T. Nagahama et al., Distribution and identification of red yeasts in deep-sea environments around the northwest Pacific Ocean, ANTON LEEUW, 80(2), 2001, pp. 101-110
Citations number
25
Categorie Soggetti
Microbiology
Journal title
ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY
We isolated 99 yeast strains, including 40 red yeasts, from benthic animals
and sediments collected from the deep-sea floor in various areas in the no
rthwest Pacific Ocean. Comparing the yeast isolates from animals and sedime
nts collected from shallow locations, the proportion of red yeasts differed
considerably, comprising 81.5% and 10.6% of the isolates from animals and
sediments, respectively. All of the red yeast isolates belonged to the gene
ra Rhodotorula and Sporobolomyces. On the basis of morphological and physio
logical characteristics, the isolates were identified as R. aurantiaca, R.
glutinis, R. minuta and R. mucilaginosa of the genus Rhodotorula, and S. sa
lmonicolor and S. shibatanus of the genus Sporobolomyces. Only R. glutinis
and R. mucilaginosa were isolated from sediments. All of the others were is
olated from animal sources. Phylogenetic analyses based on internal transcr
ibed spacer (ITS) regions and 5.8S rRNA gene sequences allowed us to establ
ish the precise taxonomic placement of each of the isolates and thereby inv
estigate the intraspecific relationships among the isolates. Twenty-two str
ains identified as members of R. glutinis, which showed a wide distribution
in the deep-sea, and five isolates identified as R. minuta, which were iso
lated only from benthic animals, showed substantial heterogeneity within th
e species. The isolates phenotypically identified as Sporobolomyces species
and R. mucilaginosa phylogenetically occupied the placements corresponding
to these species. Some strains assigned to known species on the basis of p
henotypic features should be regarded as new species as suggested by the re
sults of molecular analysis.