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During the construction and assembly of the Mars 2020 mission components at two different NASA cleanrooms, several fungal strains were isolated. Based on their colony morphology, two strains that showed yeast-like appearance were further characterized for their phylogenetic position. The species-level classification of these two novel strains, using traditional colony and cell morphology methods combined with the phylogenetic reconstructions using multi-locus sequence analysis (MLSA) based on several gene loci (ITS, LSU, SSU, RPB1, RPB2, CYTB and TEF1), and whole genome sequencing (WGS) was carried out. This polyphasic taxonomic approach supported the conclusion that the two basidiomycetous yeasts belong to hitherto undescribed species. The strain FJI-L2-BK-P3T, isolated from the Jet Propulsion Laboratory Spacecraft Assembly Facility, was placed in the Naganishia albida clade (Filobasidiales, Tremellomycetes), but is genetically and physiologically different from other members of the clade. Another yeast strain FKI-L6-BK-PAB1T, isolated from the Kennedy Space Center Payload Hazardous and Servicing Facility, was placed in the genus Cystobasidium (Cystobasidiales, Cystobasidiomycetes) and is distantly related to C. benthicum. Here we propose two novel species with the type strains, Naganishia kalamii sp. nov. (FJI-L2-BK-P3T = NRRL 64466 = DSM 115730) and Cystobasidium onofrii sp. nov. (FKI-L6-BK-PAB1T = NRRL 64426 = DSM 114625). The phylogenetic analyses revealed that single gene phylogenies (ITS or LSU) were not conclusive, and MLSA and WGS-based phylogenies were more advantageous for species discrimination in the two genera. The genomic analysis predicted proteins associated with dehydration and desiccation stress-response and the presence of genes that are directly related to osmotolerance and psychrotolerance in both novel yeasts described. Cells of these two newly-described yeasts were exposed to UV-C radiation and compared with N. onofrii, an extremophilic UV-C resistant cold-adapted Alpine yeast. Both novel species were UV resistant, emphasizing the need for collecting and characterizing extremotolerant microbes, including yeasts, to improve microbial reduction techniques used in NASA planetary protection programs.

The unambiguous application of fungal names is important to communicate scientific findings. Names are critical for (clinical) diagnostics, legal compliance, and regulatory controls, such as biosafety, food security, quarantine regulations, and industrial applications. Consequently, the stability of the taxonomic system and the traceability of nomenclatural changes is crucial for a broad range of users and taxonomists. The unambiguous application of names is assured by the preservation of nomenclatural history and the physical organisms representing a name. Fungi are extremely diverse in terms of ecology, lifestyle, and methods of study. Predominantly unicellular fungi known as yeasts are usually investigated as living cultures. Methods to characterize yeasts include physiological (growth) tests and experiments to induce a sexual morph; both methods require viable cultures. Thus, the preservation and availability of viable reference cultures are important, and cultures representing reference material are cited in species descriptions. Historical surveys revealed drawbacks and inconsistencies between past practices and modern requirements as stated in the International Code of Nomenclature for Algae, Fungi, and Plants (ICNafp). Improper typification of yeasts is a common problem, resulting in a large number invalid yeast species names. With this opinion letter, we address the problem that culturable microorganisms, notably some fungi and algae, require specific provisions under the ICNafp. We use yeasts as a prominent example of fungi known from cultures. But viable type material is important not only for yeasts, but also for other cultivable Fungi that are characterized by particular morphological structures (a specific type of spores), growth properties, and secondary metabolites. We summarize potential proposals which, in our opinion, will improve the stability of fungal names, in particular by protecting those names for which the reference material can be traced back to the original isolate.

Background: Fungi clinically relevant to human skin comprise prevalent commensals and well‐known pathogens. Only rarely human skin harbours fungi that evade identification. Objective: To characterise an enigmatic specimen isolated from a skin lesion. Methods: A comprehensive clinical and mycological workup including conventional methods for phenotypic characterisation and sequencing based on internal transcribed spacer (ITS) and large subunit (LSU) regions to infer a phylogenetic tree. Results: Cultures on common solid media were macroscopically inconspicuous initially until mycelial tufts developed on the surface, notably on potato dextrose agar. Polymorphous chlamydospores were detected but no aleurospores and ascomata. At 26°C, the isolate grew on standard agars, plant materials and garden soil and utilised peptone, keratins, lipids, inulin, erythrocytes and cellulose. It also grew at 5°C and at 37°C. Nucleotide sequences of its ITS region showed 93% similarity to sequences of different Malbranchea species. The closest matches among LSU rRNA sequences were obtained with the genera Amauroascus, Arthroderma, Auxarthronopsis and Malbranchea (93%–95%). A combined phylogenetic analysis placed the fungus in a sister clade to Neogymnomycetaceae, classified as incertae sedis in Onygenales, on a large distance to either Diploospora rosea or 'Amauroascus' aureus. Conclusions: The genus Inopinatus gen. nov. (MB854685) with the species Inopinatus corneliae sp. nov. (MB854687) is introduced to accommodate our isolate (holotype: DSM 116806; isotypes: CBS 151104, IHEM 29063). Probably Inopinatus corneliae is a geophilic species that, although potentially harmful, was no relevant pathogen in our case. Its ecology, epidemiology and pathogenicity need to be further clarified. [ABSTRACT FROM AUTHOR]

Recent DNA-based studies have shown that the built environment is surprisingly rich in fungi. These indoor fungi - whether transient visitors or more persistent residents - may hold clues to the rising levels of human allergies and other medical and building-related health problems observed globally. The taxonomic identity of these fungi is crucial in such pursuits. Molecular identification of the built mycobiome is no trivial undertaking, however, given the large number of unidentified, misidentified, and technically compromised fungal sequences in public sequence databases. In addition, the sequence metadata required to make informed taxonomic decisions - such as country and host/substrate of collection - are often lacking even from reference and ex-type sequences. Here we report on a taxonomic annotation workshop (April 10-11, 2017) organized at the James Hutton Institute/University of Aberdeen (UK) to facilitate reproducible studies of the built mycobiome. The 32 participants went through public fungal ITS barcode sequences related to the built mycobiome for taxonomic and nomenclatural correctness, technical quality, and metadata availability. A total of 19,508 changes - including 4,783 name changes, 14,121 metadata annotations, and the removal of 99 technically compromised sequences - were implemented in the UNITE database for molecular identification of fungi (https://unite.ut.ee/) and shared with a range of other databases and downstream resources. Among the genera that saw the largest number of changes were Penicillium, Talaromyces, Cladosporium, Acremonium, and Alternaria, all of them of significant importance in both culture-based and culture-independent surveys of the built environment.

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Saccharomyces cerevisiae CNCM I‐1079 as a zootechnical feed additive for dogs and all other Canidae. The additive is intended for use in feed for dogs and all other Canidae at a proposed minimum inclusion level of 1 × 109 CFU per kg of complete feed. Saccharomyces cerevisiae is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment. Since the identity of the active agent has been clearly established and no concerns are expected from other components of the product, the additive is considered safe for the target species. Since the additive is intended to be used only in feed for dogs and other non‐food‐producing animals, an assessment of the safety for the consumer and the environment is not needed. The non‐coated form of the additive was shown to be non‐irritant to skin and eyes. No conclusion can be drawn on the eye irritation potential of the coated form of the additive due to the lack of data. The additive in both forms, should be considered a skin and respiratory sensitiser and any exposure through skin and respiratory tract is considered a risk. The Panel was not in the position to conclude on the efficacy of Saccharomyces cerevisiae CNCM I‐1079 at the proposed conditions of use. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Saccharomyces cerevisiae DSM 34246 as a zootechnical feed additive for dogs and cats. The additive, with the trade name Canobios‐BL, is intended for use in feed for cats and dogs at a proposed minimum inclusion level of 5 × 109 CFU/kg complete feed. Saccharomyces cerevisiae is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment. Since the identity of the active agent has been clearly established and the additive is composed by dried cells of the active agent and an emulsifier, that are not expected to introduce any risk, the additive is considered safe for the target species. Canobios‐BL is not a skin or eye irritant but should be considered a skin and respiratory sensitiser. Canobios‐BL is considered to be efficacious in feedingstuffs for dogs and cats at the use level 5 × 109 CFU/kg complete feed. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of muramidase produced with Trichoderma reesei DSM 32338 (Balancius™) as a feed additive for laying hens. The additive is already authorised as a zootechnical additive (functional group: other zootechnical additives) for chickens, turkeys and minor poultry species for fattening or reared for breeding, and for weaned piglets. The enzyme is produced by fermentation with a genetically modified strain of Trichoderma reesei; viable cells of the production strain and its recombinant DNA were not detected in the additive. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive does not give rise to safety concerns regarding the genetic modification of the production strain. Based on the data available from a sub‐chronic oral toxicity study, the Panel concluded that the additive is safe for laying hens at the maximum recommended level of 60,000 LSU(F) (muramidase activity units)/kg feed. The Panel also concluded that the additive is safe for the consumers and the environment. The liquid formulation of the additive is considered not irritant to the skin or eyes. The solid formulation of the additive is considered not irritant to the skin. The Panel cannot conclude on the potential of the additive (both formulations) to be a dermal sensitiser or on the potential of the solid formulation to be irritant to the eyes. Due to the proteinaceous nature, both forms of the additive should be considered respiratory sensitisers. The additive has the potential to be efficacious as a zootechnical additive for laying hens at 30,000 LSU(F)/kg feed. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Huvezym® neXo 100 G/L, a product containing endo‐1,4‐β‐xylanase, endo‐1,4‐β‐glucanase and xyloglucan‐specific‐endo‐β‐1,4‐glucanase activities produced by a non‐genetically modified strain of Trichoderma citrinoviride (DSM 33578), as a zootechnical additive for all Suidae. The applicant provided information confirming the taxonomic identification of the production strain. The batches used for the characterisation of the final formulations showed compliance with the minimum specifications of the additive in terms of enzyme activities (> 15,000 EPU, > 1000 CU, > 1000 XGU per g) but not for the ratio of the enzymes, which is lower (ca. 7:1:1) than the ones specified (15:1:1). The Panel could not conclude on the representativeness of the test item used in the toxicological and tolerance studies with respect to the final formulations. Therefore, the conclusions are limited to the product with a minimum enzyme activity of 15,000 EPU, 1000 CU, 1000 XGU per g and a xylanase:glucanase:xyloglucanase ratio of 15:1:1. The Panel concluded that the additive is safe for the target species, consumers and the environment. Huvezym® neXo 100 G is not an irritant to the skin and eyes but should be considered a skin sensitiser. Huvezym® neXo 100 L is neither an irritant to the skin and eyes nor a skin sensitiser. Due to the proteinaceous nature of the active substances, the additive is considered a respiratory sensitiser. The additive has the potential to be efficacious in all reproductive Suidae at the minimum proposed use level. Owing to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for Suidae for fattening or reared for reproduction. [ABSTRACT FROM AUTHOR]