The 1982 ultraviolet eclipse of the symbiotic binary AR PAV

Observations with the International Ultraviolet Explorer (IUE) of the symbiotic binary AR Pav through its 1982 eclipse show that the hot star is not eclipsed. The hot star is associated with an extended region of continuum emission which is partially eclipsed. The eclipsed radiation is hotter near to its center, with a maximum temperature of about 9000 K. The uneclipsed flux is hotter than this. UV emission lines are not measurably eclipsed and presumably arise in a much larger region than the continuum. These data provide new constraints on models of the system but also are apparently in contradiction to those based on ground-based data.Peer reviewed: YesNRC publication: Ye

Actinostreptospora chiangmaiensis gen. nov., sp. nov., a new member of the family Pseudonocardiaceae

A novel actinonmycete strain, YIM 0006(T), was isolated from soil of a tropical rainforest in northern Thailand. The isolate displayed the following characteristics: aerial mycelium is absent, short spore chains are formed directly on the substrate mycelium, contains meso-diaminopimelic acid, arabinose and galactose (cell-wall chemotype IV), the diagnostic phospholipid is phosphaticlylcholine, MK-9(H-4) is the predominant menaquinone and the G + C content of the genomic DNA is 69.0 mol%. Phylogenetic analysis and phenotypic characteristics showed that strain YIM 0006(T) belongs to the family Pseudonocardiaceae but can be distinguished from representatives of all genera classified in the family. The novel genus and species Actinomycetospora chiangmaiensis gen. nov., sp. nov. are proposed, with strain YIM 0006(T) (=CCTCC AA 205017(T) =DSM 45062(T)) as the type strain of Actinomycetospora chiangmaiensis

Marine Actinobacteria, an important source of novel secondary metabolites with bioactivities

Actinomycetes actinobacteria are a kind of microbial resources producing the most of bioactive metabolites. Today known bioactive metabolites are more than 22,000. 10,100 of them are produced by actinomycetes. This review mainly summarized the diversity of marine actinomycetes and their various bioactive metabolites, including enzyme inhibitors, anticancer and antimicrobial compounds. The difficult areas of the study and corresponding solutions, as well as research prospects of the new metabolites discovery from marine actinomycetes are also discussed. metabolites