A fluorescently-labelled r-RNA targeted oligonucleotide probe for the in situ detection of G-bacteria of the genus Amaricoccus in activated sludge

A fluoreseently-labelled r-RNA targeted oligonucleotide probe specific for members of the genus Amaricoccus, which includes one group of the Gram-nega tive G-Bacteria seen in activated sludge systems, is described. These organ isms, previously 'identified' on their distinctive morphology of cocci in t etrads, have been associated with poor performance of biological nutrient r emoval (EBNR) plants, by out-competing the polyphosphate accumulating bacte ria, Methods of sample preparation for probing activated sludge are detaile d, and preliminary surveys of 46 plants, using this probe, show that G-Bact eria belonging to the genus Amaricoccus are seen not only in large numbers in EBNR systems but also in conventional plants. The presence of single cel ls of this organism was common, emphasizing the dangers of relying morpholo gy and cell arrangement to identify these bacteria.