Effects of nitrogen supplementation on yeast (Candida utilis) biomass production by using pineapple (Ananas comosus) waste extracted medium

Abstract

Pineapple waste medium was used to cultivate yeast, Candida utilis. It served as the sole carbon and energy source for the yeast growth. However, pineapple waste media contain very little nitrogen (0.003-0.015% w/v). Various nitrogen sources were incorporate and their effects on biomass, yield and productivity were studied. Significant (p<0.05) increment on biomass production was observed when nitrogen supplement (commercial yeast extract, peptone, ammonium dihydrogen phosphate, ammonium sulphate and potassium nitrate) was added into fermentation medium. Commercial yeast extract, Maxarome ® which increased 55.2% of biomass production at 0.09% (w/v) nitrogen content, is the most suitable among the selected organic source. On the other hand, ammonium dihydrogen phosphate at 0.09% (w/v) nitrogen content is comparable inorganic source which enhanced 53.7% of production. Total nitrogen content of each treatment at 0.05% (w/v) showed that nitrogen supplied was not fully utilized as substrate limitation in the fermentation medium.