During an investigation of indigenous prokaryotic species in the Republic of Korea, 17 bacterial strains belonging to the phylum Bacteroidota and 4 strains belonging to the phylum Bacillota were isolated from freshwater environments. These isolated bacterial strains formed a robust phylogenetic clade with type strains of the closest related bacterial species, with 16S rRNA gene sequences sharing similarities of higher than 98.7%. To date, there have been no official report of these 21 isolates in the Republic of Korea. At the genus level, these unreported species were affiliated with Mucilaginibacter and Pedobacter of class Sphingobacteriia, Flavobacterium and Gillisia of class Flavobacteriia, Hymenobacter of class Cytophagia, and Paenibacillus and Planococcus of class Bacilli. These species were further examined by performing Gram staining, analyzing their colonies and cell morphologies, and determining their basic biochemical characteristics and phylogenetic positions. Detailed descriptions of the 21 previously unreported species are provided.

Cucumber mosaic virus (CMV) poses a considerable threat to a diverse array of crops in global agriculture. CMV impacts commercially important cut lilies by diminishing both yield and flower quality. We used RNA sequencing (RNA-seq) to investigate the changes in gene expression in the leaves and bulbs of four distinct cultivars of cut lily, ‘Cancun,’ ‘Brunello,’ ‘Connecticut King,’ and ‘Casa Blanca’ following CMV infection. Notably, CMV affected photosynthetic processes by significantly downregulating genes associated with photosynthesis. In addition, CMV infection was detrimental to chloroplast function and energy production. We observed differential expression of genes associated with both dominant and recessive resistance pathways that are crucial for preventing virus entry, replication, and systemic spread within the plant. Based on functional annotation and differential gene expression analysis, we identified the regulatory genes involved in triggering immune responses, modulating signal transduction, and specific host factors during CMV infection. To validate the RNA-seq findings, we selected four genes involved in resistance, virus multiplication, and virus spread and analyzed them using real-time quantitative reverse transcription PCR (qRT-PCR) with specific primers. The qRT-PCR results aligned closely with those from RNA-seq, showing consistent fold-change responses for the genes that were differentially expressed, indicating that the RNA-seq results were reliable. These results deepen our understanding of the complex genetics behind plant-virus interactions while also providing information for breeding programs that aim to develop CMV-resistant lily cultivars.

As part of the 2024 research initiative, “Investigation and Discovery of Prokaryotes in Freshwater Systems,” samples were collected from diverse freshwater habitats, including both water and soil environments. Approximately 2,000 bacterial strains were isolated as single colonies and identified through 16S rRNA gene sequence analysis. Among these, 38 strains shared ≥98.7% 16S rRNA gene sequence similarities with those of known bacterial species not previously reported in Korea. These strains were thus categorized as newly recorded bacterial species in Korea. These 38 bacterial strains displayed significant phylogenetic diversities, spanning 2 phyla, 4 classes, 15 orders, 24 families, and 34 genera. These unrecorded species were classified into the following classes: Actinomycetia (with genera including Microcella, Conyzicola, Curtobacterium, Leucobacter, Microbacterium, Frigoribacterium, Lysinibacter, Streptomyces, Nonomuraea, Actinocorallia, Ruania, and Actinoplanes), Alphaproteobacteria (Paracoccus, Youngimonas, Loktanella, Corticibacterium, Neorhizobium, Onobrychidicola, Ferranicluibacter, Aureimonas, Asticcacaulis, and Novosphingobium), Betaproteobacteria (Rhodoferax, Rugamonas, and Cupriavidus), and Gammaproteobacteria (Rheinheimera, Shewanella, Kosakonia, Leclercia, Hafnia, Yersinia, Pseudomonas, Lysobacter, and Acinetobacter ). Further characterization included assessment of Gram reaction, colony and cell morphology, biochemical properties, and phylogenetic relationships. This report presents detailed phylogenetic and phenotypic characteristics of these bacterial species.

Background: The poultry industry experiences genetic losses due to recurring infectious diseases, necessitating effective preservation strategies. Nitric oxide plays a crucial role in male reproduction, and optimal NO (nitric oxide) levels may enhance sperm viability. This study investigated the effects of SNAP (S-nitroso-Nacetylpenicillamine) on the longevity of rooster sperm. Methods: Semen was diluted with Beltsville Poultry Semen Extender-I containing 0 or 25 μM SNAP and stored at 10°C. Sperm motility and acrosome integrity were assessed at 1, 3, and 7 days. NO levels were quantified by DAF-FM diacetate and AI trials were evaluated by fertility and hatchability. Results: On day 1, sperm motility in the SNAP 25 μM-treated group was significantly higher than in the control. NO quantification confirmed that SNAP-treated semen exhibited higher NO levels. For fertilization and hatchability assessment, hens were divided into two groups based on the presumed duration sperm resided in sperm storage tubules. Before artificial insemination, the sperm was preserved at low temperature (10°C) to maintain viability. Fertilization rates were significantly higher in the SNAP-treated group in both short-term and long-term SST storage conditions. However, hatchability was only significantly improved in the SNAP-treated group when fertilization occurred after extended storage. Conclusions: These findings suggest that NO enhances sperm viability and fertility in poultry semen stored at low temperatures. SNAP 25 μM enhances AI efficiency by maintaining sperm viability and extending fertilization potential. Further research is needed to refine NO-based fertility enhancement strategies for avian species.

In response to the urgent need for sustainable and environmentally friendly materials, this study focuses on enhancing the flame retardancy and mechanical properties of epoxy composites using eco-friendly, non-halogen flame-retardant hybrid fillers. These fillers are synthesized from tannic acid (TA) and upcycled carbon black derived from waste tires (WT-CB) via a mechano-fusion process. The resulting TA/WT-CB fillers exhibit a core–shell structure, with WT-CB uniformly coating the TA surface, significantly improving flame retardancy compared to TA alone. When incorporated into epoxy resin, the TA/WT-CB fillers not only enhance flame resistance but also improve the composite’s mechanical properties. Optimal performance was observed at a filler content of 5 wt.%, where the composite demonstrated superior flame retardancy and mechanical strength. This innovative approach not only addresses fire safety concerns but also promotes sustainability by utilizing upcycled waste materials, offering a promising solution for environmentally conscious flame-retardant technologies.

Segregated composites, where fillers are selectively placed at the matrix interface to form a segregated filler network, are attracting attention because they can provide excellent conductive properties at low filler content. In this study, the anisotropic enhancement in thermal conductivity of composites was discovered due to the unique structure of the segregated network. The segregated composites were produced using a typical mechanical mixing of matrix pellets and the internal structure was precisely analyzed using three-dimensional non-destructive analysis. The segregated composites slightly improved in the through-plane thermal conductivity, but the in-plane thermal conductivity increased rapidly, showing the anisotropic thermal conductivity. The maximum improvement in the in-plane thermal conductivity of the segregated composites increased by 112.5 (at 7 wt% graphene nanoplatelet) and 71.4% (at 10 wt% multi-walled carbon nanotube), respectively, compared to that of the random composites filled with the same amount of filler. On the other hand, the electrical conductivity of the segregated composites was isotropic due to the difference in the transport mechanisms of electrons and phonons. The anisotropic thermal conductivity developed by the segregated network was helpful in inducing effective heat dissipation of commercial smartphone logic boards.

본 연구에서는 국내에서 판매되는 24개 건어포 및 조미 건어포 제품의 종 판별 및 표시사항 준수 여부를 평가했 다. 이러한 수산가공품에 사용된 원재료의 종판별을 위해 cytochrome c oxidase subunit I 및 cytochrome b 유전자 의 염기서열을 분석하여 NCBI GenBank 및 BOLD 데이 터베이스에 등록되어 있는 생물종의 염기서열과 비교 후 계통 분석을 수행했다. 분석 결과 13개 종(Hyporhamphus quoyi, Gadus chalcogrammus, Lophius litulon, Conger myriaster, Paramonacanthus pusillus, Hyporhamphus sajori, Gadus macrocephalus, Hoplobrotula armata, Callionymus meridionalis, Liparis tanakae, Dosidicus gigas, Lagocephalus cheesemanii, and Takifugu vermicularis)이 확인되었다. 일반 명(장어, 오징어 등)을 포함할 경우 16개 제품(66.7%)에서 표시사항과 판별된 종 간에 불일치가 확인되었으며, 일반 명을 제외할 경우 불일치 비율은 41.7%로 감소했다. 식품 유형별로는 조미건어포 제품(n=20, 70%)에서 건어포 제품 (n=4, 50%) 보다 높은 비율의 불일치 비율이 관찰되었다. 원산지별 분석 결과 특정 국가와 불일치 비율과의 상관성 은 확인할 수 없었다. 이러한 연구 결과는 건포류 제품의 주기적 모니터링 수행 및 수산물의 국명 표시 선을 위한 기초자료로 쓰일 수 있을 것이다.