Effect of the Copper Content of Distillery Spent Wash on its Utilization for Single‐cell Protein Production by Geotrichum candidum, Hansenula anomala and Candida kruzei

Abstract

Geotrichum candidum, Hansenula anomala and Candida kruzei were grown in batch and continuous culture on samples of the spent wash from a malt whiskey distillery containing levels of dissolved copper up to 22 mg/l. In batch culture some inhibition of growth at the higher copper concentrations and as much as a sixfold accumulation of copper in the biomass were observed. In Geotrichum candidum this accumulation occurred in three distinct phases during the period of batch growth. Although biomass yields in mixed continuous culture declined with increasing dilution rate there was a corresponding increase in cell copper concentration such that total copper removal from the medium remained approximately constant.

Soluble Complexes of Copper and Zinc in Whiskey Distillery Spent Wash

“…Some results of this study have already been published. 13 The distribution of zinc complexes is also investigated since unpublished results in our labora tory have shown that malt whiskey spent wash consistently contains about 5 ppm dissolved zinc, much of it presumably also derived from distillery pipework and fittings. The dezincification of brass and corrosion of copper materials has recently been reviewed by Matson,8 and several instances of corrosion of copper from food and drinks processing equipment arc quoted by McMullen.9…”