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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Microbiology and Biotechnology Letters
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 30, Issue 4 - Dec 2002
Volume 30, Issue 3 - Sep 2002
Volume 30, Issue 2 - Jun 2002
Volume 30, Issue 1 - Mar 2002
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Characterization and Cloning of a Phytase from Escherichia coli WC7.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 1~7
Phytase from Escherichia coli WC7 was purified from cell extracts and its molecular mass was estimated to be 45 kDa by SDS-PAGE. Its optimum temperature and pH for phytate hydrolysis was 6
and pH 5.0, respectively. The enzyme was stable up to 6
and over broad pH range (pH 2-12). The enzyme had higher affinity for sodium phytate than p-nitrophenylphosphate (pNPP). That is, the apparent Km value for sodium phytate and pNPP were
0.02 mM and 2.82
0.05 mM, respectively. The gene encoding the phytase was cloned in E. coli XL1-Blue. Sequence analysis showed an open reading frame of 1241 Up encoding a signal peptide (22 aa) and a mature enzyme (410 aa). WC7 phytase was expressed up to 17.5 U/ml in the transformed E. coli XL1-Blue/pUEP, which was 23-fold higher than the activity from wild strain.
Cloning and Nucleotide Sequence Analysis of xylC Gene Encoding 5C-2HMS Dehydrogenase from Pseudomonas sp. S-47.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 8~14
Pseudomonas sp. S-47 is capable of degrading 4-chlorobenzoate to produce 5-chloro-2-hydroxymuconic semialdehyde (5C-2HMS) by the enzymes encoding by xylXYZLTE cluster. In this study, the resulting 5C-2HMS was confirmed to be transformed to 5-chloro-2-hydroxymuconic acid (5C-2HMA) by 5C-2HMS dehydrogenase. The xylG gene encoding 5C-2HMS dehydrogenase was cloned from the chromosomal DNA of strain S-47. The nucleotide sequence of xylG showed to be composed of 1,600 base pairs with ATG initiation and TGA termination codons. A deduced amino acid sequence of the 5C-2HMS dehydrogenase (XylG) exhibited 98％, 93％, and 89％ identity with those of the dehydrogenases from P. putida mt-2, P. putida G7, and Pseudomonas sp. CF600, respectively.
Expression Patterns of Bacillus subtilis Diacylglycerol Kinase Gene Induced by Physiological Stimuli
Lee, Mi-Young ; Suh, Seok-Jong ; Lee, Jin-Hyung ; Song, Bang-Ho ; Kim, Jong-Cuk ;
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 15~20
Diacylglycerol kinase (DGK) phosphorylates the second messenger diacylglycerol (DAG) to phosphatidic acid and it may play a role in signal transduction in Escherichia coli as well as in eukaryotic cells. In addition, DGK is important for microorganisms to adapt to several physiological stimuli. In Bacillus subtilis, the effect of stress on dgk transcription was examined by northern hybridization. The high level of dgk transcription was induced against high osmolarity, low pH value and low temperature. Transcriptional analysis revealed that the dgk gene and dgk upstream locus (ORF2, ORF3 and ORF4) were transcribed as a polycistronic mRNA to form an approximately 2.5 kb transcript.
Structural Analysis of the Antifungal Antibiotic from Bacillus sp. YJ-63.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 21~25
Structural analysis was performed by the
C-NMR, amino acid composition analysis and FAB-mass. The instrumental analysis represented that the potential antifungal antibiotic belonged to the iturin E group antibiotic, consisting of 7
-amino acid residues and a collection of
-amino acid with aliphatic side chain. Compared to the Iturin E group, notably, the potent antifungal antibiotic from Bacillus sp. YJ-63 carried longer
-amino acid side chain. In conclusion, these findings identified a potential antibiotic, which contained a stable cyclopeptide structure with long
-amino acid side chain.
Characterization of Protease Produced by Bacillus amyloliquefaciens HTP-8 Isolated from Korean Fermented Anchovy Sauce.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 26~32
For commercial production of Korean fermented anchovy sauce through rapid fermentation, a bacterial strain which showed the high protease activity was isolated from a commercially fermented anchovy sauce. The isolate was Bacillus amyloliquefaciens, and named as B. amyloliquefaciens HTP-8. The incubation temperature, initial pH, and cultivation time for optimal production of protease by B. amyloliquefaciens HTP-8 were
, 7.0, and 3 days, respectively. In jar fermenter, B. amyloliquefaciens HTP-8 showed higher protease activity when grown at pH 7.0. The protease was partially purified by 80% ammonium sulfate precipitation and CM-Sephadex C-50 ion exchange chromatography. The partially purified enzyme had specific activity of 103.3 units/mg, yield of 0.4%, and purification fold of 43.0. The optimal pH and temperature for the protease activity were 10.0 and
, respectively. The protease was relatively stable at the pH range of 7.0~12.0 and at the temperatures below 4
. The activity of the enzyme was inhibited by
and selectively inhibited by PMSF, suggesting that it is a serine protease.
Purification and Enzyme Property of a Cell-Wall Lytic Enzyme Produced by Bacillus sp. LM-8 against Lactobacillus plantarum.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 33~38
Purification and characterization of enzyme property of a cell-wall lytic enzyme against Lactobacillus plantarum were carried out. Final specific activity of purified enzyme was 5.8 units/mg and purity of the enzyme was increased 8.3 fold compared with the enzyme activity in culture broth. The molecular weight of purified enzyme was estimated to be 60,000 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis. Optimal pH and temperature for the activity of this enzyme were 3.0 and 4
, respectively. The cell-wall lytic enzyme activity was maintained at 3
when treating the enzyme for 30 mins, whereas the activity was decreased to 80% of the maximum level at 4
The enzyme activity exhibited good stability at the range of pH 4~7.
Stimulation of Nitric Oxide Production in RAW 264.7 Macrophages by the Peptides Derived from Silk Fibroin.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 39~45
It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.
Fermentation Characteristics of Koji inoculated with Cordyceps sp.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 46~50
To investigate the quality of Koji produced by Cordyceps sp., a mixed culture of Aspergillus oryzae and the Cordyceps sp. were inoculated in Koji making. Viable cell counts and counts of fungi spore during Koji making for 120 hours were increased rapidly within 24-48 hours, after then their changes were not shown significantly during Koji making. The activities of amylase and protease in Koji inoculated with the mixed culture of A. oryzae and Cordyceps sp. were superior to one with A. oryzae only. The sensory evaluation on the Koji with 0.5％ (w/w) A. oryzae and 0.5％ (w/w) Cordyceps sp. were evaluated to be superior to ones. The best quality of Koji is prepared from the mixture of Cordyceps sp. and A. oryzae with the ratio of 0.5％ and 0.5％ (w/w).
Isolation and Purification of an Antitumor Metabolite from Alternaria brassicicola SW-3, the Cause of Brassica Black Leaf Spot Disease.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 51~56
An antitumor substance was purified from the culture filtrate of phytopathogenic fungus Alternaria brassicicola SW-3 isolated from soil of a chinese cabbage patch, and its characteristics were investigated. Antitumor activity of A. brassicicola SW-3 was measured by MTT assay. The cytotoxic activity against human cancer cell line was detected in the culture filtrate of A. brassicicola SW-3, but no activity found in mycelium. Antitumor substance was isolated from the culture broth by ethyl acetate extraction and purified by silica gel column chromatography. Structure of the purified compound was analyzed by the instrumental analysis such as
C-NMR and IR spectroscopy. The purified fungal metabolite of an A. brassicicola SW-3, consists of 11 carbon chain with two hydroxyl groups and two epoxides which is identical to depudecin. The
/ values of the active compound identified as depudecin were
g/mL against mouse melanoma B16BL6 cell line, and human hepatoma SK-HEP1 cell line, respectively.
Production of Bacterial Cellulose by Acetobacter xylinum GS11.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 57~62
Productivity of bacterial cellulose by Acetobacter xylinum GS11 was investigated in the several culture conditions. In various carbon sources, others with the exception of glucose were not found to be effective for cellulose production, and 2% was better in yield than other concentration of glucose. Yeast extract and soytone among several organic nitrogens were effective, but inorganic nitrogen sources tested were not efficient for cellulose production by A. xylinum GS11. The effects of various inorganic salts, amino acids and vitamins were also investigated:
, phenylalanine and
-tocopherol gave the cellulose yield of 1.5, 1.4 and 1.4 fold, respectively, compared with basal medium. In our experiment, cellulose production by A. xylinum GS11 added with 10% coconut milk and 0.5% lignosulfonate in basal medium, was the most efficient among the several material sources employed here, and these were 2.2 and 2.1 fold, respectively.
High Density Cell Culture of Bifidobacterium by Optimization of Medium Composition and Culture Conditions.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 63~67
Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO
and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and
, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.
Selection of Yeast Mutant Strain with High RNA Content and Its High Cell-Density Fed-Batch Culture.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 68~72
To obtain a yeast mutant with high RNA content and high growth rate, Saccharomyces cerevisiae MTY62 was mutated with ethylmethane sulfonate. Among the selected mutants that were sensitive to the high concentration of KCl, M40-10 strain was finally selected due to its rapid cell growth and high RNA content in the tube and baffled-flask cultures. In the batch culture of M40-10 mutant, the maximum specific growth rate (
, RNA concentration of 3210 mg-RNA/1, and RNA content of 183 mg-RNA/g-DCW were obtained, which were 23%, 15%, and 12% increased levels, respectively, compared to those of MTY62 parent strain. The intermittent fed-batch culture of M40-10 strain resulted in the maximum cell concentration of 35.6 g-DCW/1, RNA concentration of 5677 mg/1, and RNA content of 160 mg-RNA/g-DCW. Through the constant fed-batch culture, the maximum cell concentration of 46.4 g-DCW/1, RNA concentration of 6270 mg-RNA/1, and RNA content of 135 mg-RNA/g-DCW were obtained. At the 20 h culture time in the fed-batch cultures of M40-10 strain, the cell and RNA concentrations were increased by 30% and 10%, respectively, over the parent strain MTY62. In addition, it was also found that the accumulated RNA within the mutant cell was not degraded until the end of fed-batch cultivation, indicating that the M40-10 cell is a mutant with weak acidic RNase activity.y.
Characteristics of Ammonia Removal in Biofilters Inoculated with Earthworm Cast.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 73~78
Four inorganic packing materials (zeocarbon, porous celite, porous glass, zeolite) and a earthworm cast were compared with regard to the removal of ammonia in a biofilter inoculated with earthworm cast. Physical adsorption of ammonia on packing materials were negligible except zeocarbon (23.5 g-
/kg), and cell immobilization capacity have similar values irrespective of packing materials. Pressure drops of the packed bed were in order of earthworm cast zeocarbon zeolite porous glass porous. The maximum elimination capacity (
) of ammonia, which were based on a unit volume of packing material, were in order of zeocarbon (526) earthworm cast (220) porous celite (93) > zeolite (68) > porous glass (53). By using kinetic analysis, the maximum removal rates (
) and the saturation constant (
) for ammonia were determined, and zeocarbon showed superior performance among the five materials.
Studies on Microbial Ecology of Actinomycetes in Tideland Soils.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 79~85
Ecological characteristics of microorganisms in tideland soils were studied by investigation of microbial diversity and population. Twenty soil samples were taken at surface, 10, 20 and 30 cm depth each. Bacteria, actinomycetes and fungi were isolated on each selective isolation medium containing different concentration of NaCl. Actinomycetes were the most isolated from soil samples taken at 10 cm depth and isolated by humic acid-vitamin (HV) medium without sea water or salt. Twenty nine strains of actinomycetes were isolated at surface soil and 74, 39, 37 strains were at 10, 20, and 30 cm depth, respectively. All these isolates were analysed and grouped by random amplified polymorphic DNA (RAPD)-PCR analysis. Many of the isolates were clustered into Microtetraspora and Pseudonocardia. Fungal isolates were highly distributed at the surface soil and isolated well on potato dextrose agar (PDA) medium with sea water. Bacterial isolates were higly distributed at surface soil and isolated well by nutrient medium without sea water or salt. Soil samples taken at 10 cm depth showed the highest microbial diversity and population.
Effect of Biocide (NaOCl) in Industrial Cooling Water on Biofilm Formation and Metal Corrosion.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 86~90
Cooling water sampled at Pohang Steel Company, Korea, was used to study the effect of biocide (NaOCl) on biofilm formation and metal corrosion. Planktonic microorganisms were killed in the presence of biocide (0.2％ NaOCl) within 1.5 h, but not sessile microorganisms in biofilms even after one week. Black color of biofilms, possibly due to the activity of sulfate reducing bacteria, were made with the natural cooling waters, while orange color of biofilms were formed when cooling waters were autoclaved or when 0.2％ NaOCl was added to the natural cooling waters. Microbially influenced corrosion rate in black color of biofilms was 2.3 fold higher than that in orange color of biofilms.
Removal of Malodorous Gases from Swine Manure by a Polyurethane Biofilter Inoculated with Heterotrophic and Autotrophic Bacteria.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 91~97
Removal of malodorous gases from swine manure by a polyurethane biofilter inoculated with heterotrophic and autotrophic bacteria was investigated. Ammonia, hydrogen sulfide and other gases could be efficiently treated at 3~3.6 second of empty bed retention time by the polyurethane biofilter. In the range of SV
, the average removal efficiency of odor was about 89% when the odor unit of inlet gas was below 4100. Odor elimination capacity of the polyurethane biofilter was$ 1.8
that were 84~90% of the inlet load. The critical loads of
S, which mean 97% removal with respect to the inlet loads, were 31 and
, respectively. The maximum elimination capacities of
S were 56 and
, respectively. Although the removability for
S was not influenced by
ratio (ppmv/ppmv), the
S removability was inhibited by high
S concentration more than 80 ppmv.
Production of Cellulase from Lignocellulosic Waste.
Microbiology and Biotechnology Letters, volume 30, issue 1, 2002, Pages 98~102
Lignocellulosic wastes available in abundance can be excellent substrates for the production of cellulase. Different types of substrates and various pretreatments were used to improve the production of cellulase. The steam-exploded wood chip gave the highest activities of FPase (0.84 IU/mL) and CMCase (6.5 IU/mL) in the shake-flask culture. In 30 L bioreactor the steam-exploded wood chip and residue after saccharification gave the FPase activity (0.72 IU/mL) and the CMCase activity (6.3 IU/mL), respectively, similar those obtained in lactose.