Plastic has become established over the world as an essential basic need for our daily life. Current global plastic production exceeds 300 million tons annually. Plastics have many characteristics such as low production costs, inertness, relatively low weight, and durability. The primary disadvantage of plastics is their extremely slow natural degradation. The latter results in an accumulation of plastic waste in nature. The amount of plastic waste as of 2015 was 6300 million tons worldwide, and 79% of this was placed in landfills or left in the natural environment. Moreover, recent estimates report that 12,000 million tons of plastic waste will have been accumulated on the earth by 2050. Therefore, it is necessary to develop an effective plastic biodegradation process to accelerate the natural degradation rate of plastics. More than 400 microbes have been identified as capable of plastic degradation. This is the first paper of the series on plastic-degrading fungi. This paper provides a summary of the current global production of plastic and plastic waste accumulation in nature. A list is given of all the plastic-degrading fungi recorded thus far, based on the available literature, and comments are made relating to the major fungal groups. In addition, the phylogenetic relationships of plastic-degrading fungi were analyzed using a combined ITS, LSU, SSU, TEF, RPB1, and RPB2 dataset consisting of 395 strains. Our results confirm that plastic-degrading fungi are found in eleven classes in the fungal phyla Ascomycota (Dothideomycetes, Eurotiomycetes, Leotiomycetes, Saccharomycetes, and Sordariomycetes), Basidiomycota (Agaricomycetes, Microbotryomycetes, Tremellomycetes, Tritirachiomycetes, and Ustilaginomy-cetes), and Mucoromycota (Mucoromycetes). The taxonomic placement of plastic-degrading fungal taxa is briefly discussed. The Eurotiomycetes include the largest number of plastic degraders in the kingdom Fungi. The results presented herein are expected to influence the direction of future research on similar topics in order to find effective plastic-degrading fungi that can eliminate plastic wastes. The next publication of the series on plastic-degrading fungi will be focused on major metabolites, degradation pathways, and enzyme production in plastic degradation by fungi.

Plastic, a ubiquitous part of our daily lives, has become a global necessity, with annual production exceeding 300 million tons. However, the accumulation of synthetic polymers in our environment poses a pressing global challenge. To address this urgent issue, fungi have emerged as potential agents for plastic degradation. In our previous manuscript, ‘A Review of the Fungi That Degrade Plastic’, we explored the taxonomic placement of plastic-degrading fungi across three main phyla: Ascomycota, Basidiomycota, and Mucoromycota. In this review, we built upon that foundation and aimed to further explore the taxonomic relationships of these fungi in a comprehensive and detailed manner, leaving no stone unturned. Moreover, we linked metabolic activity and enzyme production of plastic-degrading fungi to their taxonomy and summarized a phylogenetic tree and a detailed table on enzyme production of plastic-degrading fungi presented here. Microbial enzymes are key players in polymer degradation, operating intra-cellularly and extra-cellularly. Fungi, one of the well-studied groups of microbes with respect to plastic degradation, are at the forefront of addressing the global issue of plastic accumulation. Their unique ability to hydrolyze synthetic plastic polymers and produce a wide range of specific enzymes is a testament to their potential. In this review, we gather and synthesize information concerning the metabolic pathways of fungi involved in the degradation of plastics. The manuscript explores the diverse range of specific enzymes that fungi can produce for plastic degradation and the major pathways of plastic metabolism. We provide a listing of 14 fungal enzymes (Esterase, Cutinase, Laccase, Peroxidases, Manganese peroxidase, Lignin peroxidase, Oxidoreductases, Urease, Protease, Lipase, Polyesterase, Dehydrogenase, Serine hydrolase, and PETase) involved in pathways for plastic degradation alongside the relevant fungi known to produce these enzymes. Furthermore, we integrate the fungi’s enzyme-producing capabilities with their taxonomy and phylogeny. Taxonomic and phylogenetic investigations have pinpointed three primary fungal classes (Eurotiomycetes, Sordariomycetes (Ascomycota), and Agaricomycetes (Basidiomycota)) as significant plastic degraders that produce the vital enzymes mentioned earlier. This paper provides a foundational resource for recognizing fungal involvement in the biodegradation of synthetic polymers. It will ultimately advance fungal biotechnology efforts to address the global issue of plastic accumulation in natural environments.

The apothecial ascomycete family Dactylosporaceae includes saprobes and lichenicolous fungi. In recent studies, the phylogenetic position of this family was unstable within the subphylum Pezizomycotina. The present study provides a stable phylogenetic placement for Dactylosporaceae within the class Eurotiomycetes and we introduce the new order: Dactylosporales Ekanayaka, E.B.G. Jones, Q. Zhao & K.D. Hyde, ord. nov. to accommodate this family. We also introduce two new species: Dactylospora chiangraiensis Ekanayaka, E.B.G. Jones, Q. Zhao & K.D. Hyde, sp. nov. and Dactylospora fusiformis Ekanayaka, E.B.G. Jones, Q. Zhao & K.D. Hyde, sp. nov. to this family and their relationships with other taxa are represented in a multigene phylogeny.

The genus Phillipsia (Sarcoscyphaceae) is characterized by large, bright-coloured, sub-stipitate apothecia, sub-operculate asci and asymmetrical ascospores with longitudinal striations. Morphological and phylogenetic studies were carried out on new collections of Phillipsia from China and Thailand. Phillipsia subpurpurea are recorded from China and Phillipsia gelatinosa from Thailand is introduced as a new species to science. Our new collections are confirmed to be divergent from other species of Phillipsia based on morphological examination and molecular phylogenetic analyses of ITS and LSU sequence data. Descriptions and figures are provided for the taxa which are also compared with allied taxa.

The genus Rhytidhysteron is ecologically diverse, cosmopolitan group of Dothideomycetes characterized by apothecioid ascomata, in which the margin folds inwards, covers the disc incompletely in dry conditions, unfolds outwards exposing the disc by a lenticular or irregular opening when hydrated, bitunicate, cylindrical asci, and hyaline to reddish brown, ellipsoidal to fusiform, 1–3 septate ascospores. This study was conducted on five Rhytidhysteron specimens isolated from dead wood pieces in urban forest habitats (Colombo District, Sri Lanka). Detailed micro and macro morphological examinations and phylogenetic analyses inferred from ITS, LSU, and TEF1 were used to position the five specimens compared with the extant Rhytidhysteron taxa. Based on morphological and phylogenetic evidence, they were identified as R. rufulum, R. neorufulum, R. cf. bruguiereae and a novel species, R. constrictiseptum; altogether providing first records for three Rhytidhysteron species in Sri Lanka, except R. neorufulum.

Geopyxis is an ectomycorrhizal genus found in temperate forests. The members form yellow and orange to brown apothecia that range from 3–25 mm in diameter. Its ascospores are smooth to finely verrucous. The specimen collected from Mount Tlaloc, Texcoco, State of Mexico, was identified as Geopyxis carolinae sp. nov. This species typically forms sessile apothecia, cupuliform to discoid, and its ascospores are the largest [17–23(25) × 10–12 µm] within the genus. The species was found growing on a burnt ground associated with Abies religiosa. Multi-gene phylogenetic analyses inferred from ITS and LSU sequence data confirmed that Geopyxis carolinae is distinct from other Geopyxis spp. The new species is described, illustrated, and compared with similar taxa based on molecular and morphological data.