to evaluate the effectiveness of disinfection methods in microwave and immersion in peracetic acid in heat-cured, self-cured and microwave-cured acrylic resin, contaminated with Candida albicans. Methods: Five specimens were prepared for each type of acrylic resin. All were infected with Candida Albicans, incubated at 37°C for 24 hours. The group which underwent microwave energy was irradiated with a power of 840W for 1 minute and the other group underwent disinfection by soaking of 0.2% peracetic acid for 5 minutes. Results: All samples proved to be contaminated after the incubation period. After the different processes of disinfection, both immersion in 0.2% peracetic acid as microwave irradiation were effective in disinfection of the 3 types of acrylic resins contaminated by Candida Albicans. Conclusion: Concluded that soaking in 0,2% peracetic acid for 5 minutes with microwave irradiation power 840W for 1 minute are effective methods for disinfecting heat-cured acrylic resin, self-cured acrylic resin and microwave-cured acrylic resin, contaminated with Candida Albicans.

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).

scholarly journals Biology of the Wild SilkmothAnaphe panda(Boisduval) in the Kakamega Forest of Western Kenya

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
N. Mbahin ◽  
S. K. Raina ◽  
E. N. Kioko ◽  
J. M. Mueke
Keyword(s):  
Life Cycle ◽  
Incubation Period ◽  
Rainy Season ◽  
Dry Season ◽  
Developmental Period ◽  
The Other ◽  
Western Kenya ◽  
Kakamega Forest ◽  
Pupal Period ◽  
Indigenous Forest

A study on the life cycle of the silkmothAnaphe panda(Boisduval) was conducted in two different habitats of the Kakamega Forest in western Kenya: Ikuywa, an indigenous forest, and Isecheno, a mixed indigenous forest. Eggs were laid in clusters, and the incubation period ranged from 40 to 45 days. Larvae fed onBridelia micrantha(Hochst) and passed through seven instars. The developmental period took between 83 to 86 days in the dry season and 112 to118 days in the rainy season. The pupal period ranged between 158 and 178 days in the rainy season and, on the other hand, between 107 and 138 days in the dry season. But the later caught up in development with those that formed earlier. Moths emerged from mid-October until mid-May. Longevity of adultAnaphe pandamoths took between 4 and 6 days, but generally females seemed to live longer than males. The moth also seems to have higher lifespan in the indigenous forest compared to the mixed indigenous forest.

Sign in / Sign up

Export Citation Format

Share Document