scholarly journals Synergistic Antimicrobial Activity of Metabolites Produced by a Nonobligate Bacterial Predator

2003 ◽  
Vol 47 (7) ◽  
pp. 2113-2117 ◽  
Author(s):  
Cody C. Cain ◽  
Dongho Lee ◽  
Robert H. Waldo ◽  
Alexis T. Henry ◽  
Earl J. Casida ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Broad Spectrum ◽  
New Genus ◽  
Antimicrobial Activities ◽  
Cellular Fatty Acid ◽  
New Genus And Species ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Gram Negative ◽  
Naturally Occurring

ABSTRACT A naturally occurring, gram-negative, nonobligate predator bacterial strain 679-2, exhibits broad-spectrum antimicrobial activity that is due, in part, to the production of three extracellular compounds. Antimicrobial-activity-directed fractionation of a culture of strain 679-2 against a panel of microorganisms has led to the isolation of three compounds: pyrrolnitrin, maculosin, and a new compound, which we have named banegasine. Although pyrrolnitrin is well known in the literature, it has not been found in cells with the herbicide maculosin. Further, this is the first report of production of maculosin by a prokaryote. Both maculosin and banegasine, which displayed no antimicrobial activities alone, were found to potentiate the antimicrobial activity of pyrrolnitrin. Based on 16S rRNA sequence, cellular fatty acid composition, and biochemical and cultural characteristics, strain 679-2 appears to represent a new genus and species of eubacteria, Aristabacter necator. The potent, broad-spectrum antimicrobial activity of predator strain 679-2 may be due to synergism between metabolites.

scholarly journals Taxonomy and antimicrobial activity of streptosporangium strain SG163 isolated from a Saharan soil

2019 ◽  
Vol 20 (1) ◽  
pp. 35-54
Author(s):  
K. Bouti ◽  
◽  
H. Boudjella ◽  
N. Bouras ◽  
A. Zitouni ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Culture Media ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Saharan Soil ◽  
Type Strains

n a continuing search fornew antimicrobial products from actinobacteriacollected in Algerian Saharan soils, an isolateof actinobacteria,designated Sg163, was selected for its interesting antimicrobial activity.The isolate wasidentified to the genus Streptosporangium by phenotypicand molecular criteria. The cultural and physiological characterizations as well as phylogenetic analysis indicated that the isolate was different from known members of the genus Streptosporangium. Analysis of the 16S rRNA sequence showed 97.09to 98.27% similarity with those of Streptosporangium type strains. The strainSg163 produced antifungal and antibacterial activities on several culture media. The highest antimicrobial activities were obtained in ISP2 medium. Three active products C1, C2 and C3 with both antifungal and antibacterial activities were isolated and purified by chromatographic methodswith C2, as the major compound. The data of the infraredspectroscopy andthe chemical revelations, suggested that the active molecules were glycosylatedaromaticcompounds.

Synergistic Effects of Essential Oils of Ammoides verticillata and Satureja candidissima Against Many Pathogenic Microorganisms

2020 ◽  
Vol 18 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Fatima Benyoucef ◽  
Mohammed El Amine Dib ◽  
Boufeldja Tabti ◽  
Arrar Zoheir ◽  
Jean Costa ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Synergistic Effects ◽  
Lactobacillus Rhamnosus ◽  
Salmonella Typhi ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Ammoides Verticillata

Background: Antibiotic resistance is today one of the most serious threats to global health, food security and development. Due to the growing number of infections, treatment becomes more difficult, if not impossible, because of the loss of antibiotic efficacy. Objective: In the present investigation, the chemical composition of essential oils of Ammoides verticillata and Satureja candidissima and their synergistic effects on antimicrobial activities were investigated. Methods: The chemical composition of the essential oil was analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectroscopy (GC/MS). The antimicrobial activity of the essential oils was investigated using dilution-agar method against nine bacterial strains three Gram-negative Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Salmonella typhi (ATCC 14028), and six Gram-positive: Staphylococcus aureus (ATCC 43300,) Clostridium sporogenes (ATCC 19404), Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 7314), Lactobacillus rhamnosus (ATCC 53103) and Bacillus cereus (ATCC 14579). Results: The essential oil of A. verticillata was characterized principally by carvacrol (44,3%), Limonene (19,3%) and p-cymene (19,2%). The constituents identified of S. candidissima essential oil were principally oxygenated monoterpenes represented by pulegone (70,4%). The essential oil of A. verticillata had a good antimicrobial activity against four bacterial strains (Escherichia coli, Salmonella typhi, Lactobacillus rhamnosus and Bacillus cereus) with MIC and MBC values between 0.2-0.4 µl/ml and 0.2-6.2 µl/ml, respectively. While, S. candidissima essential oil had moderate antimicrobial activities against all strains with MIC and MBC values between 1.5-6.2 µl/ml and 6.2-12.5 µl/ml, respectively. The results of antimicrobial activity of essential oils blend presented higher antimicrobial activity against all tested bacteria with MIC and MBC values between 0.3-1.5 µl/ml and 0.4-6.2 µl/ml, respectively. Conclusion: The essential oils blend presented high antimicrobial activity compared to virgin oils. This activity can be due to the association of active compounds such as carvacrol and pulegone. These findings provide a new source of drugs that may help in therapy to lead to the development of a new treatment based on a combination of these essential oils against gram-negative and gram-positive bacteria that continue to pose a threat to public health.

scholarly journals Antimicrobial Activity of Lignin and Lignin-Derived Cellulose and Chitosan Composites Against Selected Pathogenic and Spoilage Microorganisms

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 670 ◽  
Author(s):  
Alzagameem ◽  
Klein ◽  
Bergs ◽  
Do ◽  
Korte ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Low Temperatures ◽  
Food Packaging ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Scavenging Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Spoilage Bacteria ◽  
Chitosan Films

The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenolic structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source showing the following trend: organosolv of softwood > kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low temperatures (0–7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both Gram-positive and Gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films, the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens.

scholarly journals Kinneretia asaccharophila gen. nov., sp. nov., isolated from a freshwater lake, a member of the Rubrivivax branch of the family Comamonadaceae

2010 ◽  
Vol 60 (4) ◽  
pp. 809-814 ◽  
Author(s):  
Margarita Gomila ◽  
Jarone Pinhassi ◽  
Enevold Falsen ◽  
Edward R. B. Moore ◽  
Jorge Lalucat
Keyword(s):  
New Genus ◽  
Cellular Fatty Acid ◽  
Fatty Acid Analysis ◽  
Strictly Aerobic ◽  
Negative Bacterium ◽  
New Genus And Species ◽  
Biochemical Tests ◽  
The Family ◽  
Bacterium Strain ◽  
Physiological And Biochemical

A strictly aerobic, Gram-negative bacterium, strain KIN192T, isolated from fresh water from Lake Kinneret, Israel, was examined using a polyphasic approach to characterize and clarify its phylogenetic and taxonomic position. Sequences of the 16S rRNA and gyrB genes and ITS1 revealed close relationships to species of the genera Pelomonas, Mitsuaria and Roseateles, in the Rubrivivax branch of the family Comamonadaceae of the Betaproteobacteria. Physiological and biochemical tests, cellular fatty acid analysis and DNA–DNA hybridizations indicated that this strain should be assigned to a new genus and species in the Rubrivivax phylogenetic branch, for which the name Kinneretia asaccharophila gen. nov., sp. nov., is proposed. The type strain of Kinneretia asaccharophila is strain KIN192T (=CCUG 53117T =CECT 7319T).

scholarly journals Microwave Irradiative Synthesis of Triazine Substituted Pyrazoles and Study of Antitubercular and Antimicrobial Activities

2019 ◽  
Vol 31 (5) ◽  
pp. 1087-1090 ◽  
Author(s):  
Pradip P. Deohate ◽  
Roshani S. Mulani
Keyword(s):  
Antimicrobial Activity ◽  
Elemental Analysis ◽  
Structural Investigation ◽  
Antimicrobial Activities ◽  
Spectral Studies ◽  
Gram Negative ◽  
Mass Spectral ◽  
The Relationship ◽  
Substituted Pyrazoles ◽  
Structure And Activity

Microwave irradiative synthesis of triazine substituted pyrazoles i.e. (4-benzylideneamino-6-methyl-[1,3,5]-triazin-2-yl)-(5-methyl-2-substituted benzoyl/isonicotinoyl/cinnamoyl-pyrazol-3-yl)-amines have been achieved by the cyclocondensation of N-(4-benzylideneamino-6-methyl-[1,3,5]-triazin-2-yl)-3-oxo butyramide with substituted acid hydrazides. Synthesis of required butyramide was done by reacting 2,4-diamino-6-methyl-[1,3,5]-triazine with benzaldehyde and then condensing the product with ethyl acetoacetate. Structural investigation of synthesized compounds has been done by chemical transformation, elemental analysis and IR, 1H NMR, mass spectral studies. Study of antitubercular and antimicrobial activity of title compounds against some selected Gram-positive and Gram-negative microorganisms was performed to establish the relationship between structure and activity of compound.

scholarly journals Synthesis of Plant-Mediated Silver Nanoparticles UsingDioscorea batatasRhizome Extract and Evaluation of Their Antimicrobial Activities

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
P. C. Nagajyothi ◽  
K. D. Lee
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Antimicrobial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Synthesis Of Nanoparticles ◽  
E Coli ◽  
Synthesize Silver Nanoparticles ◽  
Dioscorea Batatas

The eco-friendly synthesis of nanoparticles through various biological means helps to explore various plants for their ability to synthesize silver nanoparticles (AgNPs). Here we have synthesized AgNPs by using rhizome extract ofDioscorea batatasat as well as room temperature (). AgNPs were characterized under UV-vis spectrophotometer, SEM, FTIR, XRD, and EDX. The antimicrobial activity of AgNPs was evaluated on gram positive (B. substilisandS. aureus), gram negative (E. coli), and fungi (S. cerivisaeandC. albicans). At room temperature,S. cerivisaeandC. albicanswere found to be more susceptible to AgNPs than at .

Antimicrobial Activity of New 2,4-Disubstituted Thiazolidinone Derivatives

2009 ◽  
Vol 64 (11-12) ◽  
pp. 785-789 ◽  
Author(s):  
Wael A. El-Sayed ◽  
Yasser K. Abdel-Monem ◽  
Nabil M. Yousif ◽  
Nashwa Tawfek ◽  
Mohamed T. Shaaban ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Antimicrobial Activities ◽  
Gram Positive ◽  
Streptomyces Species ◽  
Gram Negative

A number of new disubstituted 2,5-thiazolidinone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). They displayed different degrees of antimicrobial activities or inhibitory actions

scholarly journals ANTIMICROBIAL ACTIVITIES OF ARTABOTRYS ODORATISSIMUS R.Br.

2021 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Poonam Sethi ◽  
Nandhagopal Karmegam
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pseudomonas Fluorescens ◽  
Methanolic Extract ◽  
Antimicrobial Activities ◽  
Experimental Plant ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Negative ◽  
Good Antibacterial Activity

ABSTRACT Artabotrys odoratissimus R.Br.  (Annonaceae) a medium sizes shrub with hooks, sweet smelling flowers and aggregate fruits, was tested for activity against gram negative bacteria. The fruit of the experimental plant was extracted with water, methanol and toluene: methanol (2:1 v/v). Artabotrys fruits showed good antibacterial activity and produced zone of inhibition of 32mm. The methanolic extract of the fruit showed maximum zone of inhibition at 300 ?g/ml against Pseudomonas fluorescens. The present study clearly indicates that A. odoratissimus had a profound antimicrobial   activity and it may be useful in the treatment of various infectious caused by bacteria. Keywords: Artabotrys, Gram Negative Bacteria, Pseudomonas, Zone Of Inhibition

scholarly journals Green synthesis of silver nanoparticles using aqueous extract of Citrus sinensis peels and evaluation of their antibacterial efficacy

2021 ◽  
Vol 10 (1) ◽  
pp. 851-859
Author(s):  
Lebogang Mogole ◽  
Wesley Omwoyo ◽  
Elvera Viljoen ◽  
Makwena Moloto
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Citrus Sinensis ◽  
Antimicrobial Activities ◽  
Antibacterial Efficacy ◽  
Gram Positive ◽  
Gram Negative ◽  
Average Size ◽  
Passivating Agent

Abstract The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae. Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity.

scholarly journals Antimicrobial and antibiofilm activity of the essential oil from dried leaves of Eucalyptus staigeriana

2019 ◽  
Vol 86 ◽  
Author(s):  
Marcos Saldanha Correa ◽  
Joseli Schwambach ◽  
Michele Bertoni Mann ◽  
Jeverson Frazzon ◽  
Ana Paula Guedes Frazzon
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Gram Positive ◽  
Promising Alternative ◽  
Gram Negative

ABSTRACT: In recent years, compounds with biological properties produced by plants have received attention as an alternative to control microorganisms. Essential oils extracted from green leaves of Eucalyptus sp. have been demonstrated to have antimicrobial activities, but so far there are no reports of antimicrobial activity of essential oils extracted from dried leaves of Eucalyptus staigeriana. So, the objectives of this study were to determine the chemical composition of the essential oils obtained from dried leaves of E. staigeriana (EOdlES) and to evaluate in vitro antimicrobial and antibiofilm activities of EOdlES against gram-positive and gram-negative, resistance and multiresistant Enterococcus faecalis isolated from food and clinical samples. The characterization of EOdlES was performed by gas chromatography-mass spectrometry (GC/MS). For this study, 26 bacterial strains were used, which included 11 reference strains and 15 antibiotic resistant and multiresistant E. faecalis strains. Antimicrobial activities of EOdlES against gram-positive and gram-negative were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) value was evaluated by a microbroth dilution technique. The antibiofilm effects were assessed by microtiter plate method. As a result, 21 compounds were identified, being oxygenated monoterpenes (69.58%) the major chemical family. EOdlES showed only antimicrobial activity against gram-positive strains. E. faecalis resistant and multiresistant strains show the lowest MIC (3.12 to 6.25%), when compared with reference E. faecalis strain. EOdlES has the ability to inhibit the biofilm formation, but little or none ability to inhibit the preformed biofilm. This study demonstrates that EOdlES is a promising alternative to control important foodborne and clinic gram-positive resistant bacteria.

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