• Korean Journal of Microbiology
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• v.55 no.3
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• pp.278-279
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• 2019

Miniimonas arenae KCTC $19750^T$ belonging to family Beutenbergiaceae of the phylum Actinobacteria was isolated from sea sand. I report here the draft genome sequence of strain KCTC $19750^T$. The draft genome comprises a size of 3,402,690 bp, a mean G + C content of 73.6%, 2,957 coding sequences, 2 ribosomal RNA genes, and 44 transfer RNA genes. Also, we found that genes involved in osmotic stress response were identified in its genome. The availability of the genome sequences will provide a more understanding of strain KCTC $19750^T$ as a unique member of the genus Miniimonas.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.368-376
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• 2009

A red pigment-producing bacterial strain was isolated from sediment sample of the East China Sea. The isolate was identified by analysis based on 16S rDNA sequence and morphological, physiological properties, biochemical characteristics and fatty acid composition. Phylogenetic analysis based on 16S rDNA sequence showed that isolate represent a phyletic lineage within the genus Zooshikella, and this strain was most closely related to Zooshikella ganghwensis KCTC $12044^T$ (AY130994) (99.79%). The strain was Gram-negative, aerobic and required NaCl at 0.5~8.0% for growth. The predominant cellular fatty acids were saturated and monounsaturated straight-chain fatty acids. Consequently, this strain was identified as a member of the genus Zooshikella and designated as Zooshikella sp. JE-34. The pigment showed characteristics similar to prodigiosin, a well-known red pigment previously detected in Serratia marcescens. The antimicrobial activity of Zooshikella sp. JE-34 bacterial pigment was tested against 18 microorganisms, which were fish and human pathogens. The Zooshikella sp. JE-34 red pigment showed high antimicrobial activity against Streptococcus iniae, S. parauberis, S. mutans, Staphylococcus aureus, and Propionibacterium acnes.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.164-168
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• 2014

The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.1
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• pp.1-8
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• 2022

This study examined the growth, fatty acid (FA) content, and carotenoids of a newly isolated freshwater microalga, Mychonastes sp. 246, in various culture media. The appropriate temperature and light intensity for culturing Mychonastes sp. 246 were determined as 18℃-22℃ and 200-250 µmol/m²/s using a high throughput photobioreactor. The microalgal cells were cultivated in 0.5 L bubble column photobioreactors using BG11, Bold's Basal media, and f/2 media. According to the growth results of the microalgae, BG11, among the tested media, showed the highest biomass concentrations (3.5 ± 0.1 g/L in 10 d). To enhance the biomass growth of the microalgae, the N:P ratio in BG11 was manipulated from 45:1 to 7:1 based on the stoichiometric cell composition. The biomass concentrations of Mychonastes sp. 246 grown on the manipulated BG11 (MBG) increased to 38% (4.6 ± 0.3 g/L in d) compared with the original BG11 (3.3 g/L). The FA content of the microalgae grown on the MBG was lower (8.4%) than that of the original BG11 (10.1%) while the FA compositions did not exhibit any significant differences. Furthermore, three kinds of carotenoids were identified in Mychonastes sp. 246, zeaxanthin, lutein, and β-carotene. These results suggest an effective strategy for increasing biomass concentrations, FA content, and carotenoids of microalgae by performing a simple N:P adjustment in the culture media.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.283-285
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• 2019

The draft genome sequencing for Pelagicola sp. DSW4-44 (= KCTC 62762 = KCCM 43261), isolated from deep seawater of East Sea in Korea, was performed using Illumina HiSeq platform. As a result, the draft genome was comprised of a total length of approximately 4.85 Mbp with G + C content of 54.3%, and included a total of 4,566 protein-coding genes, 3 rRNA genes, 48 tRNA genes, 3 non-coding RNA genes, and 67 pseudo genes. In the draft genome, the strain DSW4-44 contained genes involved in the nitrogen metabolism of dissimilatory nitrate reduction to ammonium (DNRA) and denitrification, which were not found other strains in the genus Pelagicola.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.480-482
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• 2018

The draft genome sequencing for Zhongshania marina $DSW25-10^T$, isolated from deep seawater of East Sea in Korea, was performed using Illumina HiSeq platform. As a result, the draft genome was comprised of a total length of approximately 4.08 Mbp with G + C content of 49.0%, and included a total of 3,702 protein-coding genes, 3 rRNA genes, 39 tRNA genes, 4 non-coding RNA genes, and 36 pseudogenes. In addition, the metabolic pathways of aliphatic and aromatic compounds were identified. In light of these metabolic pathways, Zhongshania marina $DSW25-10^T$ is expected to be a useful bioremediation resource.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.281-286
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• 2005

In this study, the anaerobic enrichment cultivation was performed with the sediments and the dredged soils from the cities of Ulsan, Masan, Yeosu, Gwangyang, Ansan and Seongnam. Acetate as an electron donor and PCE (perchloroethylene) or TCE (trichloroethylene) as an electron acceptor were injected into the serum bottle with an anaerobic medium. After the incubation of 12 weeks, the removal efficiency of PCE was highest at $70\%$ in the treatment with the sediment of Ulsan. Also, the bacterial community structure was analyzed by D-DGGE (double denatured gradient gel electrophoresis) through PCR-based 16S rDNA approaches. The dominant species id the anaerobic enrichment were found to belong to the genus of Desulfovibrio.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.15-22
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• 2024

This study assessed microbial contamination in seven fried fish pastes sold in Southeast Asian traditional markets during summer. It measured viable cell count, coliforms, Escherichia coli, fungi, and Staphylococcus spp. It also qualitatively analyzed Vibrio parahaemolyticus, Salmonella spp., Bacillus cereus, Listeria monocytogenes, and Clostridium perfringens. The average viable cell count, coliforms and fungi were detected as 6.34 (3.84-8.13), 2.16 (1.00-3.55), and 3.92 (1.85-7.74) log₁₀ CFU/g, respectively. Staphylococcus spp. was detected at 4.59 (2.10-7.63) log₁₀ CFU/g. Some samples had high contamination levels: viable cell count (8.13 log₁₀ CFU/g), fungi (7.74 log₁₀ CFU/g) and S. aureus (7.63 log₁₀ CFU/g). However, E. coli was not detected in any samples (ND, <1 log₁₀ CFU/g). V. parahaemolyticus, Salmonella spp., B. cereus, L. monocytogenes, and Cl. perfringens were also not detected in the samples. The microbial contamination data provide insight into managing microbial contamination and ensuring the safety of fried fish pastes in traditional summer markets.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.482-482
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• 2010

하수처리장에서 발생하는 유기성 슬러지는 대부분 해양투기에 의해 처분되고 나머지는 매립, 소각, 퇴비화 등으로 처분된다. 그러나 런던협약 '96 의정서' 발효에 의해 2012년부터 해양투기가 금지되고, 매립장 및 소각장의 신규건설은 님비(NIMBY) 현상에 의해 제한받기 때문에 효과적인 슬러지 처분 및 가용화 방법이 요구되고 있다. 현재 초음파[1]나 열처리[2], 오존[3,4], 미생물 처리[5,6] 등 물리, 화학, 생물학적 처리방안이 연구되고 있으나 이러한 방법들은 에너지 과소비, 2차 오염물질 발생에 따른 처리비용 증가 등의 단점을 가지고 있다. 따라서 본 연구에서는 기존의 연구 방법을 보안하고자 전기분해를 활용하여 슬러지 가용화를 시도함으로써 슬러지 발생을 저감시킬 수 있는 방법을 연구하였다. 본 실험에서는 전기분해를 위해 제작된 불용성 전극은 Titanium에 Iridium을 코팅하여 제작하였고, 최대 20V까지 전압을 고정시키고 시간에 따라 변화되는 전류와 전기전도도, pH 값을 관찰하였다. 실험에 사용된 활성슬러지는 3개월간 합성폐수로 순응화 시킨 후에 시료로 사용하였다. 전기분해에 의해 처리된 활성슬러지의 여액을 분석한 결과 SCOD, TN, TP 농도가 각각 510%, 9%, 106% 증가하였다. 이는 전기분해에 의해 미생물의 세포벽이 파괴되어 세포 내 물질들이 세포 외부로 용출되어 미생물들의 이용이 가능한 상태로 되었음을 알 수 있었다. 이는 국내 하 폐수의 낮은 C/N비 때문에 무산소조에 메탄올 같은 외부 탄소원을 공급하는 대신에 별도의 탄소원 공급 없이 가용화 된 슬러지를 반송시킴으로써 슬러지 저감에 따른 폐기 비용과 운전비용의 절감을 기대할 수 있어, 근본적인 슬러지 발생을 저감시킬 수 있는 해결책이라 할 수 있다.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.132-136
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• 1998

Molecular analyses of natural microbial communities are often dependent upon the obtainments of pure nucleic acids. The four methods (elution after agarose gel electrophoresis, G-75 microspin columns, hydroxyapatite mi-crospin columns, and polyvinylpolypyrrolidone (PVPP) microspin columns) were compared for the removal of PCR-inhibitory humic substances from the crude DNA extracts of marine sediment samples. The PVPP microspin columns have shown superior removal of humic substances from the crude DNA extract of marine sediment samples, with yield of $4.8{\mu}g/g$ (dry weight of sediment). The purified DNA by this rapid method was pure enough to amplify 1.5 kb fragment corresponding almost full length of 16S rRNA genes.