高生物量富硒酵母的选育及培养条件初步优化

通过筛选、单倍体分离、诱变和原生质体融合，从融合子中选育了一株高生物量富硒酵母菌株（编号为ZFF-28），其细胞硒总含量分别是原始亲株ZY-67和ZY-198的2.8倍和2.0倍。通过单因素实验和正交试验设计，确定了优化培养条件：6%糖浓度的蔗糖糖蜜，添加0.5% (NH4)2SO4、0.1% H3PO4、60μg/mL Se，pH60～6.5，装液量50mL/250mL三角瓶，接种量10%，培养时间25h。在优化培养条件下，菌株ZFF_28的生物量可达8.2g/L,细胞中硒的含量达2050μg/g，硒总含量达到了16810μg/L，是培养条件优化前的1.3倍。细胞硒含量的91%为有机硒。

The Breeding and Culture Condition Optimization of a High-biomass,Selenium-enriched Yeast Strain

The yeast fusant ZFF-28, which is high in biomass production and rich in selenium, was constructed after mutagenesis and protoplasts fusion between yeast strains. The total selenium content of ZFF-28 is 1.8 and 1.0 times higher than that of the parental strains Saccharomyces cerevisiae ZY-67 and Saccharomyces kluyveri SZY-198 respectively. Using single factor tests and a L16(4(3) x 2(1)) orthogonal design, the cultivation conditions was optimized as: 50mL culture in 250mL shake flasks in molasses containing 6% sugar and 60microg/mL Se at 28 degree C for 25h at 220 r/min, with the initial pH adjusted to 6.0 - 6.5. Under the optimized conditions, the biomass (dry weight) reached 8.2g/L and the Se content of the cells reached 2050microg/g, with organic and inorganic Se contents being 91% and 9% respectively.