Diversity and Toxigenicity of Fungi that Cause Pineapple Fruitlet Core Rot

The identity of the fungi responsible for fruitlet core rot (FCR) disease in pineapple has been the subject of investigation for some time. This study describes the diversity and toxigenic potential of fungal species causing FCR in La Reunion, an island in the Indian Ocean. One-hundred-and-fifty fungal isolates were obtained from infected and healthy fruitlets on Reunion Island and exclusively correspond to two genera of fungi: Fusarium and Talaromyces. The genus Fusarium made up 79% of the isolates, including 108 F. ananatum, 10 F. oxysporum, and one F. proliferatum. The genus Talaromyces accounted for 21% of the isolated fungi, which were all Talaromyces stollii. As the isolated fungal strains are potentially mycotoxigenic, identification and quantification of mycotoxins were carried out on naturally or artificially infected diseased fruits and under in vitro cultures of potential toxigenic isolates. Fumonisins B₁ and B₂ (FB₁-FB₂) and beauvericin (BEA) were found in infected fruitlets of pineapple and in the culture media of Fusarium species. Regarding the induction of mycotoxin in vitro, F.proliferatum produced 182 mg kg⁻¹ of FB₁ and F. oxysporum produced 192 mg kg⁻¹ of BEA. These results provide a better understanding of the causal agents of FCR and their potential risk to pineapple consumers.

New Penicillium and Talaromyces species from honey, pollen and nests of stingless bees

Penicillium and Talaromyces species have a worldwide distribution and are isolated from various materials and hosts, including insects and their substrates. The aim of this study was to characterize the Penicillium and Talaromyces species obtained during a survey of honey, pollen and the inside of nests of Melipona scutellaris. A total of 100 isolates were obtained during the survey and 82% of those strains belonged to Penicillium and 18% to Talaromyces. Identification of these isolates was performed based on phenotypic characters and β-tubulin and ITS sequencing. Twenty-one species were identified in Penicillium and six in Talaromyces, including seven new species. These new species were studied in detail using a polyphasic approach combining phenotypic, molecular and extrolite data. The four new Penicillium species belong to sections Sclerotiora (Penicillium fernandesiae sp. nov., Penicillium mellis sp. nov., Penicillium meliponae sp. nov.) and Gracilenta (Penicillium apimei sp. nov.) and the three new Talaromyces species to sections Helici (Talaromyces pigmentosus sp. nov.), Talaromyces (Talaromyces mycothecae sp. nov.) and Trachyspermi (Talaromyces brasiliensis sp. nov.). The invalidly described species Penicillium echinulonalgiovense sp. nov. was also isolated during the survey and this species is validated here.

Talarofuranone, a New Talaroconvolutin Analog from the Endophytic Fungus Talaromyces purpurogenus from Pouteria campechiana Seeds

An endophytic fungus Talaronyces pinpurogenus was isolated from the seeds of the popular edible fruit Pouteria campechiana. The fungus was fermented in potato dextrose agar and the fungal media were extracted with EtOAc. Chromatographic separation of the EtOAc extracts over silica gel, Sephadex LH-20 and preparative thin layer chromatography furnished a furanone analogue of talaroconvolutin A, named talarofuranone (1), along with talaroconvolutin A (2), 4-hydroxyactophenone, tyrosol and ergosterol. The structure of 1 was determined by comparing the NMR data with that of 2 and by HRFABMS.

Two novel Talaromyces species isolated from medicinal crops in Korea

Two novel biverticillate Talaromyces species, T. angelicus and T. cnidii, were collected from the medicinal crops Angelica gigas and Cnidium officinale, respectively, in Korea. Phylogenetic analyses with the nuclear ribosomal internal transcribed spacer (ITS) region and the β-tubulin gene as well as morphological analyses revealed that the two species differ from any known Talaromyces species. Talaromyces angelicus is related to T. flavovirens in the phylogeny of the ITS region, but the new species is grouped together with Penicillium liani and T. pinophilus in terms of its β-tubulin phylogeny, and its growth rate on Czapek yeast autolysate differs from that of T. flavovirens. Talaromyces cnidii is phylogenetically similar to T. siamensis, but exhibits differences in the morphologies of the colony margin, metulae, and conidia.

Phylogenetic analyses of penicillia based on partial calmodulin gene sequences

Partial sequences (about 600 nucleotides) of the calmodulin gene were used for the phylogenetic studies on Eupenicillium, Talaromyces and Penicillium. This region is from the 3rd base of the codon for the 9th amino acid Gln to the 3rd base of the codon for the 122th amino acid Val, flanking parts of the 2nd and 5th exons with complete sequences of two exons and three introns. Seventy-six isolates of 56 taxa of penicillia were involved. The nucleotide sequences with and without introns were analyzed respectively using the neighbor-joining (NJ) and maximum parsimony (MP) methods. The cluster analysis on relative synonymous codon usage (RSCU) of each sequence was also carried out. The fact that species of penicillia belong to the two subfamilies of the Trichocomaceae proposed by Malloch based on traditional methods is supported by our molecular data, whereas, the development of asci and patterns of penicilli show little phylogenetic information. Nine groups in the lineage of Eupenicillium and two in that of Talaromyces were recognized in our studies. In addition to the teleomorph-holomorph-anamorph evolutionary model of penicillia suggested by LoBuglio et al., and Pitt, we proposed that a mutation bias of holomorphs/anamorphs with or without selection is another evolutionary path of these organisms.