南极红酵母AN5的发酵及对海参体成分的影响

红酵母是海洋酵母中的常见种类,在水产养殖中常作为微生态制剂。本实验以第22次南极考察从海冰中分离的红酵母AN5为研究对象,对酵母菌的发酵生长条件进行了优化,结果表明,红酵母培养的最佳碳源和氮源分别为2%的糖蜜和0.5%的酵母粉,最适装液量为50 m L/250 mL,摇瓶转速为140 r·min~(–1),培养基初始pH=3.0,20℃下可获得最佳培养,此时酵母发酵密度可达5.81×10~7 cells·mL~(–1)。发酵后测得酵母中水分含量为69.15%,干酵母蛋白质含量为42.00%,多糖含量为32.08%,脂肪含量为0.39%。在幼参养殖过程中以0.3 g(湿重)·m~(–3)水体的用量投喂极地红酵母,养殖2个月后,与对照相比,幼参体内水分和脂肪含量基本没有变化,而蛋白质和多糖含量明显升高。因此,极地红酵母可大量发酵生产,作为微生态制剂应用于海参的养殖中。

Optimal cultivation of Antarctic red yeast and its effect on sea cucumber components

Red yeast Rhodotorula is a common type of marine yeast that is often used as a probiotic in aquaculture. Rhodotorula mucilaginosa AN5 was isolated from sea ice during the 22nd Chinese Antarctic expedition, and its fermentation conditions were optimized. The optimal fermentation conditions for AN5 were as follows: 2% molasses, 0.5% yeast powder, 50 mL medium in 250 mL flask, initial pH=3.0, temperature 20°C, and cultivation for 4 days. Under optimized conditions, the number of yeast cells can reach 5.81×107 cells·mL⁻¹. Component analysis of AN5 showed that the contents of water, crude protein, total sugar, and crude fat were 69.15%, 42.00%, 32.08%, and 0.39%, respectively. Juvenile sea cucumbers were fed a diet containing 0.3 g polar yeast per cubic meter water volume. After two months cultivation, in comparison with the control, the juvenile test specimens showed no differences in the contents of water and crude fat but significantly increased contents of protein and total sugar. Consequently, polar red yeast is considered to have potential application as a microecologics in the culture of sea cucumber.