Batch cultivation of kluyveromyces fragilis in cheese whey

Kluyveromyces fragilis was cultivated batchwise in an open pond rectangular bioreactor at 30°C, 2vvm of aeration, under non-sterile conditions and uncontrolled pH. The culture medium contained 7% cheese whey powder, 0.25% KH₂PO₄, 0.5% (NH₄)₂SO₄ and was adjusted to an initial pH of 4.0 with phosphoric acid. The lactose was almost completely consumed after 16 h and COD reduction attained 80% after 64 h. The maximum suspended solids concentration obtained was 11.7 g/L. The cheese whey which had initially low protein and high lactose contents was converted by this system into a high protein and low lactose carbohydrate product.