一株利用内醚糖产类胡萝卜素菌株的分离及鉴定

Isolation and identification of a strain converting levoglucosan to carotenoid

【目的】筛选一株能高效利用内醚糖的菌株,该菌株能以内醚糖为碳源产类胡萝卜素,以实现对生物质的有效利用。【方法】以纤维素生物质热解产物内醚糖为唯一碳源,筛选得到的真菌ZS1菌株。通过rDNA ITS基因序列分析,构建进化树,并结合菌落形态特征确定菌株系统发育学地位。通过高效液相色谱分析其利用内醚糖的能力,利用分光光度法检测类胡萝卜素含量。【结果】实验表明筛选得到的真菌ZS1对内醚糖有很好的同化能力,培养4 d后内醚糖的利用率为67.0%,经ITS测序和菌落形态特征鉴定该菌为红冬孢酵母菌(CGMCC No:6365)。优化培养条件后,内醚糖的利用率在5 d内达98.7%,菌体中类胡萝卜素含量为427.1μg/g(干重)。以内醚糖为碳源得到的类胡萝卜素量为460.4μg/g(内醚糖)。【结论】筛选得到的红冬孢酵母菌Rhodosporidium Kantochvilovae,能有效地利用内醚糖并产类胡萝卜素。

[ Objective] In order to use cellulosic biomass effectively, we screened a strain that can convert levoglucosan efficiently to carotenoids. [ Methods] Strain ZS1 was isolated from soil using levoglucosan of cellulosis pyrolysis products as sole carbon source. It was identified based on rDNA ITS sequence analysis and morphological characteristics. Phylogenetic tree was constructed to determine its taxonomic status. The conversion rate of levoglucosan was analyzed by high performance liquid chromatography. Carotenoid in fermentation liquid was detected by spectrophotometry. [ Results] The results show that ZSlcould ferment levoglucosan efficiently and the consumption rate of levoglucosan reached 67.0% after 4 days. Strain ZS1 was identified as Rhodosporidium kratochvilovae （CGMCC NO ：6365 ） based on the morphology features and ITS sequence analysis. After optimization of culture conditions, the conversion rate of levoglucosan reached 98.7% after 5 days. The content of carotenoid in cells was 427.1μg/g （cell dry weight）. After conversion, 460.4μg/ g （levoglucosan） of carotenoids could be produced with levoglucosan as carbon source. [ Conclusion] The strain capable fermenting levoglucosan was identified as R. kratochvilovae that could produce carotenoids with levoglucosan as carbon source.