Continuous production of lactic acid from whey permeate by free and calcium alginate entrapped Lactobacillus helveticus

Lactobacillus helveticus strain milano was used for the continuous fermentation of lactic acid in cheese whey-yeast extract permeate medium. Under high dilution rates, the cells were elongated to several times their normal size, resulting in wall growth. The cell growth on the fermentor wall caused system instability; however, it prevented cell wash-out under high dilution rates. The packed bed column system using Ca alginate entrapped cells is not suitable for practical applications. Nonuniform pH control, plugging of the column by leaked cells, and decalcification of Ca alginate beads were major drawbacks of the packed bed system.