Iron-meditated fungal starvation by lupine rhizosphere-associated and extremotolerant Streptomyces sp. S29 desferrioxamine production

ABSTRACTSiderophores are iron-chelating compounds that aid iron uptake, one of the key strategies for microorganisms to carve out ecological niches in microbially diverse environments. Desferrioxamines are the principal siderophores produced by Streptomyces spp. Their biosynthesis has been well studied and as a consequence, the chemical potential of the pathway continues to expand. With all of this in mind, our study aimed to explore extremotolerant and Lupine rhizosphere-derived Streptomyces sp. S29 for its potential antifungal capabilities. Cocultivation of isolate S29 was carried out with Aspergillus niger and Botrytis cinerea, both costly fungal phytopathogens in the wine industry, to simulate their interaction within the rhizosphere. The results indicate that not only is Streptomyces sp. S29 extraordinary at producing hydroxamate siderophores but uses siderophore production as a means to ‘starve’ the fungi of iron. High resolution LC-MS/MS followed by GNPS molecular networking was used to observe the datasets for desferrioxamines and guided structure elucidation of new desferrioxamine analogues. Comparing the new chemistry, using tools like molecular networking and MS2LDA, with the known biosynthesis, we show that the chemical potential of the desferrioxamine pathway has further room for exploration.

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Baikalomycins A-C, New Aquayamycin-Type Angucyclines Isolated from Lake Baikal Derived Streptomyces sp. IB201691-2A

Microorganisms ◽

10.3390/microorganisms8050680 ◽

2020 ◽

Vol 8 (5) ◽

pp. 680

Author(s):

Irina Voitsekhovskaia ◽

Constanze Paulus ◽

Charlotte Dahlem ◽

Yuriy Rebets ◽

Suvd Nadmid ◽

...

Keyword(s):

Natural Products ◽

Lake Baikal ◽

Structure Elucidation ◽

Genome Mining ◽

Ecological Niches ◽

Hydroxyl Groups ◽

Streptomyces Sp ◽

Drug Leads ◽

Promising Source ◽

Antiproliferative Activities

Natural products produced by bacteria found in unusual and poorly studied ecosystems, such as Lake Baikal, represent a promising source of new valuable drug leads. Here we report the isolation of a new Streptomyces sp. strain IB201691-2A from the Lake Baikal endemic mollusk Benedictia baicalensis. In the course of an activity guided screening three new angucyclines, named baikalomycins A–C, were isolated and characterized, highlighting the potential of poorly investigated ecological niches. Besides that, the strain was found to accumulate large quantities of rabelomycin and 5-hydroxy-rabelomycin, known shunt products in angucyclines biosynthesis. Baikalomycins A–C demonstrated varying degrees of anticancer activity. Rabelomycin and 5-hydroxy-rabelomycin further demonstrated antiproliferative activities. The structure elucidation showed that baikalomycin A is a modified aquayamycin with β-d-amicetose and two additional hydroxyl groups at unusual positions (6a and 12a) of aglycone. Baikalomycins B and C have alternating second sugars attached, α-l-amicetose and α-l-aculose, respectively. The gene cluster for baikalomycins biosynthesis was identified by genome mining, cloned using a transformation-associated recombination technique and successfully expressed in S. albus J1074. It contains a typical set of genes responsible for an angucycline core assembly, all necessary genes for the deoxy sugars biosynthesis, and three genes coding for the glycosyltransferase enzymes. Heterologous expression and deletion experiments allowed to assign the function of glycosyltransferases involved in the decoration of baikalomycins aglycone.

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Isolation, structure elucidation, and antibacterial evaluation of the metabolites produced by the marine-sourced Streptomyces sp. ZZ820

Tetrahedron ◽

10.1016/j.tet.2019.01.025 ◽

2019 ◽

Vol 75 (9) ◽

pp. 1186-1193 ◽

Cited By ~ 5

Author(s):

Wenwen Yi ◽

Qiao Li ◽

Tengfei Song ◽

Lei Chen ◽

Xing-Cong Li ◽

...

Keyword(s):

Structure Elucidation ◽

Streptomyces Sp ◽

Antibacterial Evaluation

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Val-Geninthiocin: Structure Elucidation and MSn Fragmentation of Thiopeptide Antibiotics Produced by Streptomyces sp. RSF18

Zeitschrift für Naturforschung B ◽

10.1515/znb-2008-1014 ◽

2008 ◽

Vol 63 (10) ◽

pp. 1223-1230 ◽

Cited By ~ 8

Author(s):

Imran Sajid ◽

Khaled A. Shaaban ◽

Holm Frauendorf ◽

Shahida Hasnain ◽

Hartmut Laatscha

Keyword(s):

Amino Acids ◽

Biological Activity ◽

Antifungal Activity ◽

Structure Elucidation ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Unusual Amino Acids ◽

Streptomyces Sp ◽

Gram Positive Bacteria ◽

Thiopeptide Antibiotics

AbstractVal-Geninthiocin (2), a new member of thiopeptide antibiotics, was isolated from the mycelium of Streptomyces sp. RSF18, along with the closely related geninthiocin (1) and the macrolide, chalcomycin. By intensive NMR and MS studies, Val-geninthiocin (2) was identified as desoxygeninthiocin, a thiopeptide, containing several oxazole and thiazole units and a number of unusual amino acids. Compound 2 shows potent activity against Gram-positive bacteria and minor antifungal activity, while it is not effective against Gram-negative bacteria or microalgae. Here we describe the fermentation, isolation and structure elucidation as well as the biological activity of 2.

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