Fungi are a promising source for bioactive secondary metabolites against various agricultural pests. Soil samples were collected from the rhizosphere of various plants at El-Khatatba, Egypt, in May 2016. Sixty-two fungal isolates were locally isolated and screened against Tetranychus urticae Koch (Acari: Tetranychidae). Four fungal strains, showed potent control activities, were morphologically identified. Laboratory evaluation of the crude extracts of the selected strains, Aspergillus melleus, A. terreus, Emericella nidulans, and Chaetomium globosum, exhibited LC50 values of 10.27, 33.05, 14.68, and 22.40 mg/ml against females of T. urticae, respectively. Correspondent LC50 values that exhibited on eggs were 8.81, 23.17, 11.66, and 11.05 mg/ml. Consequently, secondary metabolites of A. melleus were separated by liquid chromatography/mass spectrometry. Compounds separated from the active fraction were identified as mellamide, ochratoxin C, nodulisporic acid, 7-Oxocurvularin, and 6-(4′-hydroxy-2′-methyl phenoxy)-(−)-(3R)-mellein. Obtained secondary metabolites are promising sources for biopesticides to be used in bio-rationale control of T. urticae.
Actinomycetes isolated from marine habitats represent a promising source of bioactive substances. Here, we report on the isolation, identification, productivity enhancement and application of the bioactive compounds of Streptomyces qinglanensis H4. Eighteen marine actinomycetes were isolated and tested for resistance to seven bacterial diseases. Using 16S rRNA sequencing analysis (GenBank accession number MW563772), the most powerful isolate was identified as S. qinglanensis. Although the strain produced active compound(s) against a number of Gram-negative and Gram-positive bacteria, it failed to inhibit pathogenic fungi. The obtained inhibition zones were 22.0 ± 1.5, 20.0 ± 1, 16.0 ± 1, 12.0 ± 1, 22.0 ± 1 and 24.0 ± 1 mm against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 19404, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231 and Staphylococcus aureus ATCC6538, respectively. To maximize bioactive compound synthesis, the Plackett-Burman design was used. The productivity increased up to 0.93-fold, when S. qinglanensis was grown in optimized medium composed of: (g/l) starch 30; KNO 3 0.5; K 2 HPO 4 0.25; MgSO 4 0.25; FeSO 4 •7H 2 O, 0.01; sea water concentration (%) 100; pH 8.0, and an incubation period of 9 days. Moreover, the anticancer activity of S. qinglanensis was tested against two different cell lines: HepG2 and CACO. The inhibition activities were 42.96 and 57.14%, respectively. Our findings suggest that the marine S. qinglanensis strain, which grows well on tailored medium, might be a source of bioactive substances for healthcare companies.
Fungal secondary metabolites possess powerful bioactive compounds formed by fungi isolated from diverse sources. In this study, a fungus was isolated from the sandy soil of Al Mudawara Mountain at El Fayum governorate to examine its antibacterial activity, cytotoxicity against cancer cells, and antioxidant effect. The fungus was identified using morphological and molecular methods as Aspergillus flavus, with a 99.29 percent similarity rate. The fungal secondary metabolites were extracted using different organic solvents (petroleum ether, ethyl acetate, and chloroform) in order. These extracts were tested for their antimicrobial activities against some pathogenic microorganisms using the well diffusion method. Furthermore, using the MTT viability assay, the antitumor properties of the active extracts were tested against HepG2 and PC-3, two different tumor cell lines. Aspergillus flavus petroleum ether extract had high inhibitory activity against HepG2 and PC-3 cells, according to the findings, However, lower inhibitory activity was detected with ethyl acetate extract against HepG2 and PC-3 cells, respectively. Also, the DPPH free radical scavenging assay was used to assess the antioxidant activity. The petroleum ether extract from Aspergillus flavus showed moderate antioxidant activity with IC50 of 272 ± 3.7µg/ml followed by ethyl acetate 901.3 ± 42.8µg/ml. GC-MS analysis of the petroleum ether extract showed the presence of different potent products. In conclusion, Aspergillus flavus ON764430 extracts made from ethyl acetate and petroleum ether had moderate antimicrobial, antioxidant, and antitumor properties. To find out how the activities work, additional pharmacological and in vivo studies were suggested.
To evaluate the antimicrobial activity of extracts of olive leaves from Sinai and basil leaves from Iran against some selected pathogenic bacterial and fungal strains and to analyze both extracts to prove the active components responsible for their antimicrobial activity. Methodology: Methanolic/chloroform extract of olive and methanolic extract of basil leaves were prepared and their antimicrobial activities were tested against 5 types of pathogenic bacteria; Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella and one type of fungus, Candida spp. using agar well-diffusion method. HPLC was done for analysis of phenolic compounds and GC-MS was done for analysis of volatile compounds. Results: Antimicrobial activity of basil extract was stronger than that of olive. HPLC showed that the main phenolic compounds were oleuropein for olive and rosmarinic acid for basil. GC-MS showed the major peak for olive was triterpene and that for basil was Linalool. Conclusion: Basil has stronger antimicrobial activity than olive. It varies with different strains being the best against S. aureus, Pseudomonas and candida. Phenolic compounds mainly oleuropein for olive and rosmarinic acid for basil and caffeic acid in both had antimicrobial activity. In vivo study is recommended.
Fourty samples of commonly used eye drops were collected from The Egyptian Pharmacies and divided into 2 groups: group A (with antimicrobial activity) and group B (without antimicrobial activity), the two groups cultured on blood agar medium and Sabouraud agar medium two times after opening these samples in open air, 9 samples showed microbial growth. The number of colonies counted and the organisms isolated and identified as (Staphylococcus auereus, Micrococcus, Candida albicans, and coagulase negative Staphylococcus). After that group (A) samples were taken and inoculated with saline containing Candida albicans and Staphylococcus auereus then they cultured on the same two media, after the period of incubation Candida show growth in all samples while Staphylococcus auereus show positive growth in four samples. .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.