scholarly journals The antibacterial activity of bacteriocin produced by Lactobacillus acidophilus isolates against sensitive reference strain Lactobacillus acidophilus R0052 and its stability to different pH, heating and storage temperatures

2012 ◽  
Vol 36 (0E) ◽  
pp. 274-279
Author(s):  
Najim Hadi Najim
Keyword(s):  
Antimicrobial Activity ◽  
Lactobacillus Acidophilus ◽  
Storage Temperature ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Sensitive Strain ◽  
Heat Stable ◽  
Soft Cheese ◽  
And Storage ◽  
Antimicrobial Effectiveness

Two isolates of Lactobacillus acidophilus were isolated from locally homemade soft cheese and identified in accordance with their main features as described by bergeys manual of determinative bacteriology .Agar well diffusion bioassay was used for the evaluation of antimicrobial activity of cell free supernatant (culture filtrates) of Lactobacillus acidophilus isolates against the sensitive strain Lactobacillus acidophilus R0052 and the diameter of the inhibition zone was proportional to the bacteriocin concentration. The antimicrobial activity of the bacteriocin was proportional to the reciprocal of the highest dilution factor producing a detectable zone of inhibition . The storage temperature of the crude bacteriocin had a significant(P˂ 0.01) effect on its potency against the sensitive strain .The potential of the antimicrobial activities of the crude bacteriocin that was stored for 10 days at refrigeration temperature (4°C) was significantly (P˂ 0.01) higher than that stored at room temperature. The antimicrobial effectiveness of the crude bacteriocin was heat stable and retaining 100% of its activity after its exposure to 60 °C & 80°C for 10 minutes .Boiling of the crude bacteriocin for 30 minutes had significantly (P˂ 0.01) decreased its potency to 0% .The potency of the crude bacteriocin was stable after four hours of exposure to both neutral (pH7) and acidic (pH4) conditions but was inactivated at alkaline (pH9) condition.

scholarly journals Phytochemical Constituency Profiling and Antimicrobial Activity Screening of Seaweeds Extracts Collected from the Bay of Bengal Sea Coasts

2019 ◽  
Author(s):  
Mahmudul Hasan ◽  
Md. Abdus Shukur Imran ◽  
Farhana Rumzum Bhuiyan ◽  
Sheikh Rashel Ahmed ◽  
Parsha Shanzana ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activities ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Total Phenolic ◽  
Enteromorpha Intestinalis ◽  
Bacterial Strains ◽  
Hypnea Musciformis ◽  
Methanol Extracts ◽  
Seaweed Extracts

AbstractSeaweeds are able to produce a great variety of secondary metabolites that are characterized by a broad spectrum of biological activities. Two seaweeds species, namelyHypnea musciformisandEnteromorpha intestinalis werestudied to evaluate the phytochemical constituency and antimicrobial activities. First of all, crude extracts of both sea weeds were prepared by two different extraction methods (soaking and water bath) using different solvents. Phytochemicals profiling results revealed the presence of bioactive compounds (flavonoids, alkaloids, tannin, saponin and phenols) in both seaweed extracts. Quantification results for ethanolic extracts ofH. musciformis and E. intestinalisestimated 51 mg and 43 mg tannins in per gram of dried samples and flavonoids contents were found 67 mg and 57 mg/g mg QE/g respectively. Total phenolic contents were determined in terms of gallic acid equivalent (GAE).H. musciformisexhibited higher amount of phenolics (59 ± 0.0002 mg GAE/g) thanE. intestinalisextracts (41 ± 0.0002 mg GAE/g). In antimicrobial activity test, ethanol extractsof H. musciformisandE. intestinaliswere found 10 mm of inhibition diameter against all of the bacterial strains. Besides, methanol extracts ofE. intestinaliswere more susceptible toStaphylococcus aureus and Pseudomonaswhich was close to the inhibition diameter (>15 mm) of the mainstream antibiotic; Gentamicin. Moreover,Klebsiella sp. was found more susceptible to ethanol and methanol extracts of Hypnea musciformisas it showed inhibition zone greater than 15 mm. Both Seaweed extracts possessed higher amount of phytochemicals and showed promising antimicrobial activities when compared with the standards.

Characterization of crude extract prepared from Indian curd and its potential as a biopreservative

2020 ◽  
pp. 108201322094009
Author(s):  
Annada Das ◽  
Geeta Chauhan ◽  
Ravi K Agrawal ◽  
Arun K Das ◽  
Serlene Tomar ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Crude Extract ◽  
Polyacrylamide Gel Electrophoresis ◽  
Dairy Product ◽  
Sodium Dodecyl ◽  
Antimicrobial Activities ◽  
Heat Stable ◽  
Food Borne ◽  
Concentrated Solution ◽  
Antioxidant And Antimicrobial Activities

The adverse effects of chemical preservatives used to prevent food spoilage have led to the search for various biopreservatives. Considering this, a study was undertaken to prepare crude extract (CE) from Indian curd (a fermented dairy product) and characterized it in terms of antioxidant and antimicrobial activities against some common food-borne bacteria. The CE exhibited well pronounced antimicrobial activity against Bacillus cereus and Salmonella typhimurium. The minimum inhibitory concentration (MIC) of CE was recorded for 2-fold concentrated solution prepared from a 10-fold stock. The CE exhibited a significantly higher ( p < 0.05) antioxidant and antimicrobial activities compared to its fractions. The CE was found to be heat stable (up to 100 ℃ for 30 min) and exhibited a significant ( p < 0.05) increase in activity at pH 2–7 and in combination with 2% citric acid solution. Trypsin treatment suggested it to be of proteinaceous in nature. The antibacterial activity of CE remained intact at 4 ℃ for seven days, whereas non-significant ( p > 0.05) changes in its activity were noted during storage at −20 ℃ for 30 days. The curd sample used for preparation of CE, when tested for bacteriocin production and subsequent antimicrobial activity, did not show inhibition against S. typhimurium. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of CE and its fractions revealed multi-banding pattern. By virtue of its bioactivities observed, CE can be explored as a promising food biopreservative.

scholarly journals SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF FRIEDELIN [2, 3-d] SELENADIAZOLE

2010 ◽  
Vol 9 (2) ◽  
pp. 285-288 ◽  
Author(s):  
Mehtab Parveen ◽  
Sayed Hasan Mehdi ◽  
Raza Murad Ghalib ◽  
Mahboob Alam ◽  
Rokiah Hashim ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Spectral Studies ◽  
Highly Active

The new 1, 2, 3, selenadiazole derivative (3) was prepared from friedelin (1) via the corresponding semicarbazone (2) using Lalezari cyclization. The compounds were prepared, separated and characterized on the basis of microanalysis and spectral studies. The isolated friedelin and its selenadiazole were screened in vitro for their antimicrobial activities against various pathogenic bacterial were found to be highly active against all the selected pathogens. Compound 3 showed an inhibition zone of 14 mm and 12 mm respectively against highly resistant S. albus and C. albicans. A general mechanistic scheme for these reactions is also suggested based on current and previous results.   Keywords: Friedelin, semicarbazone, ketomethylene, cyclization, selenadiazole

Composition and Antimicrobial Activity of Bamboo (Phyllostachys Heterocycla cv. Pubescens) Leaf Hydrosols

2019 ◽  
Vol 18 (2) ◽  
pp. 207-219
Author(s):  
Weiqiong Yuan ◽  
Xue Han ◽  
Yi Wu ◽  
Jianzhong Hu ◽  
Zhaolin Lv
Keyword(s):  
Antimicrobial Activity ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Cell Membrane Permeability ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Components ◽  
Volatile Components ◽  
Treatment Change ◽  
Release Assay ◽  
Phyllostachys Heterocycla

The aim of this study was to examine the chemical composition of the major volatile components of bamboo leaf hydrosols and their antimicrobial activities. The chemical components were analyzed using gas chromatography-mass spectrometry and 45 compounds were identified from bamboo leaf hydrosols. The major volatile compounds (%) determined were ionone (16.76%), damasone (10.38%), geranylacetone (7.98%) and β-ionone (6.68%). The antimicrobial activities were evaluated against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Saccharomyces cerevisiae (VINTAGE WHITE and ES488). The inhibition zone and minimum inhibitory concentration test results showed that bamboo leaf hydrosols had the highest antimicrobial activity against gram-positive bacteria. The antimicrobial stability tests showed that the hydrosols also exhibited good stability under heat treatment, change in pH, and exposure to UV irradiation. Results of cell constituent release assay and atomic force microscope observations indicated that bamboo leaf hydrosols destroyed the cell wall and cell membrane permeability causing leakage of intracellular constituents.

scholarly journals The synergistic bactericidal effects of bacteriocin and pressurization against E.coli O157:H7 in raw milk

2014 ◽  
Vol 38 (1) ◽  
pp. 15-23
Author(s):  
Najim Hadi Najim
Keyword(s):  
Antimicrobial Activity ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Pressure Level ◽  
Nutrient Broth ◽  
Whole Milk ◽  
Test Kit ◽  
Bactericidal Effects ◽  
Antimicrobial Effectiveness

Colonies of E.coli O157:H7 were isolated from 35 raw milk sample and their identification were confirmed based on biochemical reactions and both cultural and serological characteristics. Presumptive E.coli O157:H7 isolates obtained by selective plating on both CT-SMAC and Chromogenic agars were further tested serologically for the presence of both O157 and H7 antigenes using the commercial available latex agglutination test kit. The unhygienic practices in the production of milk in Al-Thahab Al- Abiedh , Abu-Graib, Al-Zedan and Khan Dharie were reflected on the highest significant (p<0.01)prevalence level of contamination with E.coli O157:H7 that appeared to be 80%, 80%, 60% and60% respectively. Homogenization pressure of 1000 psi and 2000 psi for five passes had significantly (p<0.05) influenced the inactivation degree of E.coli O157:H7 in both whole milk and nutrient broth. Milk homogenized at a pressure level of 3000 psi for three passes and 4000 psi for two passes resulted in a further increase of the antimicrobial effectiveness and produced an additional significant (p<0.05) reduction of E.coli O157:H7. Complete elimination (inactivation) of viable E.coli O157:H7 was achieved when cultured whole milk was homogenized at pressure level of 5000 psi for a single pass. Agar well diffusion bioassay was used for the evaluation of antimicrobial activity of the crude bacteriocin produced by L.acidophilus LA-K against E.coli O157:H7. Enterohaemorrhagic E.coli O157:H7 expressed its resistance to the crude bacteriocin since it did not show any inhibition zone around each well treated with bacteriocin. The average diameters of the inhibition zones of crude bacteriocin against stressed E.coli O157:H7 by pressurization at 4000 psi, 3000 psi, 2000 psi and 1000 psi were 14 mm, 12mm, 10mm and 8mm respectively. The homogenization pressure level (moderate or high) had significantly (p<0.05) influenced the inactivation degree of the crude bacteriocin against the stressed E.coli O157:H7 by pressurization. Quantitative measurement of crude bacteriocin antimicrobial activity was determined by using photometric or turbidometric method. The results revealed that no growth of stressed E.coli O157:H7 with no visible turbidity in the nutrient broth with bacteriocin that diluted to 1/2, 1/4 and 1/8 were observed. Bacteriocin that diluted to 1/8 which resulted in no visible turbidity after overnight of incubation at 37C° and gave an optical density reading of 1.448.

Effect of freezing and storage temperature on stability and antimicrobial activity of an antibiotic mixture used for decontamination of tissue allografts

2018 ◽  
Vol 19 (4) ◽  
pp. 489-497 ◽  
Author(s):  
Vicente Mirabet ◽  
Ana Melero ◽  
M. Dolores Ocete ◽  
Dimitra Bompou ◽  
Miriam Torrecillas ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Storage Temperature ◽  
And Storage

scholarly journals Antimicrobial Activities of Fungus Comb Extracts Isolated From Indo-Malayan Termite Macrotermes Gilvus Mound

2021 ◽  
Author(s):  
Lucia Dhiantika Witasari ◽  
Khairunnasa Wizdjanul Wahyu ◽  
Bonifasia Junita Anugrahani ◽  
Dina Clarissa Kurniawan ◽  
Aris Haryanto ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Ethyl Acetate ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Ethyl Acetate Extract ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Alternative Source ◽  
Antibacterial And Antifungal Activities ◽  
Fungus Comb

Abstract The embodiment of antimicrobial components into the food packaging material has the ability to prevent microbial contamination. Fungus comb could be an alternative source of natural antimicrobial agents. In this study, n-hexane, ethyl acetate, methanol, and water extracts from fungus comb isolated from Indo-malayan termite Macrotermes gilvus Hagen mound were analysed for its antibacterial and antifungal activities against food spoilage microorganisms, including Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Aspergillus flavus, and Aspergillus niger. The antimicrobial activity of the fungus comb extracts was evaluated using Kirby-Bauer disc diffusion and microdilution method. The result showed that ethyl acetate extract exhibited the biggest diameter inhibition zone for all bacteria and fungi tested. Ethyl acetate extract showed antibacterial activity in all bacteria with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.39 mg/mL and 0.78 mg/mL, respectively. This extract also inhibited A. flavus and A. niger with MIC value of 0.78 mg/ml. Ethyl acetate extract contained guaiacol and syringol, which were predicted as the main antimicrobial components in fungus comb. Whereas n-hexane extract only inhibited Gram-positive bacteria. S. aureus ATCC 25923 was the most sensitive bacteria tested using all extracts. In addition, A. flavus was more sensitive compared to A. niger. Overall, fungus comb extract exhibited antimicrobial activity against E.coli ATCC 25922, P. aeruginosa ATCC 27853, S. aureus ATCC 25923, A. flavus, and A. niger. This study revealed that the fungus comb extract, especially ethyl acetate, could be considered as a new antimicrobial agent.

scholarly journals CHEMICAL COMPOSITION, ANTIBACTERIAL ACTIVITY OF ESSENTIAL OILS AND LEAF EXTRACTS OF MENTHA PULEGIUM (L) AND GLYCYRRHIZA FOETIDA (DESF) AGAINST THE PHYTOPATHOGENIC BACTERIA

2019 ◽  
Vol 31 (1) ◽  
pp. 47-54
Author(s):  
Hanane Lougraimzi ◽  
Aghraz Abdellah ◽  
Bouaichi Abdelaaziz ◽  
El J. Meryem ◽  
Achbani E. Hassan
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Minimal Bactericidal Concentration ◽  
Mentha Pulegium ◽  
Leaf Extracts ◽  
Phytopathogenic Bacteria

This research was conducted to evaluate the components of the Mentha pulegium (L) and Glycyrrhiza foetida (Desf) that were extracted by hydro distillation and analyzed using GC-MS methods. They are spontaneous plants widespread in Gharb of Morocco. The aim of the study is to investigate the antibacterial activity of the essential oils and leaf methanolic extracts of these two medicinal plants against five phytopathogenic bacteria. The evaluation of the antimicrobial activity of the two species by estimating the diameter of the inhibition zone has shown that the essential oil of M. pulegium exhibited a higher antimicrobial activity than G. foetida which varied according to the sensitivity of the phytopathogenic strains. The results obtained revealed different degrees of sensitivity toward methnolic extract. However, the methanolic extract and the essential oil of M. pulegium are more active based on the Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC). The antimicrobial activities of leaf extracts from the two plants highlighted in this study could justify their therapeutic use. These results should be strongly recommended as an alternative to a chemical compound that still represents the problem of toxic residues.

scholarly journals Comparative Evaluation of Methods Commonly Used to Determine Antimicrobial Susceptibility to Plant Extracts and Phenolic Compounds

2008 ◽  
Vol 91 (6) ◽  
pp. 1423-1429 ◽  
Author(s):  
Thea King ◽  
Gary Dykes ◽  
Ruth Kristianti
Keyword(s):  
Antimicrobial Activity ◽  
Phenolic Compounds ◽  
Plant Extract ◽  
Antimicrobial Susceptibility ◽  
Bacterial Species ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Zone Size ◽  
Logarithmic Relationship

Abstract A comparison was made to evaluate the ability of the most commonly used qualitative agar diffusion methods and a quantitative broth dilution assay to determine the antimicrobial activity of a plant extract and a variety of phenolic compounds. A disc and well diffusion technique and a microtiter broth microdilution (MBM) assay were used as antimicrobial susceptibility tests of a plant extract and several phenolic compounds against 7 bacterial species. In both the well and disc diffusion assays, the level of reproducibility was poor and a linear or logarithmic relationship did not exist between inhibition zone size and the concentration of the agents. The MBM method produced the most consistent results and allowed the determination of the relative sensitivities of each species and the relative antimicrobial activities of each agent. This study demonstrated that when a diffusion method is used, multiple concentrations of the agent must be assayed to ensure that a relationship exists between the concentration of the agent and inhibition zone size. When a relationship does not exist, antimicrobial activity should be determined by a quantitative dilution technique.

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