Elloxazinones A and B, New Aminophenoxazinones from Streptomyces griseus Acta 2871

2008

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This study was designed to determine the biogeography of six alkaliphilic Streptomyces strains which had been isolated from four locations within a 60 m transect across a beach and dune sand system. The six strains shared >99% 16S rRNA gene similarities with one another and with representative strains of Streptomyces griseus. Infraspecific diversity amongst the strains was investigated by multilocus sequence typing (MLST) in combination with carbon utilisation phenotypic testing. The results show that each of the strains is genotypically and phenotypically distinct. Furthermore, the MLST and carbon utilisation profiles were congruent thereby providing preliminary evidence which suggests that the observed infraspecific diversity is consistent with ecological selection. The results also demonstrate that infraspecific diversity can be observed over small spatial scales. These findings support the hypothesis that the six isolates are ecovars of Streptomyces griseus. The implications of these findings for prokaryotic biogeography and bioprospecting are discussed.

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Genetic and phenotypic evidence for Streptomyces griseus ecovars isolated from a beach and dune sand system

Antony-Babu

Stach

2008

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“…Indeed, it would be interesting to see if coupling between taxonomic and chemical diversity occurs below the species level, a hypothesis that could be tested by screening S. griseus ecovars isolated from sampling sites taken along a transect across a beach and dune-sand system ). Representatives of this species would be ideal candidates for testing this proposition as bona fide members of this taxon are a source of new bioactive compounds (Piel 2004;Graf et al 2007). The proposition that the search for new actinomycete diversity is an important element in our drug discovery strategy (Fig.…”

Section: Overview and New Directions Of Travelmentioning

confidence: 98%

A guide to successful bioprospecting: informed by actinobacterial systematics

Fiedler

2010

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297

200

New structurally diverse natural products are discovered when novel screening procedures are introduced or when high quality biological materials from new sources are examined in existing screens, hence it is important to foster these two aspects of novelty in drug discovery programmes. Amongst prokaryotes, actinomycetes, notably streptomycetes, remain a rich source of new natural products though it has become increasingly difficult to find such metabolites from common actinomycetes as screening 'old friends' leads to the costly rediscovery of known compounds. The bioprospecting strategy which is the subject of this review is based upon the premise that new secondary metabolites can be found by screening relatively small numbers of dereplicated, novel actinomycetes isolated from marine sediments. The success of the strategy is exemplified by the discovery of a range of novel bioactive compounds, notably atrop-abyssomicin C and proximicins A, B and C from Verrucosispora strains isolated from sediment samples taken from the Sea of Japan and the Raune Fjord, respectively, and the dermacozines derived from Dermacoccus strains isolated from the Challenger Deep of the Mariana Trench in the Pacific Ocean. The importance of current advances in prokaryotic systematics in work of this nature is stressed and a plea made that resources be sought to train, support and employ the next generation of actinobacterial systematists.

“…It is timely to selectively isolate and determine the taxonomic diversity of alkaliphilic streptomycetes as these organisms are a useful source of new bioactive compounds (Solingen et al 2001;Dieter et al 2003;Höltzel et al 2003;Bruntner et al 2005;Mehta et al 2006;Vasavada et al 2006;Graf et al 2007). The primary aim of the present study was to determine the numbers and taxonomic diversity of putative alkaliphilic streptomycetes isolated from composite sand samples collected across a beach and dune sand system and to establish the pH profiles of representative isolates and phylogenetically related streptomycetes.…”

Section: Introductionmentioning

confidence: 98%

Biosystematics of alkaliphilic streptomycetes isolated from seven locations across a beach and dune sand system

Antony-Babu

2008

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Alkaliphilic streptomycetes were isolated from composite sand samples collected from six out of seven locations across a beach and dune sand system using starch-casein-nitrate agar supplemented with cycloheximide and buffered to pH 10.5. The isolates had colonial and chemotaxonomic properties consistent with their classification in the genus Streptomyces. They were assigned to 49 multimembered and 114 single-membered colour-groups given their ability to produce pigments on oatmeal and peptone-yeast-extract-iron agars and to corresponding taxa based on whole-genome rep-PCR banding patterns. Twenty-four isolates representing the colour and rep-PCR groups grew well from pH 5 to 11, and optimally at pH 9, as did phylogenetically close members of the Streptomyces griseus 16S rRNA gene clade. One hundred and twelve representative alkaliphilic streptomycetes formed a heterogeneous but distinct clade in the Streptomyces 16S rRNA gene tree. A 3-dimensional representation of 16S rRNA sequence data showed that the alkaliphilic streptomycetes formed a distinct group in multidimensional taxospace. It is evident that alkaliphilic streptomycetes are common in the beach and dune sand system and that representatives of this community form new centers of taxonomic variation within the genus Streptomyces that can be equated with species.