测定了8类不同食品来源的12株酵母分离株26S rDNA D1/D2序列,与Genbank登陆序列比较分析,12株分离酵母鉴定为:3株酿酒酵母,2株戴尔有孢圆酵母、1株马克斯克鲁维氏酵母、1株喜仙人掌毕赤酵母、1株鲁西坦念珠菌、1株膜噗毕赤酵母、2株Kudriavzevii毕赤酵母,1株疑似新种。选用固相微萃取-气质联用(SPME-GC/MS)方法,完成了各分离株挥发性成分的检测。结果表明,酵母发酵后的香气组分主要为酯类,包括乙酸乙酯、辛酸乙酯、乙酸苯乙酯、癸酸乙酯等,其中菌株A1发酵后产生多种含量较高的挥发性组分及独有组分己酸乙酯。结果表明,酵母产生的香气组分、含量与酵母分离来源、种类有关,这可能与不同酵母代谢途径的差异相关。

Sequence analysis of the D1/D2 region of 26S rDNA was used for the identification of 12 yeast strains isolated from 8 kinds of food samples.The 12 yeast strains were identified by sequence homology comparison with known sequences in GenBank as follows: were Saccharomyces cerevisiae(A1,S2,and S3 strain),Torulaspora delbrueckii(N and Y strain),Kluyveromyces marxianus(S6 strain),Pichia cactophila(YOH strain),Clavispora lusitaniae(XZ strain),Pichia membranifaciens(P3 strain),Pichia kudriavzevii(H and S5 strain),and 1 unidentified new species(S4 strain).The free volatile compounds produced by the yeast strains were detected by gas chromatography-tandem mass spectrometer combined with SPME.Most of volatiles detected were Esters,including ethyl acetate,ethyl octanoate,phenethyl acetate,ethyl decanoate.etc.Most of volatiles detected by SPME-GC/MS were similar among all isolated fementation.Contents variation depended on different strains,and strain A1 could produce special volatile compound ethyl caproate and the appropriate proportion of free volatile compounds.The result showed that the kinds and content of free volatile compounds are in significant relation with yeast species and food sources,that maybe caused by the difference in metabolic pathways of volatiles.