产虾青素海洋酵母菌YS-185的鉴定及发酵条件优化

Identification of an astaxanthin-producing marine yeast strain YS-185 and optimization of its fermentation conditions

中文关键词: 26S rDNA  虾青素含量  发酵优化  正交实验

英文关键词: 26S rDNA  Content of astaxanthin  Fermentation optimization  Orthogonal experiment

中文摘要:

      以26S rDNA法将实验室保藏的1株产虾青素的海洋酵母菌YS-185鉴定为粘红酵母。以海洋酵母菌YS-185为试验菌株,运用摇瓶发酵优化的方式,探索培养基组分和发酵工艺条件对该菌发酵的影响。实验结果表明,该菌生长最适培养基组分为葡萄糖8 g/L、蛋白胨8 g/L，最适生长起始pH值为5.5、转速220 r/min、接种量8%、温度20℃；虾青素合成的最佳培养基组分葡萄糖8 g/L、蛋白胨8 g/L，最佳虾青素合成条件：pH 5-5，转速220 r/min，接种量8%,培养温度25℃。发酵优化后的虾青素产量2.670 μg/ml，较优化前的1.572 μg/ml提高了69.8%。温度对酵母菌的生长和虾青素的合成都有显著影响。海洋酵母菌YS-185优化后的发酵条件有规模化生产虾青素的应用潜力。

英文摘要:

      A yeast strain YS-185 isolated from the ocean can produce astaxanthin. 26S rDNA sequence analysis showed that the strain belongs to Rhodotorula glutinis. The effects of culture medium components and fermentation conditions on the marine yeast growth and pigment yield were investigated in shake flasks. The results showed that the optimum culture medium for the bacteria growth consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 200r/min, inoculum level 8%(v/v), and temperature 20℃. The optimum culture medium for astaxanthin production consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 220 r/min, inoculum level 8%(v/v) and temperature 25℃. We found that temperature had significant influence on the bacteria growth and the astaxanthin production based on the data analysis of the orthogonal experiments. An overall 69.7% increase of astaxanthin yield (2.670μg/ml) was obtained compared with that of the original conditions (1.572μg/ml). Marine yeast YS-185 had the potential to produce astaxanthin at a large scale.