• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.232-239
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• 2009

This research investigated the characteristics of antibiotic resistance of bacteria in microbial communities from municipal wastewater treatment plants (MWTPs), and monitored seasonal changes of antibiotic resistant bacteria (ARB) from MWTPs and Han river. When antibiotics were amended to either R2A agar (R2A) for general heterotrophs or MacConeky sorbitol agar (MSA) for coliform bacteria, all the MWTP samples exhibited multiple antibiotic resistance on the antibiotic-amended solid media. The antibiotic resistance appearing frequencies of ampicillin and sulfathiazole, respectively, were higher than reported data for other countries. The antibiotic resistance appearances differed depending upon the concentrations of primary substrate and nutrients and the types of cultivation media. The following 16S rRNA gene phylogenetic analysis showed that the identified multiple-antibiotic resistant microbes on R2A plates were more likely to be known human-pathogenic bacteria than the background heterotrophic bacteria were, suggesting a high risk of antibiotic resistance appearance to public health. In addition, according to our investigation of seasonal changes of ARB from urban MWTP and river samples, the frequency of ARB appearances was shown to correlate positively with temperature. This indicates a possibility that global warming result in increase in microbial risk to public health.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.403-408
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• 1996

Total bacterial community DNA, which was extracted from microcosm soil and field soil after 2,4-D amendments, was analyzed on Southern blots, using the tfdA gene probe derived from plasmid pJP4 and the Spa probe from Sphingomonas paucimobilis. Southern blot analyses with total bacterial DNA extracted from soils Inoculated with Pseudomonas cepacia/pJP4 revealed that DNA probe method could detect the 2,4-D degrading bacteria down to $10^5\;cells/g$ dry soil. In the microcosm experiment, there was a good correlation between 2,4-D degradation and banding patterns in hybridization analyses performed after each 2,4-D treatment using the two probes. When bacterial DNA extracted from microcosm soil was hybridized with the Spa probe, a change in the position of hybrid bands was observed over time in a Southern blot, suggesting that population change or possibly genetic rearrangement in 2,4-D degrading microbial populations occurred in this soil. With the Spa probe, one hybrid DNA band was persistently observed throughout the five 2,4-D additions. When bacterial DNA isolated from the field soil was probed with the tfdA and Spa, strong hybridization signal was observed in the 100 ppm-treated subplot, weak signal In the 10 ppm-treated subplot, and no significant signal in the 1 ppm-treated and control subplots. The data show that DNA probe analyses were capable of detecting and discriminating the indigenous 2,4-D degrading microbial populations in soil amended with 2,4-D under laboratory and field conditions.

• Journal of fish pathology
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• v.5 no.2
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• pp.87-92
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• 1992

Lysozymes were isolated and purified from various organs of cultured flounder by using chitin-coated cellulose column chromatography. The molecular weights of them were compared with each other in 15% SDS-PAGE gels. The result showed that all lysozymes isolated from various organs of flounder had the same molecular weight of about 14000. To clarify the role of lysoryme as a body defence, the antibacterial activities of flounder lysozyme on seven bacterial pathogens, five Gram-negative and two Gram-positive species, were investigated. The lysozyme had substancial antibacterial activity on four strains, two Gram-negative and two Gram-positive species. These suggest that flounder lysozyme plays a role in body defence against both Gram-negative and Gram-positive bacterial pathogens.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.299-305
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• 2006

D-Alaninepeptidase purified from Bacillus amyloliquefaciene CMB01 caused a reduction of survival of Proteus vulgaris, Klebsiella oxytoca, and Staphylococcus aureus placed under the osmotic pressure. D-Alaninepeptidase caused an increase of susceptibility of bacteria to antibiotics. An increased number of malformed cells in bacterial groups exposed to D-alaninepeptidase was observed by scanning electron microscopy. These data suggested that bacterial cells exposed to D-alaninepeptidase resulted in an increase of vulnerability of bacterial cells toward environmental stress, such as osmotic pressure and antibiotic substances.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.158-161
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• 2015

Bacterial dermatitis is common disease that is necessary to treat with antibiotics. In recent, antibiotic-resistant bacteria is being increased in worldwide. The purpose of the present study was to evaluate the prevalence of resistant genes in Staphylococcus (S.) pseudintermedius isolated from dogs, and to compare the resistant gene profile with the result of antibiotic disc diffusion test. A total of seven S. pseudintermedius was included in the study. Bacterial identification was performed by 16S ribosomal RNA gene sequence analysis. S. pseudintermedius isolates had more than one antibiotic resistant gene (mecA, blaZ and aac(6')/aph(2"). While all isolates were PCR positive to blaZ gene, only two isolates were resistant to amoxicillin/clavulanate. Among five isolates harboring gentamicin resistance, one isolate was negative to aac(6')/aph(2")-targeted PCR. Taken together, the results suggest that resistant gene-targeted PCR and disc diffusion test are complementary to detect antibiotic resistance.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.31-37
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• 2002

For elucidating the correlation between the eubacterial community structure and environmental parameters in Nammae Reservoir located in Kyungsan, Kyungbuk, the bacterial community structure and their structure affecting environmental parameters were analyzed using Fluorescent In Situ Hybridization (FISH) monthly over year. $\alpha$ . $\beta$ . $\gamma$-subclasses of Proteobacteria and Cytophaga-Flavobacterium (CF) group known as dominant bacterial group in freshwater were detected in 3 stations over year. The ratio of each subclass to total bacteria was determined; $\alpha$.$\beta$ . $\gamma$-subclasses and CF group varied in the range of 4.0~29.2%, 1.7~25.8%, 1.8~12.8%, 4.9~36.3%, respectively and there was no substantial differences between stations. In terms of the correlation between each group specific bacteria and environmental parameters such as temperature, SS, pH, DOC, NH$_4$-N, NO$_3$-N, PO$_4$-P, standing crops of algae, the results were as follows: 1) total bacterial numbers correlated positively with temperature, SS and DOC, 2) Eubacteria positively with DOC and Chl-$\alpha$, 3)${\gamma}$-subclass positively with DOC, and 4) CF group positively with standing crops of chlorophyceae, 5) whereas $\beta$-subclass bacteria correlated negatively with standing crop of cyanobacteria and that of total algae.

• Journal of Life Science
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• v.25 no.3
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• pp.323-328
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• 2015

The study of microbial diversity and richness in soil samples from a volcanic island named Ulleungdo, located east of South Korea. The soil bacterial communities on the Ulleungdo were analyzed using pyrosequencing method based on 16S rRNA gene. There were 1,613 operational taxonomic units (OUT) form soil sample. From results of a BLASTN search against the EzTaxon-e database, the validated reads (obtained after sequence preprocessing) were almost all classified at the phylum level. Proteobacteria was the most dominant phylum with 48.28%, followed by acidobacteria (26.30%), actionbacteria (6.89%), Chloroflexi (4.58), Planctomycetes (4.56%), Nitrospirae (1.83%), Bacteroidetes (1.51%), Verrucomicrobia (1.48%), and Gemmatimonadetes (1.11%). α-proteobacteria was the most dominant class with 36.07% followed by Acidobacteria_c (10.65%), Solibacteres (10.64%), δ-proteobacteria (4.42%), γ-proteobacteria (4.29%), Planctomycetacia (4.16%), Actinobacteria_c (4.00%), Betaproteobacteria (3.50%), EU686603_c (2.97%), Ktedonobacteria (2.91%), Acidimicrobiia (1.32%), Verrucomicrobiae (1.27%), Gemmatimonadetes_c (1.11%), Sphingobacteria (1.09%), and GU444092_c (1.06%). Bradyrhizobiaceae was the most dominant family with 22.83% followed by Acidobacteriaceae (10.62%), EU445199_f (5.72%), Planctomycetaceae (4.03%), Solibacteraceae (3.63%), FM209092_f (3.58%), Steroidobacter_f (2.81%), EU686603_f (2.73%), Hyphomicrobiaceae (2.33%), Ktedonobacteraceae (1.75%), AF498716_f (1.46%), Rhizomicrobium_f (1.03%), and Mycobacteriaceae (1.01%). Differences in the diversity of bacterial communities have more to do with geography than the impact on environmental factors and also the type of vegetation seems to affect the diversity of bacterial communities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.77-81
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• 1998

A bacteriological study of sea water in Deukryang Bay was conducted to evaluate sanitary conditions of the bay and compliance of waters with the recommended bacteriological criteria for the designated area of shellfish cultivation. Sea water samples were collected at the established sampling stations (fig. 1) from May 1995 to November 1996. During the study period, coliform group, fecal coliform, classification of coliform group with IMViC reactions and pathogenic vibrios were analyzed. Coliform group and feral coliform MPN's were ranged from $<\;3.0\~4600/100m{\ell}\;and\;<\;30\~1,100/100m{\ell}$, respectively. The bacteriological criteria of sea water in shellfish growing area should be less than 70 per l00ml of sea water for median value of coliform MPN, and below $10\%$ of the samples which contain over than 230 for coliform MPN or over than 43 for fecal coliform MPN, Most of the waters from 26 sampling stations were complied water coliform criteria recommended for designated shellfish growing area. Then, the ratios of the samples with move than 230/10ml of coliform group MPN and more than 43/100ml of fecal coliform MPN were $7.4\%$ and $8.5\%$, respectively. The bacterial density of the sea water was deeply affected by rainfall amount. For example, coliform bacterial counts of sea watery after 48 hours from 93 mm rainfall were $6\~7$ times higher than those of without rainfall. During the study period, infectious bacteria such as Vibrio cholerae, Salmonella sp. an d Shigella sp. were not detected from the samples, but detection ratios of Vibrio parahaemolyticus and Vibrio vulnificus were $15\~20\%$ in summer months.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Journal of Nutrition and Health
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• v.10 no.4
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• pp.68-83
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• 1977

영양실태조사 및 사람을 대상으로 하는 많은 영양적 연구에서 요중(尿中) 여러 성분(成分)들의 배설량을 측정하기 위해 만 하루의 소변을 완전히 채취하기는 매우 어려우므로 임의시간(任意時間)의 소변을 채취하여 사용한다. 이 경우엔 흔히 요성분(尿成分)의 농도는 요중(尿中) 크레아티닌을 양(量)을 기준으로 하여 표시되는데, 크레아티닌은 요중(尿中) 일일(一日) 배설량이 개인에 따라 알정하고 요양(尿量)에는 상관없이 비교적 일정한 속도로 배설 된다고 간주되기 때문이다. 그러나 비교적 높은 발생율을 갖는 세균재(細菌在) 요도염(尿道炎)에서는 감염균(感染菌)이 크레아티닌을 파괴할 가능성이 있고 따라서 이 경우의 요중(尿中) 크레아티닌의 여러 용도(用途)는 비합리적으로 될 수 있다. 본 연구에서는 이 가설을 규명하려고 한다. 첫 실험에서는 감염균(感染菌)이 요소(尿素)를 암모니아로 파괴함으로써 형성되는 요(尿)의 알칼리성에 대한 크레아티닌의 안정성(安定性)을 알아 보았다. 건강인(健康人)의 요중(尿中) 크레아티닌과 완충액에 용해시킨 순수 크레아티닌을 pH $4.5{\sim}9.0$으로 조정하여 $37^{\circ}C$에서 6일간 배양시켰다. 잔존한 크레아티닌을 측량한 결과, 크레아티닌은 완충용액이나 요(尿)에서서 모두 산성 pH에서 보다 알칼리 pH에서 더욱 안정(安定)함을 보여주었다. 1일간 배양 후엔 거의 변화(變化)가 없었고 6일 후에나 $4.2{\sim}8.0%$의 감소율을 나타냈을 뿐이다. 두번째 실험에서는 감염균이 크레아티닌을 성장(成長)을 위한 질소급원으로 사용하는지를 결정하기 위해 세균성(細菌性) 요도염(尿道炎)에서 자주 발견되는 13종류(種類)의 박테리아를 건강인(健康人)의 요(尿)와 크레아티닌을 질소급원으로 하는 합성배지(合成培地)에 $37^{\circ}C$로 배양하였다. 대부분의 박테리아는 크레아티닌함양(含量)을 감소시키지 않았다. 그러나 Pseudomonas aeruginosa와 Klebsiella pneumoniae는 합성배지중(合成培地中)의 크레아티닌을 상당량 파괴시켰고, 그 파괴율은 그들 성장율과 평행하였다. 배양 6일후에는 크레아티닌이 Pseudomonas aeruginosa에 의해 처음 양(量)(500mg/100m1) 의 12.8%가, Kleobsiella pneumoniae에 의해서는 11.8%가 감소되었다. 감소율은 크레아티닌의 처음 농도가 낮을수록 커져서 50mg/100ml 일 때는 각각 21.1%와 28.2%이었다. 더욱이 Klebsiella pneumoniae는 황산암모늄과 요소(尿素)같은 다른 질소급원이 크레아티닌과 공존(共存)할 때에도 크레아티닌을 어느 정도 파괴함을 보여 주었다. 결론으로, 세균성(細菌性) 요도염(尿道炎)환자의 요(尿)의 알칼리성은 요중(尿中) 크레아티닌양(量)에 중요한 영항을 주지 못한다. 그러나 본(本) 연구(硏究)에서 사용된 Klebsiella pneumoniae와 가능하게는 Pseudomonas aeruginosa 같은 몇 감염균(感染菌)은 크레아티닌을 그들 성장(成長)의 질소급원으로 사용하여 요중(尿中) 크레아티닌양(量)을 저하시킬지도 모른다. 특히 요(尿)에 요소(尿素), 요산(尿酸)같은 다른 질소급원이 크레아티닌에 비해 비교적 낮은 비율로 존재할 때에, 예(例)를 들면 저(低)단백식사(食事)인 경우, 감염균에 의한 크레아티닌의 파괴율이 더 클 것으로 기대된다.