产类胡萝卜素酵母菌的鉴定及其发酵醋糟营养价值的研究

本研究旨在对实验室前期分离的酵母菌进行鉴定,并利用其发酵醋糟,以提高醋糟饲用营养价值。利用形态学特征、生理生化特性及26S rDNA的D1/D2区核酸序列分析,鉴定了1株产类胡萝卜素的酵母菌,并对醋糟进行固态发酵。结果表明:被鉴定菌株符合红酵母的形态学特征及生理生化特性,其26S rDNA的D1/D2区核酸序列与黏性红酵母(Rhodotorula mucilaginosa)相关序列相似度达100%,故该菌株被鉴定为黏性红酵母;与未发酵醋糟相比,该菌株发酵醋糟的干物质、粗纤维、中性洗涤纤维和酸性洗涤纤维含量变化均不显著,粗脂肪和总糖含量均降低(P<0.01),粗蛋白质与真蛋白质含量均升高(P<0.01),尤其是产生了6.60 mg/kg具有多种生物学功能的类胡萝卜素。结果显示,该株产类胡萝卜素的酵母菌为黏性红酵母,该菌发酵可改善醋糟的营养价值。

Identification of Carotenoid-Producing Yeast and Its Fermentation Effect on the Nutritional Value of Vinegar Residue

The aim of this study was to identify the yeast strain from the previous trial, and then use it to ferment vinegar residue(VR) to increase its nutritional value. One strain that produced carotenoid was identified using morphological, physiological, biochemical characteristics identification and 26 S rDNA D1/D2 nucleic acid sequence analysis, and this stain was further used for VR fermentation. The results showed that the morphological, physiological and biochemical characteristics of the identified yeast strain was consistent with Rhodotorula, with 100% similarity of the 26 S rDNA sequences to Rhodotorula mucilaginosa. Compared with control group, DM, CF, NDF and ADF contents in experimental group did not alter. Interestingly, the fermentation effectively reduced both ether extract and total sugar contents(P<0.01). Moreover, the fermentation by the yeast exhibited higher contents of both CP and TP(P<0.01). Particularly, 6.60 mg/kg carotenoid was obtained after the fermentation. Taken together, the data suggested that carotenoid-producing yeast was identified, and the nutritional value of the fermented VR was improved.