Molecular Characterization of a Fungus Producing Membrane Active Metabolite and Analysis of the Produced Secondary Metabolite (original) (raw)

Antimicrobial potential of newly isolated Aspergillusterreus MK-1: An approach towards new antibiotics

2019

OBJECTIVE To attempt discovering new bioactive metabolites from fungal sources. METHODS The exploratory study was conducted at the Department of Microbiology, Federal Urdu University for Arts, Science and Technology, Karachi from January 2016 to November 2017and comprised of soil samples collected from rhizosphere region of different garden plants from the city. Fungi were screened for production of antibiotics by testing cell-free culture filtrates obtained by Shake-flask fermentation technique. Agar-Well diffusion assay method was used to evaluate antagonistic activity against pathogenic microorganisms. RESULTS Bioactive compounds extracted by ethyl acetate and thin layer chromatography revealed mixture of compounds in the crude extract. AspergillusterreusMK-1 showed significant inhibition of medically important test pathogens namely Staphylococcus aureus, Pseudomonas aeruginosa, Escherichiacoli, Salmonella typhi, Micrococcus luteus, Streptococcus epidermidis, Bacillus subtilis, C...

Chromatographic isolation and structural elucidation of secondary metabolites from the soil-inhabiting fungus Aspergillus fumigatus 3T-EGY

Acta Chromatographica, 2018

Eight compounds were isolated and identified from the soil-inhabiting fungus Aspergillus fumigatus 3T-EGY, namely, stearic acid (1), α-linolenic acid (2), physcion (3), di-(2-ethylhexyl) phthalate (4), 2,4,5,17-tetramethoxy pradimicin lactone (5), 3,5-dihydroxy-7-O-α-rhamnopyranoyl-2H-chromen-2-one (6), juglanthraquinone A-5-O-D-rhodosamine-(4′→1″)-2-deoxy-D-glucose (4″→1″′)-cinerulose B (7), and micropeptin (8). Their structures were determined on the basis of one-dimensional (1D-) and two-dimensional nuclear magnetic resonance (2D-NMR) [ 1 H-, 13 C-NMR, 1 H-1 H COSY (COrrelated SpectroscopY), and 1 H-13 C HMBC (Heteronuclear Multiple Bond Correlation) spectroscopy]. Compound 7 showed moderate in vitro antimicrobial activity against three pathogenic strains with inhibition zones values were ranged from 9.0 to 10.66 mm compared to neomycin as a positive control with inhibition zones values were ranged from 14.0 to 19.0 mm.

Isolation of Bioactive Metabolites from Soil Derived Fungus-Aspergillus fumigatus

Microorganisms

Fungi produce numerous secondary metabolites with intriguing biological properties for the health, industrial, and agricultural sectors. Herein, we report the high-yield isolation of phenolic natural products, N-formyl-4-hydroxyphenyl-acetamide 1 (~117 mg/L) and atraric acid 2 (~18 mg/L), from the ethyl acetate extract of the soil-derived fungus, Aspergillus fumigatus. The structures of compounds 1 and 2 were elucidated through the detailed spectroscopic analysis of NMR and LCMS data. These compounds were assayed for their antimicrobial activities. It was observed that compounds 1 and 2 exhibited strong inhibition against a series of fungal strains but only weak antibacterial properties against multi-drug-resistant strains. More significantly, this is the first known instance of the isolation of atraric acid 2 from a non-lichen fungal strain. We suggest the optimization of this fungal strain may exhibit elevated production of compounds 1 and 2, potentially rendering it a valuable so...

Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], 2014

Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 2(2) full factorial planning (ANOVA) and on a 2(3) factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yie...

Antibacterial activity of Aspergillus isolated from different Algerian ecosystems

African Journal of Biotechnology, 2017

Thirty two strains of Aspergillus genus were isolated from soil samples obtained from particular ecosystems: Laghouat endowed with a desert climate and Teleghma with a warm and temperate climate. Based on the morphological aspect, this collection was subdivided into ten phenotypic groups. This identification was confirmed by molecular analyzes using a molecular marker of the genu ribosomal 18s. This marker will allow us to associate our sequences with those of known organisms. In order to discover new antibiotic molecules, the antibacterial activity was performed against two Gram positive bacteria: Staphylococcus aureus and Bacillus subtilis and also two Gram-negative bacteria: Escherichia coli and Pseudomonas aeroginosa, using two different techniques: Agar cylinders and disks technique. The results show that the fungal species have an activity against at least one test bacterium. The Gram positive bacteria were the most affected, where the averages of the inhibition zones reach 34.33 mm. However, Gram-negative bacteria showed less important results from 0 to 12.00 mm. It is recorded that the antibacterial activity was studied for the first time in the following two species: Aspergillus niveus and Aspergillus wentii. Furthermore, an indepth study is underway on bioguided fractionation, which would identify individual components and lead to the isolation of the active ingredient.

Evaluation of Antimicrobial activity of secondary metabolites of fungi isolated from Sultanate Oman soil

Saudi Pharmaceutical Journal

Objective: The present study focused on isolation and identification of endophytic fungi producing antimicrobial compounds and enzymes from a draught resistant medicinal plant. Methods: Endophytic fungi were isolated from fresh live parts of Eucalyptus citriodora and studied their antimicrobial activity against pathogenic microbes and enzyme production. Secondary metabolites assayed for Minimum Bactericidal/ Fungicidal Concentration (MBC/MFC). Active endophytic fungi were identified using rDNA by molecular method. A phylogeny tree for the identified fungi was constructed using online software. Results: Three endophytic fungal isolates inhibited standard microorganisms Pseudomonas aeroginosa, Mycobacterium smegmatis and Candida albicans when tested in dual culture, well and disc diffusion methods. Isolates PECL011 and PECL014 had the best MIC value of 62.5 µg/ml against C.albicans and 125 µg/ml against both P. aeroginosa and M. smegmatis. All the ten fungal isolates were showing activity for at least one of the five enzymes tested qualitatively. The endophytic fungi showing highest inhibition to Candida albicans identified as Aspergillus sp. and Chaetomium sp. by rDNA molecular method. There are 5 isolates belongs to Preussia spp. which are rarely reported and this is the first report from E. citirodora in India. Conclusion: Crude extract of endophytic fungi Aspergillus sp and Chaetomium sp. are very active against fungi and comparable to that of standard antifungal agent flucanazole. Purified compound from this crude extract might be a promising antifungal compound for the treatment of various fungal infections.

In Vitro, Optimization of Antibacterial Activity of Secondary Metabolites Produced By Aspergillus Flavus (Mtcc-3396

The purpose of the present study was to investigate the influence of cultural conditions and environmental parameters affecting the growth and bioactive metabolite production of the fungi Aspergillus flavus (MTTC-3396) which exhibits a broad spectrum of in vitro antibacterial activity against human infecting bacterial pathogens and the high bioactive metabolites production. The effect of various parameters viz., incubation time, temperature, pH, carbon and nitrogen sources, and sodium chloride concentration on antibacterial metabolite production were studied by varying single parameter at a time. It was found that metabolite production by this isolate was greatly influenced by various cultural conditions. The optimum carbon source starch, nitrogen source beef extract, pH 6.0, temperature at 40 o C, 3 % NaCl concentration and incubation period of 144 h were found for the maximum metabolite production.

Metabolomics and Dereplication Study of the Endophytic Fungus Aspergillus chevalieriin Search of Bioactive Natural Compounds

Journal of Advanced Pharmacy Research, 2017

Objectives: This study aimed to point the significant rule of metabolomics tools to assess the chemistry of the bioactive metabolites produced by endophytic fungus Aspergillus chevalieri isolated from Lagerostromia tomentosa C. presl. The anticancer of crude extracts, fractions and pure compounds and antimicrobial of pure compounds were investigated as part of this study. Methods: An endophytic fungus (Aspergillus chevalieri) was isolated from the tissues of the stem of Lagerostromia tomentosa C. Presl and identified through molecular biological procedure by DNA isolation, PCR, DNA sequencing and through searching the Gene Bank. Metabolomics profiling and dereplication studies were employed to choose the optimum growth medium and conditions that yield the most significant metabolites. The crude extract of the 30-days rice culture of Aspergillus chevalieri was subjected to bioactivity and metabolomics guided isolation approach. The structure of the isolated compounds was determined on the basis of 1D, 2D NMR and mass spectrometry (HR-ESIMS) analysis. Results: four fractions were further purified to produce five pure compounds, which are Ergosterol (1), Ergosterol peroxide (2), Campesterol (3), Flavoglaucin (4) and 3-O-methyl caffeic acid (5). Multivariate data analysis highlighted the most significant metabolites contributed to the bioactivity. The pure compounds were tested for the anticancer and antimicrobial activity, compound (1) exhibited significant antitrypanosomal activity, while compounds (2, 3, 4 and 5) effectively inhibited the growth of Escherichia coli, Staphylococcus aureus and Candida albicans. Conclusion: A combination of metabolomic-and bioassay-guided approaches gives an access to a shorter and faster route to highlight the active metabolites, which are highly correlated to the bioactivity during the first stage of fractionation.

Metabolomics and Dereplication Study of the Endophytic Fungus Aspergillus chevelieri in Search of Bioactive Natural Compounds

Journal of Advanced Pharmacy Research

Objectives: This study aimed to point the significant rule of metabolomics tools to assess the chemistry of the bioactive metabolites produced by endophytic fungus Aspergillus chevalieri isolated from Lagerostromia tomentosa C. presl. The anticancer of crude extracts, fractions and pure compounds and antimicrobial of pure compounds were investigated as part of this study. Methods: An endophytic fungus (Aspergillus chevalieri) was isolated from the tissues of the stem of Lagerostromia tomentosa C. Presl and identified through molecular biological procedure by DNA isolation, PCR, DNA sequencing and through searching the Gene Bank. Metabolomics profiling and dereplication studies were employed to choose the optimum growth medium and conditions that yield the most significant metabolites. The crude extract of the 30-days rice culture of Aspergillus chevalieri was subjected to bioactivity and metabolomics guided isolation approach. The structure of the isolated compounds was determined on the basis of 1D, 2D NMR and mass spectrometry (HR-ESIMS) analysis. Results: four fractions were further purified to produce five pure compounds, which are Ergosterol (1), Ergosterol peroxide (2), Campesterol (3), Flavoglaucin (4) and 3-O-methyl caffeic acid (5). Multivariate data analysis highlighted the most significant metabolites contributed to the bioactivity. The pure compounds were tested for the anticancer and antimicrobial activity, compound (1) exhibited significant antitrypanosomal activity, while compounds (2, 3, 4 and 5) effectively inhibited the growth of Escherichia coli, Staphylococcus aureus and Candida albicans. Conclusion: A combination of metabolomic-and bioassay-guided approaches gives an access to a shorter and faster route to highlight the active metabolites, which are highly correlated to the bioactivity during the first stage of fractionation.