Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 1208

Inamori Yuhei, Suzuki Rie, and Sudo Ryuichi; [Mass culture of small aquatic oligochaeta]. Studies on the effect of organic wastes on the soil ecosystem research report in 1979-1980. Res.Rep.Natl.Inst.Environ.Stud.,Jap.:47:125-137, 1983

Reprint

In File

Notes

Isolation, stock, and in addition, monoxenic and mass culture of specific species of aquatic oligochaetes, Nais sp., Aeolosoma hemprichi, Pristina sp. and Dero sp. were attempted successfully. Small aquatic oligochaetes are the typical metazoa found frequently in the activated sludge and bio-film from domestic sewage treatment plant operated by low BOD loading. Using a sterilized activated sludge as the metazoan food, the monoxenic growth rate of small aquatic oligochaetes, the effects of temperature, pH, phosphate buffer solution concentration, organic concentration, share stress, food concentration and sort of bacteria as food, on the growth rate were measured. The optimum temperature of cultivation for A. hemprichi, Nais sp. and Pristina sp. were 33, 25 and 30 degrees C, respectively. Phosphate buffer concentration which could grow normally were 1/375 M for A. hemprichi and Nais sp., 1/150 M for Pristina sp. and 1/7,500 M for Dero sp. The optimum pH values in cultivating the oligochaetes ranged from 6 to 8. The growth of Nais sp. could not be observed in much stronger share stress. Specific growth rate (ยต) ranged from 0.35 to 0.43 day-1 for A. hemprichi and 0.10 to 0.13 day-1 for Nais sp., respectively when the sludge concentration was more than 500 mg/l. The growth rate of Nais sp. was increased by adding some bacteria to sludge as the food. Maximum population density of small aquatic oligochaetes under favorable conditions mentioned above are 100 per ml for A. hemprichi and 60 per ml for Nais sp. and Pristina sp. in batch culture, and 1,000 per ml for A. hemprichi and 200 per ml for Nais sp. and Pristina sp. in continuous culture.