Demirci A, Pometto A L, Cox D J
Department of Food Science and Human Nutrition, Iowa State University, Ames 50011, USA.
J Agric Food Chem. 1999 Jun;47(6):2496-500. doi: 10.1021/jf9811976.
This study describes a fed-batch fermentation protocol for enhanced production of Saccharomyces cerevisiae containing organically bound selenium. Two levels of sodium selenate concentrations were applied as either a single dose or continuous addition. Fermentations with high sodium selenate (63.2 g/L in cane molasses feeding medium) demonstrated 24 g/L of biomass with 1382 microg of selenium/g of dry biomass for single-dose addition and 40 g/L of biomass with 1491 microg of selenium/g of dry biomass for continuous addition. Low selenium concentration (31.6 g/L in cane molasses feeding medium) demonstrated higher biomass concentration with higher selenium level; 37 g/L of biomass with 2846 microg of selenium/g of dry biomass and 45 g/L of biomass with 2495 microg of selenium/g of dry biomass for single-dose and continuous addition, respectively. Also, two adapted S. cerevisiae strains were evaluated in fed-batch fermentation. A single dose of low concentration demonstrated >3000 microg of selenium/g of dry biomass, but biomass concentration was lower (< or =32 g/L) for these adapted strains.
本研究描述了一种补料分批发酵方案，用于提高含有机结合硒的酿酒酵母的产量。应用了两种亚硒酸钠浓度水平，分别作为单次剂量或连续添加。在高亚硒酸钠（甘蔗糖蜜进料培养基中为63.2 g/L）的发酵中，单次剂量添加时生物量为24 g/L，每克干生物量含1382微克硒；连续添加时生物量为40 g/L，每克干生物量含1491微克硒。低硒浓度（甘蔗糖蜜进料培养基中为31.6 g/L）显示，硒水平较高时生物量浓度更高；单次剂量和连续添加时，生物量分别为37 g/L，每克干生物量含2846微克硒，以及45 g/L，每克干生物量含2495微克硒。此外，还在补料分批发酵中评估了两种适应性酿酒酵母菌株。低浓度单次剂量显示每克干生物量含>3000微克硒，但这些适应性菌株的生物量浓度较低（≤32 g/L）。
