Competitive growth kinetics of Sphaerotilus natans and Acinetobacter anitratus

CONTRERAS E.; GIANNUZZI L.; ZARITZKY N.

Roma, Italia

Congreso; 3rd IWA International Specialised Conference on Microorganisms in Activated Sludge and Biofilm Processes; 2001

Growth kinetics of Sphaerotilus natans and Acinetobacter anitratus (strain E932) in pure and mixed cultures was studied. In order to determine mixed cultures biomass composition, an image analysis quantitative technique was developed. Pure cultures studies showed that for dilution rates less than 0.188 h-1, the filamentous microorganism will predominate leading to bulking phenomena. By using the developed techinque to determine biomass composition, mixed cultures experiments showed that changes in the dilution rate modify the microbial composition of the biomass determining which microorganism predominate. The obtained results agree satisfactorily with the stated equations that predict the predominance of S. natans at low dilution rates.