|Van wezel, Gilles|
Submitted to: Antonie Van Leeuwenhoek
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/13/2014
Publication Date: 5/1/2014
Citation: Busarakam, K., Bull, A.T., Girard, G., Labeda, D.P., van Wezel, G.P., Goodfellow, M. 2014. Streptomyces leeuwenhoekii sp. nov., the producer of chaxalactins and chaxamycins, forms a distinct branch in Streptomyces gene trees. Antonie Van Leeuwenhoek. 105(5):849-861. Interpretive Summary: A novel actinomycete strain belonging to the genus Streptomyces (C34) was isolated from extremely arid soil from the Atacama Desert in Chile. The strain produces the novel antibiotics chaxalactins and chaxamycins and, based on the sequence of the 16S rRNA gene as well as morphological and physiological characteristics, it seemed likely that it represented a new species of the genus Streptomyces, but the data were not adequate to confirm this. A comparison of the gene sequences of 5 house-keeping proteins from this strain was made against a comprehensive database of these house-keeping gene sequences being developed for all validly named species of Streptomyces. The comparison against the reference database and subsequent phylogenetic analyses provided convincing evidence that strain C34 represents a new species for which the name Streptomyces leeuwenhoekii is proposed. The study also served as an excellent demonstration of the utility of the multigene sequence database as a resource for definitive identification of novel streptomycetes.
Technical Abstract: A polyphasic study was carried out to establish the taxonomic status of an Atacama Desert isolate, Streptomyces strain C34T, which synthesises novel antibiotics, the chaxalactins and chaxamycins. The organism was shown to have chemotaxonomic, cultural, and morphological properties consistent with its classification in the genus Streptomyces. Analysis of 16S rRNA gene sequences showed that strain C34T formed a distinct phyletic line in the Streptomyces gene tree that was very loosely associated with the type strains of several Streptomyces species. Multilocus sequence analysis based on five house-keeping gene alleles underpinned the separation of strain C34T from all of its nearest phylogenetic neighbours, apart from Streptomyces chiangneiensis TA-1T which is not currently in the MLSA database. Strain C34T was distinguished readily from the S. chiangmaiensis strain by using a combination of cultural and phenotypic data. Consequently, strain C34T is considered to represent a new species of the genus Streptomyces for which the name Streptomyces leeuwenhoekii sp. nov. is proposed. The type strain is C34T (= DSM 42122T=NRRL B-24963T). Analysis of the whole-genome sequence of S. leeuwenhoekii, with 6,780 predicted open reading frames and a total genome size of around 7.86 Mb, revealed a high potential for natural product biosynthesis.