表型相似的热带假丝酵母和麦芽糖假丝酵母在脉冲电泳核型上的差异

热带假丝酵母Ｃａｎｄｉｄａ ｔｒｏｐｉｃａｌｉｓ （Ｃａｓｔｅｌｌａｎｉ ）Ｂｅｒｋｈｏｕｔ和麦芽糖假丝酵母Ｃ． ｍａｌｔｏｓａＫｏｍａｇａｔａ， Ｎａｋａｓｅ ＆ Ｋａｔｓｕｙａ是两种可利用烃类作为碳和能量来源的酵母菌，前者还是一种条件致病菌，可引起系统感染。这两种假丝酵母菌在形态和生理生化性状上非常相似，用常规分类方法不易准确地鉴别。本研究对Ｃ． Ｔｒｏｐｉｃａｌｉｓ和Ｃ ｍａｌｔｏｓａ的模式菌株以及中国普通微生物菌种保藏中心（ＣＧＭＣＣ）保藏的归于这两个种名下的其它菌株进行了脉冲电泳核型比较分析。发现这两个表型相似的种具有明显不同的染色体ＤＮＡ分子带型，而同一种内的不同菌株却具有相同或相似的分子核型。Ｃ．Ｔｒｏｐｉｃａｌｉｓ的特异染色体ＤＮＡ分子带谱为２条８．５—１．２ Ｍｂ的带， ４条２．３－３．４ Ｍｂ的带。 Ｃ ｍａｌｔｏｓａ的特异带谱为： ３～４条分子量在１．１－１．３Ｍｂ范围内的带， １条约为２．２Ｍｂ的带以及２－３条大小为３．２－３．５Ｍｂ的带。 Ｃ ｔｒｏｐｉｃａｌｉｓ与Ｃ ｍａｌｔｏｓａ在染色体ＤＮＡ分子带型上的差异与二者在可溶性淀粉的同化能力和４０℃下的生长能力上的差异具有明显的相关性…

DIFFERENTIATION BETWEEN THE TWO PHENOTYPICALLY SIMILAR YEAST SPECIES CANDIDA MALTOSA AND CANDIDA TROPICALIS BY ELECTROPHORETIC KARYOTYPING

The two hydrocarbon-utilizing yeast species Candida maltosa Komagata, Nakase & Katsuya and Candida tropicalis (Castellani) Berkhout are not easy to be clearly distinguished from each other by conventional methods because of their similar morphological, physiological and biochemical characters. Electrophoretic karyotypes of the strains preserved in the China General Microbiological Culture Collection Center (CGMCC) under these two species were analyzed by using pulsed field gel electrophoresis (PFGE). The type and representative strains of C. maltosa were clearly differentiated from those of C. tropicalis in chromosomal DNA banding patterns, while all the strains studied within each of these two species showed similar or identical electrophoretic karyotypes. The difference in electrophoretic karyotypes between C maltosa and C tropiclais coincided well with their different abilities to assimilate soluble starch and to grow at 40 C.