261 research outputs found
A taxonomic and phylogenetic revision of Penicillium section Aspergilloides
AbstractSpecies belonging to Penicillium section Aspergilloides have a world-wide distribution with P. glabrum, P. spinulosum and P. thomii the most well-known species of this section. These species occur commonly and can be isolated from many substrates including soil, food, bark and indoor environments. The taxonomy of these species has been investigated several times using various techniques, but species delimitation remains difficult. In the present study, 349 strains belonging to section Aspergilloides were subjected to multilocus molecular phylogenetic analyses using partial ÎČ-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) sequences. Section Aspergilloides is subdivided into 12 clades and 51 species. Twenty-five species are described here as new and P. yezoense, a species originally described without a Latin diagnosis, is validated. Species belonging to section Aspergilloides are phenotypically similar and most have monoverticillate conidiophores and grow moderately or quickly on agar media. The most important characters to distinguish these species were colony sizes on agar media, growth at 30 °C, ornamentation and shape of conidia, sclerotium production and stipe roughness
Ascomycetous yeast species recovered from grapes damaged by honeydew and sour rot
Aims: To identify ascomycetous yeasts recovered from sound and damaged
grapes by the presence of honeydew or sour rot.
Methods and Results: In sound grapes, the mean yeast counts ranged from
3.20 ± 1.04 log CFU g-1 to 5.87 ± 0.64 log CFU g-1. In honeydew grapes, the
mean counts ranged from 3.88 ± 0.80 log CFU g-1 to 6.64 ± 0.77 log CFU g-1.
In sour rot grapes counts varied between 6.34 ± 1.03 and 7.68 ± 0.38 log
CFU g-1. Hanseniaspora uvarum was the most frequent species from sound
samples. In both types of damage, the most frequent species were Candida vanderwaltii,
H. uvarum and Zygoascus hellenicus. The latter species was recovered
in high frequency because of the utilization of the selective medium DBDM
(Dekkera â Brettanomyces differential medium). The scarce isolation frequency of
the wine spoilage species Zygosaccharomyces bailii (in sour rotten grapes) and
Zygosaccharomyces bisporus (in honeydew affected grapes) could only be
demonstrated by the use of the selective medium ZDM (Zygosaccharomyces
differential medium).
Conclusions: The isolation of several species only from damaged grapes indicates
that damage constituted the main factor determining yeast diversity. The
utilization of selective media is required for eliciting the recovery of potentially
wine spoilage species.
Significance and Impact of the Study: The impact of damaged grapes in the yeast ecology of grapes has been underestimate
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