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微生物学报 1996
THE SIGNIFICANCE OF ELECTROPHORETIC KARYOTYPES IN THE CLASSIFICATION OF CANDIDA KRUSEI AND RELATED SPECIES
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Abstract:
The electrophoretic karyotypes of the type strains of Candida krusei(CBS 573), C. lambica (CBS 1876) , and C. valida(CBS 638) were examined by using the CHEF (contour-clamped homogenous electric field) system for pulsed field gel electrophoresis (PFGE). The chromosomal DNA banding patterns of the three phenotypically similar taxa were shown to be clearly different. Among the Candida strains preserved in China General Microbiological Culture Collection Center (CGMCC), two strains, AS 2.75 and AS 2.1182, were originally identified as C. inconspicua and C. lambica, respectively. However, on the basis of morphological and physiological recharacterization and G C content determination, AS 2.75 with 44.4 mol% G C and AS 2.1182 with 41.5 mol% G C were reidentified as C. valida and C. krusei, respectively. The reidentification of them was confirmed by comparative electrophoretic karyotyping of the two strains and the type strains of C. krusei, C. lambica, and C. valida, which indicates that a ) AS 2.75 and CBS 638 have similar chromosomal DNA banding patterns consisted of two to three bands ranging in size from 2.1 to 3.1mb; b) AS 2.1182 and CBS 573 have almost identical electrophoretic karyotypes composed of two bands with molecular sizes ranging from 1.6 to 3.2 mb; and c) CBS 1976 has an unique karyotype with at least five chromosomal DNA-bands ranging in size from 1.7 to 3.7 mb. A formerly unidentified strain AS 2.1772 was likewise classified as C. valida based on its morphological and physiological properties, its G C content, and its electrophoretic karyotype.
