Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 1096

Takahashi Rikiya, Kameyama Takao, Suzuki Masaharu, and Hitoshi Yoneyama; [Oligotrophic organisms in sewage activated sludge -Note-]. Hakkokogaku 62(2):77-80, 1984

Reprint

In File

Notes

Activated sludge was found to contain a large number of oligotrophic organisms, so-called diluted nutrient broth (DNB) organisms, with the standard agar medium of Japanese Industrial Standard and its 100-fold dilution. Total viable cells in the activated sludge were estimated as 2.8x10E7 cells/ml of mixed liquor or 3.0x10E10 cells/g -MLSS with the diluted standard agar medium, showing good agreement with previous estimates. As the number of viable cells observed with 100-fold diluted medium was 2-4 times higher than that with full-strength standard agar medium, DNB organisms in the activated sludge were estimated to number at least 1.4x10E7 cells/ml or 1.5x10E10 cells/g -MLSS. Activated sludge was thus thought to be a typical habitat for extremely high concentrations of DNB organisms.