­Genomic data mining of the marine actinobacteriaStreptomycessp. H-KF8 unveils insights into multi-stress related genes and metabolic pathways involved in antimicrobial synthesis

Abstract

Streptomyces sp. H-KF8 is an actinobacterial strain isolated from marine sediments of a Chilean Patagonian fjord. Morphological characterization together with antibacterial activity was assessed in various culture media, revealing a carbon-source dependent activity mainly against Gram-positive bacteria (S. aureus and L. monocytogenes). Genome mining of this antibacterial-producing bacterium revealed the presence of 26 biosynthetic gene clusters (BGCs) for secondary metabolites, where among them, 81% have low similarities with known BGCs. In addition, a genomic search in Streptomyces sp. H-KF8 unveiled the presence of a wide variety of genetic determinants related to heavy metal resistance (49 genes), oxidative stress (69 genes) and antibiotic resistance (97 genes). This study revealed that the marine-derived Streptomyces sp. H-KF8 bacterium has the capability to tolerate a diverse set of heavy metals such as copper, cobalt, mercury, chromate and nickel; as well as the highly toxic tellurite, a feature first time described for Streptomyces. In addition, Streptomyces sp. H-KF8 possesses a major resistance towards oxidative stress, in comparison to the soil reference strain Streptomyces violaceoruber A3(2). Moreover, Streptomyces sp. H-KF8 showed resistance to 88% of the antibiotics tested, indicating overall, a strong response to several abiotic stressors. The combination of these biological traits confirms the metabolic versatility of Streptomyces sp. H-KF8, a genetically well-prepared microorganism with the ability to confront the dynamics of the fjord-unique marine environment.

Microbial Community Responses to Vanadium Distributions in Mining Geological Environments and Bioremediation Assessment

“…Enriched Bacillus could therefore play a direct role of reducing V(V) in our soil-inoculated systems. Other enriched species observed in our study have previously been reported capable of tolerating heavy metals, such as the actinobacterial strain Streptomyces in marine sediments which tolerates Ni (Undabarrena et al, 2017), Lysobacter which has genes resistant to Co (Puopolo et al, 2016), Microvirga from the arid Taklamakan desert which strongly resists Pb through intracellular precipitations (Luo et al, 2014), and Ramlibacter from chromite ore processing residue-contaminated soils which is resistant to Cr (Min et al, 2017). These metal-tolerant species accumulated abundantly after long-term incubation, and were potentially tolerant to vanadium since vanadium is less toxic than the afore-mentioned metals.…”

Biological Significance of Marine Actinobacteria of East Coast of Andhra Pradesh, India

“…The synthesis of antimicrobial compounds including polyketide and peptide compounds involves the biosynthetic gene clusters of NRPS and PKS-I, or even the combination of both (Undabarrena et al, 2017). Therefore, an attempt was made to check the presence of these biosynthetic systems in the gDNA of eight strains through PCR specific primers.…”

Biodiversity of Actinobacteria from the South Pacific and the Assessment of Streptomyces Chemical Diversity with Metabolic Profiling

“…The phylum Actinobacteria represents the most prominent group of microorganisms for the production of bioactive compounds [ 5 , 6 , 7 ], contributing to nearly 40% of the bioactive secondary metabolite production, and nearly 80% of which are produced by the genus Streptomyces [ 8 ]. The capability of actinobacterial strains to produce bioactive secondary metabolites relies on their genomic potential, which typically contain a large number of biosynthetic gene clusters, including genes encoding for polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) [ 9 ].…”