Establishment of a Pure Culture of the Hitherto Uncultured Unicellular CyanobacteriumAphanothece sacrum, and Phylogenetic Position of the Organism

Publisher Website
Google Scholar
Abstract
Aphanothece sacrum, an edible freshwater unicellular cyanobacterium, was isolated by using novel synthetic media (designated AST and AST-5xNP). The media were designed on the basis of the ratio of inorganic elements contained inA. sacrumcells cultured in a natural pond. The isolated strain exhibits unicellular rod-shaped cells ∼6 μm in length that are scattered in an exopolysaccharide matrix, a feature similar to that of naturalA. sacrum. DNA analysis of the isolated strain revealed that it carried two ferredoxin genes whose deduced amino acid sequences were almost identical to previously published sequences of ferredoxins from naturalA. sacrum. Analysis of the 16S rRNA gene and ferredoxin genes revealed thatA. sacrumoccupies a phylogenetically unique position among the cyanobacteria.