• Journal of Food Hygiene and Safety
• /
• v.34 no.5
• /
• pp.502-507
• /
• 2019

Cephalopods are one of the most important fishery resources in the world because of their desirable taste and nutritional value. In south Korea, one of the countries in which a large amount of seafood is consumed, cephalopods (e.g., octopus, squid, and cuttlefish) have an annual consumption rate of over 400,000 metric tons. In this study, octopus and squid products (n=28) sold on the market were monitored by analyzing sequences of DNA barcode markers (cytochrome c oxidase subunit I and 16S ribosomal RNA genes). For species identification, the NCBI BLAST database was screened with the sequences and analyzed as a query. In this BLAST search, twelve squid products showed 99-100% sequence identity to Dosidicus gigas (n=3) and Todarodes pacificus (n=9). In the case of the other 16 products that were declared using octopus as raw materials on the labels, six products were identified as Cistopus taiwanicus (n=1), Amphioctopus marginatus (n=1), Scaeurgus unicirrhus (n=1), and Dosidicus gigas (n=3). Monitoring results indicated that a significant percentage (37.5%) of mislabeling was present in octopus products sold on the South Korean market.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.5
• /
• pp.939-947
• /
• 2000

Enhanced biological phosphorus removal (EBPR) was performed in an anaerobic/aerobic sequencing batch reactor (SBR). Influent was a synthetic wastewater based on acetate as a carbon source. The sludge age and hydraulic retention time were kept at 10 days and 16 hrs, respectively, Phosphate release during the anaerobic period and phosphate uptake in aerobic period were increased gradually with time. and after about 200 days, steady-state operation could be achieved with complete removal of influent phosphate. Number distribution of microbial community in the sludge performing EBPR was investigated during the steady state operation. 17 rRNA targeted oligonucleotide probes were designed and slot hybridization technique was used to determine the number distribution of each microorganism. In the acetate fed SBR, rRNA belonging to the beta subclass of proteobacteria was the most dominant in total rRNA and rRNA matching to CTE probe was the second, rRNAs of Acinetobacter, Aeromonas and Pseudomonas, which are usually thought as phosphorus accumulating organisms in EBPR processes, constituted less than 10% of total rRNA. From this community analysis, it was inferred that microorganisms belong to the beta subclass of proteobacteia (BET) and CTE such as Rhodocyclus group were important in biological phosphorus removal. Therefore, the role of Acinetobacter, Aeromonas and Pseudomonas in the EBPR might have been overestimated.

• The Korean Journal of Pesticide Science
• /
• v.18 no.4
• /
• pp.396-403
• /
• 2014

Ginseng (Panax ginseng C. A. Meyer) is an economically valuable pharmaceutical crop in Korea. In order to find promising biocontrol agents for soil-borne fungal pathogens which infect ginseng roots, we have isolated actinomycete, BK185 from soil. The isolate was investigated for the antifungal activity against to ginseng rot pathogens prior to testing genetic and chemical properties. The strain was identified as Streptomyces sp. using phylogenetic analysis based on 16S rRNA gene sequence. The most closely related species was S. sporoclivatus and S. geldanamycininus with high similarities (>99%). The isolate, BK185 showed positive reaction for PCR detection targeting biosynthetic gene clusters of PKS (Type-I polyketide synthase) and NRPS (Non-ribosomal polypeptide synthetase) genes. Major metabolite from the BK185 was analyzed by The LC/MS and identified to geldamycin, which was known to contained broad antibacterial, antifungal or anticancer activities. The results provide evidences that the strain, BK185 can be promising biocontrol agent for ginseng organic farming.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.3
• /
• pp.561-572
• /
• 2017

The global commercial cultivation of transgenic crops, including glyphosate-tolerant soybean, has increased widely in recent decades with potential impact on the environment. The bulk of previous studies showed different results on the effects of the release of transgenic plants on the soil microbial community, especially rhizosphere bacteria. In this study, comparative analyses of the bacterial communities in the rhizosphere soils and surrounding soils were performed between the glyphosate-tolerant soybean line NZL06-698 (or simply N698), containing a glyphosate-insensitive EPSPS gene, and its control cultivar Mengdou12 (or simply MD12), by a 16S ribosomal RNA gene (16S rDNA) amplicon sequencing-based Illumina MiSeq platform. No statistically significant difference was found in the overall alpha diversity of the rhizosphere bacterial communities, although the species richness and evenness of the bacteria increased in the rhizosphere of N698 compared with that of MD12. Some influence on phylogenetic diversity of the rhizosphere bacterial communities was found between N698 and MD12 by beta diversity analysis based on weighted UniFrac distance. Furthermore, the relative abundances of part rhizosphere bacterial phyla and genera, which included some nitrogen-fixing bacteria, were significantly different between N698 and MD12. Our present results indicate some impact of the glyphosate-tolerant soybean line N698 on the phylogenetic diversity of rhizosphere bacterial communities together with a significant difference in the relative abundances of part rhizosphere bacteria at different classification levels as compared with its control cultivar MD12, when a comparative analysis of surrounding soils between N698 and MD12 was used as a systematic contrast study.

• Korean Journal of Microbiology
• /
• v.45 no.2
• /
• pp.170-176
• /
• 2009

Culture-independent 16S rDNA-DGGE profiling and phylogenetic analysis were used to examine the predominant bacterial communities associated with the two sponges, Dictyonella sp. and Spirastrella abata from Jeju island. The culture-independent approach involved extraction of total bacterial DNA, PCR amplification of the 16S ribosomal DNA using primer pair 341f-GC and 518r, and separation of the amplicons on a denaturing gradient gel. Denaturing gradient gel electrophoresis banding patterns indicated 8 and 7 bands from the two sponge species, Dictyonella sp. and Spirastrella abata, respectively. There were not common major bands in two different sponges. Comparative sequence analysis of variable DGGE bands revealed from 93% to 98% similarity to the known published sequences. The dominant bacterial group of Dictyonella sp. belonged to uncultured Gammaproteobacteria, while, that of Spirastrella abata belonged to uncultured Alphaproeobacteria and Firmicutes. DGGE analysis indicated predominant communities of the sponge-associated bacteria differ in the two sponges from the same geographical location. This result revealed that bacterial community profiles of the sponges were host species-specific.

• Ocean and Polar Research
• /
• v.43 no.4
• /
• pp.371-374
• /
• 2021

Triglopsis quadricornis Linnaeus, 1758 (Cottidae) is distributed in the Atlantic and Arctic and has four unique bony protuberances on its head. Here, we report the complete, circular, and annotated mitochondrial genome of T. quadricornis. The complete T. quadricornis mitochondrion was sequenced by high-throughput Illumina HiSeq platform. The sequences are 16,736 bp in size and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, a control region, and large and small ribosomal subunits. The overall genomic structure of T. quadricornis mitochondrion was conserved with the gene arrangement of Megalocottus and Myoxocephalus species, and phylogenetic analysis supports their sister relationships. Most PCGs consist of TAA or TAG as a termination codon, whereas COII, ND4, and CYTB have T-- as a stop codon. This complete mitochondrial DNA information of T. quadricornis will provide an essential genomic resource to elucidate the phylogenetic relationship and evolutionary history of the family Cottidae.

• Journal of Veterinary Clinics
• /
• v.37 no.1
• /
• pp.57-59
• /
• 2020

A 3-year-old, captive female river cooter was presented with a 4-day history of progressive unilateral swelling of the right side of the head, lethargy, and anorexia. History, physical examination, and radiographic examination revealed an aural abscess. After administration of antibiotics and supportive care, surgical intervention was performed. Swab samples were collected from the tympanic cavity during surgery for cytology and antimicrobial susceptibility testing. Molecular analyses of 16S ribosomal RNA gene sequences identified Citrobacter spp. and Morganella morganii. The patient was treated with ciprofloxacin and meloxicam and recovered after 2 months. This report describes the successful correction of a unilateral aural abscess that responded well to surgical intervention and a properly selected antibiotic.

• Food Science and Preservation
• /
• v.21 no.2
• /
• pp.286-293
• /
• 2014

In this study, one GRAS strain was screened from doenjang, a traditional Korean fermented food, as a microorganism producing amylase due to the formation of a clear zone on the medium including soluble starch. From the analysis of the gene sequence of 16S ribosomal RNA, the strain was identified as Bacillus subtilis and was therefore named Bacillus subtilis CBD2. When the nutrient broth medium was prepared with 3% NaCl, 5% glucose, and the initial medium pH 7.0, the B. subtilis CBD2 showed maximum growth. Among soluble starch, corn starch, maize amylopectin, and wheat starch, soluble starch was the most effective carbon source in the production of amylase by B. subtilis CBD2. The amylase from B. subtilis CBD2 showed the highest activities at pH 8.0 and $50^{\circ}C$, and corn starch was the most proper substrate for the enzyme activity. When corn starch was used as a substrate, the production of sugars through enzyme activity increased for 24 h, and then the enzyme activity became constant.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.376-380
• /
• 2014

Marine beach sands with bacterial pathogens may cause increased outcomes of illness among beachgoers in summer. In this study, pyrosequencing of 16S ribosomal DNAs extracted from 12 beach sands was performed to understand how the environmental factors of wastewaters or human wastes affected the distribution of bacterial communities at the beach of North Gyeongsang province (Yeongdeok and Pohang counties) in the middle of October. It was found that Acidobacteria were dominantly distributed in the sands near the clean seawaters, Proteobacteria in the sands near the river waters, Cyanobacteria in the sands near the wastewaters, and Bacteroidetes in the sands near the beach park. Other phyla groups such as Actinobacteria, Chlorobi, Deferribacteres, Deinococcus-thermus, Firmicutes, Gemmatimonadetes, Nitrospirae, and/or Verrucomicrobia were distributed at low relative abundance (1-5%).

• Genomics & Informatics
• /
• v.1 no.1
• /
• pp.50-54
• /
• 2003

Genome of an extreme thermophile, Thermus caldophilus GK24 has been analyzed to construct the genomic map. The genomic DNAs encapsulated in agarose gel were digested with SspI, EcoRI, SpeI, and HpaI restriction endonucleases, and then the resulting genomic DNA fragments were analyzed by pulsed-field gel electrophoresis. Its restriction map has been constructed by analyzing sizes of the restriction fragments obtained from both complete and partial digestions. The circular form of its genome was composed of about 1.98 Mbp and a megaplasmid. The genomic loci for the genes of xylose isomerase, thioredoxin, tRNA-16S rRNA, 23S rRNA, L5 ribosomal protein, ADP-glucose pyrophosphorylase, DNA-ligase, and Tca DNA polymerase were determined by both Southern hybridization and PCR.