Identification Of Antimicrobial Compounds Research Articles

Identification of antimicrobial compounds from the plant growth promoting bacteria (PGPR) tested against Fusarium wilt of tomato caused by Fusarium oxysporum f.sp. Lycopersici

Infections and pests affecting plants pose significant threats to global food security. Over the top utilize of chemical pesticides is frequently utilized to diminish the impacts of plant illnesses caused by bacterial and parasitic pathogens. The greatest concern as we work towards more feasible horticulture is expanding agrarian efficiency for a developing populace. Microbial biocontrol operators (MBCAs) have illustrated their viability as a green procedure to oversee plant illnesses, invigorate edit development and execution, and increment yields. Other than their growth-promoting part, plant growth-promoting bacteria/fungi (PGPR/PGPF) can stifle plant illnesses by creating inhibitory chemicals and actuating a plant resistant reaction against plant pathogens. As biofertilizers and biopesticides, PGPR and PGPF are considered financially practical and appealing strategies for economical horticulture; This leads to a “win–win” circumstance. A few strains of PGPR and PGPF have been distinguished as compelling BCAs beneath controlled natural conditions. In common, any MBCA must overcome certain challenges some time recently it can be enrolled or broadly utilized for disease/pest control. Viable MBCA gives a down to earth arrangement to progress nursery edit execution with decreased fertilizer inputs and chemical pesticide utilization. This current audit points to fill the current crevice in information on plant growth-promoting microorganisms (PGPM), drawing consideration to the logical premise for arrangement, improvement proposals and extra investigate related to commercial utilize of PGPM.

Bioassay-guided purification and identification of antimicrobial compound from corn silk extract and postharvest application against Fusarium verticillioides on cherry tomato

Bioassay-guided purification and identification of antimicrobial compound from corn silk extract and postharvest application against Fusarium verticillioides on cherry tomato

Characterization and identification of antimicrobial compounds from endophytic Fusarium incarnatum isolated from Cymbidium orchids.

This study characterized and identified the antimicrobial compounds from an endophytic fungus (Fusarium incarnatum (C4)) isolated from the orchid, Cymbidium sp. Chromatographic techniques were employed to separate the bioactive compounds from the crude extracts of F. incarnatum (C4). Following bio-guided fractionation, two fractionated extracts (fractions 1 and 2) of F. incarnatum (C4) exhibited antibacterial and antifungal activities against Bacillus cereus (MIC: 0.156mg/mL) and Ganoderma boninense (MIC: 0.3125mg/mL), respectively. The active fractions were discovered to comprise of a variety of bioactive compounds with pharmacological importance (alkaloids, flavonoids, phenolic compounds, terpenoids, peptides and fatty acids). Liquid chromatography mass-spectrometry (LCMS) analysis detected the presence of antibacterial (kanzonol N, rifaximin, linoleic acid (d4), cannabisativine, docosanedioic acid, and stearamide) and antifungal components (3-methyl-quinolin-2-ol, prothiocarb, kanzonol N, peganine, 5Z-tridecene, and tetronasin) in fractions 1 and 2, respectively, which may have contributed to the antimicrobial effects. Findings from this study highlighted the important potential of fungal endophytes from medicinal hosts as producers of antimicrobials and antibiotics.

Isolation and Identification of Antimicrobial Compounds from Bacillus Cereus Obtained from Soil

Isolation and Identification of Antimicrobial Compounds from Bacillus Cereus Obtained from Soil

Identification of Antimicrobial Compounds in Two Streptomyces sp. Strains Isolated From Beehives.

The World Health Organization warns that the alarming increase in antibiotic resistant bacteria will lead to 2.7 million deaths annually due to the lack of effective antibiotic therapies. Clearly, there is an urgent need for short-term alternatives that help to alleviate these alarming figures. In this respect, the scientific community is exploring neglected ecological niches from which the prototypical antibiotic-producing bacteria Streptomycetes are expected to be present. Recent studies have reported that honeybees and their products carry Streptomyces species that possess strong antibacterial activity. In this study, we have investigated the antibiotic profile of two Streptomycetes strains that were isolated from beehives. One of the isolates is the strain Streptomyces albus AN1, which derives from pollen, and shows potent antimicrobial activity against Candida albicans. The other isolate is the strain Streptomyces griseoaurantiacus AD2, which was isolated from honey, and displays a broad range of antimicrobial activity against different Gram-positive bacteria, including pathogens such as Staphylococcus aureus and Enterococus faecalis. Cultures of S. griseoaurantiacus AD2 have the capacity to produce the antibacterial compounds undecylprodigiosin and manumycin, while those of S. albus AN1 accumulate antifungal compounds such as candicidins and antimycins. Furthermore, genome and dereplication analyses suggest that the number of putative bioactive metabolites produced by AD2 and AN1 is considerably high, including compounds with anti-microbial and anti-cancer properties. Our results postulate that beehives are a promising source for the discovery of novel bioactive compounds that might be of interest to the agri-food sector and healthcare pharmaceuticals.

Isolation and Identification of Antimicrobial Compounds from Berberis aristata Root Extract

Berberis aristata (Berberidaceae) is an influential medicinal plant and found in the different provinces of the world. It has compelling medicinal value in the traditional Indian system of medicine. More multitudinous secondary metabolites are contemporary within the plants, which helps to cure the disease. The chromatographic techniques have significant role in natural products chemistry and discovery of innovative compounds of pharmaceutical and biomedical importance. The aim of the present study is to evaluate sequestration of secondary metabolites using column-chromatographic techniques and this metabolites can be further secluded, identified by using LC-ESI-Q-TOF-MS system and also performed its antimicrobial activity. These metabolites were characterized for determination of medicinal properties. This study helps to identify the presence of secondary metabolic compounds in the plant.

Identification of antimicrobial compounds in chloroform extract of Polygonum minus

Medicinal plants remains as a major source of antimicrobial compounds against plant and human pathogens. The antimicrobial activity of the chloroform extract of Polygonum minus was well documented in our earlier studies. The current study was performed with the aim to detect the chemical compounds peresent in the chloroform extract of Polygonum minus. Thin layer chromatography (TLC) was performed for partial purification and separation of antimicrobial compounds from the plant extract. The bands obtained from TLC were collected and assayed for their antimicrobial activity against the selected plant pathogens of study. Active bands identified by TLC were further purified by using high performance liquid chromatography (HPLC). The fractions showing maximum peak area and yield were taken for further analysis in GC-MS to identify the antimicrobial compounds. GC-MS analysis revealed that the compounds like 1,2-heptadiene, ditetrazolo (1,5-a:5',1'-c) pyrazine, allylcyclopropane and 6-ethyl-2,3,11,12-dibenzo-1,4,7,10,13, 16-hexaoxacyclooctadeca-2,11-diene may be present in the chloroform extract of P. minus.

Identification of antimicrobial compounds in different hydrophilic larch bark extracts

Larch bark is an undervalued material, but it has unique and valuable characteristics and compounds. The objective of this study was to extract and characterize molecular compounds of bark materials from different larch trees and to test these for their antimicrobial properties. The extractions were performed using methanol or water. The obtained extracts were analysed by gas chromatography coupled to mass spectrometry (GC-MS). Antimicrobial properties also were determined using different microbial strains, for example, Staphylococcus aureus. The GC-MS analysis showed that long chain alcohols, fatty acids, and polyphenols were present in the extracts. According to the results of the agar diffusion tests, only the methanol extract of larch bark had an inhibitory effect on the growth of Staphylococcus aureus. Two compounds of flavonoids and stilbenoids were shown to affect the microbial activity of the larch bark. Therefore, larch bark can be used for the extraction of compounds with specific anti-microbial properties.

Pseudonocardiaceae sp. TD-015 from the Thar Desert, India: Antimicrobial Activity and Identification of Antimicrobial Compounds

Pseudonocardiaceae sp. TD-015 from the Thar Desert, India: Antimicrobial Activity and Identification of Antimicrobial Compounds

CALLUS INDUCTION, PHYTOCHEMICAL STUDIES AND ANTIBACTERIAL ACTIVITY OF DECALEPIS ARAYALPATHRA (JOSEPH AND CHANDRAS) VENTER

Objective: The aim of the present study was designed for the induction of callus from leaf explants of Decalepis arayalpathra (D. arayalpathra) and to analyse their phytochemical constituents and antibacterial activity.Methods: The explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentration of 2, 4-dichlorophenoxyacetic acid (2, 4-D) and later subcultured to the combination of 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA). The phytochemical constituents were analysed in the different solvent extracts using standard methods. Antibacterial activity of the different solvent extracts was carried out using agar well diffusion method against reference standards. Results: Callus induction was observed on MS medium supplemented with different concentration and combination of auxins and cytokinins. Maximum callus induction was noticed on media supplemented with 2, 4-D (2 mg/l) and BAP (1 mg/l)+NAA (0.5 mg/l) respectively. The phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, steroids and terpenoids, glycosides, coumarins and quinone etc. All the solvent extracts showed varying degree of antibacterial activities against the bacterial strains (Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescence and Staphylococcus aureus). The maximum antibacterial activity of leaf was observed in aqueous (Klebsiella pneumoniae, 19.00±1.00) and methanolic extract (Klebsiella pneumoniae, 18.33±1.15). Whereas petroleum ether extract of the callus showed maximum inhibition (Bacillus subtilis, 17.00±1.00) compare to other extracts.Conclusion: The study revealed the presence of secondary metabolites in the leaf and callus extracts of D. arayalpathra. The methanolic extracts possess higher antibacterial activity compared to other solvent extracts. However, further studies have to be carried out for the isolation and identification of antimicrobial compounds against pathogens.

Preservative effect of Camellia sinensis (L.) Kuntze seed extract in soy sauce and its mutagenicity

The purpose of this study was to investigate the applicability of green tea seed (GTS) extract as a natural preservative in food. Food preservative ability and mutagenicity studies of GTS extract and identification of antimicrobial compounds from GTS extract were carried out. The GTS extract showed only anti-yeast activity against Candida albicans with MIC value of 938μg/mL and Zygosaccharomyces rouxii with a MIC of 469μg/mL. The active compounds were identified as theasaponin E1 (1), assamsaponin A (2), and assamsaponin B (3). And GTS extracts didn't show mutagenicity because there were no dose-dependent changes in colonies of Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2uvrA regardless of the metabolic activation system. And GTS extract also showed a potent food preservation affect which eliminated all yeast below the MIC value in application test at soy sauce. Overall, these results indicate that GTS extract could be a safe and effective food preservative with anti-yeast activity.

Antimicrobial and Antiradical Activity of Extracts Obtained from Leaves of Five Species of the Genus Bergenia: Identification of Antimicrobial Compounds.

An important focus of modern medicine is the search for new substances and strategies to combat infectious diseases, which present an increasing threat due to the growth of bacterial resistance to antibiotics. Another problem concerns free radicals, which in excess can cause several serious diseases. An alternative to chemical synthesis of antimicrobial and antiradical compounds is to find active substances in plant raw materials. We prepared extracts from leaves of five species of the genus Bergenia: B. purpurascens, B. cordifolia, B. ligulata, B. crassifolia, and B. ciliata. Antimicrobial and antiradical features of extracts and raw materials were assessed, and the quantities of phenolic compounds were determined. We also evaluated, using high-performance liquid chromatography, the amounts of arbutin and hydroquinone, compounds related to antimicrobial activity of these raw materials. The strongest antiradical properties were shown by leaves of B. crassifolia and B. cordifolia, the lowest by leaves of B. ciliata. The antiradical activity of extracts showed a strong positive correlation with the amount of phenols. All raw materials have significant antimicrobial properties. Among them, the ethyl acetate extracts were the most active. Antimicrobial activity very weakly correlated with the amount of arbutin, but correlated very strongly with the contents of both hydroquinone and phenolic compounds. Additional experiments using artificially prepared mixtures of phenolic compounds and hydroquinone allowed us to conclude that the most active antimicrobial substance is hydroquinone.

Reducing the Bottleneck in Discovery of Novel Antibiotics.

Most antibiotics were discovered by screening soil actinomycetes, but the efficiency of the discovery platform collapsed in the 1960s. By now, more than 3000 antibiotics have been described and most of the current discovery effort is focused on the rediscovery of known compounds, making the approach impractical. The last marketed broad-spectrum antibiotics discovered were daptomycin, linezolid, and fidaxomicin. The current state of the art in the development of new anti-infectives is a non-existent pipeline in the absence of a discovery platform. This is particularly troubling given the emergence of pan-resistant pathogens. The current practice in dealing with the problem of the background of known compounds is to use chemical dereplication of extracts to assess the relative novelty of a compound it contains. Dereplication typically requires scale-up, extraction, and often fractionation before an accurate mass and structure can be produced by MS analysis in combination with 2D NMR. Here, we describe a transcriptome analysis approach using RNA sequencing (RNASeq) to identify promising novel antimicrobial compounds from microbial extracts. Our pipeline permits identification of antimicrobial compounds that produce distinct transcription profiles using unfractionated cell extracts. This efficient pipeline will eliminate the requirement for purification and structure determination of compounds from extracts and will facilitate high-throughput screen of cell extracts for identification of novel compounds.

Isolation and Identification of Antimicrobial Compounds from Licorice Extracts

Isolation and Identification of Antimicrobial Compounds from Licorice Extracts

English

Streptomyces atrovirens was isolated from soil samples in Egypt and showed broad spectrum antimicrobial activity. It was identified as Streptomyces atrovirens (strain H33) based upon16S rRNA gene sequencing. It was deposited in the GenBank database under accession number of KJ435269. Streptomyces atrovirens (strain H33)was cultivated by submerged fermentation bioreactor to produce the antimicrobialmetabolites. Purification and identification of antimicrobial compound was carried out. The antimicrobial compound exhibited low cytotoxic effect on human epithelial HL cells.

Identification of antimicrobial compound, diketopiperazines, from a Bacillus sp. N strain associated with a rhabditid entomopathogenic nematode against major plant pathogenic fungi

To purify and characterize antimicrobial compounds from Bacillus sp. strain N associated with rhabditid entomopathogenic nematode (EPN). The cell-free culture filtrate of a bacterium associated with an EPN, Rhabditis (Oscheius) sp., exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain three diketopiperazines (DKPs). The structure and absolute stereochemistry of this compound were determined based on extensive spectroscopic analyses (FABMS, (1) H NMR, (13) C NMR, (1) H-(1) H COSY, (1) H-(13) C HMBC) and Marfey's method. The compounds were identified as cyclo(l-Pro-l-Leu), cyclo(d-Pro-l-Leu) and cyclo(d-Pro-l-Tyr), respectively. Three DKPs were active against all the five fungi tested (Aspergillus flavus, Candida albicans, Fusarium oxysporum, Rhizoctonia solani and Penicillium expansum) and are more effective than the standard fungicide bavistin. The highest activity of 4μgml(-1) by cyclo(l-Pro-l-Leu) and cyclo(d-Pro-l-Tyr) was recorded against P.expansum, a plant pathogen responsible for causing postharvest decay of stored apples and oranges. Cyclo(d-Pro-l-Leu) recorded good antibacterial activity against all the four bacteria tested (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), and cyclo(l-Pro-l-Leu) and cyclo(d-Pro-l-Tyr) recorded good activity only against Gram-positive bacteria. To our knowledge, this is the first report of antifungal activity of the DKPs against the plant pathogenic fungi F.oxysporum, R.solani and P.expansum. The production of cyclo(l-Pro-l-Leu), cyclo(d-Pro-l-Leu) and cyclo-(d-Pro-l-Tyr) by a bacterium associated with EPN is also reported here for the first time. Isolated DKPs demonstrated high antimicrobial activity against bacteria and fungi, especially against plant pathogenic fungi. We conclude that the bacterium associated with EPN is a promising source of natural bioactive secondary metabolites which may receive great benefit in the field of agriculture. This study is a significant contribution to the knowledge of compounds unique from EPN bacteria as potential sources of new drugs in the agricultural and pharmacological industry.

Bioassay-Guided Isolation and Identification of Antimicrobial Compounds from Thyme Essential Oil by Means of Overpressured Layer Chromatography, Bioautography and GC–MS

A simple method is described for efficient isolation of compounds having an antibacterial effect. Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as prospective materials likely to feature several bioactive components when examined by thin layer chromatography coupled with direct bioautography as a screening method. The newly developed infusion overpressured layer chromatographic separation method coupled with direct bioautography assured that only the active components were isolated by means of overrun overpressured layer chromatography (OPLC) with on-line detection and fractionation. Each of the 5 collected fractions represented one of the five antimicrobial essential oil components designated at the screening. The purity and the activity of the fractions were confirmed with chromatography coupled with various detection methods (UV, vanillin–sulphuric acid reagent, direct bioautography). The antibacterial components were identified with GC–MS as thymol, carvacrol, (−)-linalool, diethyl-phthalate, and α-terpineol. The oil component diethyl-phthalate is an artificial compound, used as a plasticizer or detergent base in the industry. Our results support that exploiting its flexibility and the possible hyphenations, OPLC is especially attractive for isolation of antimicrobial components from various matrixes.

Screening and Identification of Antimicrobial Compounds from Streptomyces bottropensis Suppressing Rice Bacterial Blight

Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating pathogen to Oryza sativa and has been shown to cause bacterial blight. Two bioactive compounds showing antimicrobial activities against Xoo strain KACC 10331 were isolated from a Streptomyces bottropensis strain. The ethyl acetate extract was fractionated on a Sephadex LH-20 column, and then purified by preparative HPLC. The purified compounds were identified as bottromycin A2 and dunaimycin D3S by HR/MS and 1H NMR analyses. The MIC value against Xoo and the lowest concentration still capable of suppressing rice bacterial blight were 2 microgram/ml and 16 microgram/ml for bottromycin A2, and 64 microgram/ml and 0.06 microgram/ml for dunaimycin D3S, respectively. These two compounds were shown to exert different bioactivities in vitro and in rice leaf explants.

Isolation and identification of antimicrobial compound from Mentha longifolia L. leaves grown wild in Iraq

BackgroundMentha longifolia L. (Lamiaceae) leaves have been traditionally implemented in the treatment of minor sore throat and minor mouth or throat irritation by the indigenous people of Iraq, although the compounds responsible for the medicinal properties have not been identified. In the present study, an antimicrobial compound was isolated and characterized, and its biological activity was assessed.MethodsThe compound was isolated and characterized from the extracted essential oil using different spectral techniques: TLC, FTIR spectra and HPLC. Antimicrobial activity of the compound was assessed using both disc diffusion and microdilution method in 96 multi-well microtiter plates.ResultsA known compound was isolated from the essential oil of the plant and was identified as (-) menthol. The isolated compound was investigated for its antimicrobial activity against seven selected pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and the yeast Candida albicans. Menthol at different concentrations (1:1, 1:5, 1:10, 1:20) was active against all tested bacteria except for P. aeruginosa, and the highest inhibitory effect was observed against S. mutans (zone of inhibition: 25.3 mm) using the disc diffusion method. Minimal inhibitory concentration MIC values ranged from 15.6–125.0 μg/ml, and the most promising results were observed against S. aureus and S. mutans (MIC 15.6 μg/ml) while, S. faecalis, S. pyogenis and L. acidophilus ranked next (MIC 31.2 μg/ml). Furthermore, menthol achieved considerable antifungal activity against the yeast C. albicans (zone of inhibition range: 7.1–18.5 mm; MIC: 125.0).ConclusionThe isolation of an antimicrobial compound from M. longifolia leaves validates the use of this plant in the treatment of minor sore throat and minor mouth or throat irritation.

목단피로부터 식품부패 미생물에 대한 항균성 물질의 분리 및 동정

우리나라 야산에서 손쉽게 구할 수 있는 구황식물인 목단피를 건조시켜 분쇄한 후 methanol과 여러용매로 추출하여 식품 부패 미생물의 증식 억제 효과를 검색하고 그 항균물질을 분석하여 다음과 같은 결과를 얻었다. 목단피의 methanol 추출물은 1500 μg/mL 농도에서 B. subtilis, L. monocytogenes, V. parahaemolyticus의 증식을 100% 억제하였으며 S. aureus, E. coli도 같은 농도에서 각각 36.31%와 67.81%의 억제 효과를 보였다. 목단피의 ethylacetate 분획 추출물은 낮은 농도인 500 μg/disc의 농도에서 식품 부패 미생물 5종 모두에 대하여 clear zone을 형성하여 항균력을 나타내었다. 특히 L. monocytogenes, E. coli균에 대해서는 낮은 농도인 500 μg/disc에서 각각 12 mm, 11 mm의 clear zone을 형성하였다. 목단피의 ethylacetate 추출물을 silica gel colum chromatograhpy(7 cm×1.2 cm)한 후 thin layer chromatography(TLC)를 실시하여 항균 실험을 한 결과 B. subtilis의 경우 500 μg/disc 농도에서 2nd fra. 1이 21 mm, V. parahaemolyticus는 250 μg/disc 농도에서 14 mm를 형성하여 목단피의 methanol 추출물로부터 각 용매별로 계통 분획하여 분리한 ethylacetate 분획으로부터 silica gel column chromatograpy와 TLC를 하여 항균성을 보인 2nd fra. 1의 성분을 알아 보기 위하여 HPLC로 단일분리하여 얻은 peak Ⅸ에 대한 compound를 GC-MS로 분석한 결과 peak Ⅸ에서는 isobutyl isopentanoate가 있는 것으로 추정되었다.