Penicillium excelsum sp. nov from the Brazil Nut Tree Ecosystem in the Amazon Basin'

Two new species of Penicillium (Eurotiales, Aspergillaceae) from China based on morphological and molecular analyses

Penicillium is a large and significant genus of fungi, exhibiting widespread distribution across diverse substrates. Ongoing taxonomic and nomenclatural revisions have led to an annual increase in the number of newly described species. This study described two new Penicillium species, i.e., P.lentum and P.tibetense, discovered in China. They have been identified and characterized through morphological examination and both single gene and multigene phylogenetic analyses. Based on these analyses, P.lentum was classified within the section Brevicompacta, while P.tibetense was placed in the section Lanata-Divaricata. Both species exhibited the morphological features typical of their respective sections. Penicilliumlentum is characterized by restricted growth with dense colonies on agar media and predominantly generates terverticillate conidiophores. Penicilliumtibetense demonstrates rapid growth on media and has vigorous growth on CYA at 30 °C, producing biverticillate conidiophores. Comprehensive descriptions and detailed illustrations of these new species were presented. A morphological comparison between the new species and their closely related taxa was provided.

Anti-Insect Properties of Penicillium Secondary Metabolites

In connection with their widespread occurrence in diverse environments and ecosystems, fungi in the genus Penicillium are commonly found in association with insects. In addition to some cases possibly implying a mutualistic relationship, this symbiotic interaction has mainly been investigated to verify the entomopathogenic potential in light of its possible exploitation in ecofriendly strategies for pest control. This perspective relies on the assumption that entomopathogenicity is often mediated by fungal products and that Penicillium species are renowned producers of bioactive secondary metabolites. Indeed, a remarkable number of new compounds have been identified and characterized from these fungi in past decades, the properties and possible applications of which in insect pest management are reviewed in this paper.

Xanthoepocin, a photolabile antibiotic of Penicillium ochrochloron CBS 123823 with high activity against multiresistant gram-positive bacteria

Background

With the steady increase of antibiotic resistance, several strategies have been proposed in the scientific community to overcome the crisis. One of many successful strategies is the re-evaluation of known compounds, which have been early discarded out of the pipeline, with state-of-the-art know-how. Xanthoepocin, a polyketide widespread among the genus Penicillium with an interesting bioactivity spectrum against gram-positive bacteria, is such a discarded antibiotic. The purpose of this work was to (i) isolate larger quantities of this metabolite and chemically re-evaluate it with modern technology, (ii) to explore which factors lead to xanthoepocin biosynthesis in P. ochrochloron, and (iii) to test if it is beside its known activity against methicillin-resistant Staphylococcus aureus (MRSA), also active against linezolid and vancomycin-resistant Enterococcus faecium (LVRE)—a very problematic resistant bacterium which is currently on the rise.

Results

In this work, we developed several new protocols to isolate, extract, and quantify xanthoepocin out of bioreactor batch and petri dish-grown mycelium of P. ochrochloron. The (photo)chemical re-evaluation with state-of-the-art techniques revealed that xanthoepocin is a photolabile molecule, which produces singlet oxygen under blue light irradiation. The intracellular xanthoepocin content, which was highest under ammonium-limited conditions, varied considerably with the applied irradiation conditions in petri dish and bioreactor batch cultures. Using light-protecting measures, we achieved MIC values against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), which were up to 5 times lower than previously published. In addition, xanthoepocin was highly active against a clinical isolate of linezolid and vancomycin-resistant Enterococcus faecium (LVRE).

Conclusions

This interdisciplinary work underlines that the re-evaluation of known compounds with state-of-the-art techniques is an important strategy in the combat against multiresistant bacteria and that light is a crucial factor on many levels that needs to receive more attention. With appropriate light protecting measures in the susceptibility tests, xanthoepocin proved to be a powerful antibiotic against MRSA and LVRE. Exploring the light response of other polyketides may be pivotal for re-introducing previously discarded metabolites into the antibiotic pipeline and to identify photosensitizers which might be used for (antimicrobial) photodynamic therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01718-9.

Seven New Records of Penicillium Species Belonging to Section Lanata-Divaricata in Korea

Penicillium species are known to be ubiquitous environmental saprophytes. In the survey of diversity of genus Penicillium, seven new records of Penicillium species belonging to section Lanata-Divaricata were isolated from freshwater and soil samples collected from different locations in Korea. Based on morphological characteristics and multilocus phylogenetic analysis of the rDNA internal transcribed spacer region (ITS), β-tubulin (BenA), and calmodulin (CaM) genes, the isolated strains were identified as P. annulatum, P. camponotum, P. echinulonalgiovense, P. globosum, P. limosum, P. onobense, and P. yunnanense, respectively. This study presents detailed phylogenetic analyses and morphological descriptions of these species that contribute to section Lanata-Divaricata in Korea.

Penicillium rotoruae, a new Species from an In-Ground Timber Durability Test Site in New Zealand

A Penicillium species isolated during a 1960s study on the ecology of fungi infecting Pinus radiata timber, and subsequently held in an in-house collection in Rotorua, New Zealand, was found to differ morphologically and in growth rate from two closely related Penicillium species. Phylogenetic analysis of the rDNA internal transcribed spacer (ITS), β-tubulin, calmodulin and RNA polymerase II second largest subunit regions (RPB2) confirmed this to be a new species closely related to Penicillium ochrochloron in the Rolfsiorum series of the Lanata-Divaricata section and Aspergilloides sub-genus. Micromorphologically, the new species is characterised by predominantly monoverticilliate and occasional divaricate or biverticilliate conidiophores and smooth-walled subglobose to slightly ovoid conidia with absence of conidiogenesis at 25 °C. This new species is described here as Penicillium rotoruae sp. nov. which has potential applications in biofuel and biorefining industry.

Classification of Aspergillus, Penicillium, Talaromyces and related genera (Eurotiales): An overview of families, genera, subgenera, sections, series and species

The Eurotiales is a relatively large order of Ascomycetes with members frequently having positive and negative impact on human activities. Species within this order gain attention from various research fields such as food, indoor and medical mycology and biotechnology. In this article we give an overview of families and genera present in the Eurotiales and introduce an updated subgeneric, sectional and series classification for Aspergillus and Penicillium. Finally, a comprehensive list of accepted species in the Eurotiales is given. The classification of the Eurotiales at family and genus level is traditionally based on phenotypic characters, and this classification has since been challenged using sequence-based approaches. Here, we re-evaluated the relationships between families and genera of the Eurotiales using a nine-gene sequence dataset. Based on this analysis, the new family Penicillaginaceae is introduced and four known families are accepted: Aspergillaceae, Elaphomycetaceae, Thermoascaceae and Trichocomaceae. The Eurotiales includes 28 genera: 15 genera are accommodated in the Aspergillaceae (Aspergillago, Aspergillus, Evansstolkia, Hamigera, Leiothecium, Monascus, Penicilliopsis, Penicillium, Phialomyces, Pseudohamigera, Pseudopenicillium, Sclerocleista, Warcupiella, Xerochrysium and Xeromyces), eight in the Trichocomaceae (Acidotalaromyces, Ascospirella, Dendrosphaera, Rasamsonia, Sagenomella, Talaromyces, Thermomyces, Trichocoma), two in the Thermoascaceae (Paecilomyces, Thermoascus) and one in the Penicillaginaceae (Penicillago). The classification of the Elaphomycetaceae was not part of this study, but according to literature two genera are present in this family (Elaphomyces and Pseudotulostoma). The use of an infrageneric classification system has a long tradition in Aspergillus and Penicillium. Most recent taxonomic studies focused on the sectional level, resulting in a well-established sectional classification in these genera. In contrast, a series classification in Aspergillus and Penicillium is often outdated or lacking, but is still relevant, e.g., the allocation of a species to a series can be highly predictive in what functional characters the species might have and might be useful when using a phenotype-based identification. The majority of the series in Aspergillus and Penicillium are invalidly described and here we introduce a new series classification. Using a phylogenetic approach, often supported by phenotypic, physiologic and/or extrolite data, Aspergillus is subdivided in six subgenera, 27 sections (five new) and 75 series (73 new, one new combination), and Penicillium in two subgenera, 32 sections (seven new) and 89 series (57 new, six new combinations). Correct identification of species belonging to the Eurotiales is difficult, but crucial, as the species name is the linking pin to information. Lists of accepted species are a helpful aid for researchers to obtain a correct identification using the current taxonomic schemes. In the most recent list from 2014, 339 Aspergillus, 354 Penicillium and 88 Talaromyces species were accepted. These numbers increased significantly, and the current list includes 446 Aspergillus (32 % increase), 483 Penicillium (36 % increase) and 171 Talaromyces (94 % increase) species, showing the large diversity and high interest in these genera. We expanded this list with all genera and species belonging to the Eurotiales (except those belonging to Elaphomycetaceae). The list includes 1 187 species, distributed over 27 genera, and contains MycoBank numbers, collection numbers of type and ex-type cultures, subgenus, section and series classification data, information on the mode of reproduction, and GenBank accession numbers of ITS, beta-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) gene sequences.

Towards a better understanding of the role of nectar-inhabiting yeasts in plant-animal interactions

Flowers offer a wide variety of substrates suitable for fungal growth. However, the mycological study of flowers has only recently begun to be systematically addressed from an ecological point of view. Most research on the topic carried out during the last decade has focused on studying the prevalence and diversity of flower-inhabiting yeasts, describing new species retrieved from floral parts and animal pollinators, and the use of select nectar yeasts as model systems to test ecological hypotheses. In this primer article, we summarize the current state of the art in floral nectar mycology and provide an overview of some research areas that, in our view, still require further attention, such as the influence of fungal volatile organic compounds on the foraging behavior of pollinators and other floral visitors, the analysis of the direct and indirect effects of nectar-inhabiting fungi on the fitness of plants and animals, and the nature and consequences of fungal-bacterial interactions taking place within flowers.

Chemotaxonomic profiling of Penicillium setosum using high-resolution mass spectrometry (LC-Q-ToF-MS)

In the present study, secondary metabolites produced by an endophytic fungus Penicillium setosum were extracted using colony agar plug and culture broth extraction methods. High resolution LC-MS was used to explore the chemical nature of the secondary metabolites, as well, compare the reliability of the methods. P. setosum was chemotaxonomically distinguished from other members of section Lanata-divaricata, by its ability to produce mycotoxin, patulin and also by the presence of certain phenol-derived compounds, like quercetin, dihydroflavonols (dihydroquercetin and dihydromyricetin), kaempferol, luteolin, while some Penicillium specific compounds such as, citromycetin and andrastin D reveal its similarity towards section Lanata-Divaricata members. For the first time, the presence of dihydroquercetin is remarkably and spectrometrically confirmed from a microbial source. In addition, a few polyketides, anthroquinone compounds, hydrocarbons, and fatty acids were also detected in the culture extract. Being the first report on the production of polyphenolic compounds by an endophytic fungus of Penicillium species, the current research is crucial, and moreover the starin itself is a novel species.

Penicillium section Lanata-divaricata from acidic soil

Penicillium species in section Lanata-divaricata are common soil-inhabiting fungi, but their presence in acidic soil has rarely been investigated. In an ongoing survey of Penicillium species occurring in China, 465 strains were isolated from soil, and of which 60 belonged to section Lanata-divaricata. The majority of these strains were isolated from acidic soil. The phylogenetic relationship between these 60 isolates and accepted species of section Lanata-divaricata was studied using ITS, BenA, CaM and RPB2 sequences, which revealed the presence of seven accepted species and 13 novel lineages. Combining phylogenetic data with data generated during macro- and microscopic observations resulted in the description of 13 new species. The growth rate of the new species obtained in this study was determined under acidic, neutral and alkaline conditions (pH 4, 7, 10). With the exception of P. hainanense, which was not able to grow at pH 10, all strains were able to grow at the three examined pH levels. Eleven species (i.e. P. austrosinense, P. flaviroseum, P. globosum, P. griseoflavum, P. hainanense, P. jianfenglingense, P. laevigatum, P. rubriannulatum, P. soliforme, P. spinuliferum, P. yunnanense) grew faster at low pH (pH 4) than at pH 7 or 10, and these species are therefore referred to as acid-preferential. Penicillium viridissimum grew fastest on neutral medium and P. guangxiense grew best at pH 10, and is therefore considered to be acid-tolerant. By isolating strains from a unique environment, combined with targeted isolation using a well-designed protocol, we are able to describe new fungal diversity with specific physiological characteristics.

New Records of Four Species Belonging to Eurotiales from Soil and Freshwater in Korea

Four strains of Penicillium and Talaromyces species are described and illustrated in an inventory of fungal species belonging to Eurotiales. The strains, CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31, were isolated from soil and freshwater samples from South Korea. Based on their morphological characteristics and sequence analyses by the combined β-tubulin and calmodulin gene, the CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31 isolates were identified as Penicillium pasqualense, Penicillium sanguifluum, Talaromyces apiculatus, and Talaromyces liani, respectively. The designated strains were found to represent a previously undescribed species of Korean fungal biota. In this study, detailed morphological descriptions and phylogenetic relationships of these species are provided.

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.

Phylogeny and morphological analyses of Penicillium section Sclerotiora (Fungi) lead to the discovery of five new species

Phylogeny of Penicillium section Sclerotiora is still limitedly investigated. In this study, five new species of Penicillium are identified from the samples collected from different places of China, and named P. austrosinicum, P. choerospondiatis, P. exsudans, P. sanshaense and P. verrucisporum. The conidiophores of P. austrosinicum and P. exsudans are monoverticillate like most members of the section, while the rest species are biverticillate similar to the only two species P. herquei and P. malachiteum previously reported in the section Sclerotiora. The phylogenetic positions of the new taxa are determined based on the sequence data of ITS, BenA, CaM and RPB2 regions, which reveals that all the species with biverticillate condiophores form a well-supported subclade in the section. The new Penicillium species clearly differ from the existing species of the genus in culture characteristics on four standard growth media, microscopic features, and sequence data. Morphological discrepancies are discussed between the new species and their allies.

Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311^T = IBT 12289^T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted in the identification of 62 putative biosynthetic gene clusters. Extracts of P. arizonense were analysed for secondary metabolites and austalides, pyripyropenes, tryptoquivalines, fumagillin, pseurotin A, curvulinic acid and xanthoepocin were detected. A comparative analysis against known pathways enabled the proposal of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential industrial applications for the new species P. arizonense. The description and availability of the genome sequence of P. arizonense, further provides the basis for biotechnological exploitation of this species.

Biodiversity of mycobiota throughout the Brazil nut supply chain: From rainforest to consumer

A total of 172 Brazil nut samples (114 in shell and 58 shelled) from the Amazon rainforest region and São Paulo state, Brazil was collected at different stages of the Brazil nut production chain: rainforest, street markets, processing plants and supermarkets. The mycobiota of the Brazil nut samples were evaluated and also compared in relation to water activity. A huge diversity of Aspergillus and Penicillium species were found, besides Eurotium spp., Zygomycetes and dematiaceous fungi. A polyphasic approach using morphological and physiological characteristics, as well as molecular and extrolite profiles, were studied to distinguish species among the more important toxigenic ones in Aspergillus section Flavi and A. section Nigri. Several metabolites and toxins were found in these two sections. Ochratoxin A (OTA) was found in 3% of A. niger and 100% of A. carbonarius. Production of aflatoxins B and G were found in all isolates of A. arachidicola, A. bombycis, A. nomius, A. pseudocaelatus and A. pseudonomius, while aflatoxin B was found in 38% of A. flavus and all isolates of A. pseudotamarii. Cyclopiazonic acid (CPA) was found in A. bertholletius (94%), A. tamarii (100%), A. caelatus (54%) and A. flavus (41%). Tenuazonic acid, a toxin commonly found in Alternaria species was produced by A. bertholletius (47%), A. caelatus (77%), A. nomius (55%), A. pseudonomius (75%), A. arachidicola (50%) and A. bombycis (100%). This work shows the changes of Brazil nut mycobiota and the potential of mycotoxin production from rainforest to consumer, considering the different environments which exist until the nuts are consumed.

Penicillium pedernalense sp. nov., isolated from whiteleg shrimp heads waste compost

Novel Penicillium-like strains were isolated during the characterization of the mycobiota community dynamics associated with shrimp waste composting. Phylogenetic analysis of the partial β-tubulin (BenA) gene and the ribosomal DNA internal transcribed spacer region (ITS1-5.8S-ITS2) sequences revealed that the novel strains were members of section Lanata-Divaricata and were closely related to Penicillium infrabuccalum DAOMC 250537T. On the basis of morphological and physiological characterization, and phylogenetic analysis, a novel Penicillium species, Penicillium pedernalense sp. nov., is proposed. The type strain is F01-11T (=CBS 140770T=CECT 20949T), which was isolated from whiteleg shrimp (Litopenaeus vannamei) heads waste compost in the Pedernales region (Manabí province, Ecuador).