The transcription of structural genes encoding two hydrogenases in N(2)-fixing cultures of the cyanobacteria Nostoc muscorum and Nostoc sp. strain PCC 73102 were examined by reverse transcription-PCR. A low level of oxygen and addition of nickel induce higher transcript levels of both hydrogenases, whereas molecular hydrogen has a positive effect on the transcription of the genes encoding only ...

Two new species of oribatid mites of the family Galumnidae, Allogalumna monodactyla sp. n. and Galumna (Galumna) paracalcicola sp. n., are described from dark loamy soil under crown of Ficus sp. in southern Vietnam. Allogalumna monodactyla sp. n. is the first identified member of Allogalumna recorded for Vietnam. The identification keys to the species of Allogalumna from the Oriental region and...

Seven sesquiterpene lactones were isolated by the chromatographic separation of the MeOH extract of the aerial parts of Saussurea calcicola (Compositae). Their structures were determined spectroscopically to be cynaropicrin (1), arguerin B (2), cebellin F (3), 8alpha-hydroxy-11alpha, 13-dihydrozaluzanin C (4), desacylcynaropicrin (5), 3beta-hydroxy-8alpha-epoxymethylacriloiloxy-4(15),10(14),11(...

Isolation of cyanobacteria was attempted from herbicide applied rice soils. The predominant genera were Westiellopsis followed by Anabaena, Nostoc and Oscillatoria. The herbicide tolerance was further tested by growing the cyanobacterial cultures in BG-11 medium supplemented with varying concentrations of the commonly used rice herbicide, viz butachlor under in vitro condition. The chlorophyll-...

A new ultraviolet (UV)-A/B absorbing pigment with maxima at 312 and 330 nanometers from the cosmopolitan terrestrial cyanobacterium Nostoc commune is described. The pigment is found in high amounts (up to 10% of dry weight) in colonies grown under solar UV radiation but only in low concentrations in laboratory cultures illuminated by artificial light without UV. Its experimental induction by UV...

Nostoc sphaeroides Kuetzing has been used as a traditional medicine in China to treat a variety of ailments. This research identified the antioxidant activities of polysaccharide extract from Nostoc sphaeroides. The extract, which contains 46.2% carbohydrates, exhibited an effective scavenging capability on superoxide radical, hydroxyl radicals in non site-specific as well as site-specific assa...

Two species of thalloid liverworts, Blasia pusilla and Cavicularia densa, form stable symbioses with nitrogen-fixing cyanobacteria. Both bryophytes promote the persistence of their cyanobacterial associations by producing specialized gemmae, which facilitate the simultaneous dispersal of the host and its nitrogen-fixing symbionts. Here the genetic diversity of cyanobacterial symbionts of Blasia...