Antibiotic resistance in shellfish and major inland pollution sources in the drainage basin of Kamak Bay, Republic of Korea.

Shellfish-growing areas in marine environments are affected by pollutants that mainly originate from land, including streams, domestic wastewater, and the effluents of wastewater treatment plants (WWTPs), which may function as reservoirs of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs). The objective of this study was to identify the occurrence and distribution of antibiotic resistance at five oyster sampling sites and 11 major inland pollution sources in the drainage basin of Kamak Bay, Republic of Korea. Culture-based methods were used to estimate the diversity and abundance of antibiotic-resistant Escherichia coli strains isolated from oysters and major inland pollution sources.

Assessment of potential infectivity of human norovirus in the traditional Korean salted clam product "Jogaejeotgal" by floating electrode-dielectric barrier discharge plasma.

This study investigated the antiviral effects of floating electrode-dielectric barrier discharge (FE-DBD) plasma treatment (1.1 kV, 43 kHz, N 1.5 m/s, 5-30 min) against human norovirus (HuNoV) GII.

Virucidal Effects of Dielectric Barrier Discharge Plasma on Human Norovirus Infectivity in Fresh Oysters ().

This study investigates the effects of dielectric barrier discharge (DBD) plasma treatment (1.1 kV, 43 kHz, N 1.5 L/min, 10~60 min) on human norovirus (HuNoV) GII.

Level of contamination in the feces of several species at major inland pollution sources in the drainage basin of Yeoja Bay, Republic of Korea.

We assessed the levels of fecal contamination and the originating species of 12 major inland pollutants in the drainage basin of Yeoja Bay. The presence of the human-specific (HF183), ruminant-specific (BacR and Rum-2-Bac), pig-specific (Pig-Bac-2 and Pig-2-Bac), avian-specific (GFD), and gull-specific (Gull2) markers in water samples (n = 34) from 12 inland pollution sources around Yeoja Bay was analyzed. HF183 was detected in 97% of the water samples, and all major inland pollution sources were contaminated with human feces.

Fecal source tracking based on fecal coliform concentration and bacterial community structure in the Bong stream, Korea.

Fecal source tracking of the Bong stream, a representative inland pollutant around the drainage basin of Gangjin Bay (an area where shellfish are grown for export), was performed three times in four confluence areas with 13 sampling sites by analyzing fecal coliform concentrations and two types of bacterial community structures. Identification of the origin of major fecal pollution in the area that inflowed simultaneously via several branch streams was difficult using fecal source tracking based on fecal coliform concentration. Bacterial community analyses using high-throughput sequencing showed that the dominant groups in the entire bacterial community at the class level were Beta-, Gamma-, and Alpha-proteobacteria; Flavobacteriia; and Bacteroidia, and the most abundant groups in the Bacteroidales-specific community at the genus level were Prevotella and Bacteroides.

Microbial succession and metabolite changes during fermentation of dongchimi, traditional Korean watery kimchi.

Dongchimi, one of the most common types of watery kimchi in Korea, was prepared using radish and its pH values, microbial cell numbers, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of watery kimchi. The bacterial abundance increased quickly during the early fermentation period and the pH values concurrently decreased rapidly without any initial pH increase. After 15 days of fermentation, the bacterial abundance decreased rapidly with the increase of Saccharomyces abundance and then increased again with a decrease of Saccharomyces abundance after 40 days of fermentation, suggesting that bacteria and Saccharomyces have a direct antagonistic relationship.

Microbial succession and metabolite changes during long-term storage of Kimchi.

Kimchi is often stored for a long period of time for a diet during the winter season because it is an essential side dish for Korean meals. In this study pH, abundance of bacteria and yeasts, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of kimchi for 120 d. Bacterial abundance increased quickly with a pH decrease after an initial pH increase during the early fermentation period.

Defluviimonas aestuarii sp. nov., a marine bacterium isolated from a tidal flat, and emended description of the genus Defluviimonas Foesel et al. 2011.

A novel Gram-staining-negative, strictly aerobic bacterium, designated BS14(T), was isolated from a marine tidal flat of the South Sea in Korea. Colonies were opaque, white, smooth and circular on marine agar. Cells were moderately halophilic, non-motile rods showing catalase- and oxidase-positive reactions.

Gramella aestuarii sp. nov., isolated from a tidal flat, and emended description of Gramella echinicola.

A Gram-staining-negative, yellow-pigmented, strictly aerobic bacterial strain motile by gliding, designated BS12(T), was isolated from a tidal flat at Boseong, Korea. Cells were moderately halotolerant, catalase- and oxidase-positive rods. Growth was observed at 5-40 °C (optimum, 25 °C), at pH 5.

Effects of red pepper powder on microbial communities and metabolites during kimchi fermentation.

To investigate the effects of red pepper powder on kimchi fermentation, Baechu (Chinese cabbage) and Mu (radish) kimchi, with and without red pepper powder, were prepared and their characteristics, including pH, colony-forming units (CFU), microbial communities, and metabolites, were periodically monitored for 40days. Measurements of pH and CFU showed that the lag phases of kimchi fermentation were clearly extended by the addition of red pepper powder. Microbial community analysis using a barcoded pyrosequencing analysis showed that the bacterial diversities in kimchi with red pepper powder decreased more slowly than kimchi without red pepper powder as kimchi fermentation progressed.

Halomonas cibimaris sp. nov., isolated from jeotgal, a traditional Korean fermented seafood.

Two moderately halophilic, facultatively aerobic, motile bacteria with flagella, designated strains 10-C-3(T) and 30-C-3, were isolated from jeotgal, a traditional Korean fermented seafood. Cells of the strains were observed to be ovoid-rods showing catalase- and oxidase-positive reactions and production of creamy-pink pigments. Growth of strain 10-C-3(T) was observed at 15-35 °C (optimum, 25-30 °C), at pH 5.

Microbulbifer gwangyangensis sp. nov. and Microbulbifer pacificus sp. nov., isolated from marine environments.

Two novel Gram-stain-negative, chemoheterotrophic and strictly aerobic bacteria, strains GY2(T) and SPO729(T), were isolated from a tidal flat at Gwangyang Bay in Korea and a marine sponge sample from the Pacific Ocean, respectively. The two strains were halotolerant, catalase- and oxidase-positive, and non-motile rods. Optimum temperature and pH for growth of both strains were observed to be 35 °C and pH 7.

Altererythrobacter gangjinensis sp. nov., a marine bacterium isolated from a tidal flat.

A Gram-stain-negative, ochre-pigmented, strictly aerobic bacterium, designated strain KJ7(T), was isolated from a tidal flat of the Gangjin bay in South Korea. Cells were halotolerant, non-motile, catalase- and oxidase-positive rods. Growth of strain KJ7(T) was observed at 5-35 °C (optimum, 25 °C), at pH 6.

Arenibacter hampyeongensis sp. nov., a marine bacterium isolated from a tidal flat.

A Gram-staining-negative, dark orange, strictly aerobic bacterium, designated strain HP12(T), was isolated from a tidal flat at Hampyeong in South Korea. Cells were moderately halotolerant, catalase- and oxidase-positive, non-motile rods. Growth was observed at 5-35 °C (optimum, 25 °C), at pH 6.

Aestuariibaculum suncheonense gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from a tidal flat and emended descriptions of the genera Gaetbulibacter and Tamlana.

A Gram-staining-negative, yellow-pigmented, strictly aerobic bacterium, designated strain SC17(T), was isolated from sediment of a tidal flat of Suncheon bay in South Korea. Cells were halotolerant, catalase- and oxidase-positive and non-motile rods. Growth of strain SC17(T) was observed at 5-40 °C (optimum, 25-30 °C), at pH 6.

Kordiimonas aestuarii sp. nov., a marine bacterium isolated from a tidal flat.

A Gram-staining negative, strictly aerobic bacterium, designated 101-1(T), was isolated from a sea tidal flat, Taean, Korea. The strain formed small light-yellow, smooth, and circular colonies on marine agar. Cells were weakly halophilic, motile rods showing catalase- and oxidase-positive reactions.