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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Microbiology and Biotechnology Letters
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 27, Issue 6 - Dec 1999
Volume 27, Issue 5 - Oct 1999
Volume 27, Issue 4 - Aug 1999
Volume 27, Issue 3 - Jun 1999
Volume 27, Issue 2 - Apr 1999
Volume 27, Issue 1 - Feb 1999
Volume 9, Issue 6 - 00 1999
Volume 9, Issue 5 - 00 1999
Selecting the target year
Antagonistic Role of Chitinase and Antibiotic Produced by Promicromonospora sp. KH-28 toward F.oxysporum
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 349~353
Antagonistic Promicromonospora sp. KH-28 isolated from a suppressive soil could produced a chitinase and a antifungal antibiotic for the biocontrol ability. The chitinase and the antibiotic appeared to inhibit plant pathogens of Fusarium oxysporum. Phytophthora capsici, Alternaria kiki, fusarium solani, Stemphylium sp., and Psudomonas fluorescens. the antibiotic produced from the strain was identified as a antifungal substance of 503 dalton having a pyrimidine skeleton with an aliphatic side chain. The Promicromonospora sp. KH-28 was able to suppress effectively F. oxysporum derived-fusarium wilt of red-pepper plant in the pot in vivo test.
Antifungal Activity of Medium-chain Saturated Fatty Acids and Their Inhibitory Activity to the Plasma Membrane H+-ATPase of Fungi
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 354~358
In order to know the antifungal characteristics of saturated fatty acids having 6 to 12 carbons, their minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were estimated against Saccharomyces cerevisiae. Fatty acids from C6 to C11 exhibited increasing activity with chain length, but C12 fatty acid did not show activity at all. In relation to antifungal modes of actions, fatty acids investigated showed on inhibitory activity toward the plasma membrane H+-ATPase of Saccharomyces cerevisiae. Their inhibitions to the glucose-induced acidification and ATP hydrolysis caused by the proton pump were found to be in common wiht antifungal activities. At the test concentration of 1mM, hexanoic acid (C6) showed the lowest inhibition of about 30%, while undecanoic acid(C11) showed the strongest inhibition of over 90%. In addition, as seen with antifungal activity, the inhibitory activity of dodecanoic acid (C12) was suddenly reduced to less than 50%.
Characterization of a Mosquitocidal Delta-endotoxin from Bacillus thuringiensis subsp. guiyangiensis strain 21-2(H serotype 43)
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 359~363
To prevent appearance of resistant mosquitoes against
-endotoxin of bacillus thuringiensis subsp. israelensis (Bti) in field, a mosquitocidal Bacillus thuringiensis strain 21-2(Bt21-2) producing a new type of
-endotoxin was isolated. The strain Bt 21-2 belongs to H serotype 43, B. thuringiensis subsp. guiyangiensis (Btg). The
-endotoxins from the strain Bt 21-2 and the strain Bti were a cuboid shape morphologically, but the
-endotoxin of the strain Bt 21-2 was composed of 150, 90 and 70kDa proteins on SDS-PAGE, and the antigenicity of
-endotoxin of the strain Bt 21-2 was different from that of the strain Bti on immunoblot. The
-endotoxin gene of the strain Bt 21-2 was not amplified with specific primers of
-endotoxin gene (cry4A and cry4B) of the strain Bti on PCR.
Characterization of Endogeneous Plasmids from Two Bacillus Isolates
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 364~369
In order to obtain the suitable plasmids for constructing plasmid vectors of Bacillus species, endogeneous plasmid DNAs were screended from thermo-tolerant soil bacteria. Based on agarose gel electrophoresis patterns of the isolated plasmid DNAs, two strains harboring small-size plasmids were selected. The isolated were identified to belong to the genus Bacillus on the basis of their morphological and biochemical properties, and named Bacillus sp. 3-3 and 77-8, respectively. The restriction endonuclease maps were determined for four plasmids including two plasmids from each Bacillus isolates. It is interesting that Bacillus sp. 3-3 and 77-8 have an identical plasmid according to the restriction maps. The three kinds of hybrid plasmids constructed by introducing each plasmid of two isolates into a Escherichia coli plasmid vector. pUCCm18 containing chloramplenicol resistance gene active in Bacillus strains, could be replicated in B. subtilis and B. licheniformis. These plasmids are very stable in B. subtilis, suggesting that the Bacillus plasmids identified in this work would be useful for development of new cloning vectors for Bacillus strains.
isolation of Xylanase-producing Thermo-tolerant Bacillus sp. and Its Enzyme Production
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 370~377
Thermo-tolerant bacterium producing the xylanase was isolated from soil and identified as Bacillus pumilus. This strain, named Bacillus pumilus TX703, was able to grow ad produce xylanase at the culture temperature of 5
. The maximum xylanase production was obtained when 1%(w/v) birchwood xylan and 1% (w/v) soytone were used as carbon source and nitrogen source, respectively. The biosynthesis of xylanase was under the catabolite repression induced by glucose in the culture medium, and it was completely inhibited in the presence of 0.2% (w/v) glucose. The maximum activity of xylanase was observed from pH8.0 to 9.0 and from 50 to 6
and the enzyme was highly heat-stable, whose activity remained was over 50% at 8
, and was quite stable from pH5.0 to 10.0.
Effect of Medium Composition on Protopectinase Production from Bacillus subtilis EK11
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 378~384
Protopectinase (PPases) are heterologous group of enzymes that degrade pectin from the insoluble protopection which is constituent of the middle lamella and primary cell wall of higher plants by restricted depolymerization. From the previous report, enzymatically separated plant cells, which are produced from plant tissues by PPases treatment, showed well-conserved cellular components with their rigid cell wall and this characteristic is applicable to preparation of novel food material. The purpose of this study is to investigate the effect of medium composition of PPase production from Bacillus subtilis EK11 which was selected as a PPase producer. Various carbon sources and concentrations on PPase production were studied and corn starch at 0.7% was the most effective for production of PPase. Among the nitrogen sources, yeast extract was the most effective for PPase production and the effect of (NH4)2SO4 was notable as inotganic nitrogen source. Inorganic compounds such as KH2PO4, K2HPO4, Na3-citrate.2H2O and MgSO4 were optimized for PPase production. PPase activity was inhibited by the adition of Ba2+ or Zn2+. The optimal medium for PPase production was devised: 0.7% corn starch, 0.3% yeast extract, 1.4% KH2PO4, 0.6% K2HPO4, 0.1% Na3-citrate.2H2O and 0.02% MgSO4. PPase production by using the optimum medium was carried out with shaking cultivation at 37
. The maximum PPase activity of 256unit/ml could be obtained after the cultivation for 48hrs. The activity was increased about 2.2timesthan the activity, 112 unit/ml, in basal medium.
Bile Salt Deconjugation Activity of Lactobacillus Strains Isolated from Yogurt Products
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 385~390
To investigate bile salt hydrolase activities of the bacterial strains isolated from fermented milk products, 21 strains of Lactobacillus were tested for their abilities to produced cholic acid from taurocholic and glycocholic acids. The production of cholic acid was measured by HPLC analysis during the growth in broth media for 24hrs. All strains of Lactobacillus acidophilus and L. plantarum deconjugated both taurocholate and glycocholate, whereas none strains of L. delbrueckii subsp. bulgaricus, L. casei subsp. casei, L. casei subsp. rhamnosus, L, reuteri did. L. acidophilus stains isolated from yogurts had the higher decojugation activities on glycocholate than taurocholate, however, L. acidophilus 1009 isolated from the human intestine showed the similar deconjugation activities on both taurocholate and glycocholate.
Purification and Production Conditions of Antimicrobial Compound from Methylotrophic Actinomycetes MO-16
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 391~398
A methylotrophic actinomycetes strain MO-16, which produce the antimicrobial compound, was isolated from soil and supposed as Amycolatopsis sp. based on taxonomic studies. The cell-free extract of methanol-grown strain MO-16 showed dehydrogenase activity for methanol and formaldehyde when various electron acceptors were added for oxidation. On the other hand, methanol did not affect the production of antimicrobial compounds, and organic nitrogen sources such as corn steep liquor and peptone were better than inorganic nitrogen sources. These compounds showed broad antimicrobial spectrum to the tested strains such as bacteria and yeast. The antimicrobial comounds were very stable under heat(121
), acid(pH2.0), alkali(pH11.0) treatments. These compounds were isolated by ethylacetate extract, silica gel column chromatography and reverse phase HPLC. Two compounds(peak 1 and 2) were detected as antimicrobial compounds through the HPLC analysis. The peak 2 was purified as a single compound and revealed a 98% purity.
Characteristics of a Mutant of Trehalose-producing Micrococcus luteus and Optimization of Production Conditions
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 399~403
For the production of trehalose, microorganisms capable of producing trehalose extracellularly were screened from the stock cultures in our laboratory. among them, Micrococcus luteus IFO 12708 showed the highest productivity of trehalose. For the increase of productivity, the mutant strai Hs-208 having higher trehalose production was selected with NTG(N-methyl-N'-nitrosoguanidine) mutagenesis, which led to the decrease of the specific activity of trehalose phosphorylase(3.2-fold) as compared to the wild strain. The optimum condition for the trehalose production was established as follows: 20g/l of glucose and 6g/l of tryptone were used as a sole carbon source and nitrogen source, respectively, and cultivations were carried out at 3
and pH 6.0. After 20hrs cultivation, addition of 20unit/ml penicillin G led to the higher conversion yield of trehalose. Under the optimum condition, 6.547g/l trehalose was produced with conversion yield of 32.7%.
Medium Composition of Aspergillus oryzae PF for the Production of Proteolytic Enzyme
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 404~409
The most favorable nitrogen source for the production of protease by Aspergillus oryzae PF was 2% soybean flour among sodium nitrate, ammonium sulfate, defatted soybean, skim milk, casein, peptone, and yeast extract. The production of protease from A. oryzae PF was higher at the concentration of 2% lactose than at variable concentration of glucose, sucrose, soluble starch, corn starch, potato starch, wheat starch, rice starch, cellulose, and gum arabic. Protease production was affected by the concentration of KH2PO4, Triton X-100, CaCo3, and MgSO4, and it was the highest at the highest at the concentration of 3% KH2PO4, 0.01% Triton X-100, 0.3% CaCO3, and 0.06% MGSO4.
Changes of the Lactic Acid Bacteria and Selective Inhibitive Substances against Homo and Hetero Lactic Acid Bacteria Isolated from Kimchi
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 410~414
This study was carried out to investigate distribution of homofermentative lactic acid bacteria(LAB) and heterofermentative LAB during kimchi fermentation period. The number of heterofermentative LAB was decreased during the fermentation. The ethanol extracts of Lithospermum erythrorhizon and Sophrora flavescens AITON showed strong antimicrobial activities against both homofermentative LAB and heterofermentative LAB. The extracts of Glycyrrhiza uralensis and Curcuma longa showed stronger antimicrobial activity against hetrofermentative LAB than against homofermentative LAB. the antimicrobial activities of the plant extracts against LAB were accelerated by mixing of two or three kinds.
Variations in Growth and Pathogenicity of Beauveria bassiana and Paecilomyces fumosoroseus Pathogenic to the Pine Gall Midge, Thecodiplosis japonensis
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 415~418
Thecodiplosis japonensis is an important insect pest in pine trees and hard to be controlled by chemical pesticides due to its characteristic life cycle. Experiments were conducted to determine the pathogenicity and growth temperature of several entomopathogenic fungi as potential microbial insectcides for T. japonensis. Beauveria bassiana SFB-SC and Paecilomyces fumosoroseus SFP-198 were highly pathogenic against T. japonensis. B. bassiana SFB-SC had also pathogenicity against a beneficial insect Bombyx mori. Growth rate and pathogenicity of P. funmosoroseus SFP-198 under 15
was higher than those of B. bassians SFB-SC. These results indicated that P. fumosoroseus SFP-198 is a potential microbial control candidate for control of T. japonensis.
Prophylactic Effects of Bifidobacterium longum HY8001 against Escherichia coli O157:H7 and Salmonella typhimurium DT104 Enteric Infection and Evaluation of Vero Cytotxin Neutralizing Effects
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 419~425
Prophylactic effects of Bifidobacterium longum HY8001, Korean isolate, against Escherichia coli O157:H7 and Salmonella typhimurium DT104 enteric infection were examined at four groups of specific pathogen free(SPF)-ICR mouse for each pathogen. B. longum HY8001+B. typhimurium DT104+B. longum HY8001(BL+ST+BL) group and B. longum HY8001+E. coli O157:H7+B. longum HY8001(BL+E+BL) group were fed with B. longum HY8001 before and after E. coli O157:H7 or s. typhimurium DT104 challenge, while B. longum HY8001+S. typhimurium DT104(BL+ST) and B. longum HY8001+e. coli O157:H7(BL+E) groups were fed with B. longum HY8001 only before E. coli O157:H7 or S. typhimurium DT104 challenge. E. coli O157:H7(E) and S. typhimurium DT104(ST) groups were challenged with each pathogen without B. longum HY8001 administration and control groups were administered with phosphate buffered solution(PBS). After the oral administration with B. longum HY8001(109cfu), th emice were challenged with E. coli O157:H7(2
1010cfu) or S. typhimurium DT104(108cfu) and the mortality rate and the fecal shedding of challenged pathogen were also examined define the reactivity of the B. longum HY8001. Production of toxin neutralizing substance(s) of B. longum HY8001 was determined by cell cytotoxicity assay using Vero cells. Fecal shedding of th eS. typhimurium DT104 was significantly decreased in BL+ST+BL group fed with B. longum HY8--1 before and after challenge(p<0.05), while the fecal shedding s of S. typhimurium DT104 in BL+ST and St groups remained more than 106cfu. the protective effect of the B. longum HY8001 against E. coli O157:H7 was significantly high only in BL+E+BL group fed with b. longum Hy8001 before and after E. coli O157:H7 challenge from the result of fecal E. coli O157:H7 isolation rate, mortality rate, and intestinal contents culture to detect E. coli O157:H7. the mortality rate of the BL+e and E groups. The cytopathic effect (CPE) of the Vero cytotoxin (Shiga like toxin I & II) in Vero cell was neutralized in B. longum HY8001 culture supernatant added wells which indicate the presence of soluble Vero cytotxin neutralizing substance(s) in B. longum HY8001 culture suprnatant.
Isolation of Siderophore-producing Pseudomonas fluorescens GL7 and Its Biocontrol Activity against Root-rot Disease
Microbiology and Biotechnology Letters, volume 27, issue 5, 1999, Pages 427~432
For the development of a multifunctional biocontrol agent, the siderophore-producing strain GL7 was isolated from a rhizosphere on chrome azurol S agar. The GL7 was identified as a strain of Pseudomonas fluorescents on the basis of their reactions to standard physicochemcial tests from Bergey's manual, API diagnostic test, and fatty acid analysis. P. fluorescents GL7 considerably inhibited spore germination and hyphal growth of phytopathogenic fungus Funsarium solani in a dual culture. In pot trials of bean with P. fluorescens GL7, the disease incidence was significantly reduced down to 5% from 70% of incidence in the untreated control. P. fluorescens GL7 also enhanced plant growth to nearly 1.5 times than that of the untreated control, promoting elongation and development of the roots. These results suggest that the plant growth-promoting P. fluorescens GL7 can play an important role in the biological control of soil-borne plant disease in a rhizosphere.