Behaviour of Streptomycetes in Soil

Lloyd, A. B.

doi:10.1099/00221287-56-2-165

Cited by 29 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent work by Williams and his coworkers (Williams & Mayfield, 1971;Mayfield, etai, 1972) has shown that streptomycetes exist in soil mainly as spores; mycelial growth occurred infrequently in sites when adequate nutrients were available, confirming observations made by many other earlier workers (Skinner, 1951;Lloyd, 1969).…”

Section: Introductionsupporting

confidence: 60%

Actinomycetes in lake muds: dormant spores or metabolically active mycelium?

Johnston¹,

Cross²

1976

Freshwater Biology

View full text Add to dashboard Cite

Homogenizatian and ultrasonication experiments on samples of lake muds indicated that Micromonospora strains were present as a mixture of mycelium and spores. In contrast, strains of streptomycetes and nocardioforms appeared to be in the form of arthrospores or fragmentation spores respectively.Micromonospora strains originally isolated from lakes were able to grow in both native and enriched muds incubated in the laboratory. Numbers of streptomycetes and nocardioforms did not increase in these muds and are presumed to be relatively inactive in this habitat.We postulate that Micromonospora strains have an active role in the lacustrine environment as well as in soil.

show abstract

Section: Introductionsupporting

confidence: 60%

Actinomycetes in lake muds: dormant spores or metabolically active mycelium?

Johnston¹,

Cross²

1976

Freshwater Biology

View full text Add to dashboard Cite

show abstract

“…Streptomycetes are high G + C Gram-positive, sporeforming bacteria of the family Streptomycetaceae (order Actinomycetales), which includes more than 500 species [1]. They are widely distributed in soils and may exceed in abundance the other soil bacterial genera [2]. Many pathogenic streptomycetes have been isolated from soil samples.…”

Section: Introductionmentioning

confidence: 99%

Diversity and geographic distribution of soil streptomycetes with antagonistic potential against actinomycetoma-causing Streptomyces sudanensis in Sudan and South Sudan

et al. 2020

View full text Add to dashboard Cite

Background: Production of antibiotics to inhibit competitors affects soil microbial community composition and contributes to disease suppression. In this work, we characterized whether Streptomyces bacteria, prolific antibiotics producers, inhibit a soil borne human pathogenic microorganism, Streptomyces sudanensis. S. sudanensis represents the major causal agent of actinomycetomaa largely under-studied and dreadful subcutaneous disease of humans in the tropics and subtropics. The objective of this study was to evaluate the in vitro S. sudanensis inhibitory potential of soil streptomycetes isolated from different sites in Sudan, including areas with frequent (mycetoma belt) and rare actinomycetoma cases of illness.Results: Using selective media, 173 Streptomyces isolates were recovered from 17 sites representing three ecoregions and different vegetation and ecological subdivisions in Sudan. In total, 115 strains of the 173 (66.5%) displayed antagonism against S. sudanensis with different levels of inhibition. Strains isolated from the South Saharan steppe and woodlands ecoregion (Northern Sudan) exhibited higher inhibitory potential than those strains isolated from the East Sudanian savanna ecoregion located in the south and southeastern Sudan, or the strains isolated from the Sahelian Acacia savanna ecoregion located in central and western Sudan. According to 16S rRNA gene sequence analysis, isolates were predominantly related to Streptomyces werraensis, S. enissocaesilis, S. griseostramineus and S. prasinosporus. Three clusters of isolates were related to strains that have previously been isolated from human and animal actinomycetoma cases: SD524 (Streptomyces sp. subclade 6), SD528 (Streptomyces griseostramineus) and SD552 (Streptomyces werraensis). Conclusion:The in vitro inhibitory potential against S. sudanensis was proven for more than half of the soil streptomycetes isolates in this study and this potential may contribute to suppressing the abundance and virulence of S. sudanensis. The streptomycetes isolated from the mycetoma free South Saharan steppe ecoregion show the highest average inhibitory potential. Further analyses suggest that mainly soil properties and rainfall modulate the structure and function of Streptomyces species, including their antagonistic activity against S. sudanensis.

show abstract

“…As a result, the following 9 different taxonomic orders, 15 families, and 25 genera of actinomycetales were identified: Corynebacteriales , Micrococcales , Micromonosporales , Propionibacteriales , Pseudonocardiales , Streptomycetales , Streptosporangiales , Frankiales, and Kineosporiales ( Tables S1 and S2 ). The order Streptomycetales grouped the highest number of strains ( n = 47), all from the genus Streptomyces , a widely studied group of actinobacteria, distributed in soils [ 13 ]. The second most representative order of the actinobacterial population was the Micrococcales , with five different families identified; Brevibacteriaceae ( n = 3), Microbacteriaceae ( n = 5), Micrococcaceae ( n = 6), Promicromonosporaceae ( n = 4) and Dermabacteraceae ( n = 1), followed by the Micromonosporales order, with 2 families; Micromonospora ( n = 17) and Xiangella ( n = 1).…”

Section: Resultsmentioning

confidence: 99%

Kribbellichelins A and B, Two New Antibiotics from Kribbella sp. CA-293567 with Activity against Several Human Pathogens

et al. 2022

View full text Add to dashboard Cite

Current needs in finding new antibiotics against emerging multidrug-resistant superbugs are pushing the scientific community into coming back to Nature for the discovery of novel active structures. Recently, a survey of halophilic actinomyectes from saline substrates of El Saladar del Margen, in the Cúllar-Baza depression (Granada, Spain), led us to the isolation and identification of 108 strains from the rhizosphere of the endemic plant Limonium majus. Evaluation of the potential of these strains to produce new anti-infective agents against superbug pathogens was performed through fermentation in 10 different culture media using an OSMAC approach and assessment of the antibacterial and antifungal properties of their acetone extracts. The study allowed the isolation of two novel antibiotic compounds, kribbellichelin A (1) and B (2), along with the known metabolites sandramycin (3), coproporphyrin III (4), and kribelloside C (5) from a bioassay-guided fractionation of scaled-up active extracts of the Kribbella sp. CA-293567 strain. The structures of the new molecules were elucidated by ESI-qTOF-MS/MS, 1D and 2D NMR, and Marfey’s analysis for the determination of the absolute configuration of their amino acid residues. Compounds 1–3 and 5 were assayed against a panel of relevant antibiotic-resistant pathogenic strains and evaluated for cytotoxicity versus the human hepatoma cell line HepG2 (ATCC HB-8065). Kribbellichelins A (1) and B (2) showed antimicrobial activity versus Candida albicans ATCC-64124, weak potency against Acinetobacter baumannii MB-5973 and Pseudomonas aeruginosa MB-5919, and an atypical dose-dependent concentration profile against Aspergillus fumigatus ATCC-46645. Sandramycin (3) confirmed previously reported excellent growth inhibition activity against MRSA MB-5393 but also presented clear antifungal activity against C. albicans ATCC-64124 and A. fumigatus ATCC-46645 associated with lower cytotoxicity observed in HepG2, whereas Kribelloside C (5) displayed high antifungal activity only against A. fumigatus ATCC-46645. Herein, we describe the processes followed for the isolation, structure elucidation, and potency evaluation of these two new active compounds against a panel of human pathogens as well as, for the first time, the characterization of the antifungal activities of sandramycin (3).

show abstract

Behaviour of Streptomycetes in Soil

Cited by 29 publications

References 4 publications

Actinomycetes in lake muds: dormant spores or metabolically active mycelium?

Actinomycetes in lake muds: dormant spores or metabolically active mycelium?

Diversity and geographic distribution of soil streptomycetes with antagonistic potential against actinomycetoma-causing Streptomyces sudanensis in Sudan and South Sudan

Kribbellichelins A and B, Two New Antibiotics from Kribbella sp. CA-293567 with Activity against Several Human Pathogens

Contact Info

Product

Resources

About