The genus Gemmobacter grows phototrophically, aerobically, or anaerobically, and utilizes methylated amine. Here, we present two high-quality complete genomes of the strains con4 and con5^T isolated from a culture of Anabaena. The strains possess sMMO (soluble methane monooxygenase)-oxidizing alkanes to carbon dioxide. Functional genes for methane-oxidation (prmAC, mimBD, adh, gfa, fdh) were identified. The genome of strain con5^T contains nirB, nirK, nirQ, norB, norC, and norG genes involved in dissimilatory nitrate reduction. The presence of nitrite reductase gene (nirK) and the nitric-oxide reductase gene (norB) indicates that it could potentially use nitrite as an electron acceptor in anoxic environments. Taxonomic investigations were also performed on two strains through polyphasic methods, proposing two isolates as a novel species of the genus Gemmobacter. The findings obtained through the whole genome analyses provide genome-based evidence of complete oxidation of methane to carbon dioxide. This study provides a genetic blueprint of Gemmobacter fulva con5^T and its biochemical characteristics, which help us to understand the evolutionary biology of the genus Gemmobacter.

Periphyton comprises a broad range of autotrophic and heterotrophic organisms that grow on submerged surfaces in aquatic environments. To investigate the ecological roles of periphyton and their symbiotic bacterial assemblages related to the control of cyanobacterial blooms, mesocosm experiments were performed in a eutrophic lake that is usually infested with harmful cyanobacterial blooms. Our results showed that periphyton, together with their symbionts, reduced Chl-aconcentrations (up to 94%), improved water clarity and effectively controlled cyanobacterial blooms in the treatment mesocosm. Planktonic bacterial compositions varied greatly in the pre-bloom/bloom/post-bloom periods in both mesocosms and were mainly influenced by total dissolved nitrogen (TDN) concentrations. The phylumCyanobacteriawas the major component in the water samples until bloom peak, but it was replaced byActinobacteriain the post-bloom period. However, periphyton niches were dominated byAlphaproteobacteriathroughout the experiments,Cyanobacteriaproportion being lower. Overall, the results indicated that periphyton and their unique bacterial partners could effectively compete with cyanobacteria and improve water quality. Their underlying interaction mechanism was also suggested to explain how periphyton and their symbionts can reduce cyanobacterial blooms in eutrophic water.

Colletotrichum and Fusarium are globally important plant-pathogenic fungi that cause serious diseases in chili pepper and other crops, leading to substantial yield losses due to their broad host range, environmental persistence, and the limited effectiveness of chemical control, thereby highlighting the need for sustainable alternatives such as biological control. We investigate the biological control and plant growth-promoting potential of Burkholderia vietnamiensis FBCC-B8049, isolated from freshwater environments. The strain exhibited significant antifungal activity against Colletotrichum gloeosporioides, Colletotrichum acutatum, and Fusarium oxysporum in dual-culture assays, with stronger effects against Colletotrichum species. The inhibition was likely due to direct antagonism and volatile organic compounds (VOCs) produced by FBCC-B8049, which were particularly effective against Colletotrichum species. Additionally, FBCC-B8049 demonstrated plant growth-promoting activities including siderophore production for iron acqusition, phosphate solubilization for enhanced nutrient availability, and indole-3-acetic acid synthesis to promote root development. These combined activities enhance nutrient availability and promote seed germination and seedling growth in chili pepper. Ex vivo assays further revealed the effectiveness of FBCC-B8049 in suppressing anthracnose disease on pepper fruits through both direct application and bacterial VOCs emission. Phylogenetic analysis of 16S rRNA and recA gene sequences positioned FBCC-B8049 closely to Burkholderia vietnamiensis, a known plant growth-promoting rhizobacterium. These findings highlight FBCC-B8049 as a promising candidate for sustainable agricultural applications.

한국가금학회지(The Journal of Curriculum Evaluation)

Lagoons are natural bodies of water that are isolated from the sea due to the development of a sand bar or spit. Each lagoon has distinct ecological characteristics, and these sites also serve as popular tourist attractions because they are common habitats for migratory birds and are characterized by beautiful natural scenery. Lagoons also have distinct ecological characteristics from those of their associated estuaries, and there are active research efforts to classify, qualify, and quantify the high biodiversity of lagoons. The lagoons in Korea are primarily distributed in the East Sea, and are represented by Hwajinpo, Yeongrangho, and Gyeongpoho. Here, we report the discovery of 11 unrecorded diatom species (Diploneis didyma, Mastogloia elliptica, Cosmioneis citriformis, Haslea crucigera, Pinnularia bertrandii, Pinnularia nodosa var. percapitata, Gyrosigma sinense, Gomphonema guaraniarum, Gomphonema italicum, Navicula freesei, Trybionella littoralis var. tergestina) among samples collected from the Hwajinpo, Hyangho, Maeho, Gapyeongri wetland, Cheonjinho, and Gyeongpoho lagoons in Korea during a survey from 2018–2020. We present the taxonomic characteristics, ecological information, habitat environmental conditions, and references for these 11 species.