赤藓糖醇高产菌株的筛选、鉴定及发酵特性的初步研究

Screening,Identification of Erythritol-producing Osmophilic Yeast and Studies on Fermentation Characteristics

目的:筛选出发酵性能优良的赤藓糖醇高产菌株。方法:利用含50%葡萄糖的高渗培养基筛选出耐高渗酵母,采用薄层层析和高效液相色谱分析发酵液中多元醇的组成和含量,并通过形态和生理生化试验对菌株进行初步鉴定。结果:由泰山养蜂场上采集的蜂蜜、花粉、蜂巢里筛选出13株单产赤藓糖醇的野生菌,其中7株赤藓糖醇产量高于20g/L。菌株K-23经初步鉴定为球拟酵母属,在含20%葡萄糖、1%酵母膏、0.1%尿素的发酵培养基中培养144h后赤藓糖醇的浓度达46.8g/L,转化率达23.4%。结论:所获得的菌株K-23具有一定的赤藓糖醇生产能力,且具有产物单一的优良发酵性能,为该菌株的菌种改良奠定了基础。

Abstract：Objective： To obtained high erythritol- producing strains with excellent fermenting property is the key of the research.Methods： Eryth-ritol- producing strains were isolated from the medium containing 50% glucose,the erythritol in the fermentation broths was confimed and measured by TLC and HPLC, and the strain was identified and denominated by the morphological and physiological studies.Results： 13 erythritol- producing strains were isolated from pollen, honey and honeycomb collected in apiary in MountainTai. Amongst these, 7 strains were high erythritol-producers with the productivity higher than 20g/L. A strain was identified,as Torulopsis sp. K - 23, and showed the highest erythritol conversion yield and productivity. It produced 46.8g/L erythritol after 144h and 23.4% of erythritol conversion yield based on glucose in a medium containing 20% glucose, 1% yeast extract and 0.1%urea. Conclusion： Strain K- 23 with the highest erythritol production without formation of by - produets such as ribitol and mannitol is the foundation of microbial mutation.