title: Candida milleri species reveals intraspecific genetic and metabolic polymorphisms.
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 CBS6897(T) and CBS5658(T). 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.
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Ileana
authors.initials: I
authors.lastname: Vigentini
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Antoniani
authors.affiliation: Università degli Studi di Perugia, Department of Applied Biology, Borgo XX Giugno 74, 06121 Perugia, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Roscini
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Comasio
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galafassi
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Picozzi
authors.affiliation: Università degli Studi di Perugia, Department of Applied Biology, Borgo XX Giugno 74, 06121 Perugia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Corte
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Compagno
authors.affiliation: Clerici-Sacco Group, R&D Division, Via Manzoni 29/A, 22071 Cadorago, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Dal Bello
authors.affiliation: Università degli Studi di Perugia, Department of Applied Biology, Borgo XX Giugno 74, 06121 Perugia, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Cardinali
authors.affiliation: Università degli Studi di Milano, Department of Food, Environmental and Nutritional Science, via Celoria 2, 20133 Milan, Italy. Electronic address: roberto.foschino@unimi.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Foschino
mesh_terms: D001939:Bread / Q000382:microbiology*; D002175:Candida / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005838:Genotype; D008969:Molecular Sequence Data; D016533:Mycological Typing Techniques; D010641:Phenotype; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal
keywords: Candida humilis; Candida milleri; FT-IR; Sourdough; Strain typing; Yeasts