Candida milleri, together with Candida humilis, is the most representative yeast species found in type I sourdough ecosystems. In this work, comparison of the {ITS} region and the {D1/D2} domain of {26S} {rDNA} gene partial sequences, karyotyping, {mtDNA-RFLP} analysis, Intron Splice Site dispersion ({ISS-PCR)} and ({GTG)5} microsatellite analyses, assimilation test of different carbohydrates, and metabolome assessment by {FT-IR} analysis, were investigated in seventeen strains isolated from four different companies as well as in type strains {CBS6897T} and {CBS5658T.} Most isolates were ascribed to C. milleri, even if a strong relatedness was confirmed with C. humilis as well, particularly for three strains. Genetic characterization showed a high degree of intraspecific polymorphism since 12 different genotypes were discriminated. The number of chromosomes varied from 9 to 13 and their size ranged from less than 0.3 to over 2 Mbp. Phenotypic traits let to recognize 9 different profiles of carbon sources assimilation. {FT-IR} spectra from yeast cells cultivated in different media and collected at different growth phases revealed a diversity of behaviour among strains in accordance with the results of {PCR-based} fingerprinting. A clear evidence of the polymorphic status of C. milleri species is provided thus representing an important feature for the development of technological applications in bakery industries.
Candida milleri species reveals intraspecific genetic and metabolic polymorphisms
ROSCINI, LUCA;CORTE, LAURA;CARDINALI, Gianluigi;
2014
Abstract
Candida milleri, together with Candida humilis, is the most representative yeast species found in type I sourdough ecosystems. In this work, comparison of the {ITS} region and the {D1/D2} domain of {26S} {rDNA} gene partial sequences, karyotyping, {mtDNA-RFLP} analysis, Intron Splice Site dispersion ({ISS-PCR)} and ({GTG)5} microsatellite analyses, assimilation test of different carbohydrates, and metabolome assessment by {FT-IR} analysis, were investigated in seventeen strains isolated from four different companies as well as in type strains {CBS6897T} and {CBS5658T.} Most isolates were ascribed to C. milleri, even if a strong relatedness was confirmed with C. humilis as well, particularly for three strains. Genetic characterization showed a high degree of intraspecific polymorphism since 12 different genotypes were discriminated. The number of chromosomes varied from 9 to 13 and their size ranged from less than 0.3 to over 2 Mbp. Phenotypic traits let to recognize 9 different profiles of carbon sources assimilation. {FT-IR} spectra from yeast cells cultivated in different media and collected at different growth phases revealed a diversity of behaviour among strains in accordance with the results of {PCR-based} fingerprinting. A clear evidence of the polymorphic status of C. milleri species is provided thus representing an important feature for the development of technological applications in bakery industries.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
