轮梗霉融合菌株D-A1富集硒的培养条件研究

Orthogonal-array-design Optimization of Culture Conditions for Selenium Enrichment by Recombinant Diasporangium sp. Strain D-A1

采用轮梗霉融合株D-A1作为富硒的载体,进行轮梗霉富硒条件优化。通过单因素试验研究不同的碳源、氮源、碳源浓度、温度、转速、pH值、接种量和装液量对轮梗霉富硒的影响。并选取对轮梗霉富硒影响较大的碳源、氮源、温度和转速进行正交试验。结果表明,发酵培养基中亚硒酸钠浓度为90μg/ml时,轮梗霉在优化的发酵条件下:麦芽糖100g/L、酵母膏10g/L、温度18℃、摇床转速120r/min,菌体硒含量最终可达3266.79μg/g,细胞富集的有机态硒占总富硒量的85.08%。以不加硒处理为对照,富硒轮梗霉的不饱和脂肪酸含量提高,亚油酸的含量是对照的1.20倍,花生四烯酸含量是对照的1.24倍,二十碳五烯酸(EPA)含量是对照的1.71倍。

The optimal fermentation conditions of recombinant Diasporangium sp. strain D-A1 for Se accumulation in its mycelia were investigated in this study. First, single factor experiments were conducted for exploring the effects of various factors including kinds of carbon source and nitrogen source, carbon source concentration, culture temperature, shaking speed, pH, inoculation amount and culture medium volume poured into 250 ml flask on selenium accumulation in D-A1 mycelia. Subsequently, the most important affecting factors such as kinds of carbon source and nitrogen source, culture temperature and shaking speed were optimized using orthogonal array design. Results showed that after fermentation at 18 ℃ with a shaking speed of 120 r/min in a culture medium consisting of 100 g/L maltose and 10 g/L yeast extract with an initial concentration of sodium selenite of 90 μg/ml, D-A1 mycelia exhibited a Se content of 3266.79 μg/g dry weight and a percentage of organic Se accounting for total Se of 85.08%. Compared with non-Se-enriched mycelia, Se-enriched mycelia had higher unsaturated fatty acids content with 1.20, 1.24 and 1.71-fold enhancements for linoleic acid, arachidonic acid and EPA, respectively.