• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.36-39
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• 2005

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.561-571
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• 1994

The comparative study on the predominant cultivable periodontopathic bacteria were done 2 weeks after the application of the e-PTFE membrane and collagen membrane in the controlled tissue regeneration procedures. The purpose of the present study also included the antibiotic susceptibility test (ciprofloxacin, tetracycline, clindamycin) of these cultured organisms. 0.1% chlorhexidine mouthwash (10ml twice/day for 6 weeks) and systemic doxycycline (200mg/day for 2 weeks) were administered for supragingival and subgingival plaque control respectively. Four clinical isolates of A.a. from 2 patients were found to be resistant to tetracycline which were susceptible to clindamycin and ciprofloxacin. One isolate of W.r. and two unidcntified microorganisms were resistant only to clindamycin and one isolate of NID BPB and E.c. and two isolates of unidentified microorganisms were resistant only to ciprofloxacin. Overall susceptibility of tested microorganisms to ciprofloxacin, tetracycline and clindamycin were 85%, 77% and 89% respectively. The results indicated no significant differences in the percentage of cultivable periodontopathic bacteria between the two membranes, and also the microorganisms resistant to tetracycline after systemic administration of doxycycline turned out to be susceptible to either ciprofloxacin or clindamycin.

• Journal of Marine Bioscience and Biotechnology
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• v.7 no.2
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• pp.42-51
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• 2015

The community structure of cultivable bacteria associated with the marine sponge, Petrosia corticata, collected from Jeju Island in summer (September) of 2012 and winter (January) of 2013, were compared by the PCR-ARDRA method. Bacterial strains were cultured for 4 days at $26^{\circ}C$ on Zobell medium and marine agar medium. After PCR amplification of 16S rRNA gene of individual strains, the restriction enzymes MspI and HaeIII were used to make restriction patterns. As a result, 24 ARDRA patterns from the summer sponge and 20 ARDRA patterns from the winter sponge were obtained. The sequencing result of 1-3 selected strains from each pattern showed over 98% similarities with the known sequences from the public database. At the phylum level, the bacterial community structures of both sponges (summer and winter) were identical qualitatively and composed of 4 phyla : Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Alphaproteobacteria accounted for 42.5% of total in summer sponge and 25.2% in winter, decreasing in the winter sample. Gammaproteobacteria accounted for 27.5% of total in summer sponge and 35.2% in winter, increasing in the winter sample. At the genus and species level, summer sponge had more diverse bacterial communities than winter sponge. Actinobacteria, Bacteroidetes, and Firmicutes increased in the winter sample.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.328-331
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• 2012

Microbial diversity in the 1500 m depth sea waters off the coast of Ulleung island of the East Sea, Korea, was investigated. Genomic DNAs were extracted directly from the marine microbes filtered through ultramembrane filters. Pyrosequencing of 16S rDNAs of these microbes resulted in 13,029 reads, of which uncultured bacteria consisted of 54.1%, alphaproteobacteria 23.4%, and gammaproteobacteria 22.3%. Other classes such as flavobacteria, actinobacteria, and epsilonproteobacteria were distributed within 0.2% of total reads. Among the cultivable bacteria, it was found that Rhodobacteraceae family of alphaproteobacteria, Alteromonadaceae, Halomonadaceae, and Piscirickettsiaceae families of gammaproteobacteria were mostly distributed in the deep-sea waters.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.437-447
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• 2012

Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plant-growth-promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 ${\mu}M$ auxin per ${\mu}g$ of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.

• Mycobiology
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• v.36 no.1
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• pp.40-44
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• 2008

Various bacteria were isolated from the casing layer soil of the culture bed of P. ostreatus and their role in fruiting body induction of the edible mushroom, P. ostreatus, was investigated. Analysis of the bacterial community isolated from the casing layer soil revealed that the composition of genera and number of cultivable bacteria were different for each sterilizing treatment. Bordetella was predominant in the bulk soil whereas Flavobacterium was predominant after sterilization of the casing layer soil. Fluorescent Pseudomonas was predominant in the non-sterilized casing layer soil. Total number of the bacterial genera in the casing layer soil was higher than that in the bulk soil. In particular, an increase in the fluorescent Pseudomonas population was observed in the non-sterilized casing layer accompanied by induction of fruiting body and enhanced mushroom production yield. The results suggested that specific bacterial populations in the casing layer play an important role in the formation of primodia and the development of basidiome in P. ostreatus.

• KSBB Journal
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• v.25 no.4
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• pp.319-329
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• 2010

Bifidobacteria comprises up to 25% of the cultivable fecal bacteria in adults and 80% in infants. Many in vivo and clinical research results supporting its efficacy in the prevention and improvement of gastrointestinal health have been accumulated. As a consequence, expert committee WHO/FAO expert committee recommended Bifidobacterium as representative probiotics together with Lactobacillus acidophilus. In this review, research trends in bifidobacteria concerning the classification and identification of the genus Bifidobacterium, modulation of intestinal microflora, improvement of constipation, prevention of diarrhea, alleviation of atopy and allergy, barrier function through antimicrobial activity andimmune enhancement of the host will be introduced. Several gene expression systems based on bifidobacterial plasmids have been developed and successfully used to express several heterologous genes including anticancer proteins in Bifidogacterium. In animal test, bifidobacteria was proven to be a promising candidate for safe gene delivery system which can specifically colonize in the solid tumor.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.283-291
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• 2012

Bioremediation efforts often rely on the application of surfactants to enhance hydrocarbon bioavailability. However, synthetic surfactants can sometimes be toxic to degrading microorganisms, thus reducing the clearance rate of the pollutant. Therefore, surfactant-resistant bacteria can be an important tool for bioremediation efforts of hydrophobic pollutants, circumventing the toxicity of synthetic surfactants that often delay microbial bioremediation of these contaminants. In this study, we screened a natural surfactant-rich compartment, the estuarine surface microlayer (SML), for cultivable surfactant-resistant bacteria using selective cultures of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Resistance to surfactants was evaluated by colony counts in solid media amended with critical micelle concentrations (CMC) of either surfactants, in comparison with non-amended controls. Selective cultures for surfactant-resistant bacteria were prepared in mineral medium also containing CMC concentrations of either CTAB or SDS. The surfactantresistant isolates obtained were tested by PCR for the Pseudomonas genus marker gacA gene and for the naphthalene-dioxygenase-encoding gene ndo. Isolates were also screened for biosurfactant production by the atomized oil assay. A high proportion of culturable bacterioneuston was tolerant to CMC concentrations of SDS or CTAB. The gacA-targeted PCR revealed that 64% of the isolates were Pseudomonads. Biosurfactant production in solid medium was detected in 9.4% of tested isolates, all affiliated with genus Pseudomonas. This study shows that the SML is a potential source of surfactant-resistant and biosurfactant-producing bacteria in which Pseudomonads emerge as a relevant group.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.585-595
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• 2019

Analysis of bacterial communities based on their 16S rDNA sequences revealed the predominance of Proteobacteria (Aeromonas sp., Acinetobacter sp. and Thaueraamino aromatica sp.) and uncultured bacterium in activated sludge from the effluent treatment plant (ETP) of Mother Dairy, Calcutta (India). Each isolate was used for bioremediation of dairy wastewater with simultaneous conversion of nitrogenous pollutants into ammonia. A consortium developed using seven of these isolates and three Bacillus strains from different environmental origins could reduce 93% nitrate with simultaneous production of ammonia (626 ㎍/100 ml) within 20 h in non-aerated, immobilized conditions as compared to 82% nitrate reduction producing 2.4 ㎍/100 ml ammonia in 96 h with extensive aeration in a conventional ETP. The treated ammonia-rich effluent could be used instead of freshwater and fertilizer during cultivation of mung bean with 1.6-fold increase in grain yield. The ETP with the surrounding agricultural land makes this process a zero liquid discharge technology for using the biofertilizer generated. In addition, the process requires minimal energy supporting sustained environmental health. This method is thus proposed as an alternative approach for small-scale dairy ETPs.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.263-272
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• 2010

One hundred sixty three strains showing different colony morphological characteristics on different concentration of marine agar (MA) plates were isolated from ambient seawater near Dokdo island. Bacterial diversity and distributions were studied by phylogenetic analysis of the partial 16S rRNA gene sequences. One hundred sixty three strains were partially sequenced and analyzed phylogenetically. They were composed of 5 phyla, of which gamma-proteobacteria (58%), alpha-proteobacteria (20%), bacteriodetes (16%) were predominant. They were affiliated with 90 species. The 16S rRNA sequence similarity of the isolates was in 93.3 to 100 % range to reported sequence data. Thirty six isolates of among them were assumed to be novel species candidates based on similarity analysis of the 16S rRNA gene sequences. Overall, Proteobacteria and Bacteriodetes of the Dokdo coastal sea water showed a high diversity.