ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The Impact of Different Aeration Conditions on Whey Bioutilization

L. Krzystek, T. Jamroz, B. Sencio, P. G Luszcz, and S. Ledakowicz

Department of Bioprocess Engineering, Faculty of Process & Environmental Engineering, Technical University of Lódz, PL-93 005 Lódz

E-mail: krzystek@ck-sg.p.lodz.pl

Received: 11 April 2001

Abstract: The aim of this paper was to investigate the impact of increased pressurein the bioreactor and oxygen concentration increase in the inlet stream by enrichment of the air with pure oxygen on the yield and productivity of Kluyveromyces fragilis yeast and parallel lactose utilization and reduction of organic load of a medium simulating dairy waste (whey). On the basis of biomass yield and productivity and the degree of COD reduction, the optimum range of oxygen concentrations in the media was estimated.
The experiments were performed for a wide range of levels of dissolved oxygen in the media. The air supplied to the bioreactor was enriched with pureoxygen to increase the dissolved oxygen concentration in the liquid phase. The culture was also grown in the bioreactor at the pressure equal to 0.35 MPa.
The highest biomass yield was obtained in the process in which the air supplied to the bioreactor was not enriched with oxygen, and the lowest dissolved oxygen concentration in the culture medium was 3.2 mg dm⁻³, which corresponded to about 40 % of saturation at aeration carried out at atmospheric pressure (without the enrichment with oxygen). In this case, high experimental yield coefficient constituted about 90 % of the theoretical yield and maximum COD reduction of about 80 % was observed.

Full paper in Portable Document Format: 561a57.pdf

Chemical Papers 56 (1) 57–61 (2002)