Molecular Identification of Selected Streptomyces Strains Isolated from Mexican Tropical Soils and their Anti-Candida Activity

The increasing incidence of Candida albicans infections and resistance to current antifungal therapies has led to the search for new and more effective antifungal compounds. Actinobacterial species from the Streptomyces genus are recognized as some of the major producers of antimicrobial compounds. Therefore, the aims of this study were: (1) the identification of Streptomyces strains isolated from Mexican tropical acidic soils, (2) the evaluation of their antifungal activity on C. albicans, and (3) the exploration of the presence of polyketide synthase genes in their genome and antifungal secondary metabolites in their extracts. Four actinobacterial strains, isolated from previously unexplored soils with antibacterial antecedents, were selected. These strains were identified as Streptomyces angustmyceticus S6A-03, Streptomyces manipurensis S3A-05 and S3A-09, and Streptomyces parvisporogenes S2A-04, according to their molecular analyses. The ethanol extract of the lyophilized supernatant of S. parvisporogenes displayed the most interesting antifungal activity against C. albicans, with a minimum inhibitory concentration (MIC) of 0.5 mg/mL. Type I polyketide synthase (PKS-I) and non-ribosomal peptide synthase (NRPS) genes were detected in all strains. In addition, type II PKS genes (PKS-II) were also found in S. manipurensis S3A-05 and S. parvisporogenes. LC-UV-HRMS analysis of the active organic extract of S. parvisporogenes indicated the presence of the known antifungal compound carbazomycin G as the major component.

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Genome Sequence-Guided Finding of Lucensomycin Production by Streptomyces achromogenes Subsp. streptozoticus NBRC14001

Microorganisms ◽

10.3390/microorganisms10010037 ◽

2021 ◽

Vol 10 (1) ◽

pp. 37

Author(s):

Sho Nishimura ◽

Kazune Nakamura ◽

Miyako Yamamoto ◽

Daichi Morita ◽

Teruo Kuroda ◽

...

Keyword(s):

Antifungal Activity ◽

Gene Cluster ◽

Genome Sequence ◽

Polyketide Synthase ◽

Macrolide Antibiotic ◽

Biosynthetic Gene Cluster ◽

Antifungal Compound ◽

Type I ◽

Biosynthetic Gene ◽

Polyketide Synthase Gene

Information on microbial genome sequences is a powerful resource for accessing natural products with significant activities. We herein report the unveiling of lucensomycin production by Streptomyces achromogenes subsp. streptozoticus NBRC14001 based on the genome sequence of the strain. The genome sequence of strain NBRC14001 revealed the presence of a type I polyketide synthase gene cluster with similarities to a biosynthetic gene cluster for natamycin, which is a polyene macrolide antibiotic that exhibits antifungal activity. Therefore, we investigated whether strain NBRC14001 produces antifungal compound(s) and revealed that an extract from the strain inhibited the growth of Candida albicans. A HPLC analysis of a purified compound exhibiting antifungal activity against C. albicans showed that the compound differed from natamycin. Based on HR-ESI-MS spectrometry and a PubChem database search, the compound was predicted to be lucensomycin, which is a tetraene macrolide antibiotic, and this prediction was supported by the results of a MS/MS analysis. Furthermore, the type I polyketide synthase gene cluster in strain NBRC14001 corresponded well to lucesomycin biosynthetic gene cluster (lcm) in S. cyanogenus, which was very recently reported. Therefore, we concluded that the antifungal compound produced by strain NBRC14001 is lucensomycin.

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ANTIFUNGAL ACTIVITY OF KEBAR GRASS (BIOPHYTUM PETERSIANUM KLOTSZCH) STEM ETHANOL EXTRACT ON THE GROWTH OF AFLATOXIGENIC ASPERGILLUS FLAVUS IN CORN AND PEANUT-BASED MEDIA

Jurnal Teknologi ◽

10.11113/jt.v82.13641 ◽

2019 ◽

Vol 82 (1) ◽

Author(s):

Meike Meilan Lisangan ◽

Gino Nemesio Cepeda ◽

Mathelda Kurniaty Roreng

Keyword(s):

Chemical Composition ◽

Antifungal Activity ◽

Aspergillus Flavus ◽

Ethanol Extract ◽

Isobutyric Acid ◽

Aflatoxin Contamination ◽

Antimicrobial Compounds ◽

Natural Antimicrobial ◽

Toxigenic Fungi ◽

Biophytum Petersianum

Cereals and legumes are very easily damaged by fungi, including toxigenic fungi species such as Aspergillus flavus which can produce aflatoxins. Various methods have been carried out to reduce aflatoxin contamination in foods, including the use of plant extracts based antimicrobial compounds. One of indigenous herbs in Papua that has potency as natural antimicrobial is Kebar grass (Biophytum petersianum Klotszch). The aims of this study were to investigate the chemical composition and the effect of kebar grass stem ethanol extract on the growth of toxigenic A. flavus. Kebar grass stem ethanol extract at concentrations of 5, 10, 15, 20, 25, and 30 mg mL-1 was tested on the growth of A. flavus in two types media i.e. corn based-medium and peanut based-medium. The result showed that kebar grass stem ethanol extract at concentration of 15 mg ml-1 in corn based-medium and peanut based-medium caused 100% growth inhibition of A. flavus. The major compounds in kebar grass stem ethanol extract were: Pyrocatechol, Methylhydrazine hydrochloride, 2-Fluoropropane, Isobutyric acid, 2,6-Dimethoxyphenol. The results obtained from this study suggested that the ethanol extract of the kebar grass stem can be used as a natural antifungal agent to inhibit the growth of aflatoxigenic A. flavus.

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Anti-CandidaProperties of Urauchimycins from Actinobacteria Associated withTrachymyrmexAnts

BioMed Research International ◽

10.1155/2013/835081 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Thais D. Mendes ◽

Warley S. Borges ◽

Andre Rodrigues ◽

Scott E. Solomon ◽

Paulo C. Vieira ◽

...

Keyword(s):

Minimum Inhibitory Concentration ◽

Antifungal Activity ◽

Broad Spectrum ◽

Inhibitory Concentration ◽

Bioactive Molecules ◽

Bioactive Metabolites ◽

Medical Applications ◽

Antimicrobial Compounds ◽

Shake Culture ◽

First Time

After decades of intensive searching for antimicrobial compounds derived from actinobacteria, the frequency of isolation of new molecules has decreased. To cope with this concern, studies have focused on the exploitation of actinobacteria from unexplored environments and actinobacteria symbionts of plants and animals. In this study, twenty-four actinobacteria strains isolated from workers ofTrachymyrmexants were evaluated for antifungal activity towards a variety ofCandidaspecies. Results revealed that seven strains inhibited the testedCandidaspecies.Streptomycessp. TD025 presented potent and broad spectrum of inhibition ofCandidaand was selected for the isolation of bioactive molecules. From liquid shake culture of this bacterium, we isolated the rare antimycin urauchimycins A and B. For the first time, these molecules were evaluated for antifungal activity against medically importantCandidaspecies. Both antimycins showed antifungal activity, especially urauchimycin B. This compound inhibited the growth of allCandidaspecies tested, with minimum inhibitory concentration values equivalent to the antifungal nystatin. Our results concur with the predictions that the attine ant-microbe symbiosis may be a source of bioactive metabolites for biotechnology and medical applications.

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Antifungal activity improved by coproduction of cyclodextrins and anabaenolysins in Cyanobacteria

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1510432112 ◽

2015 ◽

Vol 112 (44) ◽

pp. 13669-13674 ◽

Cited By ~ 8

Author(s):

Tania K. Shishido ◽

Jouni Jokela ◽

Clara-Theresia Kolehmainen ◽

David P. Fewer ◽

Matti Wahlsten ◽

...

Keyword(s):

Antifungal Activity ◽

Polyketide Synthase ◽

Gene Clusters ◽

Biosynthetic Gene Cluster ◽

Antifungal Compound ◽

Hydrophobic Compounds ◽

Cell Extracts ◽

Peptide Synthetase ◽

Hydrophilic Fraction ◽

Ancient Lineage

Cyclodextrins are cyclic oligosaccharides widely used in the pharmaceutical industry to improve drug delivery and to increase the solubility of hydrophobic compounds. Anabaenolysins are lipopeptides produced by cyanobacteria with potent lytic activity in cholesterol-containing membranes. Here, we identified the 23- to 24-kb gene clusters responsible for the production of the lipopeptide anabaenolysin. The hybrid nonribosomal peptide synthetase and polyketide synthase biosynthetic gene cluster is encoded in the genomes of three anabaenolysin-producing strains of Anabaena. We detected previously unidentified strains producing known anabaenolysins A and B and discovered the production of new variants of anabaenolysins C and D. Bioassays demonstrated that anabaenolysins have weak antifungal activity against Candida albicans. Surprisingly, addition of the hydrophilic fraction of the whole-cell extracts increased the antifungal activity of the hydrophobic anabaenolysins. The fraction contained compounds identified by NMR as α-, β-, and γ-cyclodextrins, which undergo acetylation. Cyclodextrins have been used for decades to improve the solubility and bioavailability of many drugs including antifungal compounds. This study shows a natural example of cyclodextrins improving the solubility and efficacy of an antifungal compound in an ancient lineage of photosynthetic bacteria.

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Phenolic Imidazole Derivatives with Dual Antioxidant/Antifungal Activity: Synthesis and Structure-Activity Relationship

Medicinal Chemistry ◽

10.2174/1573406414666181005143431 ◽

2019 ◽

Vol 15 (4) ◽

pp. 341-351 ◽

Cited By ~ 3

Author(s):

Ana P. Bettencourt ◽

Marián Castro ◽

João P. Silva ◽

Francisco Fernandes ◽

Olga P. Coutinho ◽

...

Keyword(s):

Antioxidant Activity ◽

Antifungal Activity ◽

Organic Molecules ◽

Inhibitory Concentration ◽

Yeast Species ◽

Dpph Radical ◽

Dpph Assay ◽

Gram Negative ◽

Structure Activity ◽

Deoxyribose Degradation

Background: Previous publications show that the addition of a phenolic antioxidant to an antifungal agent, considerably enhances the antifungal activity. Objective: Synthesis of novel compounds combining phenolic units with linear or cyclic nitrogencontaining organic molecules with antioxidant/antifungal activity using methodologies previously developed in the group. Methods: Several N- [1,2-dicyano-2- (arylidenamino) vinyl]-O-alkylformamidoximes 3 were synthesized and cyclized to 4,5-dicyano-N- (N´-alcoxyformimidoyl)-2-arylimidazoles 4 upon reflux in DMF, in the presence of manganese dioxide or to 6-cyano-8-arylpurines 5 when the reagent was refluxed in acetonitrile with an excess of triethylamine. These compounds were tested for their antioxidant activity by cyclic voltammetry, DPPH radical (DPPH•) assay and deoxyribose degradation assay. The minimum inhibitory concentration (MIC) of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans, and against bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram negative). Their cytotoxicity was evaluated in fibroblasts. Results: Among the synthetised compounds, five presented higher antioxidant activity than reference antioxidant Trolox and from these compounds, four presented antifungal activity without toxic effects in fibroblasts and bacteria. Conclusion: Four novel compounds presented dual antioxidant/antifungal activity at concentrations that are not toxic to bacteria and fibroblasts. The active molecules can be used as an inspiration for further studies in this area.

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In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

International Journal of Bioassays ◽

10.21746/ijbio.2016.04.0011 ◽

2016 ◽

Vol 5 (04) ◽

pp. 4512

Author(s):

Jackie K. Obey ◽

Anthoney Swamy T* ◽

Lasiti Timothy ◽

Makani Rachel

Keyword(s):

Antibacterial Activity ◽

Minimum Inhibitory Concentration ◽

Inhibitory Concentration ◽

Ethanolic Extract ◽

Ethanol Extract ◽

E Coli ◽

Zones Of Inhibition ◽

In Vitro Antibacterial Activity ◽

Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

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Lupeol acetate as a potent antifungal compound against opportunistic human and phytopathogenic mold Macrophomina phaseolina

Scientific Reports ◽

10.1038/s41598-021-87725-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shabnam Javed ◽

Zaid Mahmood ◽

Khalid Mohammed Khan ◽

Satyajit D. Sarker ◽

Arshad Javaid ◽

...

Keyword(s):

Antifungal Activity ◽

Ethyl Acetate ◽

Oleanolic Acid ◽

Vanillic Acid ◽

Fungal Biomass ◽

Protocatechuic Acid ◽

Methanolic Extract ◽

Antifungal Compound ◽

Chloroform Fraction ◽

Lupeol Acetate

AbstractAntifungal activity of Monothecabuxifolia methanolic extract and its various fractions were assessed against Macrophominaphaseolina, a soil-borne fungal pathogen of more than 500 vegetal species as well as rare and emerging opportunistic human pathogen. Different concentrations of methanolic extract (3.125 to 200 mg mL−1) inhibited fungal biomass by 39–45%. Isolated n-hexane, chloroform and ethyl acetate fractions suppressed fungal biomass by 32–52%, 29–50% and 29–35%, respectively. Triterpenes lupeol and lupeol acetate (1, 2) were isolated from n-hexane while betulin, β-sitosterol, β-amyrin, oleanolic acid (3–6) were isolated from chloroform fraction. Vanillic acid, protocatechuic acid, kaempferol and quercetin (7–10) were isolated from the ethyl acetate fraction and identified using various spectroscopic techniques namely mass spectroscopy and NMR. Antifungal activity of different concentrations (0.0312 to 2 mg mL−1) of the isolated compounds was evaluated and compared with the activity of a broad spectrum fungicide mancozeb. Different concentrations of mencozeb reduced fungal biomass by 83–85%. Among the isolated compounds lupeol acetate (2) was found the highest antifungal against M.phaseolina followed by betulin (3), vanillic acid (7), protocatechuic acid (8), β-amyrin (5) and oleanolic acid (6) resulting in 79–81%, 77–79%, 74–79%, 67–72%, 68–71% and 68–71%, respectively. Rest of the compounds also showed considerable antifungal activity and reduced M.phaseolina biomass by 41–64%.

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Two Symmetrical Squarylium Cyanine Dyes: Synthesis, Photophysics and Antifungal Activity in Saccharomyces cerevisiae

Chemistry Proceedings ◽

10.3390/ecsoc-24-08423 ◽

2020 ◽

Vol 3 (1) ◽

pp. 106

Author(s):

Vanessa S. D. Gomes ◽

João C. C. Ferreira ◽

Renato E. F. Boto ◽

Paulo Almeida ◽

Maria João M. F. Sousa ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Minimum Inhibitory Concentration ◽

Antifungal Activity ◽

Emission Spectroscopy ◽

Inhibitory Concentration ◽

Analytical Techniques ◽

Cyanine Dyes ◽

Absorption And Emission ◽

Nir Absorption ◽

Absorption And Emission Spectroscopy

Two squarylium cyanine dyes were synthesized and characterized by the usual analytical techniques, including Vis-NIR absorption and emission spectroscopy. Their antifungal activity was evaluated, through the obtention of minimum inhibitory concentration (MIC) values, using yeasts of the species Saccharomyces cerevisiae as a biological model.

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