The Mucorales is a group of ancient fungi with global distribution. In the current study we accessed mucoralean fungi isolated from two countries on opposite sides of the Earth and in different hemispheres: South Korea and Brazil. Mucorales isolates were obtained from freshwater, soil, invertebrates, and fruit seeds and identified using phenotypic techniques combined with the DNA sequence data. These analyses revealed 15 new species including one that we affiliated to a newly proposed genus, Neofennellomyces. Names proposed for these 15 new species are Absidia cheongyangensis, A. fluvii, A. kunryangriensis, A. paracylindrospora, A. tarda, A. variiprojecta, A. variispora, Backusella varians, Mucor albicolonia, M. aurantiacus, M. cryophilus, M. glutinatus, M. paraorantomantidis, M. timomeni, and Neofennellomyces jeongsukae. Of these new species, 12 were isolated from South Korea: A. cheongyangensis, A. fluvii, A. kunryangriensis, A. paracylindrospora, B. varians, M. albicolonia, M. aurantiacus, M. cryophilus, M. glutinatus, M. paraorantomantidis, M. timomeni, and N. jeongsukae, and three from Brazil: A. tarda, A. variiprojecta, and A. variispora. Niche specificity of these fungi is discussed including newly recorded invertebrate hosts and a new geographic distribution for species of Backusella, Circinella, Cunninghamella, and Mucor. Given these findings, we provide an inventory of Mucorales. Taxonomic novelties: New genus: Neofennellomyces Hyang B. Lee & T.T.T. Nguyen. New species: Absidia cheongyangensis Hyang B. Lee & T.T.T. Nguyen, Absidia fluvii Hyang B. Lee, A.L. Santiago, P.M. Kirk, K. Voigt & T.T.T. Nguyen, Absidia kunryangriensis Hyang B. Lee & T.T.T. Nguyen, Absidia paracylindrospora Hyang B. Lee & T.T.T. Nguyen, Absidia tarda T.R.L. Cordeiro, Hyang B. Lee & A.L. Santiago, Absidia variiprojecta T.R.L. Cordeiro & A.L. Santiago, Absidia variispora T.R.L. Cordeiro & A.L. Santiago, Backusella varians Hyang B. Lee & T.T.T. Nguyen, Mucor aurantiacus Hyang B. Lee & T.T.T. Nguyen, Mucor cryophilus Hyang B. Lee & T.T.T. Nguyen, Mucor albicolonia Hyang B. Lee & T.T.T. Nguyen, Mucor glutinatus Hyang B. Lee & T.T.T. Nguyen, Mucor paraorantomantidis Hyang B. Lee & T.T.T. Nguyen, Mucor timomeni Hyang B. Lee & T.T.T. Nguyen, Neofennellomyces jeongsukae Hyang B. Lee & T.T.T. Nguyen. Citation: Nguyen TTT, de A. Santiago ALCM, Hallsworth JE, Cordeiro TRL, Voigt K, Kirk PM, Crous PW, Júnior MAM, Elsztein C, Lee HB (2024). New Mucorales from opposite ends of the world. Studies in Mycology 109: 273-321. doi: 10.3114/sim.2024.109.04.

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research.

During an investigation of endophytic fungi associated with the leaves of Tillandsia catimbauensis (Bromeliaceae) in Brazil, we obtained two endophytic Syncephalastrum isolates (URM 8356 and KF360). Based on molecular data (ITS and LSU rDNA sequences), they were recognized as a unique lineage of Syncephalastrum that differs from all other known species of this genus. Morphologically, the new species is quite different from the other four Syncephalastrum species in concomitantly forming merosporangiophores with bizarre, irregular-shaped vesicles and merosporangia with up to 20 merospores each, which were commonly globose or subglobose, elliptical, and oblong with a few being more dilated at one end. Based on phylogenetic and morphological evidences, a new species of Syncephalastrum is hereby proposed.

Fungi are one of the most diverse groups of organisms with an estimated number of species in the range of 2-3 million. The higher-level ranking of fungi has been discussed in the framework of molecular phylogenetics since Hibbett et al., and the definition and the higher ranks (e.g., phyla) of the 'true fungi' have been revised in several subsequent publications. Rapid accumulation of novel genomic data and the advancements in phylogenetics now facilitate a robust and precise foundation for the higher-level classification within the kingdom. This study provides an updated classification of the kingdom Fungi, drawing upon a comprehensive phylogenomic analysis of Holomycota, with which we outline well-supported nodes of the fungal tree and explore more contentious groupings. We accept 19 phyla of Fungi, viz. Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Chytridiomycota, Entomophthoromycota, Entorrhizomycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota, Sanchytriomycota, and Zoopagomycota. In the phylogenies, Caulochytriomycota resides in Chytridiomycota; thus, the former is regarded as a synonym of the latter, while Caulochytriomycetes is viewed as a class in Chytridiomycota. We provide a description of each phylum followed by its classes. A new subphylum, Sanchytriomycotina Karpov is introduced as the only subphylum in Sanchytriomycota. The subclass Pneumocystomycetidae Kirk et al. in Pneumocystomycetes, Ascomycota is invalid and thus validated. Placements of fossil fungi in phyla and classes are also discussed, providing examples.

Mucor pseudolusitanicus was isolated from soil samples collected in an Atlantic Forest area located in Pernambuco, Brazil. Its identity was confirmed by morphology and ITS/LSU rDNA sequence analysis. It forms short and tall sporangiophores, frequently sympodially branched. Columellae are globose, subglobose or slightly elongated, and sporangiospores are ellipsoidal, some irregular, smooth-walled. Chlamydospores are abundant in vegetative hyphae, intercalary, singly or in chains. Detailed description and illustration of the species are presented herein. This is the first record of M. pseudolusitanicus in the Neotropics.

Herbivore dung is a favorable substrate for growing Mucorales (Mucoromycota) fungi. However, the Mucorales community of many animals dungs is unknown, especially of animals from the Caatinga area. Furthermore, it is not known whether the gut type of these animals influences the structure of the dung -inhabiting Mucorales community. Thus, this study aimed to assess the community mucoralean fungi on herbivores dung from Caatinga and analyze whether the digestive system (ruminant and monogastric) modulate the mucoralean community on dung of animals. We found eighteen species (10 genera). Pilobolus and Mucor were the most representative genera and Thamnostylum piriforme was the most frequent species. The species richness, diversity, and evenness of fungal communities did not differ significantly between the dungs of ruminant and monogastric herbivores. The Mucorales communities on horse and donkey dung were more similar. An identification key to all coprophilous Mucorales from Caatinga is presented. This study confirms knowledge about the ecological aspects of coprophilous fungi and raises new ecological perspectives about these Caatinga microorganisms.

Backusella comprises saprobe species commonly isolated from soil, as well as from leaf litter, plant debris, herbivore dung, invertebrates, and some amphibians. During a survey of fungi in upland forest soils located in Pernambuco state, in northeastern Brazil, six strains of Backusella were isolated. Based on morphological, physiological, and molecular data, two new Backusella species were delimited: B. applanata and B. variicolumellata. In addition, B. locustae and B. solicola were isolated for the first time in the New World.

During the assessment of coprophilous mucoralean diversity in northeastern areas of Brazil, a Lichtheimia -like specimen (URM 8358) was isolated from rabbit dung. It was characterized based on morphological, physiological, and molecular analyses of the internal transcribed spacer (ITS), large subunit ribosomal (LSU) and actin DNA sequences. These analyses revealed a novel Lichtheimia species, which is described herein. The novel species forms abundantly branched sporangiophores, with most branches arising near the main sporangia, various-shaped columellae, and irregularly shaped sporangiospores. Furthermore, this manuscript provides notes of all Lichtheimia species, and an identification key for the genus is provided. These findings contribute to the existing knowledge on the taxonomy and distribution of Lichtheimia . Because of the clinical relevance of other Lichtheimia species, we encourage future research to determine whether URM 8358 can be pathogenic to humans.

Mucorales includes saprobic and facultative phytopathogenic fungi that cause soft rot in various fruits and vegetables. Among Mucorales, Rhizopus and Mucor are frequently reported associated with post-harvest losses and devaluation of agricultural products. The aim of this study was to identify and describe Mucorales species from fruits and vegetables with soft rot symptoms and to confirm the pathogenicity of the isolates in their hosts. Fruits and vegetables with symptoms of soft rot were collected in markets located in the city of Recife, Pernambuco, Brazil. In total, 66 Mucorales isolates were obtained from 18 different hosts. Using morphological and phylogenetic (LSU and ITS rDNA sequences) approaches, we have identified 41 isolates of R. stolonifer and 25 distributed among M. inaequisporus, M. merdicola and M. variisporus. The pathogenicity of these fungi was confirmed, and lesions with fungal structures appeared between 2 and 7 days. This study brings the first report of M. inaequisporus causing soft rot in cashew pseudofruit, guava and red jambo fruits, as well as the first evidence of association of this species with breadfruit. This is the first time that M. merdicola is reported as a plant pathogen, specifically causing soft rot in watermelon fruit. In addition, this is the first report of M. variisporus causing soft rot in banana fruit; the first report of R. stolonifer infecting avocado, eggplant and pear fruits in Brazil. We are also providing the first register of the latter species as plant pathogen of achachairu fruit.

A new species of Cunninghamella was isolated during an expedition searching for mucoralean fungi from soil in an upland tropical forest area in the state of Pernambuco, Brazil. The new species was described based on morphophysiological and phylogenetic data (ITS and LSU rDNA sequences). It typically forms unbranched sporophores, though there is some monopodial and sympodial branching. Verticillate branches arising in whorls of up to three from the main sporophore are rarely observed. Vesicles varied-shaped with one to several broken pedicels or warts on their surface and commonly with immature pedicellate sporangiola are formed. Chlamydospores are globose. Better growth was observed at temperatures of 25 and 30 degrees C on MEA. The new species was positioned closer to a clade containing C. clavata, C. subclavata, and C. verrucosa with high support values. In this study, a new species of Cunninghamella is proposed and an updated identification key for Cunninghamella is provided.

During a survey of mucoralean fungi in soil from an upland forest area located in Pernambuco, Brazil, a strain of Backusella (URM 8637) was isolated. Based on morphological, physiological, and molecular data [internal transcribed spacer (ITS) and large subunit (LSU) ribosomal DNA regions], it was recognized that this Backusella differed from all other species in the genus. Morphologically, the new species is characterized as forming varied-shaped columellae, including elongated, basally constricted, unisporate (rare) and multisporate sporangiola, and ellipsoidal sporangiospores. The maximum temperature growth of URM 8637 on malt extract agar and potato dextrose agar was 36 °C. In the phylogram, it was closely related to B. constricta. Based on the evidence from the analyzed datasets, a new species of Backusella is proposed. An updated identification key for Backusella from the Americas is provided.

During a survey on the diversity of Mucoromycota in Atlantic Forest soils from northeastern Brazil, one strain belonging to Absidia that was morphologically and genetically [internal transcribed spacer (ITS) and large subunit (LSU) rDNA] distinct from other species was isolated. The new species produces simple or repeatedly branched (up to five times) sporangiophores that arise single or in whorls of up to eight from stolons, and hemispherical, globose, and fig-shaped columellae with no projections or with up to two projections on its surface. Sporangiospores are exclusively cylindrical and slightly constricted in the center. The specimen grew better at 25 and 30 degrees C, with no development at 40 degrees C. Based on the evidence of the analyzed datasets, a new species of Absidia is proposed. A table with the morphological characteristics of Absidia species from America (North, Central, and South) and species that are phylogenetically closest to the new species is provided.

Mucorales is an order of mostly saprobic fungi which includes broad host range plant pathogens. They are often associated with fruits, causing post-harvest deterioration and economic loss. In markets in the municipality of Recife, Pernambuco, Brazil, fruits with symptoms of soft rot and the presence of fungi with the appearance of Mucorales have been observed. Sporangiophores bearing black and globose sporangia were visualized on the surface of the rotten tissues. Isolates obtained from symptomatic tissues were cultured in potato dextrose agar culture medium, and cultural and microscopic observations were performed. According to the morphological characteristics, the isolates were identified as Gilbertella persicaria and their identity was confirmed by phylogenetic analyses of the ITS and LSU rDNA regions. Gilbertella persicaria , the unique species of the genus, is commonly found in soil, water, dung and often isolated from fruit with post-harvest soft rot. In the present study, nine isolates were obtained and identified, five from acerola, two from cashew, one from papaya and breadfruit. To our knowledge, this is the first report of G. persicaria causing acerola and papaya rot in Brazil and the first report of the species as a cashew and breadfruit pathogen in the world.

The Global Consortium for the Classification of Fungi and fungus-like taxa is an international initiative of more than 550 mycologists to develop an electronic structure for the classification of these organisms. The members of the Consortium originate from 55 countries/regions worldwide, from a wide range of disciplines, and include senior, mid-career and early-career mycologists and plant pathologists. The Consortium will publish a biannual update of the Outline of Fungi and fungus-like taxa, to act as an international scheme for other scientists. Notes on all newly published taxa at or above the level of species will be prepared and published online on the Outline of Fungi website (https://www.outlineoffungi.org/), and these will be finally published in the biannual edition of the Outline of Fungi and fungus-like taxa. Comments on recent important taxonomic opinions on controversial topics will be included in the biannual outline. For example, 'to promote a more stable taxonomy in Fusarium given the divergences over its generic delimitation', or 'are there too many genera in the Boletales?' and even more importantly, 'what should be done with the tremendously diverse 'dark fungal taxa?' There are undeniable differences in mycologists' perceptions and opinions regarding species classification as well as the establishment of new species. Given the pluralistic nature of fungal taxonomy and its implications for species concepts and the nature of species, this consortium aims to provide a platform to better refine and stabilise fungal classification, taking into consideration views from different parties. In the future, a confidential voting system will be set up to gauge the opinions of all mycologists in the Consortium on important topics. The results of such surveys will be presented to the International Commission on the Taxonomy of Fungi (ICTF) and the Nomenclature Committee for Fungi (NCF) with opinions and percentages of votes for and against. Criticisms based on scientific evidence with regards to nomenclature, classifications, and taxonomic concepts will be welcomed, and any recommendations on specific taxonomic issues will also be encouraged; however, we will encourage professionally and ethically responsible criticisms of others' work. This biannual ongoing project will provide an outlet for advances in various topics of fungal classification, nomenclature, and taxonomic concepts and lead to a community-agreed classification scheme for the fungi and fungus-like taxa. Interested parties should contact the lead author if they would like to be involved in future outlines.

Mucor ardhlaengiktus is reported for the first time in South America, where it was iso-lated from soil in an upland rainforest area, located in the municipality of Sanharo, state of Pernam-buco, Brazil. The strain URM 8592 is characterized by forming simply branched sporangiophores, some monopodially branched, globose and subglobose columellae, infrequently ellipsoid with a slight constriction at the base. The sporangiospores are mostly ellipsoid, although some are ovoid, reniform and rarely irregularly shaped, and chlamydospores are frequently formed. This study pre-sents a detailed morphological description of this rare mucoralean fungus. Aspects of its taxonomy and geographical distribution are also commented.

Species of Lichtheimia are important opportunistic fungal pathogens in the order Mucorales that are isolated from various sources such as soil, indoor air, food products, feces, and decaying vegetables. In recent years, species of Lichtheimia have become an emerging causative agent of invasive mucormycosis. In Europe and USA, Lichtheimia are the second and third most common causal fungus of mucormycosis, respectively. Thus, the aim of this study was to survey the diversity of species of Lichtheimia hidden in poorly studied hosts, such as invertebrates, in Korea. Eight Lichtheimia strains were isolated from invertebrate samples. Based on morphology, physiology, and phylogenetic analyses of ITS and LSU rDNA sequence data, the strains were identified as L. hyalospora, L. ornata, L. ramosa, and a novel species, L. koreana sp. nov. Lichtheimia koreana is characterized by a variable columellae, sporangiophores arising solitarily or up to three at one place from stolons, and slow growth on MEA and PDA at all temperatures tested. The new species grows best at 30 and 35 °C and has a maximum growth temperature of 40 °C. Detailed descriptions, illustrations, and a phylogenetic tree are provided.

The mucoralean genus Backusella comprises saprobe species commonly isolated from soil and leaf litter but also from wood, invertebrates, and toads. Molecular species recognition of Backusella has been mainly based on the ITS and LSU regions. Because mucoralean fungi tend to have high intraspecific variability of ITS sequences, we established the gene encoding the largest subunit of RNA polymerase II (RPB1) as phylogenetic marker in Backusella. The topologies of the ITS/LSU and RPB1 trees were widely similar. The maximum growth temperature is shown to represent a valuable taxonomic feature because it varied strongly within the genus. Seven Backusella spp. are capable of growing at temperatures ≥ 36 °C, four of which were positioned in a same clade. Based on the evidence of molecular phylogenetic analyses as well as on morphological and physiological (maximum growth temperature) features, Backusella gigaspora sp. nov. and B. pernambucensis sp. nov. are described.

Piptocephalis includes mycoparasitic fungi, mainly targeting mucoralean species. Until now, there has been no compilation of data on the taxonomy and geographic distribution of Piptocephalis, which is a barrier to the proper identification of species of this genus by taxonomists. The present study provides an overview of Piptocephalis with taxonomic and occurrence data, in addition to reporting P. graefenhanii and P. xenophila for the first time in South America. Both species were observed parasitizing Mucor spp. The P. graefenhanii was observed growing on paca dung and P. xenophila was observed on guinea-pig dung in Recife, northeastern Brazil. Aspects of their morphology are discussed and a key for the genus is presented.

Backusella is morphologically and phylogenetically related to Mucor. Previously, due to various morphological similarities, distinction between these two genera was difficult and various Backusella species were classified within Mucor. However, in the last decade, with the advent of molecular phylogeny, the phylogenetic placement of the genus and its representative taxa was stabilised. In this study, a Backusella strain was isolated from soil samples in Thailand. A combination of morphology, phylogeny and physiology was used to characterize it. Phylogenetic analyses using the nuclear rDNA internal transcribed spacer (ITS1-5.8S-ITS2) and large subunit ribosomal ribonucleic acid (28S) genetic markers showed that the isolate is sister to Backusella gigacellularis. The new isolate is characterised by the production of simple or sympodially branched sporangiophores bearing a terminal sporangium. Columellae of sporangia are ellipsoidal, oblong to cylindrical, pyriform, and conical, often constricted in the centre. Sporangiola are globose to subglobose, often produced in short sympodially branched sporophores containing 4–8 sporangiospores each. The isolate grows on a relatively narrow temperature range of 15 °C–28 °C. The results of the three approaches indicated the novelty of the species. This is the first record of Backusella in Thailand.

During a survey of Mucorales from a forest located in Pernambuco state, Brazil, two new Backusella species were discovered and described based on morphological and molecular data (internal transcribed spacer and large subunit ribosomal DNA sequences). Both species were characterized as unbranched sporangiophores and sporangia with columellae of varied shapes forming. Multispored sporangiola were frequent, whereas unispored sporangiola were rare. URM 8395 forms sporangiophores that may support hyaline, slightly curved or circinate pedicels with multispored sporangiola at their apical portion, and abundant giant cells and chlamydospores. Columellae of sporangia are hyaline, conical (majority), or ellipsoidal with a truncate base, globose to subglobose or subglobose to conical, and, rarely, with slight medial constriction. URM 8427 does not form sporangiola from pedicels, giant cells are not observed, and columellae of sporangia are globose to subglobose, cylindrical with a truncate base, some with a slight constriction, applanate, obovoid, ellipsoidal, or, rarely, conical. Some columellae may have one side more swollen than the other and some are arranged obliquely on the sporangiophores. Sterile sporangia may or may not be formed on short sporophores. The detailed description and illustration of both novel species as well as an identification key for Backusella from the Americas are provided.