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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Microbiology and Biotechnology Letters
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 34, Issue 4 - Dec 2006
Volume 34, Issue 3 - Sep 2006
Volume 34, Issue 2 - Jun 2006
Volume 34, Issue 1 - Mar 2006
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Interaction Between Plants and Rhizobacteria in Phytoremediation of Heavy Metal- Contaminated Soil
Koo So-Yeon ; Cho Kyung-Suk ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 83~93
In heavily industrialized areas, soil sites are contaminated with high concentrations of heavy metals. These pollutants are highly accumulated to the human body through the food web and cause serious diseases. To remove heavy metals from the soil, a potential strategy is the environmental friendly and cost effective phytoremediation. For the enhancement of remediation efficiency, the symbiotic interaction between the plant and plant growth-promoting rhizobacteria (PGPR) has been attended. In this review, the interaction of the plant and PGPR in the heavy metal-contaminated soil has been reviewed. The physicochemical and biological characteristics of the rhlzosphere can influence directly or indirectly on the biomass, activity and population structure of the rhizobacteria. The root exudates are offered to the soil microbes as useful carbon sources and growth factors, so the growth and metabolism of rhizobacteria can be promoted. PGPR have many roles to lower the level of growth-inhibiting stress ethylene within the plant, and also to provide iron and phosphorus from the soil to plant, and to produce phytohormone such as indole acetic acid. The plant with PGPR can grow better in the heavy metal contaminated soil. Therefore higher efficiency of the phytoremediation will be expected by the application of the PGPR.
An Auxin Producing Plant Growth Promoting Rhizobacterium Bacillus subtilis AH18 which has Siderophore-Producing Biocontrol Activity
Jung Hee-Kyoung ; Kim Jin-Rak ; Woo Sang-Min ; Kim Sang-Dal ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 94~100
To isolate a bacterium that produces plant growth promoting hormone, a total of 29 bacteria were obtained from the soil in Gyeongsan, Korea. Among these, 14 strains were selected by their positive reaction on Salkowski to produce auxin. All of these were then tested for their property to produce siderophore using CAS (chrome azurol S) blue agar, and one was chosen for its ability to produce both, auxin and siderophore. This strain, denoted, AHl8, showed 1.5 times higher adventitious root induction rates than controls, using mung-beans. The strain also showed efficient biocontrol properties towards Fusarium-wilt of tomatoes in artificial pot assays. The strain was identified as Bacillus subtilis by 16s rDNA comparison and Biolog analyses. Growth and media conditions for Bacillus subtilis AH1 8 to highly produce siderophore were also investigated.
Taxonomy of a Soil Bacteria YNB54 Strain Which Shows Specific Antagonistic Activities against Plant Pathogenic Phytophthora spp.
Kim Sam-Sun ; Kwon Soon-Wo ; Lee Seon-Young ; Kim Soo-Jin ; Koo Bon-Sung ; Weon Hang-Yeon ; Kim Byung-Yong ; Yeo Yun-Soo ; Lim Yoong-Ho ; Yoon Sang-Hong ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 101~108
YNB54 strain which shows inhibitory activities specific to the plant pathogenic Phytophthora sp. on potato dextrose agar medium was screened among lots of strains isolated from Korean soils. To identify taxonomy of the Phytophthora specific antagonistic bacteria YNB54, 165 rDNA sequence, MIDI fatty acid composition, DNA-DNA hybridization, GC content, and commercial multitest systems such as API 20E and Biolog GN were performed. Results of commercial kits including lots of biochemical and physiological reactions showed that this strain was closely related to taxa including Enterobacter cloacae and Enterobacter cancerogenus species than other genera(Citerobacter Klebsiella, Leclercia). Also, analysis of its MIDI, G+C contents, and DNA-DNA hybridization suggests that this strain was more similiar to the Genus Enterobacter than other genera (Citerobacter Klebsiella, Leclercia). This strain was potentially identified as Enterobacter sp. by these results. But our 16S ribosomal DNA sequences (rDNA) analysis confirmed that it was more closely related to the cluster of Citerobacter freundii ATCC 29935 than any other Enterobacter species. In the absence of defined phylogenetic critia for delineating genera, the results observed with Citrobacter and Enterobacter species suggest that further studies are needed to clarify their relationships. This investigation demonstrates that YNB54 strain is genetically diverse and potentially more taxonomically complex than hitherto realized. Further study is necessary to confirm their taxonomic positions.
Isolation and Characterization of Yam-Putrefactive Psychrotrophic Bacteria from Rotted Yam
Ryu Hee-Young ; Kim Young-Sook ; Park Sang-Jo ; Lee Bong-Ho ; Kwon Soon-Tae ; Sohn Ho-Yong ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 109~114
Yam has been recognized as healthy food due to its various biological activities, such as anti-obesity, antimicrobial, anticancer and immuno-stimulation activities, and its consumption has been increased during last decades. In this study, to investigate low-temperature, long-term storage of yam and to develop processed yam products, yam-putrefactive psychrotrophic bacteria were isolated from rotted yam and identified based on BBL identification system, fatty acid analysis in cell membrane and 16S rDNA sequence analysis. The putrefaction activity of isolated thirteen bacteria was evaluated using yam-slices (NaOCl-treated, autoclaved yam and without treatment), and YAM-10 and YAM-12 were identified as major psychrotrophic putrefactive bacteria. Both YAM-10 (Pseudomonas cepacia) and YAM-12 (Pseudomonas rhodesiae) bacteria grew well at 4
and showed strong activity of polymer degrading enzymes, especially amylase, carboxy methyl cellulase and xylanase, at 20
. But they failed to grow at acidic pH (<5) or alkaline pH (>10). Our results suggested that the control of psychrotrophic Pseudomonas sp. by pH change and inhibition of polymer degrading enzymes, such as amy-lase, are necessary to long-term storage of yam.
Preparation of Soluble Silk Peptides by Food-grade Proteinases
Ha Jae-Seok ; Song Jae-Jun ; Cho Hyoung-Kwon ; Lee Seung-Goo ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 115~120
Enzymatic hydrolysis of silk fibers were investigated for the preparation of soluble silk peptides by ten food-grade proteases from Bacillus, Aspergilius, and plant sources. Silk fibers were dissolved for 1 hr in a 2:1 cosolvent (50%
: ethanol) by heating at
. The silk solution was filtered to remove Impurity particles and desalted for 50 hours by a dialysis process to remove the used cosolvent. When the silk hydrolysis was performed at
for 2 hours, most proteases from Bacillus and Aspergillus generated large amounts of insoluble aggregates. On the contrary, proteases from plant sources produced much less aggregates during prolonged incubations and also exhibited high hydrolysis activities. In regards of the solubility and broad molecular sizes of produced silk peptides, Bromelain was finally selected and applied for the enzymatic hydrolysis of silk fibers.
Identification of Amino Acid Residues Involved in Xylanase Activity from Bacillus alcalophilus AX2000 by Chemical Modifiers
Park Young-Seo ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 121~128
The purified xylanase from Bacillus alcalophilus AX2000 was modified with various chemical modifiers to determine amino acid residues in the active site of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results suggested that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and N-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.
Cloning and Characterization of Zebrafish Microsomal Epoxide Hydrolase Based on Bioinformatics
Lee Eun-Yeol ; Kim Hee-Sook ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 129~135
A gene encoding for a putative microsomal epoxide hydrolase (mEH) of a zebrafish, Danio rerio, was cloned and characterized. The putative mEH protein of D. rerio exhibited sequence similarity with mammalian mEH and some other bacterial EHs. A structural model for the putative mEH was constructed using homology modeling based on the crystallographic templates, 1 qo7 and 1 ehy. The catalytic triad consisting of
was identified, and the characteristic features such as two tyrosine residues and oxyanion hole were found to be highly conserved. Based on bioinformatic analysis together with EH activity assay, the putative protein was annotated as mEH of D. rerio. Enantiopure styrene oxide with enantiopurity of 99%ee and yield of 33.5% was obtained from racemic styrene oxide by the enantioselective hydrolysis activity of recombinant mEH of D. rerio for 45 min.
Enhancement of Astaxanthin Production of Haematococcus pluvialis by Mutation
Park Bok-Jun ; Kim Beob-Min ; Shim Su-Hyun ; Kim Jeong-Dong ; Lee Choul-Gyun ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 136~142
Haematococcus pluvialis is a great producer of astaxanthin (3,3'-dihydroxy-
-carotene-4,4'-dione). The activities of astaxanthin include potential cancer prevention, immune response enhancement, antioxidant activity, and so on. Nevertheless, it tried to manipulate by mutation for overcoming low growth rate of wild type and limited production of astaxanthin. Mutated colony that is lager and more reddish one than wild type was selected by attempting to expose strains to UV irradiation and to treat chemical such as EMS and colchicines as mutagen. Selected mutants were further screened using inhibitors of the carotenoid biosynthetic pathway. Inhibitors used were nicotine and diphenylamine and both had decreased the survival rate by 40-50%. Among over 50,000 mutant colonies screened, two strains were selected. One selected mutant strain (U15-5) from UV treatment showed 1.68-fold higher total carotenoid contents per cell than that of the wild type strain. On the other hand, the other selected mutant strains (DS, M4-3) from colchicine treatment showed 20
30% faster cell growth than the wild type strain.
Comparison of Anticacer Activities from the Culture and Extraction Conditions of the Spirulina platensis
Kim Hyou-Sung ; Kim Cheol-Hee ; Kim Jung-Hwa ; Kwon Min-Chul ; Cho Jung-Hwan ; Gwak Hyeong-Geun ; Hwang Bo-Young ; Kim Jin-Chul ; Lee Hyeon-Yong ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 143~149
A extract from Spirulina platensis of seawater and freshwater was obtained by using the water and ethanol. Extraction yields of seawater S. platensis were observed about 3% higher than freshwater S. platensis. Cytotoxicity (HEK293) and inhibition ratio of cancer cell line (A549, AGS, MCF7, Hep3B) in adding of the extracts from the S. platensis of seawater and freshwater were measured by SRB assay. Cytotoxicity of all of the extracts in adding 1.0 mg/ml was below 26%. Ctotoxicity of the extracts from the seawater S. platensis were about 6% less than freshwater S. platensis. Inhibition ratio of cancer cell growth was inhibited by adding 1.0 mg/ml of the extracts that was obtained about 80%. Inhibition effect of cancer cell growth in adding seawater S. platensis was observed higher than freshwater S. platensis. Differentiation ratio of HL-60 cells in adding the extracts of seawater S. platensis was observed highly that was 160.9%.
Optimization of Keratinolytic Protease Productions from Bacillus sp. SMMJ-2
Park Sung-Min ; Yu Tae-Shick ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 150~157
Bacillus sp. SMMJ-2 producing extracellular keratinolytic protease was isolated from the Swedish soils. The optimal culture conditions for production of keratinolytic protease by Bacillus sp. SMMJ-2 were investigated. The optimal medium compositions for the keratinolytic protease production were 0.7%
, 1.0% fructose,1.2% soybean meal (roasted), and 0.01%
. Optimal initial pH and temperature for the production of keratinolytic protease were 7.0 and 30
, respectively. The keratinolytic protease production showed a maximum of 105 units/ml/min after 72 hours cultivation under the optimal culture conditions.
Characteristics of Citrus By-Product Ferment Using Probiotics as Starter
Moon Young-Gun ; Lee Kyeong-Jun ; Kim Ki-Young ; Song Choon-Bok ; Jeon You-Jin ; Heo Moon-Soo ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 158~165
In this study, we investigated the biological activity of antioxidant and antibacterial activity of citrus by-product ferment. Among the six probiotic bacteria, Bacillus subtilis and Saccharomyces cerevisiae had the highest antioxidant activity. Hot water extracts from citrus by-product of ferment were screened for antibacterial activity fish pathogenic bacteria by paper disc method. Among the various hot water extracts, the Bacillus subtilis, Saccharomyces cerevisiae, Pediococcus pentosaceus, Lactobacillus rhamnosus, Lactobacillus plantarum, Enterococcus faecium showed relatively strong antibacterial activities in the order. The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and
and OH radical scavenging potential were sequentially screened, in search for antioxidant activities of citrus by-product ferment.
Analysis of Bacterials Community Structure in Leadchate-Contaminated Groundwater using Denaturing Gradient Gel Electrophoresis
Kim Jai-Soo ; Kim Ji-Young ; Koo So-Yeon ; Ko Kyung-Seok ; Lee Sang-Don ; Cho Kyung-Suk ; Koh Dong-Chan ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 166~173
This research has been performed to clarify the relationship between hydrogeochemistry and bacterial community structure in groundwater contaminated with landfill leachate. We collected and analyzed samples from 5 sites such as leachate (KSG1-12), treated leachate (KSG1-16), two contaminated groundwaters (KSG1-07 and KSG1-08) and non-contaminated groundwater (KSG1-13). pH was 8.83, 8.04, 6.87, 6.87 and 6.53 in order; redox potential (Eh) 108, 202, 47, 200 and 154 mV; electric conductivity (EC) 3710, 894, 1223, 559 and 169.9
S/cm; suspended solids (SS) 86.45, 13.74, 4.18, 0.24 and 11.91 mg/L. In KSG01-12, the ion concentrations were higher especially in
than other sites. The concentrations of Fe, Mn and
were higher In KSG1-07 than in KSG1-08, and vise versa in
. In the comparison of DGGE fingerprint patterns, the similarity was highest between KSG1-13 and KSG1-16 (57.2%), probably due to common properties like low or none contaminant concentrations. Otherwise KSG1-08 showed lowest similarities with KSG1-13 (25.8%) and KSG1-12 (27.6%), maybe because of the degree of contamination. The most dominant bacterial species in each site were involved in
-Proteobacteria (55.6%) in KSG1-12,
-Proteobacteria (50.0%) in KSG1-16,
-Proteobacteria (66.7%) in KSG1-07,
-Proteobacteria (54.5%) in KSG1-08 and
-Proteobacteria (36.4%) in KSG1-13. These results indicate that the microbial community structure might be changed according to the flow of leachate in grounderwater, implying changes in concentrations of pollutants, available electron accepters and/or other environmental conditions.
Biodegradation of Biphenyl by Sphingbium yanoikuyae BK-10
Lee Jung-Bok ; Kim Dong-Geol ; Choi Chung-Sig ; Sohn Ho-Yong ; Kim Jang-Eok ; Kwon Gi-Seok ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 174~179
Bacterium capable of using biphenyl as a sole source of carbon and energy were isolated from soil, and based on the results of 16S rDNA sequence, strain BK10 identified as a Sphingobium yanoiktiyae. The optimum cultural conditions were as follows;
0.2 g per 1 liter of distilled water. The Sphingobium yanoikuyae BK10 strain was completely utilized biphenyl in mineral salt media containing biphenyl at concentration 500
g/ml of biphenyl as a sole carbon and energy source within 48 hours. Optimumal pH and temperature for biphenyl degradation and cell growth of strains were 6.0
8.0 and 20
, respectively. Especially, at 30
, cell-growth were higher than other temperature. Cell grown on biphenyl has been shown to have a higher removal rate for biphenyl than grown on sucrose. This study shows that Sphingobium yanoikuyae BK10 strain had a high biodegradation capability of biphenyl and can be simulate a candidate compounds the bioremediation of PCBs (Polychlorinated biphenyl) contaminant soil and water.
Characterization of Diazotrophs Isolated from Rice Rhizosphere and Their Antifungal Activities
Jeong Dae-Eun ; Lee Su-Jin ; Seul Keyung-Jo ; Park Yu-Mi ; Ghim Sa-Youl ;
Microbiology and Biotechnology Letters, volume 34, issue 2, 2006, Pages 180~184
Nineteen nitrogen-fixing bacteria were isolated from rice roots cultivated in the southern part of the Korean peninsula. Among them, three isolates - Stenotrophomonas sp. KNUC89, Pseudomonas sp. KNUC116, and Delftia sp. KNUC133 - showed antifungal activities against phytopathogenic fungi Rhizoctonia solani and Fusarium oxysporum. Besides they could produce auxin and siderophores.