scholarly journals Isolation, Selection and Antimicrobial Activity of Actinomycetes from Mangrove Soil of Can Gio Forest, Hochiminh City, Vietnam

2021 ◽  
pp. 7-22
Author(s):  
Nguyen Tuan Hai ◽  
Cao Ngoc Diep
Keyword(s):  
Antimicrobial Activity ◽  
Biosphere Reserve ◽  
Active Metabolites ◽  
Genus Streptomyces ◽  
Gram Positive Bacteria ◽  
Mangrove Soil ◽  
Rdna Sequencing ◽  
Peptide Synthetase ◽  
Can Gio Mangrove ◽  
And Staphylococcus Aureus

The Can Gio Mangrove is a Biosphere Reserve of UNESCO since 2000 and it is also a well-known example of “mangrove afforestation and reforestation area’’. A total of 63 actinomycetes were isolated from 25 samples of 9 different sites in mangrove forest soil Can Gio, HoChiMinh city, Vietnam. Almost their colonies have round-shaped; milky, white clear and yellow, entire or loabate margin; diameter size of these colonies varied from 0.2 to 3.0 mm. Twenty-nine of 63 tested isolates could produce antimicrobial active metabolites inhibiting at least one of the tested pathogens and 9 isolates were selected for 16S rDNA sequencing. The result showed that genus Streptomyces (8 isolates) and other genera including 1 isolates were Gram-negative bacteria (Stenotrophomonas). The antimicrobial activity and the amplifying genes coding for polyketide synthetase (PKS) and nonribosomal peptide synthetase (NRPS) showed that 8 strains had broad-spectrum antimicrobial activity, mainly against gram-positive bacteria as Bacillus cereus and Staphylococcus aureus.

Antimicrobial Activity and Chemical Composition of the Essential Oil of Nepeta crispa Willd. from Iran

2004 ◽  
Vol 59 (9-10) ◽  
pp. 653-656 ◽  
Author(s):  
Ali Sonboli ◽  
Peyman Salehi ◽  
Morteza Yousefzadi
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Essential Oil ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aerial Parts ◽  
Total Oil ◽  
And Staphylococcus Aureus

Abstract The composition and antimicrobial activity of the essential oil of Nepeta crispa Willd., an endemic species from Iran, was studied. The oil was obtained from the aerial parts of the plant and analyzed by GC and GC/MS. Twenty-three compounds, accounting for 99.8% of the total oil, were identified. The main constituents were 1,8-cineol (47.9%) and 4aα,7α,7aβ- nepetalactone (20.3%). The antimicrobial activity of essential oil of N. crispa was tested against seven gram-negative or gram-positive bacteria and four fungi. The results of the bioassays showed the interesting antimicrobial activity, in which the gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, were the most sensitive to the oil. Also, the oil exhibited a remarkable antifungal activity against all the tested fungi.

scholarly journals Green synthesis: characterization and biological activity of silver nanoparticles using aqueous extracts of plants from the Arecaceae family

2021 ◽  
Vol 43 ◽  
pp. e52011
Author(s):  
Alan Kelbis Oliveira Lima ◽  
Arthur Abinader Vasconcelos ◽  
Renata Katsuko Takayama Kobayashi ◽  
Gerson Nakazato ◽  
Hugo de Campos Braga ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Gram Negative Bacteria ◽  
Leaf Extracts ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Clinical Interest ◽  
The Mean ◽  
And Staphylococcus Aureus

This study proposes the preparation, characterization, and evaluation of the antimicrobial activity of silver nanoparticles (AgNPs). AgNPs were synthesized from the leaf extracts of plants from the Arecaceae family, which are abundant in the Amazon region. AgNPs were characterized using UV/Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), dynamic light scattering (DLS), and their minimum inhibitory concentrations (MIC) against the bacteria Escherichia coli and Staphylococcus aureus. AgNPs presented maximum absorbance between 420 and 430 nm, the mean diameter obtained by DLS ranged from 130.43 to 352.93 nm and the polydispersity index (PdI) ranged from 0.523 to 0.689. The surface charge measured by the Zeta potential was negative and ranged from -17.2 to -26.97 mV. FTIR analysis suggests that the phenolic compounds and/or proteins in the chemical composition of the plants studied may have been responsible for the reduction of Ag+ ions and stabilization of AgNPs. The morphology of AgNPs observed was largely spherical and presented some agglomerates. Transmission electron microscopy analyses showed polydispersed AgNPs without the formation of large agglomerates. The synthesized AgNPs presented homogeneity and rapid bioreduction. The concentration of AgNPs required to eliminate microorganisms by up to 90% was lower for Gram-negative bacteria (2.75 μg mL-1) than for Gram-positive bacteria (21.75 μg mL-1). In addition, AgNPs synthesized from plant species that are native to the Amazon proved to be promising, since they showed excellent antimicrobial activity against microorganisms of clinical interest.

Investigating the antioxidant potential of Streptomyces sp. MUSC 11 from mangrove soil in Malaysia

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Hefa Mangzira Kemung ◽  
Loh Teng-Hern Tan ◽  
Kok-Gan Chan ◽  
Hooi-Leng Ser ◽  
Jodi Woan-Fei Law ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Biological Activities ◽  
Biologically Active ◽  
Mangrove Forests ◽  
Genus Streptomyces ◽  
Streptomyces Sp ◽  
Gram Positive Bacteria ◽  
Mangrove Soil ◽  
Life Saving ◽  
Distinguished Group

Streptomyces are a distinguished group of gram-positive bacteria mostly acknowledged for their immense contribution to life-saving drugs and lines of compounds with diverse bioactivities. To date, there remains limited studies on Streptomyces with biological activities residing in underexplored ecosystems such as the mangrove forests. For this purpose, the present work aimed at investigating the biological activity of Streptomyces sp. MUSC 11 collected from soil sample in mangrove forests, situated in the State of Pahang, Peninsular of Malaysia. The cultured strain resembled phenotypic and genotypic traits of genus Streptomyces. Investigations of the methanolic extract from Streptomyces sp. MUSC 11 revealed antioxidant activities in form of scavenging free radicals ABTS, DPPH, chelating iron and reducing ferric iron. Besides the antioxidant tests, antioxidant results corresponded well to the presence of phenolic content. In summary, Streptomyces derived from extreme and understudied ecosystem such as the mangrove forests are potential sources of biologically active and therapeutically useful compounds.

scholarly journals Detection of antibiotic-resistant bacteria endowed with antimicrobial activity from a freshwater lake and their phylogenetic affiliation

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2103 ◽  
Author(s):  
Zothanpuia ◽  
Ajit K. Passari ◽  
Vijai K. Gupta ◽  
Bhim P. Singh
Keyword(s):  
Antimicrobial Activity ◽  
Genetic Relatedness ◽  
Freshwater Lake ◽  
Biologically Active ◽  
Resistant Bacteria ◽  
Global Public Health ◽  
Active Metabolites ◽  
Antibiotic Resistant ◽  
Phylogenetic Affiliation ◽  
Rdna Sequencing

Antimicrobial resistance poses a serious challenge to global public health. In this study, fifty bacterial strains were isolated from the sediments of a freshwater lake and were screened for antibiotic resistance. Out of fifty isolates, thirty-three isolates showed resistance against at least two of the selected antibiotics. Analysis of 16S rDNA sequencing revealed that the isolates belonged to ten different genera, namelyStaphylococcus(n= 8), Bacillus(n= 7), Lysinibacillus(n= 4),Achromobacter(n=3), bacterium(n= 3),Methylobacterium(n= 2),Bosea(n= 2), Aneurinibacillus(n= 2), Azospirillum(n= 1), Novosphingobium(n= 1). Enterobacterial repetitive intergenic consensus (ERIC) and BOX-PCR markers were used to study the genetic relatedness among the antibiotic resistant isolates. Further, the isolates were screened for their antimicrobial activity against bacterial pathogens viz.,Staphylococcus aureus(MTCC-96),Pseudomonas aeruginosa(MTCC-2453) andEscherichia coli(MTCC-739), and pathogenic fungi viz.,Fusarium proliferatum(MTCC-286),Fusarium oxysporum(CABI-293942) andFusarium oxy. ciceri(MTCC-2791). In addition, biosynthetic genes (polyketide synthase II (PKS-II) and non-ribosomal peptide synthetase (NRPS)) were detected in six and seven isolates, respectively. This is the first report for the multifunctional analysis of the bacterial isolates from a wetland with biosynthetic potential, which could serve as potential source of useful biologically active metabolites.

scholarly journals MOLECULAR DETECTION OF PSEUDOMONAS AERUGINOSA ISOLATED FROM MINCED MEAT AND STUDIES THE PYOCYANIN EFFECTIVENESS ON PATHOGENIC BACTERIA

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
D. A. Qasim
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Molecular Detection ◽  
Gram Positive Bacteria ◽  
Diffusion Technique ◽  
Low Sensitivity ◽  
Minced Meat ◽  
And Staphylococcus Aureus ◽  
16Srrna Gene

This study was aimed to collected Minced meat from the local markets in Baghdad governorate during 2018, and examined for the presence of Pseudomonas aeruginosa, in order to extract and purify pyocyanin and examined it as an antimicrobial activity against pathogenic bacteria in foods. Fifteen isolates were isolated from 50 samples and identified as P. aeruginosa using the API20E system and finally confirmed with PCR using 16SrRNA gene. Four tested media were used for the production of pigment after incubation within 72 h, One strain which given a vigorous pigmentation was chosen and extracted with chloroform and HCl then analyzed with Gas chromatography (GC-Mass) which showed a sharp peak at the time of acquisition of 27.13 minutes at the chromatographic analysis recognized with mass spectrometry as Hemipyocanin (alpha-hydroxy phenazine) which produced molecular ion with intensive peak at 205 m/z. Agar well diffusion technique was applied for estimating the antimicrobial activity of purified (pyocyanin) with variable concentrations (25, 50, 75 and 100 mg/ml) which monitored toward  Gram-negative and  Gram-positive bacteria that isolated of minced meat. Escherichia coli and staphylococcus aureus was the most affected with pyocyanin were followed by Serratia marcescens and Klebsiella sp. at the same level. While Enterobacter sp, Bacillus cereus, Proteus mirabilis, and Proteus vulgaris showed intermediate sensitivity, the Pseudomonas fluorescens was shown low sensitivity to pyocyanin.

Synthesis, SAR, In-Silico appraisal and Anti-Microbial Study of substituted 2-aminobenzothiazoles derivatives

2019 ◽  
Vol 15 ◽  
Author(s):  
Devidas G. Anuse ◽  
Suraj N. Mali ◽  
Bapu R. Thorat ◽  
Ramesh S. Yamgar ◽  
Hemchandra K. Chaudhari
Keyword(s):  
Antimicrobial Activity ◽  
In Silico ◽  
Docking Study ◽  
Moderate Activity ◽  
Molecular Docking Study ◽  
Mass Spectral ◽  
Gram Positive Bacteria ◽  
Ft Ir ◽  
In Silico Molecular Docking

Background: Antimicrobial resistance is major global health problem, which is being rapidly deteriorating the quality of human health. Series of substituted N-(benzo[d]thiazol-2-yl)-2-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)acetamide (3a-j) were synthesized from substituted N-(benzo[d]thiazol-2-yl)-2-chloroacetamide/bromopropanamide (2a-j) and 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole (2) and further evaluated for their docking properties and antimicrobial activity. Methods: All synthesized compounds were characterized by FT-IR, NMR and Mass spectral analysis. All compounds were allowed to dock against different antimicrobial targets having PDB ID: 1D7U and against common antifungal target having PDB ID: 1EA1. Results: The compounds 3d and 3h were showed good activity against Methicillin-resistant Staphylococcus aureus (MRSA, resistance Gram-positive bacteria). All synthesized compounds showed good to moderate activity against selected bacterial and fungal microbial strains. If we compared the actual in-vitro antimicrobial activity and in-silico molecular docking study, we found that molecules 3i and 3h were more potent than the others. Conclusion: Our current study would definitely pave the new way towards designing and synthesis of more potent 2-aminobenzothiazoles derivatives.

Chemical Composition and in-vitro antimicrobial screening of leaf essential oil of Plectranthus gerardianus Benth., and isolation of the major constituent of oil

2020 ◽  
Vol 10 ◽  
Author(s):  
Navadha Bhatt ◽  
Navabha Joshi ◽  
Kapil Ghai ◽  
Om Prakash
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Major Constituent ◽  
In Vitro Antimicrobial Activity ◽  
Gram Positive Bacteria ◽  
Medicinal Value ◽  
Leaf Essential Oil ◽  
Plant Families ◽  
Total Oil

Background: The Lamiaceae (Labiatae) is one of the most diverse and widespread plant families’ in terms of ethno medicine and its medicinal value is based on the volatile oils concentration. This family is important for flavour, fragrance and medicinal properties. Manyplants belonging to this family have indigenous value. Method: The essential oil of Plectranthus gerardianusBenth. (Lamiaceae), was analysed by GC and GC-MS analysis, while the major component was isolated and conformed by NMR spectroscopy. Result: The oil was found to be rich in oxygenated monoterpenes, which contribute around 62% of the total oil. The major components identified were fenchone (22.90%) and carvenone oxide (16.75%), besides other mono and sesquiterpenoids. The in-vitro antimicrobial activity of essential oil was tested against three gram negative bacteria viz. Pasteurellamultocida, Escherichia coli, and Salmonella enterica, two gram positive bacteria viz. Staphylococcus aureus and Bacillus subtilis and two fungi viz. Candida albicans and Aspergillusflavus. The antimicrobial activity of the oil was also compared to the antimicrobial activity of leaf essential oil of another Himalayan plant viz. Nepetacoerulescens. Conclusion: The oil showed in-vitro antimicrobial activity against all the microbial strains and can lessen the ever-growing demand of potentially hazardous antibiotics for treatment.

scholarly journals Antimicrobial Activity and Mode of Action of Celastrol, a Nortriterpen Quinone Isolated from Natural Sources

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 591
Author(s):  
Nayely Padilla-Montaño ◽  
Leandro de León Guerra ◽  
Laila Moujir
Keyword(s):  
Antimicrobial Activity ◽  
Cytoplasmic Membrane ◽  
Bactericidal Effect ◽  
Inoculum Size ◽  
Bacterial Populations ◽  
Gram Positive Bacteria ◽  
Dna And Rna ◽  
Dna And Rna Synthesis ◽  
Natural Derivative ◽  
Interesting Alternative

Species of the Celastraceae family are traditionally consumed in different world regions for their stimulating properties. Celastrol, a triterpene methylene quinone isolated from plants of celastraceas, specifically activates satiety centers in the brain that play an important role in controlling body weight. In this work, the antimicrobial activity and mechanism of action of celastrol and a natural derivative, pristimerin, were investigated in Bacillus subtilis. Celastrol showed a higher antimicrobial activity compared with pristimerin, being active against Gram-positive bacteria with minimum inhibitory concentrations (MICs) that ranged between 0.16 and 2.5 µg/mL. Killing curves displayed a bactericidal effect that was dependent on the inoculum size. Monitoring of macromolecular synthesis in bacterial populations treated with these compounds revealed inhibition in the incorporation of all radiolabeled precursors, but not simultaneously. Celastrol at 3 µg/mL and pristimerin at 10 µg/mL affected DNA and RNA synthesis first, followed by protein synthesis, although the inhibitory action on the uptake of radiolabeled precursors was more dramatic with celastrol. This compound also caused cytoplasmic membrane disruption observed by potassium leakage and formation of mesosome-like structures. The inhibition of oxygen consumption of whole and disrupted cells after treatments with both quinones indicates damage in the cellular structure, suggesting the cytoplasmic membrane as a potential target. These findings indicate that celastrol could be considered as an interesting alternative to control outbreaks caused by spore-forming bacteria.

scholarly journals Edible Films from Carrageenan/Orange Essential Oil/Trehalose—Structure, Optical Properties, and Antimicrobial Activity

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 332
Author(s):  
Jancikova Simona ◽  
Dordevic Dani ◽  
Sedlacek Petr ◽  
Nejezchlebova Marcela ◽  
Treml Jakub ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Antibacterial Properties ◽  
Edible Films ◽  
Attenuated Total Reflectance ◽  
Practical Application ◽  
Film Properties ◽  
Gram Positive Bacteria ◽  
Edible Packaging ◽  
Orange Essential Oil

The research aim was to use orange essential oil and trehalose in a carrageenan matrix to form edible packaging. The edible packaging experimentally produced by casting from an aqueous solution were evaluated by the following analysis: UV-Vis spectrum, transparency value, transmittance, attenuated total reflectance Fourier-Transform spectroscopy (FTIR), scanning electron microscopy (SEM) and antimicrobial activity. The obtained results showed that the combination of orange essential oil with trehalose decreases the transmittance value in the UV and Vis regions (up to 0.14% ± 0.02% at 356 nm), meaning that produced films can act as a UV protector. Most produced films in the research were resistant to Gram-positive bacteria (Staphylococcus aureus subsp. aureus), though most films did not show antibacterial properties against Gram-negative bacteria and yeasts. FTIR and SEM confirmed that both the amount of carrageenan used and the combination with orange essential oil influenced the compatibility of trehalose with the film matrix. The research showed how different combinations of trehalose, orange essential oils and carrageenan can affect edible film properties. These changes represent important information for further research and the possible practical application of these edible matrices.

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