The commercial feed additive, native rumen microbes (RC), derived from a diverse microbial community isolated from the rumen of Hanwoo steers is being explored to enhance rumen fermentation and improve ruminant feed utilization. This study evaluated the impact of native rumen microbes supplementation on methane emissions, microbial diversity, and fermentation efficiency on in vitro assessment. Treatments were as follows: CON (basal diet, without RC); T1 (basal diet + 0.1% RC); T2 (basal diet + 0.2% RC). Rumen fermentation parameters, total gas, and methane production were assessed at 12, 24, and 48 h of incubations. The in vitro gas production was carried out using the Ankom RF Gas Production System. Supplementation of RC significantly reduced the total gas production at 12, 24, and 48 hours of incubation (p < 0.05). Volatile fatty acid concentrations were increased, while acetate and propionate were decreased (p < 0.05) at 48 h by the supplementation of RC. Notably, the 0.1% inclusion level of RC significantly reduced methane production by 28.30% and 21.21% at 12 and 24 hours. Furthermore, microbial diversity analysis revealed significant shifts (p < 0.05) in bacterial composition between the control and treatment groups, while supplementation also promoted the growth of bacterial populations, such as Succiniclasticum. These findings suggest that native rumen microbes supplementation, particularly at 0.1% inclusion level, can enhance rumen microbial composition while significantly reducing methane production in vitro.

The long-tailed goral (Naemorhedus caudatus) is classified as an endangered species in South Korea due to population declines driven by human development and habitat fragmentation. This study aimed to investigate genetic characteristics and microsatellite genotypes in long-tailed goral populations using fecal samples collected from Uljin and Samcheok regions, which are geographically important habitats for the distribution and dispersal of this species in South Korea. The mean expected heterozygosity (HE) and observed heterozygosity (HO) across 10 microsatellite loci were 0.600 and 0.461 for the Uljin population and 0.644 and 0.571 for the Samcheok population, respectively. These values indicate a moderate level of genetic diversity compared to other closely related species. Genetic differentiation between the two populations had a low level, while a moderate gene flow was observed. The genetic evidence obtained in this study suggests that these two populations share a similar genetic pool, resulting in a low level of genetic differentiation between them. Therefore, they should be considered as one continuous population. Results of this study provide fundamental data and valuable genetic insights for long-term management of the long-tailed goral population in Uljin and Samcheok regions.

The oral microbiome plays a vital role in maintaining oral and overall health and affects immune responses, digestion, and pathogen suppression. While most studies focus on age groups prone to specific conditions, such as dental caries in children or periodontal disease in older adults, limited data exist on preschool-aged children and young adults. This study investigates the composition and diversity of the oral microbiome between these age groups for enhanced understanding of a healthy oral microbiome. Microbial samples from the supragingival regions of 41 children and 31 young adults in Korea were analyzed using 16S rRNA gene sequencing. Alpha and beta diversity were assessed, and linear discriminant analysis effect size (LEfSe) identified taxa with significant differences in abundance between the groups. No significant differences in alpha diversity were observed between children and young adults however, beta diversity analysis revealed notably compositional differences. At the phylum level, Firmicutes were more abundant in children, whereas Actinobacteria were more prevalent in young adults. Genera such as Veillonella and Lautropia were more abundant among children, whereas Haemophilus and Rothia were more common among young adults. LEfSe analysis identified Veillonella rogosae and Lautropia mirabilis as more abundant in children, whereas Haemophilus parainfluenzae and Rothia dentocariosa were more prevalent in young adults. The observed differences suggest that children’s microbiomes are associated with biofilm development, while young adults’ microbiomes involve biofilm maturation and immune modulation. These findings highlight the age-related shift in oral microbiome composition, emphasizing the importance of monitoring these changes to support long-term oral health.

Biodiversity encompasses species diversity, which includes species richness and species evenness. High species diversity is known to contribute to community stability and the potential for maintaining healthy ecosystem functioning. However, the most commonly used species diversity indices have some limitations, as they require species-specific abundance data for each community. In contrast, phylogenetic diversity measures the evolutionary distances between species within a community, reflecting ecological and/or evolutionary divergences and niche differences, without requiring abundance data. This study assessed biodiversity by calculating phylogenetic diversity indices for freshwater fishes (19 species) and aquatic insects (49 species) at three sites within Seoraksan and Odaesan National Parks. The aquatic insects studied belong to the EPT group (Ephemeroptera, Plecoptera, and Trichoptera), which are widely used as bioindicators of aquatic ecosystems. Two mitochondrial DNA genes were used as molecular markers: COI and cyt b for fish, and COI and 16S rRNA for the EPT - group. Overall, Odaesan National Park exhibited higher phylogenetic diversity in both fishes and aquatic insects compared to Seoraksan National Park, although this difference was not statistically significant. The highest phylogenetic and species diversity were observed for fish at the OD2 site (Woljeong District) and for the EPT group at the OD1 (Gyebangsan) and SA2 (Jangsudae) sites. Correlation analysis revealed that phylogenetic diversity indices were more positively associated with species richness than species diversity indices. This study serves as a pilot project for establishing standardized methods for assessing biodiversity in national park habitats using phylogenetic diversity. It also aims to inform various policies, such as the development of biodiversity assessment systems and the prioritization of protected areas within national parks.

This study analyzed the epilithic diatom community and ecological health of freshwater streams using environmental DNA (eDNA)-based metabarcoding technology. eDNA metabarcoding is a method that analyzes biological communities by performing PCR amplification followed by next-generation sequencing (NGS), offering higher sensitivity and faster results compared to traditional microscopic analyses. The study compared the eDNA metabarcoding results of ribulose bisphosphate carboxylase large chain gene (rbcL) targeting epilithic diatoms according to Taq polymerases (SuperFi II, GainBlue, EzPCR, and AccuPower). SuperFi II and GainBlue yielded the highest number of reads and zOTUs, with GainBlue showing particularly uniform read distribution, allowing for more accurate analysis for community diversity of epilithic diatoms. On the other hand, EzPCR and AccuPower exhibited lower number of reads and zOTUs, making them less suitable for the community diversity. In terms of community similarity analysis, SuperFi II and GainBlue produced highly similar results, while EzPCR and AccuPower showed significant differences. This study demonstrates that PCR Taq polymerases significantly influence community diversity and similarity analyses of epilithic diatoms, with GainBlue providing the most stable and accurate results. Our findings serve as a valuable foundation for improving the accuracy of eDNA-based metabarcoding analyses of diatoms.

Tricholoma matsutake is an economically important ectomycorrhizal mushroom, but artificial cultivation remains challenging. While much research has been conducted on the bacteria and fungi associated with T. matsutake, studies on archaea have been limited. This study compared and analyzed the diversity and structural differences of archaeal communities in the fairy ring and non-fairy ring soils using a metabarcoding approach. The alpha diversity analysis revealed that the archaeal community in fairy ring soil had lower diversity compared to non-fairy ring soil, and beta diversity analysis clearly separated the community structures between the two soil types. Among all analyzed soils, Nitrososphaeria (Nitrososphaerota) dominated the archaeal community at class level. In fairy ring soils, Nitrosotalea (Nitrosotaleaceae) was predominant, while in non-fairy ring soils, Nitrosocaldaceae dominated. These results suggest that Nitrosotalea may have a close association with T. matsutake, highlighting the need for further in-depth research on archaea as potential growth promoting microorganism for T. matsutake mycelial growth.

Tricholoma matsutake is a commercially valuable fungus that produces gourmet mushrooms. The artificial cultivation method that is currently used to produce fruiting bodies involves the transplantation of pine trees infected with T. matsutake from their natural habitats and the successful infection of young pine trees and mushroom production have been reported in Hongcheon. In this study, T. matsutake genetic diversity and relationships in this region were investigated. A genotype analysis was conducted on 25 fruiting bodies collected from an area approximately 2.56 km2 in size using 10 simple sequence repeat (SSR) markers. The analysis revealed 25 genotypes and 23 alleles with mean observed (HO) and expected (HE) heterozygosities of 0.312 and 0.293, respectively. The average polymorphism information content (PIC), which indicates marker polymorphism, was 0.257. A phylogenetic analysis showed no clear correlation between collection location and genetic distance; a spatial autocorrelation analysis indicated no significant genetic structure within 1600 m; and the Mantel test showed no significant correlation between genetic and geographic distances. These results were consistent with previous reports on Japanese populations. This study provides insights into the genetic diversity and structure of T. matsutake at a local scale and highlights the need for further studies across broader geographical ranges.