The study was conducted to evaluate the potential of mixed culture of Kluyveromyces marxianus and
Candida krusei to enhance COD removal efficiency, minimize contamination at extreme conditions (high
temperature 40 C and low pH 3.5) during batch and continuous aerobic fermentation and to obtain
improved quality single-cell protein (SCP) using whey as substrate. The batch fermentation of monoculture
and mixed culture result showed that the mixed culture resulted in 8.8% higher COD removal
efficacy with 19% higher biomass yield and 33% increased productivity. The maximum COD removal
80.2% (including residual protein) was obtained at 24 h HRT with biomass productivity of 0.17 g/L/h;
however, maximum biomass productivity of 0.38 g/L/h and 34% COD removal were obtained at 6 h
HRT. The results showed that the mixed culture of acid resistance and thermo-tolerant yeasts was a
potential way to produce SCP (animal feed) and simultaneous COD removal under extreme operating
conditions.