Production of Siderophores by an Apple Root-Associated Streptomyces ciscaucasicus Strain GS2 Using Chemical and Biological OSMAC Approaches

Abstract

Apple Replant Disease (ARD) is a significant problem in apple orchards that causes root tissue damage, stunted plant growth, and decline in fruit quality, size, and overall yield. Dysbiosis of apple root-associated microbiome and selective richness of Streptomyces species in the rhizosphere typically concurs root impairment associated with ARD. However, possible roles of Streptomyces secondary metabolites within these observations remain unstudied. Therefore, we employed the One Strain Many Compounds (OSMAC) approach coupled to high-performance liquid chromatography-high-resolution tandem mass spectrometry (HPLC-HRMSn) to evaluate the chemical ecology of an apple root-associated Streptomycesciscaucasicus strain GS2, temporally over 14 days. The chemical OSMAC approach comprised cultivation media alterations using six different media compositions, which led to the biosynthesis of the iron-chelated siderophores, ferrioxamines. The biological OSMAC approach was concomitantly applied by dual-culture cultivation for microorganismal interactions with an endophytic Streptomyces pulveraceus strain ES16 and the pathogen Cylindrocarpon olidum. This led to the modulation of ferrioxamines produced and further triggered biosynthesis of the unchelated siderophores, desferrioxamines. The structures of the compounds were elucidated using HRMSn and by comparison with the literature. We evaluated the dynamics of siderophore production under the combined influence of chemical and biological OSMAC triggers, temporally over 3, 7, and 14 days, to discern the strain’s siderophore-mediated chemical ecology. We discuss our results based on the plausible chemical implications of S. ciscaucasicus strain GS2 in the rhizosphere.

Production and Potential Genetic Pathways of Three Different Siderophore Types in Streptomyces tricolor Strain HM10

“…Streptomyces are numerous soil microbes, widely distributed, and an excellent source of secondary metabolites and bioactive compounds such as antibiotics, siderophores, and extracellular enzymes [55]. The Streptomyces genus can produce a wide variety of siderophore types, and a specific strain can produce more than one siderophore compound [35,38,56].…”

“…Since siderophores produced by Klebsiella pneumoniae can act as an antimalarial agent, siderophores have been used to treat malaria caused by Plasmodium falciparum [33,34]. The bacteria, Streptomyces, produce a wide variety of siderophore types (i.e., hydroxamate-type siderophores [35][36][37][38], catechol-type siderophores [39,40], hydroxycarboxylate-type siderophores [41]). The present work aimed to (i) characterize the siderophore production in S. tricolor HM10 isolated from Qassim, Saudi Arabia; (ii) determine the siderophore types produced by the mentioned strain; (iii) identify the proposed pathways involved in each type of production; and (iv) identify the probability of using strain HM10 as a new source for siderophore production.…”

Metabolomic Insights Into Endophyte-Derived Bioactive Compounds

“…Using various state-of-art techniques such as SPME-GC-MS (for expressed volatilome), HPLC-HRMS n (to target the expressed metabolome), and MALDI-HRMSI (for spatial-temporal visualization of metabolites), the authors demonstrated the production of geosmin (a volatile chemical that attracts soil arthropods), mirubactin (iron-chelating siderophore) and polycyclic tetramate macrolactams (biocontrol activity against various pathogens) under stress conditions ( Armin et al, 2021a ). In addition to chemical OSMAC (by alteration/optimization of chemical media), biological OSMAC involving interaction with other microbial species (endophytic or pathogenic) can be used to increase the diversity of endophyte-derived bioactive compounds ( Armin et al, 2021b ).…”

Antibiotic resistance and siderophores production by clinical Escherichia coli strains

“…In contrast, other strains failed to produce siderophores in the M9 medium, although they produced a yellow halo on CAS agar. This could be because the growth and amount of siderophores produced by an organism under different culture conditions are different (McRose et al, 2017;McRose et al, 2018;Armin et al, 2021;Kang-Yun et al, 2021) Although the genes responsible for regulating siderophores are located on the chromosome (Thode et al, 2018;Massip and Oswald, 2020), it has been reported that the genes responsible for siderophores production were originally plasmid encoded (Faoro et al, 2019;Sarowska et al, 2019;Choby et al, 2020;Heiden et al, 2020) .…”