During the screening of Korean microflora, a fungal strain (KNU-PT-1804) belonging to the genus Pestalotiopsis was isolated from persimmon tree (Diospyros kaki) bark collected from North Gyeongsang Province, Korea. The strain, KNU-PT-1804, produced smaller conidia compared with related species P. kenyana, P. neglecta, and P. telopeae. The novelty of the strain was confirmed based on phylogenetic analysis using molecular datasets of internal transcribed spacer (ITS) regions, β-tubulin (TUB2), and translation elongation factor 1-alpha (TEF1α) genes. Molecular phylogeny strongly supports that the strain is distinct from previously known Pestalotiopsis species, and we proposed the novel species, Pestalotiopsis kaki sp. nov., and provide a detailed description and illustration.

Polylactic acid (PLA) and polycaprolactone (PCL) are commercially available bioplastics that are exploited worldwide, and both are biodegradable. The PLA and PCL polymer-degrading activity of 30 fungal strains that were isolated from terrestrial environments were screened based on the formation of a clear zone around fungal colonies on agar plates containing emulsified PLA or PCL. Among them, five strains yielded positive results of biodegradation. Strains Korean Agricultural Culture Collection (KACC) 83034BP and KNUF-20-PPH03 exhibited PCL degradation; two other strains, KACC 83035BP and KNUF-20-PDG05, degraded PLA; and the fifth strain, KACC 83036BP, biodegraded both tested plastics. Based on phylogenetic analyses using various combinations of the sequences of internal transcribed spacer (ITS) regions, RPB2, LSU, CAL, and β-TUB genes, the above-mentioned strains were identified as Apiotrichum porosum, Penicillium samsonianum, Talaromyces pinophilus, Purpureocillium lilacinum, and Fusicolla acetilerea, respectively. Based on our knowledge, this is the first report on (i) plastic biodegraders among Apiotrichum and Fusicolla species, (ii) the capability of T. pinophilus to degrade biodegradable plastics, (iii) the biodegradative activity of P. samsonianum against PCL, and (iv) the accurate identification of P. lilacinum as a PLA biodegrader. Further studies should be conducted to determine how the fungal species can be utilized in Korea.

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4–34.3 × 8.0–12.0 μm. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.

This review provides a critical summary of the biological remediation of heavy metals by leveraging the potential of microbes in soils and water ecosystems, highlighting major research findings and practical obstacles. Heavy metals (HMs) pose a severe threat to environmental health due to their toxicity and persistence, necessitating effective remediation strategies. Biological remediation, especially through microorganisms and enzymatic actions, offers a promising alternative to conventional methods due to its eco-friendly and cost-effective nature. The review discusses various microbes, including bacteria, fungi, and algae known for their metal-binding capacities and transformation abilities. It delves into the mechanisms of bioremediation, such as biosorption, bioaccumulation, and biotransformation, facilitated by microbial enzymes like oxidoreductases and hydrolases that remove or bind the chemical structure of HMs. This paper also explores genetic engineering approaches to enhance microbial efficacy in HMs’ uptake and resistance. Furthermore, the review addresses the significant challenges in scaling bioremediation from a laboratory to the field, such as the complexity of environmental conditions, the presence of mixed contaminants, and the need for system optimization to improve efficiency and sustainability. It also evaluates the current legislative framework governing bioremediation practices, suggesting a need for clearer policies to support the integration of biological methods into mainstream remediation strategies. Conclusively, while microbial and enzymatic remediation presents considerable potential, extensive research is needed to overcome existing hurdles and develop robust, field-applicable systems. This paper calls for a multidisciplinary approach combining microbiology, engineering, and environmental sciences to advance this promising field.