Nautella italica gen. nov., sp. nov., isolated from a marine electroactive biofilm.
ABSTRACT Five isolates obtained from a marine electroactive biofilm grown on a stainless steel cathode were investigated by using a polyphasic taxonomic approach. Analyses of whole-cell fatty acid methyl esters and 16S rRNA gene sequences showed that the isolates belonged to the Roseobacter lineage of the class Alphaproteobacteria. Both phenotypic and genotypic analyses demonstrated that the five new isolates constituted a single species that did not represent a recognized member of the Roseobacter lineage. Therefore the five isolates represent a novel genus and species, for which the name Nautella italica gen. nov., sp. nov. is proposed. The type strain is LMG 24365(T) (=CCUG 55857(T)). The DNA G+C content of the type strain is 61 mol%.
Article: Genomes and virulence factors of novel bacterial pathogens causing bleaching disease in the marine red alga Delisea pulchra.[show abstract] [hide abstract]
ABSTRACT: Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolysins, and global regulatory mechanisms that may allow for the switch of Nautella sp. R11 to a pathogenic lifestyle. Many virulence effectors common in phytopathogenic bacteria are also found in the R11 genome, such as the plant hormone indole acetic acid, cellulose fibrils, succinoglycan and nodulation protein L. Comparative genomics with non-pathogenic Roseobacter strains and a newly identified pathogen, Phaeobacter sp. LSS9, revealed a patchy distribution of putative virulence factors in all genomes, but also led to the identification of a quorum sensing (QS) dependent transcriptional regulator that was unique to pathogenic Roseobacter strains. This observation supports the model that a combination of virulence factors and QS-dependent regulatory mechanisms enables indigenous members of the host alga's epiphytic microbial community to switch to a pathogenic lifestyle, especially under environmental conditions when innate host defence mechanisms are compromised.PLoS ONE 01/2011; 6(12):e27387. · 4.09 Impact Factor