无机硒添加方式及 NADPH 或果糖添加对酵母富硒培养的影响

文章以酿酒酵母(Saccharomyces cerevisiae)诱变菌株 HXS-02 为出发菌株，以菌株的生长、总硒和有机硒质量浓度及产率为指标，考察无机硒添加方式及还原型辅酶Ⅱ(NADPH)或果糖的添加对酵母富硒培养的影响。结果显示：菌株富硒培养时加入亚硒酸钠的适宜时间和适宜质量浓度分别为8 h和62.5 mg/L，在此条件下继续培养至24 h，菌株的干质量浓度和富硒能力最好，总硒产率和有机硒产率分别达到 $ (8760.7 \pm 50.6) $ $ \mu $g/L 和 $ (8573.5 \pm 46.5) $ $ \mu $g/L；NADPH 和果糖的添加可显著影响菌株的生长和富硒能力，在无机硒添加的同时向培养基中添加NADPH 至浓度为0.20 mmol/L 或果糖至质量浓度为6 g/L 后，菌株的总硒产率和有机硒产率与未添加的菌株相比，分别增加了32.6%~42.6% 和38.1%~51.5%。以上研究表明，适合的无机硒添加方式并辅以添加适量的NADPH 或果糖，可以有效促进酵母转化无机硒为有机硒的能力，提高富硒酵母总硒和总有机硒的产率。

The Saccharomyces cerevisiae strain HXS-02 was used as the starting strain, the supplementation of inorganic selenium with reduced coenzyme II (NADPH) or fructose was performed to investigate their effects on selenium-enriched culture by evaluating strain growth as well as contents and yields of total selenium and organic selenium of the strain. The optimized experiments showed that the optimal supplementation time and concentration of sodium selenite for the selenium-enriched culture of strain were 8 h of culture and 62.5 mg/L, respectively. Under this condition of inorganic selenium supplementation, the strain after 24 h of culture reached the highest dry weight growth and selenium enrichment ability, and the yields of total selenium and organic selenium were $ (8\ 760.7 \pm 50.6)\ \mu g/L $ and $ (8\ 573.5 \pm 46.5)\ \mu g/L $, respectively. The supplementation of NADPH and fructose could significantly improve the growth and selenium enrichment ability of strain. When the medium was added with 0.20 mmol/L NADPH or 6 g/L fructose along with supplementation of inorganic selenium, the yields of total selenium and organic selenium in strain were increased by 32.6%-42.6% and 38.1%.