• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.91-104
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• 2019

The taxonomic and functional characteristics of bacterial communities in the pre-chlorinated rapid filters and ozonated biological activated carbon (BAC) filters were compared using Illumina MiSeq sequencing of the 16S rRNA gene and community-level physiological profiling (CLPP) based on sole-carbon-source utilization patterns. Both the rapid filters and BAC filters were dominated by Rhizobiales within ${\alpha}-proteobacteria$, but other abundant orders and genera were significantly different in both types of filter. Firmicutes were abundant only in the intermediate chlorinated rapid filter, while Acidobacteria were abundant only in the BAC filters. Bacterial communities in the rapid filter showed high utilization of carbohydrates, while those in the BAC filters showed high utilization of polymers and carboxylic acids. These different characteristics of the bacterial communities could be related to the different substrates in the influents, filling materials, and residual disinfectants. Chlorination and ozonation inactivated the existing bacteria in the influent and formed different bacterial communities, which could be resistant to the oxidants and effectively utilize different substrates produced by the oxidant, including Phreatobacter in the rapid filters and Hyphomicrobium in the BAC filters. Bradyrhizobium and Leptothrix, which could utilize compounds adsorbed on the GAC, were abundant in the BAC filters. Ozonation increased taxonomic diversity but decreased functional diversity of the bacterial communities in the BAC filters. This study provides some new insights into the effects of oxidation processes and filling materials on the bacterial community structure in the biological filters of drinking water treatment plants.

• Journal of Applied Biological Chemistry
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• 제44권1호
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• pp.16-19
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• 2001

Soybean plants(Glycine max [L.] merr.) inoculated with Bradyrhizobium japonicum MN110 were grown in growth chambers under 400 or $800{\mu}l{\cdot}l^{-1}$ atmospheric $CO_2$ and harvested at 25, 28, 32, and 35 DAT to examine the effect of $CO_2$ enrichment on phosphorus accumulation, uptake, and utilization efficiency during vegetative growth. Phosphorus concentration in leaf was lower in high $CO_2$ plant by 47% at 25 DAT and 34% at 35 DAT than those in the control plant but phosphorus concentrations in stem, root and nodule were not affected by $CO_2$ enrichment. Total phosphorus accumulation increased 3.9-fold in high $CO_2$ plant and 3.2-fold in the control plant between 25 and 35 DAT. Elevated $CO_2$ caused a decrease in the whole plant phosphorus concentration by 35%, which was due almost entirely to a decrease in the phosphorus concentration of leaves. $CO_2$ enrichment increased phosphorus utilization efficiency in the whole plant by 70% during the experimental period. Plants exposed to high $CO_2$ had larger root systems than under ambient $CO_2$, but high $CO_2$ plants had lower P-uptake efficiency. Averaged over four harvests, plants at high $CO_2$ had 38% larger root mass that was more than offset the 20% lower efficiency of P-uptake and accounted for increased phosphorus accumulation by high $CO_2$ plant. These results suggest that the reduced phosphorus concentration in soybean plant under $CO_2$ enrichment may be an acclimation response to high $CO_2$ concentration or enhanced starch accumulation, resulting in the plants to have a lower phosphorus requirement on a unit dry weight basis or a high phosphorus utilization efficiency under these conditions.

• Current Research on Agriculture and Life Sciences
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• 제15권
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• pp.25-32
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• 1997

근류균과 두과작물의 공생에서 숙주결합성을 조사하기 위하여 대두 종자 및 및 유근으로부터 분리한 lectin과 근류균의 표피다당과의 결합성을 확인한 결과는 다음과 같다. 팔달, 백운 및 황금으로부터 분리한 종자선을 형성하였다. 대두 종자 lectin 및 뿌리추출물은 R. japonicum및 B. japonicum과 결합하였고 R. viceae와는 결합 하지 않았으며 완두의 lectin은 R. viceae와 결합하였으나 R. japonicum및 B. japonicum과는 결합 하지 않았다. B. japonicum과 R. viceae로 부터 분리한 세포표피 다당의 겔 여과한 결과 두개의 분획으로 각각 나타났다. B. japonicum으로 부터 분리한 표피다당은 대두의 종자 lectin과 결합하였으나 R. viceae로 부터 분리한 표피다당은 대두 lectin과 결합하지 않았다. 이상의 결과로 부터 근류균이 숙주세포와 결합할 때 숙주를 인식하는 초기 단계에서 lectin이 관여함을 추론할 수 있고 이것이 상호접종군을 형성하는데 매개역할을 하는 것으로 추정할 수 있었다.

• Genomics & Informatics
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• 제10권4호
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• pp.249-255
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• 2012

In this study, fosmid cloning strategies were used to assess the microbial populations in water from the International Space Station (ISS) drinking water system (henceforth referred to as Prebiocide and Tank A water samples). The goals of this study were: to compare the sensitivity of the fosmid cloning strategy with that of traditional culture-based and 16S rRNA-based approaches and to detect the widest possible spectrum of microbial populations during the water purification process. Initially, microbes could not be cultivated, and conventional PCR failed to amplify 16S rDNA fragments from these low biomass samples. Therefore, randomly primed rolling-circle amplification was used to amplify any DNA that might be present in the samples, followed by size selection by using pulsed-field gel electrophoresis. The amplified high-molecular- weight DNA from both samples was cloned into fosmid vectors. Several hundred clones were randomly selected for sequencing, followed by Blastn/Blastx searches. Sequences encoding specific genes from Burkholderia, a species abundant in the soil and groundwater, were found in both samples. Bradyrhizobium and Mesorhizobium, which belong to rhizobia, a large community of nitrogen fixers often found in association with plant roots, were present in the Prebiocide samples. Ralstonia, which is prevalent in soils with a high heavy metal content, was detected in the Tank A samples. The detection of many unidentified sequences suggests the presence of potentially novel microbial fingerprints. The bacterial diversity detected in this pilot study using a fosmid vector approach was higher than that detected by conventional 16S rRNA gene sequencing.

• 미생물학회지
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• 제38권4호
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• pp.293-298
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• 2002

다양한 농도의 영양배지(nutrient broth, NB; diluted nutrient broth, DNB)를 이용하여 음용 지하수중의 세균수를 계수한 결과, 통상농도의 NB배지에 비해 저영양배지인 DNB배지에서 2～50배 이상 높은 계수치를 나타내었다. 이와 같은 결과로부터 지하수중에는 NB배지에서는 중식이 현저히 저해되고 DNB배지에서만 중식이 가능한 저영양세균(oligotrophic bacteria)이 다수 분포하고 있음이라 판단되어 DNB배지로부터 184균주의 저영양세균을 분리하였다. 본 연구에서는 시판 음용수(CW, CJ )와 광천수(DPG, CJG1)에서 분리된 저영양세균 102 균주의 165 rDNA 염기서열을 결정하여 계통분류학적 특성을 검토한 결과 세 개의 주요한 계통군: Proteobacteria $\alpha$-subdivision (49 균주), $\beta$-subdivision (50 균주), $\gamma$-subdivision (3 균주)으로 분류되었다. Proteobacteria $\alpha$-subdivision에는 Afipia, Blastobacter, Bradyrhizobium, Caulobacter, Phenylobacterium, Rhizobioum, Sphingomonas가 포함되었으며, $\beta$-subdivision에는 Acidovorax, Azonexus, Ferribacterium, Janthinobacterium, Leptothrix, Polaromonas, Variovorax가 포함되었고, $\gamma$-subdivision에는 Rhodanobacter 등 다양한 계통군이 확인되었다.

• 상하수도학회지
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• 제29권1호
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Applied Biological Chemistry
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• 제40권6호
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• pp.551-555
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• 1997

본 연구는 숙주특이적인 근류형성에 두과작물의 뿌리분비물에 포함된 기주특이적인 flavonoids와 근류균의 상호작용에 대해 실험하였다. Flavonoid 화합물에 대한 근류균의 생물학적 활성은 B. japonocum의 경우 대두의 뿌리분비물에 포함된 flavonoid화합물인 daidzein과 genistein에서는 생장 증진 효과가 나타났으며, alfalfa의 뿌리분비물에 포함된 flavonoid인 luteolin에서는 생장 저해 효과가 나타났으며, R. meliloti의 경우 luteolin의 경우 생장증진 효과가 나타났으며, daidzein과 genistein의 경우 생장저해효과가 나타났다. 각 근류균의 흡수 특이성은 B. japonicum에서 daidzein과 genistein이 각각 $14.95\;{\mu}g/g$와 $14.20\;{\mu}g/g$로 가장 높고 luteolin이 가장 낮게 나타났으며, R. meliloti의 경우 luteolin이 $18.31\;{\mu}g/g$으로 가장 높고 daidzein과 genistein이 가장 낮게 나타났다. 이와 같은 사실로 숙주특이적인 flavonoids가 근류균의 숙주특이성에 깊은 관련이 있을 것으로 사료된다.

• Applied Biological Chemistry
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• 제40권6호
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• pp.546-550
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• 1997

근류균과 대두의 공생에서 숙주 결합성을 조사하기 위하여 대두종자로 부터 분리한 lectin과 뿌리추출물과의 동일성 여부를 조사한 결과는 다음과 같다. 탈지 대두분으로 부터 분리한 lectin은 크로마토그라피와 전기영동상 단일물질로 분리되었고 백운 및 팔달로 부터 분리한 lectin은 표준 lectin의 항체와 항원-항체 반응을 나타내어 동일한 물질이었다. 종자lectin 및 뿌리추출물 및 뿌리분비물에 대한 화학주성은 RCR 3407, KCTC 2422에서 뿌리분비물에 대한 주성이 가장 높았고 종자 lectin과 뿌리추출물은 비슷한 화학주성을 나타내었다. 대두의 유근으로 부터 분리한 뿌리추출물은 표준 lectin의 항체와 침강선을 형성하여 대두 종자 lectin과 동일한 물질임을 알수 있었으며 뿌리 분비물과는 침강선을 형성치 않았다. 대두와 상호접종군을 형성하는 RCR3407, KCTC2422 및 LPN-101은 대두의 종자 lectin 및 뿌리추출물과 결합하였으나 완두의 lectin과는 결합하지 않았고 대두와 근류형성을 하지않는 LPN-100은 대두의 lectin과 결합하지 않았다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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• pp.150-156
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• 2000

Oligotrophic bacteria isolated from forest soil showed a specific community consisting of various taxonomic groups compared with those in other soil or aquatic habitats. Based on the cell shape, the isolates were divided into four groups: regular rod, curved/spiral rod, irregular rod, and prosthecate bacteria. The cellular fatty acids 60 oligotrophic isolates were analyzed. The 30 fatty acids which were identified or characterized are classified. At the dendrogram based on cellular fatty acid composition, four clusters(I-IV) were separated at a euclidian distance of about 50. Cluster 3 and 4-a strains were containing Q-8, these strains are accommodated in the Proteobacteria gamma and beta subdivision. The chemotaxonomic profiles of the cluster 4-a strains showed good agreement with those of the genus Burkholderia. Cluster 3 was characterized by the presence of branched-chain fatty acids, iso-C15:0, iso-C17:1, and iso-C17:0 as the major components. These chemotaxonomy suggested the close relationship of the isolates with Xathomonas/Sterotrophomonas group. Based on the 16S rDNA sequence analysis, the two representative strains(MH256 and MA828) of cluster 3 showed the close relation to genera, Xathomonas/Sterotrophomonas, but were not included in these genera. These strains were even further away from core Xanthomonas, and clearly were seen to branch outside the cluster formed by the Sterotrophomonas maltophilia. MH256 and MA828 16S rDNA sequence was different enough to put new genus on a separate branch. The isolates with Q-10 were also studied. They are corresponded to the two large groups in Proteobacteria alpha subdivision. One was incorporated in the genus Bradyrhizobium cluster, which also includes Agromonas, a genus for oligotrophic bacteria. The strains of the other group showed high similarity to the genus Agrobacterium.

• Journal of Species Research
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• 제9권4호
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• pp.362-374
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• 2020

A total of 35 bacterial strains were isolated from various sediment samples. From 16S rRNA gene sequence similarities higher than 98.7% and the formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to independent and predefined bacterial species. No previous official reports have described these 35 species in Korea. The unrecorded species were assigned to 6 phyla, 10 classes, 18 orders, 23 families, and 31 genera. At the genus level, the unrecorded species were affiliated with Terriglobus of the phylum Acidobacteria, as well as with Mycobacterium, Rhodococcus, Kineococcus, Phycicoccus, Agromyces, Cryobacterium, Microbacterium, and Arthrobacter; Catellatospora of the class Actinomycetia; Lacibacter of the class Chitinophagia; Algoriphagus and Flectobacillus of the class Cytophagia; Flavobacterium and Maribacter of the class Flavobacteriia; Bacillus, Cohnella, Fontibacillus, Paenibacillus, Lysynibacillus, and Paenisporosarcina of the class Bacilli; Bradyrhizobium, Gemmobacter, Loktanella, and Altererythrobacter of the class Alphaproteobacteria; Acidovorax of the class Betaproteobacteria; Aliiglaciecola, Cellvibrio, Arenimonas, and Lysobacter of class Gammaproteobacteria; and Roseimicrobium of the class Verrucomicrobia. The selected strains were subjected to further taxonomic characterization, including Gram reaction, cellular and colonial morphology, and biochemical properties. This paper provides detailed descriptions of the 35 previously unrecorded bacterial species.