STUDIES ON FILAMENTOUS BACTERIA FROM AUSTRALIAN ACTIVATED-SLUDGE PLANTS

In a survey of activated sludge plants in Australia, where both foams and mixed liquor samples were examined, the organism most frequently d ominant in both was Microthrix parvicella. Although Nocardia amarae-li ke organisms and Nocardia pinensis were often seen as dominant organis ms in foams, they only rarely occurred as dominants in mixed liquor sa mples from the same plants. Instead, Types 0041/0675, 0092 and Halisco menobacler hydrossis were more usually present. There appeared to be l ittle relationship between filament community composition and plant op erating parameters, and most filament types were seen in plants with d iverse characteristics. Partial success was achieved in isolating a fe w of these filaments in pure culture, although in some cases, the medi a successfully used in other studies did not support their growth here . Their morphological properties are described.