Freshwater environments are rich ecosystems that support diverse microbial communities, including members of the phylum Actinomycetota critical for nutrient cycling, organic matter decomposition, and water quality maintenance. Actinomycetota known to produce numerous bioactive secondary metabolites are valuable in biotechnology, medicine, and agriculture. Despite their significance, the diversity and distribution of Actinomycetota in freshwater habitats, especially in the Republic of Korea, are underexplored. This study aimed to report the isolation and characterization of 22 previously unrecorded bacterial species of Actinomycetota from various freshwater environments in Korea. Using standard dilution plating techniques on six different culture media, 22 bacterial strains were isolated, incubated, and characterized based on colony and cellular morphologies, Gram staining, and biochemical properties. Genomic DNA was extracted and the 16S rRNA gene was sequenced to determine species identity using the EzBioCloud service with a cutoff of 98.7% sequence similarity for classification as unreported species. These strains were phylogenetically diverse, belonging to two classes, ten orders, and eighteen genera. This study enhances our understanding of bacterial diversity in freshwater ecosystems and underscores the importance of exploring microbial diversity in underexplored habitats, potentially leading to discovery of novel bioactive compounds. Findings of this study contribute valuable insights into ecological roles and biotechnological potential of Actinomycetota in freshwater environments.

Background: Sarcopenia refers to a decrease in functional ability due to the loss of skeletal muscle. Sarcopenia can be prevented, delayed, and treated more effectively the sooner the intervention, and muscle mass and strength can be effectively increased through physical exercise and adequate protein intake. Because symptoms of sarcopenia do not appear in the early stages, awareness among healthcare professionals is essential for early diagnosis and subsequent intervention. Objectives: The purpose of this study was to develop sarcopenia questionnaire items and investigate additional factors in Korean clinical practice. Design: Qualitative research. Methods: A qualitative survey was conducted targeting eight physical therapists affiliated with the sarcopenia associations or physical therapists with extensive clinical experience. A preliminary sarcopenia questionnaire and a qualitative survey questionnaire created by the researchers were sent to the participants together. All questions were open-ended. Results: Through a qualitative survey, themes were derived, including barriers to equipment and healthcare reimbursement, the need for awareness of sarcopenia, and improvement of survey questions. Conclusion: The diagnosis and treatment of sarcopenia requires efforts not only from physical therapists, but also from patients, government, and professional societies.

Background: Community welfare centers in Korea offer various exercise programs aimed at improving the physical and mental health of individuals with intellectual disabilities. This systematic review assesses the impact of these programs. Objectives: To systematically review and evaluate the effectiveness of exercise programs provided by community welfare centers in Korea on the physical, psychological, and mental health of children, adolescents, and adults with intellectual disabilities. Design: A systematic review. Methods: A comprehensive literature search was conducted from inception to December 1, 2023, using databases such as Korea Citation Index, Research Information Sharing Service, and Korean Medical Database. Inclusion criteria were studies focusing on individuals with intellectual disabilities engaged in exercise or exercise-based rehabilitation programs. Results: A total of 3,968 records were identified, with 14 studies meeting the inclusion criteria. Of these, 6 studies focused on children and adolescents, while 8 studies involved adults. Significant improvements were observed in physical fitness, motor performance, mobility skills, pelvic alignment, abdominal obesity, blood lipids, spontaneity, physical self-concept, adaptive behavior, and social competence for children and adolescents. For adults, notable improvements were reported in balance, physical fitness, physical activity levels, upper limb function, inflammatory markers, blood lipids, adaptive behavior, satisfaction, stress reduction, self-efficacy, emotional function, and cognitive function. Conclusion: Exercise programs provided by community welfare centers in Korea have a significant positive impact on the physical, psychological, and mental health of individuals with intellectual disabilities. These programs are essential for enhancing the quality of life for this population.

As part of the research program “Freshwater Prokaryotic Organisms Research and Discovery,” freshwater samples were collected from the Nakdonggang River. After plating the samples on several culture media and incubating aerobically, approximately 900 bacterial strains were isolated and identified using 16S rRNA gene sequences. Among the bacterial isolates showing higher than 98.7% 16S rRNA gene sequence similarity with those of already confirmed bacterial species previously unreported in Korea, 29 strains were selected. These strains were phylogenetically diverse and belonged to 3 phyla, 6 classes, 13 orders, and 21 genera. At the genus level, these previously unreported species were found to be affiliated with Novosphingobium, Sphingomonas, Polymorphobacter, Croceibacterium, Devosia, Endobacterium, Agaricicola, Bradyrhizobium, Paracoccus, and Pseudotabrizicola of the class Alphaproteobacteria; Undibacterium, Azonexus, and Dechloromonas of the class Betaproteobacteria; Acinetobacter and Budvicia of the class Gammaproteobacteria; Streptomyces, Nocardioides, Mycobacterium, and Cellulomonas of the phylum Actinomycetota; Flavobacterium and Pedobacter of the phylum Bacteroidota. These species were further characterized by examining their Gram reaction, colony and cell morphologies, biochemical properties, and phylogenetic positions. Detailed descriptions of these 29 previously unreported species are provided.

Nine fish and one clam species were collected from freshwater environments in Korea, including four lakes, two streams, and the Nakdong River, to investigate the host-associated bacteria. Hundreds of bacterial strains were isolated from the samples using a cell sorter and a dilution plating method. After identification of the bacterial strains using 16S rRNA gene sequences, 42 strains with greater than 98.7% sequence similarity with validly published species were determined to be unrecorded bacterial species in Korea. These strains were phylogenetically diverse and assigned to four phyla, six classes, 17 orders, 27 families, and 32 genera. At the genus level, the unrecorded species were classified as Corynebacterium, Mycobacterium, Mycolicibacterium, Gordonia, Williamsia, Modestobacter, Brachybacterium, Sanquibacter, Arthrobacter, and Mycolicibacterium of the class Actinobacteria; Empedobacter, and Flavobacterium of the class Flavobacteriia; Fictibacillus, Psychrobacillus, Cohnella, Paenibacillus, Rummeliibacillus, Enterococcus, and Vagococcus of the class Bacilli; Aquamicrobium, Paracoccus, and Sphingomonas of the class Alphaproteobacteria; Achromobacter, Delftia, and Deefgea of the class Betaproteobacteria; and Aeromonas, Providencia, Yersinia, Marinomonas, Acinetobacter, and Pseudomonas of the class Gammaproteobacteria. The 42 unrecorded species were subjected to further taxonomic characterization using gram staining, cellular and colony morphological determination, biochemical analyses, and phylogenetic analyses. This paper provides detailed descriptions of the 42 previously unrecorded bacterial species.

As part of the research program “2018 Rapid screening and identification of freshwater microorganisms using MALDI-TOF/MS library” freshwater samples were collected from a branch of the Nakdong River. Almost 300 antibiotic-resistant bacterial strains were isolated from freshwater samples and subsequently identified by 16S rRNA gene sequencing. Seventeen strains among the isolates shared high 16S rRNA gene sequence similarity (>99.0%) with known species that were not previously recorded in Korea, and each of the isolates also formed a robust phylogenetic clade with the closest species. These species were phylogenetically diverse, belonging to four phyla, seven classes, 10 orders, and 13 genera. At the genus and class level, the previously unrecorded species belonged to Rhodovarius, Xanthobacter, and Shinella of the class Alphaproteobacteria; Ottowia, Simplicispira, and Zoogloea of Betaproteobacteria; Pseudomonas, Acinetobacter, and Shewanella of Gammaproteobacteria; Arcobacter of Epsilonproteobacteria; Sphingobacterium of Sphingobacteriia; Trichococcus of Bacilli; and Leucobacter of Actinobacteria. The previously unrecorded species were further characterized by examining their gram-staining, colony and cell morphology, biochemical properties, and phylogenetic position.

Ostrea denselamellosa and Eriocheir japonica samples were collected from the Seomjin River in 2019 as part of the “Research of Host-Associated Bacteria” research program. Almost 200 bacterial strains were isolated from the O. denselamellosa and E. japonica samples and subsequently identified by 16S rRNA gene sequencing. Among the bacterial isolates, ten strains possessed greater than 98.7% sequence similarity with published bacterial species that had not previously been recorded in Korea. These species were phylogenetically diverse, belonging to three phyla, four classes, seven orders, and eight genera. At the genus and class level, the previously unrecorded species belonged to Pseudoalteromonas, Aliivibrio, Rheinheimera, Leucothrix, and Shewanella of the class Gamma-proteobacteria, Olleya of the class Flavobacteriia, Algoriphagus of the class Cytophagia, and Lactococcus of the class Bacilli. The previously unrecorded species were further characterized by examining their Gram staining, colony and cell morphology, biochemical properties, and phylogenetic positions.