Taxonomic studies of the Penicillium glabrum complex and the description of a new species P. subericola

Abstract

A mycological survey of fungi, present in several stages of the manufacturing of cork discs for champagne stoppers in Portugal, was made. Sixty-nine strains belonging to the Glabra series of the genus Penicillium were isolated and subsequently grouped according to their partial β-tubulin gene sequences. Six groups with different partial β-tubulin gene sequences were observed, and a selection of isolates of each group was made. These selected isolates and various related ex-type strains were subjected to a taxonomical study using a polyphasic approach. This approach included analysis of macro-and microscopic features, the comparison of extrolite profiles and sequencing a part of the β-tubulin and calmodulin gene. The six β-tubulin types were reduced to three different species. One group of isolates was centred on the ex-type strain of P. glabrum, a second group accommodated the type strain of P. spinulosum and a third group contained isolates which were unique in their β-tubulin and calmodulin sequences, extrolite profiles and growth characteristics. This group of isolates is described as the new species Penicillium subericola. The type strain of P. subericola CBS 125096 T was isolated from Portuguese raw cork, but additional isolates were found from soil, air and lumen.

Blue mould decay of stored onion bulbs caused by Penicillium polonicum, P. glabrum and P. expansum

“…Nucleotide sequences 1 and 2 in Serbian onion isolates correspond with types 1 and 2 described by Barreto et al. (), while ntseq 3 was unique. Houbraken et al.…”

“…(), and the variability in colony morphology of isolates was seen in cork isolates of P. glabrum as demonstrated by Barreto et al. ().…”

“…Barreto et al. () showed high intraspecific variability of cork isolates of P. glabrum in micro‐ and macromorphology and extrolite profiles which was supported by partial β‐tubulin and calmodulin sequence analyses. Similarly, in this research, variability of P. glabrum isolates was observed in their molecular, macromorphological and pathogenic features and these features were correlated.…”

“…Barreto et al. () observed four different types of β‐tubulin sequences within cork isolates of P. glabrum . Also, they noted that BLAST searches on the NCBI database and local databases of the CBS‐Fungal Biodiversity Centre displayed that many more sequence types are present in P. glabrum .…”

Unveiling the fungal mycobiota present throughout the cork stopper manufacturing process

“…Knowledge of the mycobiota that colonizes cork during all the stages of the manufacturing process of cork discs (stoppers) allowed us to locate the phases in which the colonization shifts occur, making it possible to eliminate fungal isolates that could endanger cork. In fact, previous studies (Barreto et al ., ,c) showed that the most common fungal species isolated in post‐boiling cork did not produce any chemical compound that could spoil the final product.…”