• KSBB Journal
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• v.30 no.5
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• pp.239-244
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• 2015

Bacterial vaginosis (BV) is caused by microbial imbalance of the vaginal ecosystem and overgrowth of anaerobic bacteria. The antibiotic treatment often results in very high recurrence of BV because it disturbs the vaginal ecosystem. The high recurrence rates suggest a need for alternative therapeutic methods and probiotics are being recognized as alternative or additional treatment method for BV. The purpose of this study was to investigate how human vaginal isolates of Lactobacillus spp. inhibit the BV-associated pathogen Gardnerella vaginalis. Results show that selected strains significantly reduced the viability of G. vaginalis. Among these selected strains KLB410 and KLB416 were further selected based on acid/bile tolerance and identified through 16S rRNA gene sequencing being Lactobacillus plantarum. Further studies are underway to demonstrate that the selected strain can be applied as potential probiotics for recovering vaginal ecosystem.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.547-554
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• 2012

Chromium is generated from several industrial processes. It occurs in different oxidation states, but Cr(III) and Cr(VI) are the most common ones. Cr(VI) is a toxic, soluble environmental contaminant. Some bacteria are able to reduce hexavalent chromium to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of considerable interest. An indigenous chromium-reducing bacterial strain, Rb-2, isolated from a tannery water sample, was identified as Ochrobactrum intermedium, on the basis of 16S rRNA gene sequencing. The influence of factors like temperature of incubation, initial concentration of Cr, mobility of bacteria, and different carbon sources were studied to test the ability of the bacterium to reduce Cr(VI) under variable environmental conditions. The ability of the bacterial strain to reduce hexavalent chromium in artificial and industrial sewage water was evaluated. It was observed that the mechanism of resistance to metal was not due to the change in the permeability barrier of the cell membrane, and the enzyme activity was found to be inductive. Intracellular reduction of Cr(VI) was proven by reductase assay using cell-free extract. Scanning electron microscopy revealed chromium precipitates on bacterial cell surfaces, and transmission electron microscopy showed the outer as well as inner distribution of Cr(VI). This bacterial strain can be useful for Cr(VI) detoxification under a wide range of environmental conditions.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.485-490
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• 1994

A restriction endonuclease, PsyI, has been isolated from Pseudomonas syringae pv. pha- seolicola, and its catalytic properties have been studied. This enzyme was purified through strepto- mycin sulfate and ammonium sulfate fractionation, phosphocellulose Pll, DEAE-cellulose, hydroxy- apatite and Sephadex G-100 column chromatography. It's molecular weight was about 50,000 dalton as determined by 7.5% polyacrylamide gel electrophoresis containing 0.1% SDS. In catalytic proper- ties, PsyI shows stable at wide ranges of pH between 7.0 and 10.0, of temperature between 30$\circ$C and 37$\circ$C, and its thermal stability is between 25$\circ$C, and 45$\circ$C, at the presence Of 10 mM MgCl$_{2}$-PsyI essentially require Na salt for enzyme reaction, is rather inhibited in the high Na salt concent- ration. The presence of 2-mercaptoethanol is absolutely required for the enzyme activity. This endonuclease, PsyI was determined to be an isoschizomer of SalI from the results of the restriction mapping and DNA sequencing.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.302-307
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• 2010

Nitrogen is an element need to grow plants growth. Plants take up nitrogen in the form of nitrate or ammonium. Most of plants absorb nitrogen source as fertilizers. But from 50 to 70% of fertilizers applied were washed away. This study was conducted to isolate free-living nitrogen fixing bacteria from reed and to examine its beneficial traits for developing sustainable biofertilizers. Enriched consortium obtained from a reed in Ansan was developed for the fixing of nitrogen. Nitrogen fixing bacteria isolated from an enriched culture in Congo Red Medium was analyzed by 16s rDNA sequencing. AKC-10 was isolated and shown to have excellent nitrogen fixing ability. The optimum conditions of nitrogen fixing ability were $25^{\circ}C$ ($237.50{\pm}39.65\;nmole{\cdot}mg-protein^{-1}{\cdot}h^{-1}$ and pH 7 ($168.335{\pm}12.84$ nmole/hr mg-protein). It was identified as Microbacterium hominis [(AKC-10 (similarity : 99%)]. This strain was had to IAA (indole-3-acetic acid) productivity and ACC(1-aminocyclopropane-1-carboxylic acid) deaminase activity. Therefore, Microbacterium hominis AKC-10 stimulated plant development in the soil, enhancing the efficiency of remediation.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.431-435
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• 2012

In this study, we describe a novel approach to achieve replicative selectivity of conditionally replicative adenovirus that is based upon trans-splicing ribozyme-mediated replacement of cancer-specific RNAs. We developed a specific ribozyme that can reprogram human telomerase reverse transcriptase (hTERT) RNA to induce adenoviral E1A gene expression selectively in cancer cells that express the RNA. Western blot analysis showed that the ribozyme highly selectively triggered E1A expression in hTERT-expressing cancer cells. RT-PCR and sequencing analysis indicated that the ribozyme-mediated E1A induction was caused via a high fidelity trans-splicing reaction with the targeted residue in the hTERT-expressing cells. Moreover, reporter activity under the control of an E1A-dependent E3 promoter was highly transactivated in hTERT-expressing cancer cells. Therefore, adenovirus containing the hTERT RNA-targeting trans-splicing ribozyme would be a promising anticancer agent through selective replication in cancer cells and thus specific destruction of the infected cells.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.429-435
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• 1998

Lectins and its A- and B-chains from Korean mistletoe (Viscum album var. coloratum) were isolated by affinity chromatography on the Sepharose 4B modified by lactose-BSA conjugate synthesized by reductive amination of ligand (lactose) to .epsilon.-amino groups of lysine residues of spacer (BSA) after reduction by $NaCNBH_3$. The lactose-BSA conjugate was coupled to Sepharose 4B activated by cyanogen bromide. The molecular weight determined by SDS-PAGE were a 31 kD of A-chain and a 35kD of B-chain. Amino acid analysis and N-terminal sequencing were performed. The effects of pH, temperature and guanidine chloride on the conformation of the lectin were investigated by measuring its intrinsic fluorescence and compared with its hemagglutinating activities. Blue shift was detected on the acidic pH and there was a close relationship between activities and conformation of the lectin. Under denaturing conditions, the tryptophan emission profile of lectin showed typical denaturaiional red shift which also correspond to the conformations and activity of lectin.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.6
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• pp.538-543
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• 2006

A packed bed reactor (PBR) was fed with nitrate containing synthetic wastewater or effluent from a sequencing batch reactor used for nitrification. The C source introduced into the PBR consisted of volatile fatty acids (VFAs) produced from anaerobic acidogenesis of food wastes. When nitrate loading rates ranged from $0.50\;to\;1.01\;kg\;N/m^{3}{\cdot}d$, the PBR exhibited $100{\sim}98.8%\;NO_{3}^{-}-N$ removal efficiencies and nitrite concentrations in the effluent ranged from $0\;to\;0.6\;NO_{2}^{-}-N\;mg/L$. When the PBR was further investigated to determine nitrate removal activity along the bed height using a nitrate loading rate less than $1.01\;kg\;N/m^{3}{\cdot}d$, 100% nitrate removal efficiency was observed. Approximately 83.2% nitrate removal efficiency was observed in the lower 50% of the packed-bed height. When reactor performance at a C/N ratio of 4 and a C/N ratio of 5 was compared, the PBR showed better removal efficiency (96.5%) of nitrate and less nitrite concentration in the effluent at the C/N ratio of 5. VFAs were found to be a good alternative to methanol as a carbon source for denitrification of a municipal wastewater containing 40 mg-N/L.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.670-676
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• 2000

Several clones obtained from Serratia marcescens stimulated E. coli TP2139 (${\Delta}lac, \;{\Delta} crp$) cells to use maltose as a carbon source. The crp gene clone, pCKB12, was confirmed to stimulate the $\beta$-galactosidase activity, by Southern hybridization [31]. The nucleotide sequence of the crp region consisting of 1,979 bp was determined. The sequencing of the fragment led to the identification of two open reading frames: One of these, the crp gene, encoded 210 amino acid and the other encoded a truncated protein. The S. marcescens and E. coli crp genes showed a higher degree of divergence in their nucleotide sequence with 120 changes, however, the corresponding amino acid sequences showed only two amino acid differences. Yet, an analysis of the amino acid divergence revealed that the catabolite gene activator protein, the crp gene product, was the most conserved protein observed so far. Using a crp-lac protein fusion, it was demonstrated that S. marcescens CRP could repress its own expression, probably via a mechanism similar to that previously described for the E. coli crp gene.

• Genomics & Informatics
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• v.18 no.4
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• pp.37.1-37.11
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• 2020

BET inhibitor, as an epigenetic regulator inhibitor, reduces the expression of oncogenes such as Myc and Bcl-2, which affects cancer growth and development. However, it has modest activity because of the narrow therapeutic index. Therefore, combination therapy is necessary to increase the anti-tumor effect. Paclitaxel, an anti-mitotic inhibitor, is used as second-line therapy for gastric cancer (GC) as a monotherapy or combination. In this study, we performed RNA sequencing of GC cells treated with iBET-151 and/or paclitaxel to identify the differentially expressed genes associated with possible mechanisms of synergistic effect. We also performed Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses to determine the most enriched terms and pathways of upregulated and downregulated genes. We found 460 genes in which iBET-151 and paclitaxel combination treatment changed more than single-treatment or no-treatment. Thus, additional functional studies are needed, but our results provide the first evidence of the synergistic effect between iBET-151 and paclitaxel in regulating the transcriptome of GC cells.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.312-316
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• 2018

BACKGROUND: Yeast biotechnology finds applications in various industries. Hence, we sought to explore the yeasts associated with the flower of Aster spathulifolius Maxim. This study aimed to isolate yeasts from the flower of the plant and screen for biosurfactant-producing yeasts. METHODS AND RESULTS: We collected flowers of Aster spathulifolius Maxim. and performed pure isolation using four types of media. In total, 117 strains belonging to 4 genera, namely, Cryptococcus (75 strains), Aureobasidium pullulans (30 strains), Candida (11 strains), and Rhodotorula (1 strain), were isolated and identified by ITS sequencing. Upon in-depth analysis, Cryptococcus, the most dominant genus (75 strains) was categorized into the 'Unknown group'. Upon in-depth analysis of A. pullulans, we discovered the 'Unknown group I' (27 strains) and the 'Unknown group II' (2 strains), which have not been reported previously. Two A. pullulans isolates with potent surfactant activity were selected via the screening procedure. CONCLUSION: In this study, a total of 117 strains were isolated from the flower of Aster spathulifolius Maxim. In addition, two biosurfactant-producing yeasts were identified from among the isolated yeasts.