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Continuous Production of Single Cell Protein from Cheese Whey Lactose Using Kluyveromyces Fragilis

1995; Volume: 38; Issue: 4 Linguagem: Inglês

10.13031/2013.27929

2151-0059

R. M. Ben‐Hassan, A. E. Ghaly,

Microbial Inactivation Methods

A 25-L working volume fermenter, made of stainless steel material, was used to study the effects of hydraulic retention time at three levels (12, 18, and 24 h), air flow rate at two levels (1 and 3 VVM) and mixing speed at three levels (200, 400, and 600 rpm) on the continuous production of single cell protein (SCP) from cheese whey using the yeast Kluyveromyces fragilis. The cell mass and lactose consumption were dependent on the hydraulic retention time, air flow rate and mixing speed used. Lactose consumption of 75 to 99% and cell mass of 1.3 to 34.3 g/L were achieved depending on the hydraulic retention time, air flow rate, and mixing speed. There were significant gains in the suspended solids and organic nitrogen ranging from 10.99 to 65.10 5% and from 1.76 to 8.50 %, respectively. The results indicated that, at the 12 h retention time, the 3 VVM air flow rate and the 600 rpm mixing speed, the microbial yield coefficient was 0.74 g of yeast per g of lactose. Comparing this to a stochimetric yield of 0.79 g yeast/g lactose, a conversion efficiency of up to 93.7% was obtained.