Fermentation of milkwhey by Kluyveromyces marxianus usingJerusalem artichoke

Process of whey fermentation by the yeastKl. marxianus using Jerusalem artichoke was studied. The inulinase activity of the stain Kl. marxianusY-1148 and the effect of the carbon source in thegrowth medium on its value were studied. Themaximum inulinase activity (150 U/g) was observedin the medium with inulin. This indicates that inulinhas the inducing effect. During fermenting wheyinulin has been shown to stimulate the rate ofgrowth and multiplication of Kl. marxianus strainY-1148. The maximum accumulation of yeastbiomass (10,5 g/l) was at inulin concentration inwhey 4 %, which is more than 2 times higher thanthe control. The increase of inulin content to 5 %caused the 24 % decrease of biomass as a resultof inhibition of the enzyme with inulinase activity.Juice from fresh Jerusalem artichoke containing18,7 % inulin during fermenting whey with aerationwas used. It was found that the weight of yeast-protein mass depends on the concentration ofjuice of Jerusalem artichoke in whey and time offermentation. The maximum yeast-protein precipitate was at juice concentration 15 % after24 hours of fermentation (61,4 g/l), exceeding thecontrol by 2,8 times. After 48 and 72 hours thestimulating effect was reduced to 43 % and 29 %respectively. Thus the use of inulin and juice fromfresh tubers of Jerusalem artichoke in the processesof fermentation of whey by Kl. marxianus strainY-1148 increases the yield of biomass, its biologicalvalue and enriches bioconversion products withbiologically active substances. Biomass of yeastKl. marxianus, obtained by the bioconversion ofwhey with inulin-containing products of processing Jerusalem artichoke, can be used for food andfeed purposes.

Kluyveromyces marxianus, milk whey, yeast, Kluyveromycesmarxianus, Jerusalem artichoke, inulin