Cobus M. Visagie

Delimitation and characterisation of Talaromyces purpurogenus and related species.

Taxa of the Talaromyces purpurogenus complex were studied using a polyphasic approach. ITS barcodes were used to show relationships between species of the T. purpurogenus complex and other Talaromyces species. RPB1, RPB2, β-tubulin and calmodulin sequences were used to delimit phylogenetic species in the complex. These data, combined with phenotypic characters, showed that the complex contains four species: T. purpurogenus, T. ruber comb. nov. and two new species T. amestolkiae sp. nov. and T. stollii sp. nov. The latter three species belong to the same clade and T. purpurogenus is located in a phylogenetic distant clade. The four species all share similar conidiophore morphologies, but can be distinguished by macromorphological characters. Talaromyces ruber has a very distinct colony texture on malt extract agar (MEA), produces bright yellow and red mycelium on yeast extract sucrose agar (YES) and does not produce acid on creatine sucrose agar (CREA). In contrast, T. amestolkiae and T. stollii produce acid on CREA. These two species can be differentiated by the slower growth rate of T. amestolkiae on CYA incubated at 36 °C. Furthermore, T. stollii produces soft synnemata-like structures in the centre of colonies on most media. Extrolite analysis confirms the distinction of four species in the T. purpurogenus complex. The red diffusing pigment in T. purpurogenus is a mixture of the azaphilone extrolites also found in Monascus species, including N-glutarylrubropunctamine and rubropunctatin. Talaromyces purpurogenus produced four different kinds of mycotoxins: rubratoxins, luteoskyrin, spiculisporic acid and rugulovasins and these mycotoxins were not detected in the other three species.

A new species of Penicillium, P. ramulosum sp. nov., from the natural environment

During a recent survey of Penicillium spp. from fynbos soils in the Western Cape Province of South Africa, several undescribed species were isolated. Similar isolates of one of these species also were collected in the Western Cape from Protea infructescences. These strains were compared morphologically to known species of Penicillium but could not be identified with previously published keys. Morphologically these strains belong to subgenus Biverticillium. They are distinguished by strongly funiculose colonies covered by glutinous exudates and conidiophores with thin acerose phialides (8.5–10[−12] × 2.0–2.5 μm) that give rise to chains of subspheroidal to ellipsoidal conidia (2.5–3.0 × 1.5–2.5 μm). Characteristically short (100–150[−250] μm) determinate synnemata are produced in culture after prolonged incubation with much longer synnemata produced in nature. Based on differences in morphology and molecular characters, the strains are described here as Penicillium ramulosum sp. nov.

Taxonomic re-evaluation of species in Talaromyces section Islandici, using a polyphasic approach

The taxonomy of Talaromyces rugulosus, T. wortmannii and closely related species, classified in Talaromyces sect. Islandici, is reviewed in this paper. The species of Talaromyces sect. Islandici have restricted growth on MEA and CYA, generally have yellow mycelia and produce rugulosin and/or skyrin. They are important in biotechnology (e.g. T. rugulosus, T. wortmannii) and in medicine (e.g. T. piceus, T. radicus). The taxonomy of sect. Islandici was resolved using a combination of morphological, extrolite and phylogenetic data, using the Genealogical Concordance Phylogenetic Species Recognition (GCPSR) concept, with special focus on the T. rugulosus and T. wortmannii species complexes. In this paper, we synonymise T. variabilis, Penicillium concavorugulosum and T. sublevisporus with T. wortmannii, and introduce four new species as T. acaricola, T. crassus, T. infraolivaceus and T. subaurantiacus. Finally, we provide a synoptic table for the identification of the 19 species classified in the section.

Three new additions to the genus Talaromyces isolated from Atlantis sandveld fynbos soils

During a survey of Penicillium spp. in soils from the diverse fynbos region in the Western Cape, South Africa, a number of previously undescribed species were isolated. Three of these belong to subg. Biverticillium sensu Pitt, recently incorporated into its previously associated teleomorph genus, Talaromyces s.str. These species displayed symmetrical biverticillate penicilli, acerose phialides and poor growth at reduced water activity, typical of this group. Morphological characters of the new species were compared to known Talaromyces species. The ITS and β-tubulin gene regions were used for phylogenetic comparisons, which confirmed the distinct nature of the three fynbos soil species described here as Talaromyces chloroloma sp. nov., T. ptychoconidium sp. nov. and T. solicola sp. nov., respectively. Talaromyces chloroloma is typically recognised by its strongly funiculose colony texture and after prolonged incubation, synnemata can be observed on CYA. Talaromyces ptychoconidium is characterised by closely appressed conidiophores that produce spirally rough-walled conidia, while T. solicola typically struggle to grow on CYA and is distinguished from similar species by its prominently rough-walled, spheroid conidia.

Penicillium species associated with preharvest wet core rot in south africa and their pathogenicity on apple

Symptoms associated with the core region of apple fruits (Malus domestica) can be classified as moldy core (MC), wet core rot (WCR), and dry core rot (DCR). Infections leading to WCR are thought to occur primarily postharvest, although in South Africa preharvest symptoms also have been reported. The first aim of this study was to investigate the causative agent(s) of preharvest WCR by isolating fungi from eight internal positions in asymptomatic, MC, WCR, and DCR fruits. Secondly, the pathogenicity and virulence of all Penicillium isolates were investigated using three apple fruit inoculation methods: surface wounding, deep wounding, and nonwounding. Isolation of fungi from WCR fruits showed that Penicillium was the predominant fungal genus from most isolation positions including the lesion area. Penicillium ramulosum was the predominant species isolated from all fruits. However, in WCR fruits, the incidence (58%) of P. ramulosum was much higher than in MC (6%), DCR (7%), or asymptomatic (7%) fruits. Less frequently isolated Penicillium species included P. expansum and a few other species. Pathogenicity testing using the nonwounding method was best at discriminating highly virulent isolates. P. expansum was the most virulent species, followed by a putative new Penicillium species with closest sequence similarity to P. dendriticum. P. ramulosum isolates, although showing varying degrees of virulence, all had low virulence, causing only small lesions in wounded apple fruits.

Phylogenetic relationships and the newly discovered sexual state of Talaromyces flavovirens , comb. nov.

Typical Talaromyces ascomata were observed on dry Quercus suber leaf litter amongst the characteristic synnemata of Penicillium aureocephalum, and they appear to represent the sexual state of the latter species. The species is a synonym of the older Lasioderma flavovirens, and we propose the new combination Talaromyces flavovirens. Lectotype and epitype specimens are designated for this name. The defining characters of the asexual state include yellow, short-stalked, mycetozoan-like synnemata with an unusual, almost closed terminal head of penicillate conidiophores intermixed with sinuous hyphae, and dark green conidia. Ascomata could not be induced in culture, but PCR amplifications of mating-type genes indicate the species is heterothallic. In nature, ascocarp initials appear to be antheridia coiled around clavate ascogonia, similar to those of T. flavus, and the thick-walled, spiny ascospores are also similar to those of T. flavus. ITS barcodes and β-tubulin sequences place T. flavovirens in a clade with T. apiculatus, T. flavus, T. funiculosus, T. galapagensis, T. pinophilus, T. macrosporus, and seven other species.

Diversity of Penicillium section Citrina within the fynbos biome of South Africa, including a new species from a Protea repens infructescence.

During a survey of the fynbos biome in the Western Cape of South Africa, 61 Penicillium species were isolated and nine belong to Penicillium section Citrina. Based on morphology and multigene phylogenies, section Citrina species were identified as P. cairnsense, P. citrinum, P. pancosmium, P. pasqualense, P. sanguifluum, P. sizovae, P. sumatrense and P. ubiquetum. One of the species displayed unique phenotypic characters and DNA sequences and is described here as P. sucrivorum. Multigene phylogenies consistently resolved the new species in a clade with P. aurantiacobrunneum, P. cairnsense, P. miczynksii, P. neomiczynskii and P. quebecense. However, ITS, β-tubulin and calmodulin gene sequences are unique for P. sucrivorum and growth rates on various media, the ability to grow at 30 C, a positive Ehrlich reaction and the absence of sclerotia on all media examined, distinguish P. sucrivorum from all of its close relatives.

A taxonomic review of Penicillium species producing conidiophores with solitary phialides, classified in section Torulomyces

The genus Torulomyces was characterised by species that typically have conidiophores consisting of solitary phialides that produce long chains of conidia connected by disjunctors. Based on the phylogenetic position of P. lagena (generic ex-neotype), the genus and its seven species were transferred to Penicillium and classified in sect. Torulomyces along with P. cryptum and P. lassenii. The aim of this study was to review the species currently classified in sect. Torulomyces using morphology and phylogenies of the ITS, BenA, CaM and RPB2 regions. Based on our results, we accept 16 species in sect. Torulomyces, including 12 new species described as P. aeris, P. austricola, P. cantabricum, P. catalonicum, P. oregonense, P. marthae-christenseniae, P. riverlandense, P. tubakianum, P. variratense, P. williamettense, P. wisconsinense and P. wollemiicola. In addition, we reclassify P. laeve and P. ovatum in sect. Exilicaulis and correct the typification of P. lagena. We provide descriptions and notes on the identification of the species.