Yarrowia porcina sp. nov. and Yarrowia bubula f.a. sp. nov., two yeast species from meat and river sediment

Abstract

Eleven yeast strains representing two hitherto undescribed species were isolated from different kinds of meat samples in Hungary and one from the sediment of a tropical freshwater river in Southeastern Brazil. The analysis of the sequences of their large subunit rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) regions placed the two new species in the Yarrowia clade. Some of the seven strains representing the first new species can mate and give rise to asci and form ascospores embedded in capsular material, which qualifies it as the third teleomorph species of the Yarrowia clade. The name Yarrowia porcina sp. nov. (type strain: NCAIM Y.02100(T) = CBS 12935(T) = NRRL Y-63669(T), allotype strain UFMG-RD131(A) = CBS 12932(A)) is proposed for this new yeast species, which, based on physiological characters, is indistinguishable from Yarrowia lipolytica and some other species of the genus. Considerable intraspecific variability was detected among the sequences of the large subunit rRNA gene D1/D2 domains of the seven strains. The variability among the D1/D2 sequences exceeded the divergence observed among the ITS sequences and in some cases more than 1 % substitution among the D1/D2 sequences was detected. The conspecificity of these strains was supported by the low (0-3 substitutions) sequence divergence among their ITS sequences, the result of a parsimony network analysis utilizing the concatenated ITS and D1/D2 sequences and also by the fingerprint patterns generated by microsatellite primed PCR. No ascospore formation was observed in the group of the other five strains representing the second new species. These strains shared identical D1/D2 and ITS sequences. Yarrowia bubula f.a., sp. nov. (type strain: NCAIM Y.01998(T) = CBS 12934(T) = NRRL Y-63668(T)) is proposed to accommodate these strains.

Isolation and diversity of food spoilageYarrowiayeast strains from meat

“…We proposed the fi rst new species revealed in this study, Y. divulgata f.a., a new anamorphic member of the genus in a study published last year (NAGY et al, 2013) to accommodate some animal related yeast strains. The description of two additional new Yarrowia species, Y. porcina and Y. bubula f.a., also revealed in this study was published very recently (NAGY et al, 2014), increasing the number of the species of the Yarrowia group to thirteen species. Earlier, based on conventional phenotypic tests, the majority of the isolated strains would have been identifi ed as Y. lipolytica, though actually only 20% of them (24 strains) belong to this species.…”

“…Forty-fi ve percent of the yeast strains (the strains of Y. deformans, Yarrowia divulgata, and Yarrowia porcina) isolated during this experiment would have been misidentifi ed (as Y. lipolytica). Thirty-fi ve percent of the isolated yeast strains of the Yarrowia group belonged to Y. deformans (41 strains), 15% of them to C. galli (17 strains), 10% of them to C. alimentaria (12 strains), and 20% of them could be assigned to three new, recently described species, 10% to Y. bubula, 5% to Y. porcina (NAGY et al, 2014), and 5% to Y. divulgata (NAGY et al, 2013) (Fig. 1).…”

Comprehensive Analysis of a Yeast Lipase Family in the Yarrowia Clade

“…In contrast, the two LIP2 copies in CAHI shared only 55.9% identity and 69.3% similarity, probably resulting from a long evolution. Sequencing the LIP2 locus of additional species of the Yarrowia clade, especially those which have been described very recently, will provide clues to decipher the strange phylogeny of the LIP2 gene [ 48 – 50 ].…”

Identification of food and beverage spoilage yeasts from DNA sequence analyses

“…4). In contrast to Zygosaccharomyces and related genera, Yarrowia species are characterized by production of lipases and proteases and develop on cheeses and meat products where they form off-flavors Nagy et al, 2014). Some of the species are also occasional clinical isolates.…”