ARTP诱变筛选增香、高产酒精的富硒酵母菌

Screening of Selenium-enriched Yeasts with Enhanced Aroma and High Alcohol Production by ARTP Mutagenesis

为了得到产酒精和产香能力较强的枸杞内生富硒酵母菌,进而促进富硒发酵产品的开发和风味的提升,本研究以实验室保藏的枸杞内生酵母菌为实验材料,通过耐硒法和红硒法初筛得到富硒能力较强的酵母菌,采用常压室温等离子体(Atmospheric room temperature plasma,ARTP)诱变技术,经TTC培养基、杜氏小管发酵法、产酒精、产酯产酸、耐受性等实验筛选出增香和高产酒精的目标菌株,并用氢化物发生原子荧光光谱法测定酵母胞内和发酵液中硒含量。结果表明,富硒初筛得到了M1酿酒酵母(Saccharomyces cerevisiae)和M16葡萄牙棒孢酵母(Clavispora lusitaniae),经ARTP诱变分别筛选出产酒精能力较高的S.cerevisiae诱变菌株M1-5和产香能力较高的C.lusitaniae诱变菌株M16-28,M1-5的产酒精能力比M1提高了38.07%,M16-28的产酯能力比M16提升了107.62%,遗传稳定性均良好。经测定M1-5菌株胞内和发酵液中的硒含量分别为204.8和1158μg/L,M16-28胞内和发酵液中的硒含量分别为666.45和1830μg/L,因此,菌株M16-28比M1-5的富硒能力强,且发酵液硒含量极显著高于酵母细胞硒含量(P<0.001)。本研究筛选出诱变菌株M1-5产酒精和M16-28产香能力强的富硒酵母具有优良的发酵特性,在发酵食品和富硒功能性产品的挖掘和开发方面具有潜在的应用前景。

In order to obtain endophytic selenium-rich yeast from Lycium barbarum with strong ability producing alcohol and aroma,and then promote the selenium-rich fermentation products and improve the flavor,this study took the endophytic yeast of L.barbarum stored in the laboratory as experimental materials,and the yeast with strong selenium-rich ability was obtained through the initial screening of selenium-resistant method and red selenium methods.Atmospheric room temperature plasma(ARTP)technology was used to obtain mutant strains and through TTC medium,Duchenne tubule fermentation,alcohol production,ester and acid production,tolerance and other experiments to screen out the target strains of aroma enhancement and high alcohol production.The content of selenium in yeast cell and fermentation liquid was determined by hydride generation atomic fluorescence spectrometry.The results showed that M1 Saccharomyces cerevisiae and M16 Clavispora lusitaniae were obtained by primary selenium screening,the mutagenic strain M1-5 of S.cerevisiae with higher alcohol production capacity and the mutagenic strain M16-28 of C.lusitaniae with higher aroma production capacity were obtained through ARTP mutagenesis.The alcohol production capacity of M1-5 increased by 38.07%compared with M1,and the ester production capacity of M16-28 increased by 107.62%compared with M16,and the genetic stability was good.The selenium contents in the intracellular and fermentation broth of the M1-5 strains were 204.8 and 1158μg/L,respectively,and in M16-28 were 666.45μg/L and 1830μg/L,respectively.Therefore,the selenium enrichment capacity of M16-28 was higher than that of M1-5,and the selenium content of fermentation liquid was extremely significantly higher than that of yeast cells(P<0.001).In conclusion,the selenium-rich yeast with mutagenic strain M1-5 producing alcohol and M16-28 producing aroma were screened out,which had excellent fermentation characteristics and potential application prospects in the development and mining of fermented food and selenium-rich functional products.