对虾养殖环境中红酵母的筛选及其发酵工艺研究

Screening of Rhodotorula sp.in Culture Environment of Shrimp and Study on Its Fermentation Technology

[目的]对对虾养殖环境中红酵母进行筛选,并对其发酵工艺进行研究。[方法]首先利用PDA固体培养基从对虾养殖环境中筛选出红酵母菌株HL-6;然后,根据26S rDNA基因序列的系统发育树分析,对菌株HL-6进行鉴定;最后,在单因素试验的基础上,通过正交试验对发酵工艺进行优化。[结果]经初步鉴定确定菌株HL-6为胶红酵母,该菌株的最佳发酵工艺如下:糖蜜浓度为8%,酵母膏浓度为1.5%,硫酸铵浓度0.6%,磷酸二氢钾浓度为0.3%,发酵温度为30℃,发酵时间为48 h。在此工艺条件下,发酵液中红酵母的活菌数高达11.2×10^8 CFU/mL。[结论]该研究对对虾养殖所用红酵母的发酵生产具有一定的参考价值。

[Objective]To screen out Rhodotorula sp. in culture environment of shrimp, and study its fermentation technology. [Method] Firstly, Rhodotorula sp. strain HL-6 was screened out from culture environment of shrimp by using PDA solid medium. Secondly, the strain HL-6 was identified based on phylogenetic tree analysis of 26 S rDNA gene sequence. Finally, the fermentation technology was optimized by orthogonal experiment on the basis of single factor experiment. [Result] The strain HL-6 was preliminarily identified as Rhodotorula mucilaginosa. The optimum fermentation conditions of the strain were as follow: molasses 8%, yeast extract 1.5%, ammonium sulfate 0.6%, potassium dihydrogen phosphate concentration 0.3%, fermentation temperature 30 ℃ and fermentation time 48 h. Under the above conditions, the number of Rhodotorula sp. in the fermentation broth was as high as 11.2×10^8 CFU/mL. [Conclusion] The study had certain reference values for the fermentation production of Rhodotorula sp. used in shrimp culture.