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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 21, Issue 12 - Dec 2011
Volume 21, Issue 11 - Nov 2011
Volume 21, Issue 10 - Oct 2011
Volume 21, Issue 9 - Sep 2011
Volume 21, Issue 8 - Aug 2011
Volume 21, Issue 7 - Jul 2011
Volume 21, Issue 6 - Jun 2011
Volume 21, Issue 5 - May 2011
Volume 21, Issue 4 - Apr 2011
Volume 21, Issue 3 - Mar 2011
Volume 21, Issue 2 - Feb 2011
Volume 21, Issue 1 - Jan 2011
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Genetic Diversity of Cultivable Plant Growth-Promoting Rhizobacteria in Korea
Kim, Won-Il ; Cho, Won-Kyong ; Kim, Su-Nam ; Chu, Hyo-Sub ; Ryu, Kyoung-Yul ; Yun, Jong-Chul ; Park, Chang-Seuk ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 777~790
DOI : 10.4014/jmb.1101.01031
To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories:
- proteobacteria, and
-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.
Effect of Fermented Sea Tangle on the Alcohol Dehydrogenase and Acetaldehyde Dehydrogenase in Saccharomyces cerevisiae
Cha, Jae-Young ; Jeong, Jae-Jun ; Yang, Hyun-Ju ; Lee, Bae-Jin ; Cho, Young-Su ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 791~795
DOI : 10.4014/jmb.1103.02039
Sea tangle, a kind of brown seaweed, was fermented with Lactobacillus brevis BJ-20. The gamma-aminobutyric acid (GABA) content in fermented sea tangle (FST) was 5.56% (w/w) and GABA in total free amino acid of FST was 49.5%. The effect of FST on the enzyme activities and mRNA protein expression of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) involved in alcohol metabolism in Saccharomyces cerevisiae was investigated. Yeast was cultured in YPD medium supplemented with different concentrations of FST powder [0, 0.4, 0.8, and 1.0% (w/v)] for 18 h. FST had no cytotoxic effect on the yeast growth. The highest activities and protein expressions of ADH and ALDH from the cell-free extracts of S. cerevisiae were evident with the 0.4% and 0.8% (w/v) FST-supplemented concentrations, respectively. The highest concentrations of GABA as well as minerals (Zn, Ca, and Mg) were found in the cell-free extracts of S. cerevisiae cultured in medium supplemented with 0.4% (w/v) FST. The levels of GABA, Zn, Ca, and Mg in S. cerevisiae were strongly correlated with the enzyme activities of ADH and ALDH in yeast. These results indicate that FST can enhance the enzyme activities and protein expression of ADH and ALDH in S. cerevisiae.
Characterization of Novel Plasmid p1B146 from Corynebacterium tuberculostearicum
Wieteska, Lukasz ; Szewczyk, Eligia M. ; Szemraj, Janusz ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 796~801
DOI : 10.4014/jmb.1101.01011
Corynebacterium tuberculostearicum B146, a strain derived from healthy human skin, contains a medium copy plasmid, p1B146. This plasmid was cloned and its complete nucleotide sequence determined. As a result, p1B146 was found to be 4,2 kb in size with a 53% G+C content, plus six open reading frames (ORFs) were distinguished. According to a computer-assisted alignment, two of the ORFs exhibited significant similarities to already-known common plasmid proteins, the first being the RepA gene, responsible for plasmid replication via a rolling-circle mechanism, and the second being an FtsK-like protein, the function of which remains unclear. The presence and quantity of RNA fragments in the putative ORFs were also evaluated.
Enhancement of Gene Delivery Using Novel Homodimeric Tat Peptide Formed by Disulfide Bond
Lee, Soo-Jin ; Yoon, Sung-Hwa ; Doh, Kyung-Oh ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 802~807
DOI : 10.4014/jmb.1105.05041
Cationic liposomes have been actively used as gene delivery vehicle because of their minimal toxicity, but their relatively low efficiency of gene delivery is the major disadvantage of these vectors. Recently, cysteine residue incorporation to HIV-1 Tat peptide increased liposomemediated transfection compared with unmodified Tat peptide. Therefore, we designed a novel modified Tat peptide having a homodimeric (Tat-CTHD, Tat-NTHD) and closed structure (cyclic Tat) simply by using the disulfide bond between cysteines to develop a more efficient and safe nonviral gene delivery system. The mixing of Tat-CTHD and Tat-NTHD with DNA before mixing with lipofectamine increased the transfection efficiency compared with unmodified Tat peptide and lipofectamine only in MCF-7 breast cancer cells and rat vascular smooth muscle cells. However, cyclic Tat did not show any improvement in the transfection efficiency. In the gel retardation assay, Tat-CTHD and Tat-NTHD showed more strong binding with DNA than unmodified Tat and cyclic Tat peptide. This enhancement was only shown when Tat-CTHD and Tat-NTHD were mixed with DNA before mixing with lipofectamine. The effects of Tat- CTHD and Tat-NTHD were also valid in the experiment using DOTAP and DMRIE instead of lipofectamine. We could not find any significant cytotoxicity in the working concentration and more usage of these peptides. In conclusion, we have designed a novel transfection-enhancing peptide by easy homodimerization of Tat peptide, and the simple mix of these novel peptides with DNA increased the gene transfer of cationic lipids more efficiently with no additional cytotoxicity.
Purification, and Biochemical and Biophysical Characterization of Cellobiohydrolase I from Trichoderma harzianum IOC 3844
Colussi, Francieli ; Serpa, Viviane ; Da Silva Delabona, Priscila ; Manzine, Livia Regina ; Voltatodio, Maria Luiza ; Alves, Renata ; Mello, Bruno Luan ; Nei, Pereira Jr. ; Farinas, Cristiane Sanches ; Golubev, Alexander M. ; Santos, Maria Auxiliadora Morim ; Polikarpov, Igor ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 808~817
DOI : 10.4014/jmb.1010.10037
Because of its elevated cellulolytic activity, the filamentous fungus Trichoderma harzianum has a considerable potential in biomass hydrolysis applications. Trichoderma harzianum cellobiohydrolase I (ThCBHI), an exoglucanase, is an important enzyme in the process of cellulose degradation. Here, we report an easy single-step ion-exchange chromatographic method for purification of ThCBHI and its initial biophysical and biochemical characterization. The ThCBHI produced by induction with microcrystalline cellulose under submerged fermentation was purified on DEAE-Sephadex A-50 media and its identity was confirmed by mass spectrometry. The ThCBHI biochemical characterization showed that the protein has a molecular mass of 66 kDa and pI of 5.23. As confirmed by smallangle X-ray scattering (SAXS), both full-length ThCBHI and its catalytic core domain (CCD) obtained by digestion with papain are monomeric in solution. Secondary structure analysis of ThCBHI by circular dichroism revealed
- helices and
-strands contents in the 28% and 38% range, respectively. The intrinsic fluorescence emission maximum of 337 nm was accounted for as different degrees of exposure of ThCBHI tryptophan residues to water. Moreover, ThCBHI displayed maximum activity at pH 5.0 and temperature of
with specific activities against Avicel and p-nitrophenyl-
-D-cellobioside of 1.25 U/mg and 1.53 U/mg, respectively.
Isolation and Characterization of a Novel Agarase-Producing Pseudoalteromonas spp. Bacterium from the Guts of Spiny Turban Shells
Oh, Young-Hoon ; Jung, Chang-Kyou ; Lee, Jin-Won ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 818~821
DOI : 10.4014/jmb.1012.12027
An agar-degrading bacterium was isolated from the guts of spiny turban shells. It was identified as a Pseudoalteromonas species and named Pseudoalteromonas sp. JYBCL 1. The viscosity of the inoculated agar medium decreased by more than 60% after 20 h cultivation. The agarase produced by the isolate had optimal activities at
and pH 7. The enzyme had extremely strong resistance to ionic stress compared with other known agarases. Its molecular mass was estimated at about 60 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The agarase could saccharify Gelidium amansii directly, with an efficiency about half that compared with agar saccharification.
Effects of Penicillin G on Morphology and Certain Physiological Parameters of Lactobacillus acidophilus ATCC 4356
Khaleghi, M. ; Kermanshahi, R. Kasra ; Zarkesh-Esfahani, S.H. ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 822~829
DOI : 10.4014/jmb.1012.12020
Evidence shows that probiotic bacteria can undergo substantial structural and morphological changes in response to environmental stresses, including antibiotics. Therefore, this study investigated the effects of penicillin G (0.015, 0.03, and 0.06 mg/l) on the morphology and adhesion of Lactobacillus acidophilus ATCC 4356, including the colony morphotype, biofilm production, hydrophobicity,
formation, S-layer structure, and slpA gene expression. Whereas only smooth colonies grew in the presence of penicillin, rough and smooth colony types were observed in the control group. L. acidophilus ATCC 4356 was found to be hydrophobic under normal conditions, yet its hydrophobicity decreased in the presence of the antibiotic. No biofilm was produced by the bacterium, despite testing a variety of different culture conditions; however, treatment with penicillin G (0.015-0.06 mg/l) significantly decreased its production of
formation and altered the S-layer protein structure and slpA gene expression. The S-protein expression decreased with 0.015 mg/l penicillin G, yet increased with 0.03 and 0.06 mg/l penicillin G. In addition, the slpA gene expression decreased in the presence of 0.015 mg/l of the antibiotic. In conclusion, penicillin G was able to alter the S-layer protein production, slpA gene expression, and certain physicochemical properties of Lactobacillus acidophilus ATCC 4356.
Molecular Cloning of Maltooligosyltrehalose Trehalohydrolase Gene from Nostoc flagelliforme and Trehalose-Related Response to Stresses
Wu, Shuangxiu ; He, Liang ; Shen, Rongrong ; Zhang, Xiu ; Wang, Quanxi ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 830~837
DOI : 10.4014/jmb.1101.10068
A genomic DNA fragment encoding a putative maltooligosyltrehalose trehalohydrolase (NfMTH) for trehalose biosynthesis was cloned by the degenerate primer- PCR from cyanobacterium Nostoc flagelliforme. The ORF of NfMTH is 1,848 bp in length and encodes 615 amino acid residues, constituting a 70 kDa protein. The deduced amino acid sequence of NfMTH contains 4 regions highly conserved for MTHs. By expression of NfMTH in E. coli, the function of this protein was demonstrated, where the recombinant protein catalyzed the hydrolysis of maltooligosyl trehalose to trehalose. The expressions of MTH and maltooligosyltrehalose synthase in the filaments of N. flagelliforme were upregulated significantly under dehydration stress, NaCl stress, and high temperature-drought stress. The accumulations of both trehalose and sucrose in the filaments of N. flagelliforme were also improved significantly under the above stresses. Furthermore, trehalose accumulated in smaller quantities than sucrose did when under NaCl stress, but accumulated in higher quantities than sucrose did when under temperature-drought stress, indicating that both trehalose and sucrose were involved in N. flagelliforme adapted to stresses and different strategies conducted in response to various stress conditions.
Molecular Characterization of Bile Salt Hydrolase from Bifidobacterium animalis subsp. lactis Bi30
Jarocki, Piotr ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 838~845
DOI : 10.4014/jmb.1103.03028
The present work describes the identification, purification, and characterization of bile salt hydrolase (BSH) from Bifidobacterium animalis subsp. lactis. The enzyme was purified to electrophoretic homogeneity by hydrophobic chromatography, ion-exchange chromatography and ultrafiltration. SDS-PAGE analysis of putative BSH and gel filtration revealed that the analyzed protein is presumably a tetramer composed of four monomers each of about 35 kDa. The purified enzyme was analyzed by liquid chromatography coupled to LTQ FT ICR mass spectrometry and unambiguously identified as a bile salt hydrolase from B. animalis. The isoelectric point of the studied protein was estimated to be around pH 4.9. The pH optimum of the purified BSH is between 4.7 to 6.5, and the temperature optimum is around 50oC. The BSH of B. animalis could deconjugate all tested bile salts, with clear preference for glycine-conjugated bile salts over taurine-conjugated forms. Genetic analysis of the bsh showed high similarity to the previously sequenced bsh gene from B. animalis and confirmed the usefulness of bile salt hydrolase as a genetic marker for B. animalis identification.
Production of 1,2-Propanediol from Glycerol in Saccharomyces cerevisiae
Jung, Joon-Young ; Yun, Hyun-Shik ; Lee, Jin-Won ; Oh, Min-Kyu ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 846~853
DOI : 10.4014/jmb.1103.03009
Glycerol has become an attractive carbon source in the biotechnology industry owing to its low price and reduced state. However, glycerol is rarely used as a carbon source in Saccharomyces cerevisiae because of its low utilization rate. In this study, we used glycerol as a main carbon source in S. cerevisiae to produce 1,2-propanediol. Metabolically engineered S. cerevisiae strains with overexpression of glycerol dissimilation pathway genes, including glycerol kinase (GUT1), glycerol 3-phosphate dehydrogenase (GUT2), glycerol dehydrogenase (gdh), and a glycerol transporter gene (GUP1), showed increased glycerol utilization and growth rate. More significant improvement of glycerol utilization and growth rate was accomplished by introducing 1,2-propanediol pathway genes, mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase) from Escherichia coli. By engineering both glycerol dissimilation and 1,2-propanediol pathways, the glycerol utilization and growth rate were improved 141% and 77%, respectively, and a 2.19 g 1,2- propanediol/l titer was achieved in 1% (v/v) glycerolcontaining YEPD medium in engineered S. cerevisiae.
Optimization of Rhamnetin Production in Escherichia coli
Sung, Su-Hyun ; Kim, Bong-Gyu ; Ahn, Joong-Hoon ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 854~857
DOI : 10.4014/jmb.1104.04048
POMT7, which is an O-methyltransferase from poplar, transfers a methyl group to several flavonoids that contain a 7-hydroxyl group. POMT7 has been shown to have a higher affinity toward quercetin, and the reaction product rhamnetin has been shown to inhibit the formation of beta-amyloid. Thus, rhamnetin holds great promise for use in therapeutic applications; however, methods for mass production of this compound are not currently available. In this study, quercetin was biotransformed into rhamnetin using Escherichia coli expressing POMT7, with the goal of developing an approach for mass production of rhamnetin. In order to maximize the production of rhamnetin, POMT7 was subcloned into four different E. coli expression vectors, each of which was maintained in E. coli with a different copy number, and the best expression vector was selected. In addition, the S-adenosylmethionine biosynthesis pathway was engineered for optimal cofactor production. Through the combination of optimized POMT7 expression and cofactor production, the production of rhamnetin was increased up to 111 mg/l, which is approximately 2-fold higher compared with the E. coli strain containing only POMT7.
Replacement of Hexachlorocyclohexane to Environmentally Friendly Biosurfactant as Precursor for the Production of Biosurfactant from Pseudomonas
Anu Appaiah, K.A. ; Parvathy, A. ; Mathew, Mariam ; Karanth, N.G.K. ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 858~860
DOI : 10.4014/jmb.1012.12024
Production of biosurfactant can be substantially increased by the addition of precursors like vegetable oils, petroleum products, and other water-insoluble substances. Pseudomonas Ptm+ strain produces biosurfactant in the presence of hexachlorocyclohexane (HCH), which specifically emulsifies HCH, a recalcitrant organochlorine pesticide. Addition of previously produced crude biosurfactant by the same organism as a precursor instead of HCH increased production of biosurfactants with a decrease in the total fermentation time from 32 to 24 h. The main objective of this paper was to find alternatives for HCH as an inducer.
Cloning, Expression, and Characterization of a New Xylanase from Alkalophilic Paenibacillus sp. 12-11
Zhao, Yanyu ; Meng, Kun ; Luo, Huiying ; Yang, Peilong ; Shi, Pengjun ; Huang, Huoqing ; Bai, Yingguo ; Yao, Bin ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 861~868
DOI : 10.4014/jmb.1102.02024
A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at
and was thermostable at
and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent
values were 1.18 mg/ml and 1,961
/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.
Submerged Monoxenic Culture Medium Development for Heterorhabditis bacteriophora and its Symbiotic Bacterium Photorhabdus luminescens: Protein Sources
Cho, Chun-Hwi ; Whang, Kyung-Sook ; Gaugler, Randy ; Yoo, Sun-Kyun ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 869~873
DOI : 10.4014/jmb.1010.10055
Most medium formulations for improving culture of entomopathogenic nematodes (EPN) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. Most results, however, showed unstable yields and longer production time. Many of the results do not show the detailed parameters of fermentation. Soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydrolysate as protein sources were tested to determine the source to support optimal symbiotic bacteria and nematode growth. The protein hydrolysates selected did not improve bacterial cell mass compared with the yeast extract control, but soy flour was the best, showing 75.1% recovery and producing more bacterial cell number (
/ml) than all other sources. The highest yield (
IJs/ml), yield coefficient (
IJs/g medium), and productivity (
IJs/l/day) were also achieved at enriched medium with soybean protein.
Rehmannia glutinosa Ameliorates Scopolamine-Induced Learning and Memory Impairment in Rats
Lee, Bom-Bi ; Shim, In-Sop ; Lee, Hye-Jung ; Hahm, Dae-Hyun ;
Journal of Microbiology and Biotechnology, volume 21, issue 8, 2011, Pages 874~883
DOI : 10.4014/jmb.1104.04012
Many studies have shown that the steamed root of Rehmannia glutinosa (SRG), which is widely used in the treatment of various neurodegenerative diseases in the context of Korean traditional medicine, is effective for improving cognitive and memory impairments. The purpose of this study was to examine whether SRG extracts improved memory defects caused by administering scopolamine (SCO) into the brains of rats. The effects of SRG on the acetylcholinergic system and proinflammatory cytokines in the hippocampus were also investigated. Male rats were administered daily doses of SRG (50, 100, and 200 mg/kg, i.p.) for 14 days, 1 h before scopolamine injection (2 mg/kg, i.p.). After inducing cognitive impairment via scopolamine administration, we conducted a passive avoidance test (PAT) and the Morris water maze (MWM) test as behavioral assessments. Changes in cholinergic system reactivity were also examined by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) and the reactivity of acetylcholinesterase (AchE) in the hippocampus. Daily administration of SRG improved memory impairment according to the PAT, and reduced the escape latency for finding the platform in the MWM. The administration of SRG consistently significantly alleviated memory-associated decreases in cholinergic immunoreactivity and decreased interleukin-
) and tumor necrosis factor-
) mRNA expression in the hippocampus. The results demonstrated that SRG had a significant neuroprotective effect against the neuronal impairment and memory dysfunction caused by scopolamine in rats. These results suggest that SRG may be useful for improving cognitive functioning by stimulating cholinergic enzyme activities and alleviating inflammatory responses.