Food value of live yeasts and dry yeast-based diets fed to Sydney rock oyster Saccostrea commercialis spat

Six yeast species, cultured on both glucose and acetate as carbon sources, and three dry yeast-based diets (Microfeast ® ) were compared as potential algae substitutes for feeding Sydney rock oyster spat. At the 80% substitution level, two of the dry yeast-based diets containing 7.6 and 21.5% total lipid gave 72 and 76%, respectively, of the dry spat weight gain obtained with the algae-fed control. Weight gains of 58–67% of that of the algae-fed control were also obtained with the following live yeast diets: Dipodascus capitatus and Candida utilis cultured on either glucose or acetate, and Saccharomyces cerevisiae cultured on glucose. There was a negative correlation between the increase in spat dry weight and nitrogen free extract ( r = −0.58; y = 30.34 − 0.26 x ; P r = 0.51; y = 6.10 + 0.31 x ; P