• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.442-454
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• 2022

A total of 31 bacterial strains were isolated from the Geum River basin in the Republic of Korea during our investigation of indigenous prokaryotic species. The isolated bacterial strains had high 16S rRNA gene sequence similarity (>98.7%) with those of validly published bacterial species, which have not been reported in Republic of Korea. The 31 bacterial strains were phylogenetically diverse and assigned to 4 phyla, 8 classes, 18 orders, 21 families, and 27 genera. At the genus level, the unreported species were affiliated with Kineococcus, Pedococcus, Rhodoluna, Salinibacterium, Rhodoluna, Arthrobacter, Williamsia, Nakamurella, Nocardioides of the class Actinobacteria, Patulibacter of the class Thermoleophilia, Pontibacter, Hymenobacter of the class Cytophagia, Flavobacterium of the class Flavobacteriia, Geomicrobium of the class Bacilli, Brevundimonas, Gellertiella, Rhizobium, Paracoccus, Taonella, Sphingomonas of the class Alphaproteobacteria, Burkholderia, Polaromonas, Hydrogenophaga, Chitinilyticum, Azospira, Zoogloea of the class Betaproteobacteria, and Pseudomonas of the class Gammaproteobacteria. The unreported bacterial species were further characterized by examining their morphological, cultural, physiological, and biochemical properties. The detailed descriptions of the 31 bacterial strains were provided.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.405-412
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• 2022

Suncheon Bay Ecological Park, possessing abundant fisheries and biological diversity, was registered as a Ramsar wetland in Korea. Approximately 300 bacterial strains were isolated from the Suncheon Bay in a comprehensive study of indigenous prokaryotic species conducted during 2019-2020 in South Korea. A total of 12 bacterial strains were identified using 16S rRNA gene sequencing, demonstrating >98.7% sequence similarity with validly published species. These species were determined to be unrecorded bacterial species in Korea. A total of six strains were isolated from brackish water and Phragmites communis Trin (reed) species. These unrecorded species were phylogenetically diverse and belonged to three classes, six orders, and ten genera. Regarding the genus and class levels, the previously unrecorded species belonged to Jiella, Martelella, Rhizobium, Paracoccus, Rhodovulum, and Altererythrobacter of the class Alphaproteobacteria; Mycolicibacterium, Demequina, and Microbacterium of the class Actinobacteria; Confluentibacter of the class Flavobacteria. The twelve species were further characterized by gram staining, colony and cell morphology, biochemical properties, and phylogenetic position.

• Journal of Species Research
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• v.12 no.spc2
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• pp.54-59
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• 2023

To obtain unrecorded bacterial species from Korean islands, various samples were collected from the islands in 2022. After plating the samples on marine agar or Reasoner's 2A, and incubating aerobically, approximately 1,200 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 10 strains showed ≥98.7% 16S rRNA gene sequence similarity with the bacterial species that were validly published but not reported in Korea. The unrecorded bacterial strains belong to three phyla, five classes, 10 orders, 10 families, and 10 genera, which are assigned to Sphingomonas, Falsirhodobacter and Asticcacaulis of the class Alphaproteobacteria; Colwellia and Halomonas of the class Gammaproteobacteria; Chitinophaga of the class Chitinophagia; Chryseobacterium of the class Flavobacteriia; Microlunatus, Zhihengliuella, and Streptomyces of the class Actinomycetia. The details of the unreported species including Gram reaction, colony and cell morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.

• Journal of Species Research
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• v.12 no.spc2
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• pp.1-6
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• 2023

During an investigation into the indigenous prokaryotic species diversity in Korea, a total of five bacterial strains were isolated from various environments in Korea. The isolated bacterial strains were identified by analyzing their 16S rRNA gene sequences, and those with a minimum of 98.7% sequence similarity with known bacterial species but not reported in Korea were designated as unrecorded species. These isolates were assigned to three phyla, five orders, five families, and five different genera. The isolates were identified as Cumulibacter manganitolerans (99.1%) and Myolicibacterium tusciae (98.7%) of the class Actinomycetes; Bacillus marasmi (99.9%) of the class Bacilli; and Novosphingobium mathurense (100%) and Microvirga ossetica (98.8%) of the class Alphaproteobacteria. Gram reaction, colony and cellular morphology, basic biochemical characteristics, and phylogenetic position of theses isolates are also described.

• Journal of Species Research
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• v.12 no.4
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• pp.267-276
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• 2023

To obtain unrecorded bacterial species in Korea, various soils of coastal areas were collected from the Republic of Korea in 2022. After plating the samples on marine agar and incubating aerobically and anaerobically, approximately 1,700 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 20 strains showed ≥98.7% 16S rRNA gene sequence similarity with validly published bacterial species but not reported in Korea, indicating they are unrecorded bacterial species in Korea. The unrecorded bacterial strains belonged to four phyla, six classes, 15 orders, 16 families, and 19 genera which were assigned to Blastomonas and Sphingomonas of the class Alphaproteobacteria; Pseudidiomarina, Kushneria, Salinicola, and Salinisphaera of the class Gammaproteobacteria; Evansella, Virgibacillus, and Paenibacillus of the class Bacilli; Cyclobacterium of the class Cytophagia; Pedobacter of the class Sphingobacteriia; and Demequina, Ornithinimicrobium, Blastococcus, Jatrophihabitans, Kineococcus, Glaciihabitans, Aeromicrobium and Streptomyces of the class Actinomycetes. The details of the 20 unreported species, including Gram reaction, morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.

• Journal of Species Research
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• v.13 no.3
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• pp.310-317
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• 2024

Various samples from island and coastal ecosystems in South Korea were investigated to discover unrecorded bacterial species. Soils from these areas, along with seawater samples, were plated on marine agar and R2A agar (containing 3% sea salt). From these samples, approximately 1,070 bacterial strains were isolated as single colonies and identified using 16S rRNA gene sequences. A total of 20 strains, which exhibited at least 98.7% similarity in their 16S rRNA gene sequences to those of validly published bacterial species not yet reported in Korea, were identified as unrecorded bacterial species. These strains belonged to three phyla, six classes, 10 orders, 14 families, and 16 genera. These were assigned as follows: Thioclava, Breoghania, Acidovorax, Erythrobacter, Paracoccus, Jiella, Aurantimonas, and Qipengyuania within the class Alphaproteobacteria; Pseudomonas, Cobetia, and Rheinheimera within the class Gammaproteobacteria; Aequorivita, Leeuwenhoekiella, and Polaribacter within the class Flavobacteriia; Algoriphagus within the class Cytophagia; and Microbacterium within the class Actinobacteria. The unreported species underwent further taxonomic characterization, which included assessments of Gram reaction, colony and cell morphology, biochemical and phylogenetic characteristics.

• Journal of Species Research
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• v.13 no.3
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• pp.293-305
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• 2024

Various samples were collected from Korean islands in order to obtain unrecorded bacterial species in 2023. After aerobically incubating on marine agar and Reasoner's 2A agar, approximately 1,200 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 36 strains showed ≥98.7% sequence similarity to previously published and validated bacterial species. However, these strains have not previously been reported in the Republic of Korea, indicating that they belong to Korean unrecorded bacterial species. The unrecorded bacterial species were assigned to the classes Actinomycetes, Bacilli, Bacteroidia, Flavobacteriia, Sphingobacteriia, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. The information we obtained by examining the strains includes details of the Gram reactions, colony and cell morphology, biochemical characteristics, and phylogenetic positions of the unrecorded species.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.585-592
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• 2013

To estimate the effect of long-term fertilization on metabolically active bacterial communities in a rice field, RNA was extracted from endosphere (rice root), rhizosphere, and bulk soil that had been subjected to different fertilization regimes for 59 years, and the 16S rRNAs were analyzed using the pyrosequencing method. The richness and diversity of metabolically active bacteria were higher in bulk soil than in the endosphere and rhizosphere, and showed no significant difference between non-fertilized and fertilized plots. Weighted UniFrac analysis showed that each compartment had characteristic bacterial communities and that the effect of long-term fertilization on the structure of bacterial community was more pronounced in bulk soil than in the endosphere and rhizosphere. The 16S rRNAs affiliated with Alphaproteobacteria and Firmicutes were more abundant in the endosphere than in bulk soil while those affiliated with Chloroflexi and Acidobacteria were more abundant in bulk soil than in the endosphere. Several dominant operational taxonomic units (clustered at a 97% similarity cut-off) showed different frequencies between non-fertilized and fertilized plots, suggesting that the fertilization affected their activities in the rice field.

• Korean Journal of Environmental Biology
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• v.31 no.2
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• pp.158-164
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• 2013

A microcystin-degrading bacterium was isolated from Daechung reservoir, Korea. The isolated bacterium was identified as Microbacterium sp. by 16S rRNA gene sequence analysis, and designated as Microbacterium sp. MA21. This strain degraded cyanobacterial hepatotoxin, microcystin-LR, over 80% when incubated at $30^{\circ}C$ for 12 hr in R2A medium. Two unknown metabolites of microcystin were also identified during the degradation process. Although only Sphinogomonas and Actinobacteria have been known to degrade microcystin previously, this is the first report that Microbacterium sp. MA21 could degrade microcystin.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1141-1147
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• 2012

Polyhydroxyalkanoate (PHA) is a class of biodegradable plastics that have great potential applications in the near future. In this study, the micro-biodiversity and productivity of PHA-accumulating bacteria in activated sludge from a domestic wastewater treatment plant were investigated. A previously reported primer set and a self-designed primer set (phaCF1BO/phaCR2BO) were both used to amplify the PHA synthase (phaC) gene of isolated colonies. The new primers demonstrated higher sensitivity for phaC, and combining the PCR results of the two primer sets was able to widen the range of detected genera and raise the sensitivity to nearly 90%. Results showed that 85.3% of the identified bacteria were Gram-negative, with Ralstonia as the dominant genus, and 14.7% were Gram-positive. In addition, Zoogloea and Rhizobium contained the highest amounts of intracellular PHA. It is apparent that glucose was a better carbon source than pentone or tryptone for promoting PHA production in Micrococcus. Two different classes, class I and class II, of phaC were detected from alphaproteobacteria, betaproteobacteria, and gammaproteobacteria, indicating the wide diversity of PHA-accumulating bacteria in this particular sampling site. Simultaneous wastewater treatment and PHA production is promising by adopting the high PHA-accumulating bacteria isolated from activated sludge.