Cultivation of autotrophic ammonia-oxidizing archaea from marine sediments in coculture with sulfur-oxidizing bacteria.

The role of ammonia-oxidizing archaea (AOA) in nitrogen cycling in marine sediments remains poorly characterized. In this study, we enriched and characterized AOA from marine sediments. Group I.

Isolation, characterization, and abundance of filamentous members of Caldilineae in activated sludge.

Chloroflexi are currently believed to serve as backbone forming agents in the activated sludge of wastewater treatment plants (WWTPs). In this study, we isolated and characterized filamentous bacteria in the class Caldilineae of the phylum Chloroflexi in municipal WWTPs. Diversity analysis using Chloroflexi-specific 16S rRNA gene clone libraries showed that 97% of the clones belonged to the subdivision Anaerolineae comprising the two classes Anaerolineae (95%) and Caldilineae (2%).

Marinobacterium maritimum sp. nov., a marine bacterium isolated from Arctic sediment.

A Gram-negative, aerobic, rod-shaped, motile, marine bacterium, strain AR11(T), was isolated from Arctic marine sediment. Strain AR11(T) grew with 0.5-7 % NaCl and at 7-37 degrees C and pH 5.

Molecular analysis of the diversity of the sulfide : quinone reductase (sqr) gene in sediment environments.

Our newly designed primers were evaluated for the molecular analysis of specific groups of the sqr gene encoding sulfide : quinone reductase (SQR) in sediment environments. Based on the phylogenetic analysis, we classified the sqr sequences into six groups. PCR primers specific for each group were developed.

Microeukaryotic diversity in marine environments, an analysis of surface layer sediments from the East Sea.

Molecular techniques, based on clone library of 18S rRNA gene, were employed to ascertain the diversity of microeukaryotic organisms in sediments from the East Sea. A total of 261 clones were recovered from surface sediments. Most of the clone sequences (90%) were affiliated with protists, dominated by Ciliates (18%) and Dinoflagellates (19%) of Alveolates, phototrophic Stramenopiles (11%), and Cercozoa (20%).