Multilocus sequence identification of Penicillium species in cork bark during plank preparation for the manufacture of stoppers

Abstract

Despite several studies reporting Penicillium as one of the most frequent fungal genera in cork planks, the isolates were rarely identified to species level. We conducted a detailed study to identify Penicillium species from the field to the factory environment prior to and after boiling the cork planks. A total of 84 samples were analyzed. Of the 486 Penicillium isolates phenotypically identified, 32 representative or unusual strains were selected for identification by multilocus DNA sequence type. Cork proved to be a rich source of Penicillium biodiversity. A total of 30 taxa were recognized from cork including rarely seen species and 6 phylogenetically unique groups. Spores of some species lodged deep in cork can survive the boiling process. P. glabrum, P. glandicola and P. toxicarium, species with high CFU numbers in the field, are still frequently present in cork after boiling. Other species are killed by the boiling treatment and replaced by Penicillium species originating from the factory environment. Species known to contribute to cork taint were isolated at all stages. Good manufacturing practices are necessary at all stages in the preparation of cork planks to minimize the load of Penicillium species that produce cork taint.

Investigating Aspergillus nidulans secretome during colonisation of cork cell walls

“…Similar observations were attained in the wood control (data not shown). A comparable hyphal colonisation profile on cork has been reported before in Ascomycota [14], even though in some cases hyphae perforating the cork cell walls have been detected [13]. The heterothallic Penicillium spp.…”

“…The heterothallic Penicillium spp. has also formed conidia during the colonisation of cork [14]. In the present study, it remains unclear if A. nidulans sexual spores were produced by the submerged mycelia (rarely observed [33]) or in the floating mycelial mat.…”

Assessment of exposure to the Penicillium glabrum complex in cork industry using complementing methods / Ocjena izloženosti kompleksu Penicillium glabrum u proizvodnji pluta s pomoću komplementarnih metoda

“…This type of industry has already been associated with exposure to several fungal species, most commonly with the Penicillium glabrum complex and Chrysonilia sitophila (5)(6)(7)(8)(9)(10)(11)(12)(13). The presence of the P. glabrum complex in this industry involves the risk of respiratory diseases such as suberosis, a type of hypersensitivity pneumonitis that is one of the most prevalent diseases among cork workers (8)(9)(10)(11)(12)(13)(14)(15).…”

“…The presence of the P. glabrum complex in this industry involves the risk of respiratory diseases such as suberosis, a type of hypersensitivity pneumonitis that is one of the most prevalent diseases among cork workers (8)(9)(10)(11)(12)(13)(14)(15).…”

Screening pentachlorophenol degradation ability by environmental fungal strains belonging to the phyla Ascomycota and Zygomycota

“…The species diversity amongst the cork-colonising fungal communities is largely inXuenced by the origin of the cork, explaining some of the discrepancy found in the strains reported by diVerent authors [1,2,8,11,17,[26][27][28][29]. In this study, the fungal strains used were isolated from cork bark samples, which were collected during plank preparation for the manufacture of stoppers.…”