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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 15, Issue 6 - Dec 2005
Volume 15, Issue 5 - Oct 2005
Volume 15, Issue 4 - Aug 2005
Volume 15, Issue 3 - Jun 2005
Volume 15, Issue 2 - Apr 2005
Volume 15, Issue 1 - Feb 2005
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Chloramphenicol Arrests Transition of Cell Cycle and Induces Apoptotic Cell Death in Myelogenous Leukemia Cells
KANG KI YOUNG ; CHOI CHUL HEE ; OH JAE YOUNG ; KIM HYUN ; KWEON GI RYANG ; LEE JE CHUL ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 913~918
Chloramphenicol is a broad-spectrum antimicrobial agent against Gram (+) and Gram (-) bacteria. Its clinical application has recently been limited, due to severe side effects such as bone marrow suppression and aplastic anemia. In the present study, the cytotoxic effects of chloramphenicol were investigated in vitro using chronic myelogenous leukemia K562 cells. Chloramphenicol inhibited the growth of K562 cells in a dose-dependent manner, but their growth was restored after the cessation of chloramphenicol, indicating reversible cytotoxic effects. The expression of cell cycle regulatory molecules, including E2F-1 and cyclin D1, was decreased at the translational and/or transcriptional level after being treated with a therapeutic blood level (
) of chloramphenicol. Chloramphenicol also induced apoptotic cell death through a caspase-dependent pathway, which was verified by Western blot analysis and the enzymatic activity of caspase-3. These results demonstrated that chloramphenicol inhibited the cell growth through arresting the transition of the cell cycle, and induced apoptotic cell death through a caspase-dependent pathway at therapeutic concentrations.
An Unusual Bioconjugate of Glycerol and Poly(
-Glutamic Acid) Produced by Bacillus subtilis C1
SHIH ING-LUNG ; WU JANE-YII ; WU PEI-JEN ; SHEN MING-HAU ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 919~923
A bacterium capable of poly(
-glutamic acid) production was isolated from nonpasteurized soy sauce. It was judged to be a variety of Bacillus subtilis and designated as B. subtilis C1. B. subtilis C1 produced
-PGA in the absence of exogenous glutamic acid; therefore, it is a de novo PGAproducing bacterium. The product produced by B. subtilis C1 was characterized by amino acid analysis to be composed of solely glutamic acid. However, the
spectra showed chemical shifts of glycerol protons in addition to those of authentic
-PGA, indicating that the product is in fact a bioconjugate of
-PGA. The finding is unique, because the microbial production of
-PGA bioconjugate has never been reported before. The molecular mass of the product was over 10,000 kDa as determined by GPC, and
of the product was D-glutamate, indicating that L-glutamate was converted to its D-form counterpart by B. subtilis C1.
In Vitro Antiviral Activity of Aqueous Extracts from Korean Medicinal Plants Against Influenza Virus Type A
Park, Kap-Joo ; Lee, Hyung-Hoan ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 924~929
Boiled-water extracts from 101 Korean medicinal plants were tested in vitro for their inhibitory activity against influenza virus type A by means of a modified hemagglutination inhibition test. Thirteen of the 101 extracts exhibited strong anti-influenza virus type A activity at concentrations of less than
. Out of the above 13 extracts, MW-40 (Chaenomeles speciosa), MW-88 (Citrus junos), and MW-100 (Zingiber officinale) exhibited marked antiviral activity in the concentration range of
to 100 mg/ml,
to 100 mg/ml, and
to 100 mg/ml, respectively. The extracts MW-88 and MW-100 were not cytotoxic to red blood cells, whereas MW-40 showed very weak cytotoxicity in the concentration range of 50 mg/ml to 100 mg/ml. Therefore, the present results demonstrate that boiled water extracts of 2 Korean medicinal plants, MW-88 and MW-100, have strong anti-influenza virus type A activity and no cytotoxic effects, and they may inhibit attachment of the virus to the cell and may be used for prophylaxis.
Statistical Approach to Development of Culture Medium for Ansamitocin P-3 Production with Actinosynnema pretiosum ATCC 31565
BANDI SRINIVASULU ; KIM YOON JUNG ; SA SOON OK ; CHANG YONG-KEUN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 930~937
The Plackett-Burman design and the response surface method (RSM) with a central composite design (CCD) were employed to develop a culture medium for ansamitocin P-3 production using Actinosynnema pretiosum ATCC 31565. Among the 11 nutrients tested using the Plackett-Burman design, two carbon sources, sucrose and dextrin, and two nitrogen sources, polypeptone and yeast extract, were selected. Optimization of the concentrations of the selected nutrients was then performed using RSM with CCD. After two rounds of RSM, the optimum concentrations (
) of sucrose, dextrin, polypeptone, and yeast extract were identified as 4.5, 4.5, 0.16, and 0.89, respectively. The maximum ansamitocin P-3 titer was 45.2 mg/l with the optimized medium, which was about 6 times higher than that (7.315 mg/l) obtained with an
medium before optimization.
Microbial Characterization of Excessive Growing Biofilm in Sewer Lines Using Molecular Technique
LEE YOUNG-OK ; PARK JIN-HWA ; PARK JAE-K. ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 938~945
For elucidating excessive growth of biofilm that subsequently leads to the clogging problem in a small town's sewer lines of Wisconsin, the FISH method was employed. At the beginning of the simulated experiments,
-subclass proteobacteria prevailed in runs fed with industrial wastewater, while
-subclass proteobacteria dominated in runs with domestic wastewater. However, the bacterial community structure changed significantly over six weeks; Cytophaga-Flavobacterium (CF)group bacteria dominated in most runs fed with the small town's wastewater regardless of their source, while CF-group decreased strongly in run fed with domestic sewage from another city (Madison). It was also microscopically confirmed that most of those clogging materials was toilet tissue, which in turn may lead to vigorous growth of cellulose-degrading CF-group bacteria. This dominant presence of CF-group bacteria in the small town's sewer indicates that the main constituent of biofilm, toilet tissue (cellulose) in sewage, might have induced the unique pattern of their microbial community structure. Therefore, it suggests that molecular technique is useful for monitoring the clogging problems in sewer lines.
Kinetics of di-n-Butyl Phthalate Degradation by a Bacterium Isolated from Mangrove Sediment
XU XIANG-RONG ; GU JI-DONG ; LI HUA-BIN ; LI XIAO-YAN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 946~951
Biodegradation of the endocrine-disrupting chemical di-n-butyl phthalate (DBP) was investigated using a bacterium, Pseudomonas fluorescens B-1, isolated from mangrove sediment. The effects of temperature, pH, salinity, and oxygen availability on DBP degradation were studied. Degradation of DBP was monitored by solid-phase extraction using reversed-phase HPLC and UV detection. The major metabolites of DBP degradation were identified as mono-n-butyl phthalate and phthalic acid by gas chromatography-mass spectrometry (GC-MS) and a pathway of degradation was proposed. Degradation by P. fluorescens B-1 conformed to first-order kinetics. Degradation of DBP was also tested in seawater by inoculating P. fluorescens B-1, and complete degradation of an initial concentration of
was achieved in 144 h. These results suggest that DBP is readily degraded by bacteria in natural environments.
Bacterial Communities of Biofilms Sampled from Seepage Groundwater Contaminated with Petroleum Oil
CHO WONSIL ; LEE EUN-HEE ; SHIM EUN-HWA ; KIM JAISOO ; RYU HEE WOOK ; CHO KYUNG-SUK ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 952~964
The diesel-degrading activities of biofilms sampled from petroleum-contaminated groundwaters in urban subway drainage systems were examined in liquid cultures, and the microbial populations of the biofilms were characterized by denaturing gel gradient electrophoresis (DGGE) and 16S rDNA sequence analysis. Biofilm samples derived from two sites (19 K and 20 K) at subway Station N and Station I could degrade around
of applied diesel within 20 and 40 days, respectively, at
, and these results were strongly correlated with the growth patterns of the biofilms. The closest phylogenetic neighbor of a dominant component in the 19 K biofilm was Thiothrix fructosivorans strain Q (
similarity). Four dominant strains in the 20 K biofilm were closely related to Thiothrix fructosivorans strain Q (
similarity), Thiothrix sp. CC-5 (
similarity), Sphaerotilus sp. IF14 (
similarity), and Cytophaga-Flexibacter-Bacterioides (CFB) group bacterium RW262 (
similarity). Three dominant members in the Station I biofilms were very similar to uncultured Cytophagales clone CRE-PA82 (
similarity), Pseudomonas sp. WDL5 (
similarity), and uncultured CFB group bacterium LCK-64 (
similarity). The microbial components of the biofilms differed depending on the sampling site. This is the first report on the isolation of clones highly similar to Thiothrix fructosivorans and Thiothrix sp. from biofilms in petroleum-polluted groundwaters, and the first evidence that these organisms may play major roles in petroleum degradation and/or biofilm-development.
Effect of Trehalose on Stabilization of Cellular Components and Critical Targets Against Heat Shock in Saccharomyces cerevisiae KNU5377
PAIK SANG-KYOO ; YUN HAE-SUN ; IWAHASHI HITOSHI ; OBUCHI KAORU ; JIN INGNYOL ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 965~970
In our previous study , we found that heat-shock exposure did not stimulate the neutral trehalase activity in Sacchromyces cerevisiae KNU5377, but did in ATCC24858. Consequently, the trehalose content in KNU5377 became 2.6 times higher than that in ATCC24858. Because trehalose has been shown to stabilize the structure and function of some macromolecules, the present work was focused to elucidate the relationship between trehalose content of these strains and thermal stabilities of whole cells, through differential scanning calorimetry (DSC), and to predict critical targets calculated from the hyperthermic cell killing rates. These analyses showed that the prominent DSC transition of both strains gave identical
(transition temperature) values in exponentially growing cells, and that the
values of critical targets was about
higher in KNU5377 than in ATCC24858. Both heat-shocked KNU5377 and ATCC24858 cells displayed similar shifts in their DSC transition profiles. On the other hand, the
value of the critical target of KNU5377 was decreased by
, which was still higher than ATCC24858 showing no changes. In view of these results, the intrinsic thermotolerance of KNU5377 did not appear to result from the stability of entire cellular components, but rather possibly from that of particular macromolecules, including critical targets, even though it should be investigated in more details. Although the trehalose levels in heat-shocked cells are significantly different, as described in our previous study , the overall pattern of thermal stabilities and their predicted critical targets in two heat-shocked strains seemed to be identical. These data suggest that the trehalose levels examined before and after heat shock of exponentially growing cells are not closely correlated with the stabilities of whole cells and/or critical targets in both yeast strains.
Relationship Between Fractal Dimension and Morphological Features of Cephalosporium acremonium M25 in a 30-1 Bioreactor Culture
Lim Jung-Soo ; Kim Jung-Mo ; Kim Jong-Chae ; Kim Chang-Ho ; Yang Dae-Ryook ; Chang Hyo-Ihl ; Kim Seung-Wook ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 971~976
In a 30-1 bioreactor culture, whole differentiation occurred from 48 h, and then proceeded rapidly. As swollen hyphal fragments and arthrospores increased, cephalosporin C (CPC) production increased exponentially to
at 72 h. To explain the morphological changes of Cephalosporium acremonium M25 more quantitatively, specific differentiation rates and fractal analysis were employed. Specific differentiation rates of morphological factors varied greatly during the period of culture time from 48 h to 72 h, when CPC production increased significantly. Changes of fractal dimensions showed a pattern similar to that of the specific rate of arthrospores. Furthermore, it was inversely related to the specific rate of tips. Overall, it was suggested that the fractal dimension had potential for a new morphological parameter of fungal morphology, showing complex differentiation patterns.
Removal Characteristics of Ethyl Acetate and 2-Butanol by a Biofilter Packed with Jeju Scoria
KAM SANG-KYU ; KANG KYUNG-HO ; LEE MIN-GYU ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 977~983
The removal characteristics of ethyl acetate and 2-butanol were investigated in a bench-scale down-flow biofilter packed with Jeju scoria medium. Various inlet concentrations and gas flow rates were tested. The adaptation times of microorganisms to the change of the influent concentration of ethyl acetate and 2-butanol gas were found to be about 3 days. At the inlet concentration of 300 ppmv and empty bed contact time (EBCT) of 15 see, the removal efficiencies of the biofilter for ethyl acetate and 2-butanol were above
. The maximum removal capacity of the biofilter for ethyl acetate was
and that for 2-butanol was
. Overall, the removal capacity of the biofilter for ethyl acetate was
larger than that for 2-butanol. During the operation of 65 days, the pressure drop through the biofilter column was maintained below
. Although the pH in the drain water decreased from 7.2 to 5.0, the pH drop did not affect the removal of the gases. From the above results, the biofilter using Jeju scoria as a packing material seemed to very effectively treat waste gases such as ethyl acetate and 2-butanol.
Nature of a Root-Associated Paenibacillus polymyxa from Field-Grown Winter Barley in Korea
RYU CHOONG-MIN ; KIM JINWOO ; CHOI OKHEE ; PARK SOO-YOUNG ; PARK SEUNG-HWAN ; PARK CHANG-SEUK ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 984~991
Soil or seed applications of plant growth-promoting rhizobacteria (PGPR) have been used to enhance growth of several crops as well as to suppress the growth of plant pathogens. In this study, we selected a PGPR strain, Paenibacillus polymyxa strain E681, out of 3,197 heat-stable bacterial isolates from winter wheat and barley roots. Strain E681 inhibited growth of a broad spectrum plant pathogenic fungi in vitro, and treatment of cucumber seed with E681 reduced incidence of damping-off disease caused by Pythium ultimum, Rhizoctonia solani, or Fusarium oxysporum. When inoculated onto seeds as vegetative cells or as endospores, E681 colonized whole cucumber root systems and root tips. Different temperatures such as
did not affect root colonization by strain E681. This colonization was associated with a consistent increase in foliar growth of cucumber in the greenhouse. These results indicate that strain E681 is a promising PGPR strain for application to agricultural systems, particularly during the winter season.
Isolation, Identification, and Characterization of Aero-Adaptive Campylobacter jejuni
LEE YOUNG-DUCK ; MOON BO-YOUN ; CHOI JUNG-PIL ; CHANG HAK-GIL ; NOH BONG-SOO ; PARK JONG-HYUN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 992~1000
Campylobacter is one of the emerging foodborne pathogens, and its worldwide incidence rate is extremely high. This study was undertaken to isolate and identify Campylobacter strains from chicken carcasses in the local markets, and analyze their characteristics regarding oxygen tolerance. They were isolated after aerobic enrichment and identified by biochemical, physiological, and morphological characteristics, PCR, and 16S rDNA sequencing. Their oxygen tolerances were analyzed in terms of the cell surface hydrophobicity, cell fatty acid composition, and oxidoreductase. Five strains of C. jejuni were isolated and identified from 61 isolates from 50 chickens. Among them, C. jejuni IC21 grew well in Brucella broth and commercial milk under aerobic condition. However, in the aerobic exposure, the cell surface hydrophobicity of C. jejuni IC21 was almost the same as the other isolates, even though its morphology changed from the spiral-bacilli form into the coccoid form. Fatty acid analyses showed that all Campylobacter strains had a high composition of
, cyclopropane fatty acid, and that the amount of the other fatty acids were very similar between them. Interestingly, however, only oxidoreductase activities of C. jejuni IC21 increased highly under aerobic exposure even though its activities were almost the same as the other C. jejuni strains just after microaerobic culture. It had 11.8 times higher catalase activity, 4.4 times higher for SOD, and 2.0 times higher for NADH oxidase activities. Therefore, in the case of the aero-adaptive C. jejuni IC21, expression of oxidoreductase significantly increased under oxidative stressed condition, which might allow it to survive for a longer time and grow on food under aerobic exposure. Such new strain might be one of the explanations for the increase of campylobacteriosis.
An Antifungal Antibiotic Purified from Bacillus megaterium KL39, a Biocontrol Agent of Red-Pepper Phytophthora-Blight Disease
JUNG HEE KYOUNG ; KIM SANG-DAL ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1001~1010
Bacillus megaterium KL39, an antibiotic-producing plant growth promoting rhizobacterium (PGPR), was selected from soil. The antifungal antibiotic, denoted KL39, was purified from culture filtrate by column chromatography using Dion HP-20, Silica gel, Sephadex LH-20, and prep-HPLC. Thin layer chromatography, employing the solvent system of ethanol:ammonia:water=8:1:1, showed the
. value of 0.32. The antibiotic KL39 showed a negative reaction with ninhydrin solution, positive with iodine vapor, and also positive with Ehrlich reagent. It was soluble in methanol, ethanol, butanol, and acetonitrile, but insoluble in chloroform, toluene, hexane, ethyl ether, or acetone. Its UV spectrum had the maximum absorption at 208 nm. Amino acid composition, FAB-mass,
, and atomic analyses showed that the antibiotic KL39 (MW=1,071) has a structure very similar to iturin E. The antibiotic KL39 has a broad antifungal spectrum against a variety of plant pathogenic fungi including Rhizoctonia solani, Pyricularia oryzae, Monilinia froeticola, Botrytis cinenea, Altenaria kikuchiana, Fusarium oxysporum, and F. solani. An MIC value of
was determined for Phytophthora capsici. Macromolecular incorporation studies with P. capsici using radioactive [
] as the precursor, indicated that the antibiotic KL39 strongly inhibits the DNA biosynthesis of the fungal cell. Microscopic observation of the antifungal action showed abnormal hyphal swelling of P. capsici. The purified antibiotic KL39 was very effective for the biocontrol of in vivo Phytophthora-blight disease of pepper.
Biological Control of Phytopathogenic Fungi by Bacillus amyloliquefaciens 7079; Suppression Rates are Better Than Popular Chemical Fungicides
CHUNG SOOHEE ; KIM SANG-DAL ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1011~1021
Rhizobacteria are actively sought for the substitution of chemical fertilizers and pathogen control agents in environment-friendly sustainable agriculture. To be successfully commercialized in the current Korean market as agriculture biomaterials, microbial agents should exhibit both properties of plant growth promotion and pathogen control. That is, the organism must be a phytostimulator as well as a biocontrol agent. These criteria and the survival rate of a rhizobacterium, Bacillus amyloliquefaciens 7079, in the soil system were investigated to evaluate the suitability for future commercialization. B. amyloliquefaciens 7079-treated seedlings showed
maximum increase in leaf-length growth, compared with water-treated controls, showing the phytostimulating property. The disease suppression rates of Phytophthora-blight of peppers and Fusarium-wilt of tomatoes by B. amyloliquefaciens 7079 were 1.5 and 2.2 times better, respectively, than by three popular chemical fungicides used in actual agricultural practices to control the respective pathogens. Survival of B. amyloliquefaciens 7079 on the rhizoplane and in the rhizosphere was favorable up to 50 days in the soil system employed. These positive properties show that B. amyloliquefaciens 7079 is likely to be a suitable candidate for commercialization to market as agricultural biomaterials.
In Vitro Selection of High Affinity DNA-Binding Protein Based on Plasmid Display Technology
Choi, Yoo-Seong ; Joo, Hyun ; Yoo, Young-Je ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1022~1027
Based on plasmid display technology by the complexes of fusion protein and the encoding plasmid DNA, an in vitro selection method for high affinity DNA-binding protein was developed and experimentally demonstrated. The GAL4 DNA-binding domain (GAL4 DBD) was selected as a model DNA-binding protein, and enhanced green fluorescent protein (EGFP) was used as an expression reporter for the selection of target proteins. Error prone PCR was conducted to construct a mutant library of the model. Based on the affinity decrease with increased salt concentration, mutants of GAL4 DBD having high affinity were selected from the mutant protein library of protein-encoding plasmid complex by this method. Two mutants of (Lys33Glu, Arg123Lys, Ile127Lys) and (Ser47Pro, Ser85Pro) having high affinity were obtained from the first generation mutants. This method can be used for rapid in vitro selection of high affinity DNA-binding proteins, and has high potential for the screening of high affinity DNA-binding proteins in a sequence-specific manner.
Phylogeny of Phellinus and Related Genera Inferred from Combined Data of ITS and Mitochondrial SSU rDNA Sequences
JEONG WON JIN ; LIM YOUNG WOON ; LEE JIN SUNG ; JUNG HACK SUNG ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1028~1038
To elucidate phylogenetic relationships of Phellinus and its related genera, nuclear internal transcribed spacer and mitochondrial small subunit ribosomal DNA sequences from 65 strains were determined and compared. The combined dataset of two sequences increased informative characters and led to the production of trees with higher levels of resolution. Phylogenetic analysis of the combined dataset revealed thirteen evolutionary lineages and several unresolved species that were together subdivided into two large clusters consisting of oligonucleate species and binucleate species. These results coincided with previous cytological, morphological, and molecular studies. It is newly recognized that the Phellinus linteus complex forms a sister clade to Inonotus, and that Fulvifomes is somehow related to Inocutis. The Phellinus linteus complex of dimitic perennial taxa made an independent clade from Inonotus and suggested that hyphal miticity and fruitbody permanence had enough phylogenetic significance to keep the complex within the traditional genus Phellinus. Taxa lacking setae were clustered into Fulvifomes, Phylloporia, Inocutis, and Fomitiporia, and the first three were closely related sister groups, but Fomitiporia was a genus distantly related to them. Several taxa with branched setae were shown among distantly related genera. Molecular evidence indicated that the ancestral nuclear type could be a binucleate feature, and that there might be parallel gains of branched setae and parallel losses of setae in the Hymenochaetales.
Synergistic Killing Effect of Synthetic Peptide P20 and Cefotaxime on Methicillin-Resistant Nosocomial Isolates of Staphylococcus aureus
Jung, Hyun-Jun ; Choi, Kyu-Sik ; Lee, Dong-Gun ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1039~1046
The salt resistance of antibacterial activity and synergistic effect with clinically used antibiotic agents are critical factors in developing effective peptide antibiotic drugs. For this reason, we investigated the resistance of antibacterial activity to antagonism induced by NaCl and
and the synergistic effect of P20 with cefotaxime. P20 is a 20-residue synthetic peptide derived from a cecropin A (CA)-melittin(ME) hybrid peptide. In this study, P20 was found to have potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) strains without hemolytic activity against human erythrocytes. The combination study revealed that P20 in combination with cefotaxime showed synergistic antibacterial activity in an energy-dependent manner. We also confirmed the synergism between P20 and cefotaxime by fluorescence-activated flow cytometric analysis by staining bacterial cells with propidium iodide (PI) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (BOX). This study suggests that P20 may be useful as a therapeutic antibiotic peptide with synergistic effect in combination with conventional antibiotic agents.
Cyclosporin A Binding Protein Type-19 kDa Peptidyl-Prolyl Cis/Trans Isomerase from Euglena gracilis
SONG HYUK-HWAN ; PARK SUNG-YONG ; LEE CHAN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1047~1053
Cyclosporin A binding protein type-19 kDa peptidyl-prolyl cis/trans isomerase (PPIases, EC 22.214.171.124) of Euglena gracilis was purified and some of its biochemical characters were elucidated. Purification of the PPIase was achieved by employing a series of steps involving ammonium sulfate precipitation, Superdex G-75 gel filtration chromatography, MonoQ anion and Mono-S cation exchange chromatographies, and Superdex S-200 gel filtration chromatography on FPLC. Purified PPIase had a specific activity of 8,250 units/mg, showing a 27-fold increase compared with that of cell-free extract of Euglena gracilis. The enzyme consisted of a single polypeptide chain with a molecular mass of 19 kDa. It showed high substrate specificity to succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, and
, for this substrate was found to be
. The isomer distributions were investigated at an equilibrium of seven different peptide substrates, varying Xaa in Suc-Ala-Xaa-Pro-Phe-p-nitroanilide in dimethylsulfoxide. The cis/trans equilibrium constants were estimated to be from 0.14 (Ile) to 0.63 (Gly), which correspond to
of the cis population, respectively, under experimental condition. The enzyme was highly sensitive to the immunosuppressive ligand cyclosporin A, but not to other immunosuppressants such as FK506 and rapamycin. Thus, it appears to belong to the class of cyclophilin.
Mass-Spectral Identification of an Extracellular Protease from Bacillus subtilis KCCM 10257, a Producer of Antibacterial Peptide Subtilein
SONG HYUK-HWAN ; GIL MI-JUNG ; LEE CHAN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1054~1059
An extracellular protease was identified from Bacillus subtilis KCCM 10257 by N-terminal sequencing and mass spectral analysis. The molecular mass of the extracellular protease was estimated to be 28 kDa by SDS-PAGE. Sequencing of the N-terminal of the protease revealed the sequence of A(G,S,R)QXVPYG(A)V(P,L)SQ. The N-terminal sequence exhibited close similarity to the sequence of other proteases from Bacillus sp. A mass list of the monoisotopic peaks in the MALDI-TOF spectrum was searched after peptide fragmentation of the protease. Six peptide sequences exhibiting monoisotopic masses of 1,276.61, 1,513.67, 1,652.81, 1,661.83, 1,252.61, and 1,033.46 were observed from the fragmented protease. These monisotopic masses corresponded to the lytic enzyme L27 from Bacillus subtilis 168, and the Mowse score was found to be 75. A doubly charged Top product (MS) at a m/z of 517.3 exhibiting a molecular mass of 1034.6 was further analyzed by de novo sequencing using a PE Sciex QSTAR Hybrid Quadropole-TOF (MS/MS) mass spectrometer. MS/MS spectra of the Top product (MS) at a m/z of 517.3 obtained from the fragmented peptide mixture of protease with Q-star contained the b-ion series of 114.2, 171.2, 286.2, 357.2, 504.2, 667.4, 830.1, and 887.1 and y-ion series of 147.5, 204.2, 367.2, 530.3, 677.4, 748.4, 863.4, and 920.5. The sequence of analyzed peptide ion was identified as LGDAFYYG from the b- and y-ion series by de novo sequencing and corresponded to the results from the MALDI-TOF spectrum. From these results the extracellular protease from Bacillus subtilis KCCM 10257 was successfully identified with the lytic enzyme L27 from Bacillus subtilis 168.
Gene Expression Profiling of Eukaryotic Microalga, Haematococcus pluvialis
EOM HYUNSUK ; PARK SEUNGHYE ; LEE CHOUL-GYUN ; JIN EONSEON ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1060~1066
Under environmental stress, such as strong irradiance or nitrogen deficiency, unicellular green algae of the genus Haematococcus accumulate secondary carotenoids, i.e. astaxanthin, in the cytosol. The induction and regulation of astaxanthin biosynthesis in microalgae has recently received considerable attention owing to the increasing use of secondary carotenoids as a source of pigmentation for fish aquacultures, and as a potential drug in cancer prevention as a free-radical quencher. Accordingly, this study generated expressed sequence tags (ESTs) from a library constructed from astaxanthin-induced Haematococcus pluvialis. Partial sequences were obtained from the 5' ends of 1,858 individual cDNAs, and then grouped into 1,025 non-overlapping sequences, among which 708 sequences were singletons, while the remainder fell into 317 clusters. Approximately
of the EST sequences showed similarity to previously described sequences in public databases. H. pluvialis was found to consist of a relatively high percentage of genes involved in genetic information processing (
) and metabolism (
), whereas a relatively low percentage of sequences was involved in the signal transduction (
), structure (
), and environmental information process (
). In addition, a relatively large fraction of H. pluvialis sequences was classified as genes involved in photosynthesis (
) and cellular process (
). Based on this EST analysis, the full-length cDNA sequence for superoxide dismutase (SOD) of H. pluvialis was cloned, and the expression of this gene was investigated. The abundance of SOD changed substantially in response to different culture conditions, indicating the possible regulation of this gene in H. pluvialis.
Screening and Characterization of an Esterase from a Metagenomic Library
KIM JEONG-NYEO ; SEO MYUNG-JI ; CHO EUN-AH ; LEE SANG-JAE ; KIM SEONG-BO ; CHEIGH CHAN-ICK ; PYUN YU-RYANG ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1067~1072
A metagenomic library was constructed using a fosmid vector, and total genomic DNA was extracted directly from soil at Cisolok (hot spring area, Indonesia). This library was composed of 10,214 clones and screened for lipolytic enzyme on tributyrin agar plates. An esterase gene (estMa) was subcloned and sequenced from a positive lipolytic active clone. Esterase EstMa was encoded by a 954-bp open reading frame and showed low (
) amino acid similarity to known esterases. The amino acid sequence analysis demonstrated that the enzyme is a new member of lipolytic enzyme family VI. The estMa gene encodes a preprotein of 317 amino acids with a predicted molecular mass of 34,799 Da. The purified enzyme exhibited optimal activity at
and pH 6.5. The
values of EstMa for the hydrolysis of p-nitrophenyl valerate were
and 4.45 U/mg, respectively.
Quantitative Changes of Plant Defense Enzymes in Biocontrol of Pepper (Capsicium annuum L.) Late Blight by Antagonistic Bacillus subtilis HJ927
LEE HYUN-JIN ; PARK KEUN-HYUNG ; SHIM JAE-HAN ; PARK RO-DONG ; KIM YONG-WOONG ; CHO JEUNG-YONG ; HWANGBO HOON ; KIM YOUNG-CHEOL ; CHA GYU-SUK ; KRISHNAN HARI B. ; KIM KIL-YONG ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1073~1079
To investigate plant protection, pathogenesis-related (PR) proteins and plant defense enzymes related to cell wall lignification were studied in pepper plants inoculated with antagonistic Bacillus subtilis HJ927 and pathogenic strain Phytophthora capsici. Phytophthora blight disease was reduced by
in pepper roots when preinoculated with B. subtilis HJ927 against P. capsici. The activities of PR proteins (chitinase and
-1,3,-glucanase) and defense-related enzymes (peroxidase, polyphenoloxidase, and phenylalanine ammonia lyase) decreased in roots of B. subtilis+P capsid-treated plants, but increased in leaves with time. The decrease and increase were much greater in P. capsici-treated plants than in B. subtilis HJ927+P capsici-treated plants, although P. capsici-treated plants had more severe damage. Therefore, changes of enzyme activities do not seem to be directly related to plant protection. We suggest that the change of these enzymes in pathogen-treated plants may be related to plant response rather than to resistance against pathogen attacks.
Enzymatic and Energetic Properties of an Aerobic Respiratory ChainLinked NADH Oxidase System in Marine Bacterium Vibrio natriegens
Kang, Ji-Won ; Kim, Young-Jae ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1080~1086
Membranes prepared from Vibrio natriegens oxidized both NADH and deamino-NADH as substrates. The maximum activity of the membrane-bound NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl, whereas that of the NADH:ubiquinone oxidoreductase was obtained at about pH 7.5 in the presence of 0.2 M NaCl. Electron transfer from NADH or deamino-NADH to ubiquinone-l or oxygen generated a considerable membrane potential (
), which occurred even in the presence of
carbonylcyanide m-chlorophenylhydrazone (CCCP). However, the
was completely collapsed by the combined addition of
monensin. On the other hand, the activity of the NADH oxidase and the
generated by the NADH oxidase system were inhibited by about
HQNO, whereas the activity of the NADH:ubiquinone oxidoreductase and the
generated at the NADH:ubiquinone oxidoreductase segment were inhibited by about
. Interestingly, the activity of the NADH:ubiquinone oxidoreductase and the
generated at the NADH:ubiquinone oxidoreductase segment were resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and
, and the activity of the NADH oxidase and the
generated by the NADH oxidase system were very sensitive only to
. It was concluded, therefore, that V. natriegens cells possess a
pump that is different from the
pump of a marine bacterium, Vibrio alginolyticus.
Molecular and Cultivation-Based Characterization of Bacterial Community Structure in Rice Field Soil
KIM MI-SOON ; AHN JAE-HYUNG ; JUNG MEE-KUM ; YU JI-HYEON ; JOO DONGHUN ; KIM MIN-CHEOL ; SHIN HYE-CHUL ; KIM TAESUNG ; RYU TAE-HUN ; KWEON SOON-JONG ; KIM TAESAN ; KIM DONG-HERN ; KA JONG-OK ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1087~1093
The population diversity and seasonal changes of bacterial communities in rice soils were monitored using both culture-dependent approaches and molecular methods. The rice field plot consisted of twelve subplots planted with two genetically-modified (GM) rice and two non-GM rice plants in three replicates. The DGGE analysis revealed that the bacterial community structures of the twelve subplot soils were quite similar to each other in a given month, indicating that there were no significant differences in the structure of the soil microbial populations between GM rice and non-GM rice during the experiment. However, the DGGE profiles of June soil after a sudden flooding were quite different from those of the other months. The June profiles exhibited a few intense DNA bands, compared with the others, indicating that flooding of rice field stimulated selective growth of some indigenous microorganisms. Phylogenetic analysis of l6S rDNA sequences from cultivated isolates showed that, while the isolates obtained from April soil before flooding were relatively evenly distributed among diverse genera such as Arthrobacter, Streptomyces, Terrabacter, and Bacillus/Paenibacillus, those from June soil after flooding mostly belonged to the Arthrobacter species. Phylogenetic analysis of 16S rDNA sequences obtained from the soil by cloning showed that April, August, and October had more diverse microorganisms than June. The results of this study indicated that flooding of rice fields gave a significant impact on the indigenous microbial community structure; however, the initial structure was gradually recovered over time after a sudden flooding.
Characterization of the Gene for the Light-Harvesting Peridinin-Chlorophyll-Protein of Alexandrium tamarense
LEE SOON-YOUL ; KANG SUNG-HO ; JIN EONSEON ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1094~1099
Photosynthetic dinoflagellates contain a water-soluble, light-harvesting antenna called the peridinin-chlorophyll-protein (PCP) complex, which has an apoprotein with no sequence similarity to other known proteins. There are two forms of PCP apoproteins; the 15-kDa short form and the 32- to 35kDa long form. The present study describes the PCP protein and its cDNA from Alexandrium tamarense. A cDNA library was constructed from mRNA isolated from A. tamarense. The complete PCP cDNA was generated by reverse-transcription coupled to polymerase chain reaction (RT-PCR), together with rapid-amplification of cDNA ends (RACE). The A. tamarense PCP cDNA encoded a 55-amino acid signal peptide and a 313-amino acid mature protein with a calculated mass of 32 kDa, which corresponded to that of the long form of PCP. Phylogenetic analysis indicated that the sequence of A. tamarense PCP did not cluster with the short-form PCPs, to which it was only about
identical, but which were
identical to other long-form PCPs. The deduced amino acid sequence of A. tamarense PCP contains an internal duplication, which suggests the possibility that long-form PCPs arose by gene duplication or by the fusion of genes encoding the short form. The abundance of PCP mRNA changed substantially in response to different light conditions, indicating the possible existence of a photo-acclimation response in A. tamarense.
Species-Specific Cleavage by RNase E-Like Enzymes in 5S rRNA Maturation
RYOU SANG-MI ; KIM JONG-MYUNG ; YEOM JI-HYUN ; KIM HYUN-LI ; GO HA-YOUNG ; SHIN EUN-KYOUNG ; LEE KANGSEOK ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1100~1105
Previous work has identified a Streptomyces coelicolor gene, rns, encoding a 140 kDa protein (RNase ES) that exhibits the endoribonucleolytic cleavage specificity characteristic of RNase E and confers viability on and allows the propagation of E. coli cells lacking RNase E. Here, we identify a putative S. coelicolor 9S rRNA sequence and sites cleaved by RNase ES. The cleavage of the S. coelicolor 9S rRNA transcript by RNase ES resulted in a 5S rRNA precursor (p5S) that had four and two additional nucleotides at the 5' end and 3' ends of the mature 5S rRNA, respectively. However, despite the similarities between RNase E and RNase ES, these enzymes could accurately process 9S rRNA from just their own bacteria, indicating that these ancient enzymes and the rRNA segments that they attack appear to have co-evolved.
Antimicrobial Effect of the Wood Vinegar from Cryptomeria japonica Sapwood on Plant Pathogenic Microorganisms
HWANG YOUNG-HEE ; MATSUSHITA YOH-ICHI ; SUGAMOTO KAZUHIRO ; MATSUI TAKANAO ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1106~1109
The antimicrobial effect of the wood vinegar of C. japanica sapwood and its constituents was evaluated against Ralstonia salanacearum, Phytophthora capsid, Fusarium oxysporum, and Pythium splendens. Phenols and guaiacols had a strong antimicrobial effect against four kinds of microorganisms, but methanol and acetic acid exhibited little or no antimicrobial activity.
RT-PCR-Based Detection of Six Garlic Viruses and Their Phylogenetic Relationships
PARK KWANG-SOOK ; BAE YOUNG-JOO ; JUNG EUN-JEONG ; KANG SOON-JA ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1110~1114
Six viruses of the genera Carlavirus (Garlic mosaic virus, GarMV, and Garlic latent virus, GarLV), Allexivirus (Garlic virus X, GarV-X, and Garlic mite-borne filamentous virus, GarMbFV) and Potyvirus (Leek yellow stripe virus, LYSV, and Onion yellow dwarf virus, OYDV) from Korean garlic plants with mosaic symptoms were simultaneously detected by multiplex RT-PCR and subsequently sequenced. An immunocapture RT-PCR for the detection of GarLV, LYSV, and OYDV was also performed. The coat protein phylogenetic analysis of the garlic viruses showed that the Korean isolates were most closely related to the isolates from China, Japan, Brazil, and Argentina. This study is the first report for the differentiation of six garlic viruses in Korea by simultaneous detection using multiplex RT-PCR.
Improvement of Photoheterotrophic Hydrogen Production of Rhodobacter sphaeroides by Removal of B800-850 Light-Harvesting Complex
KIM EUI-JIN ; YOO SANG-BAE ; KIM MI-SUN ; LEE JEONG K. ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1115~1119
production of Rhodobacter sphaeroides was significantly increased through disruption of the genes coding for uptake hydrogenase and poly-
-hydroxybutyrate (PHB) synthase (Lee et al., Appl. Microbiol. Biotechnol. 60: 147-153, 2002). In this work, we further removed the B800-850 light-harvesting (LH) complex from the strain and found an increase in
production at the light-saturating cell growth (
). Neither the mutant nor the wild-type produced more
at the brighter light. Accordingly, light does not appear to be limited for the
production by the presence of B800-850. However, increase in the level of the spectral complexes resulted in decrease of
production. Thus, although the B875 is essential for light harvesting, the consumption of cellular energy for the synthesis of B800-850 and the surplus LH complexes may reduce the energy flow into the
production of R. sphaeroides.
Molecular Structure of the PHA Synthesis Gene Cluster from New mcl-PHA Producer Pseudomonas putida KCTC1639
KIM TAE-KWON ; VO MINH TRI ; SHIN HYUN-DONG ; LEE YONG-HYUN ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1120~1124
Pseudomonas putida KCTC 1639 was newly identified as a potential producer of biodegradable medium chain length polyhydroxyalkanoates. It exhibited a carbon assimilation pattern quite different from other known P. putida strains, but a more similar pattern with P. oleovorans, which assimilates the carbon sources mainly through
-oxidation rather than the fatty acid biosynthesis pathway. The PHA synthesis gene cluster from P. putida KCTC1639 was composed of two gene loci; the PHA synthase gene locus and granule-associated gene locus, which were cloned and deposited in the GenBank under accession numbers AY286491 and AY750858 as a new nucleotide sequence, respectively. The molecular structure and amino acid homology of the new gene cluster were compared with those from Pseudomonas species, including other P. putida strains and P. oleovorans, and a higher than
homology was observed.
Identification of the sprU Gene Encoding an Additional sprT Homologous Trypsin-Type Protease in Streptomyces griseus
YANG HYE-YOUNG ; CHOI SI-SUN ; CHI WON-JAE ; KIM JONG-HEE ; KANG DAE-KYUNG ; CHUN JAESUN ; KANG SANG-SOON ; HONG SOON-KWANG ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1125~1129
Cloning of a 6.6-kb BamHI digested chromosomal DNA from S. griseus IFO13350 revealed the presence of an additional gene encoding a novel trypsin-like enzyme, named SprU. The SprU protein shows a high homology (
similarity) with the SGT protease, which has been reported as a bacterial trypsin in the same strain. The amino acid sequence deduced from the nucleotide sequence of the sprU gene suggests that SprU is produced as a precursor consisting of an amino-terminal presequence (29 amino acid residues), prosequence (4 residues), and mature trypsin consisting of 222 amino acids with a molecular weight of 22.94 kDa and a calculated pI of 4.13. The serine, histidine, and aspartic acid residues composing the catalytic triad of typical serine proteases are also well conserved. When the trypsin activity of the SprU was spectrophotometrically measured by the enzymatic hydrolysis of the artificial chromogenic substrate, N-
-benzoyl-DL-arginine-p-nitroanilide, the S. lividans transformant with pWHM3-U gave 3 times higher activity than that of control. When the same recombinant plasmid was introduced into S. griseus, however, the gene dosage effect was not so significant, as in the cases of other genes encoding serine proteases, such as sprA, sprB, and sprD. Although two trypsins, SprU and SGT, have a high degree of homology, the pI values, the gene dosage effect in S. griseus, and the gene arrangement adjacent to the two genes are very different, suggesting that the biochemical and biological function of the SprU might be quite different from that of the SGT.
Investigation of Possible Horizontal Gene Transfer from the Leaf Tissue of Transgenic Potato to Soil Bacteria
KIM YOUNG TAE ; KIM SUNG EUN ; PARK KI DUK ; KANG TAE HOON ; LEE YUN MI ; LEE SANG HAN ; MOON JAE SUN ; KIM SUNG UK ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1130~1134
To monitor the possibility of horizontal gene transfer between transgenic potato and bacteria in the environment, the gene flow from glufosinate-tolerant potato to bacteria in soils was investigated. The soil samples treated with the leaf tissue of either glufosinate-tolerant or glufosinate-sensitive potato were subjected to PCR and Southern hybridization to determine possible occurrence of glufosinate-resistant soil bacteria and to detect the bar (phosphinothricin acetyltransferase) gene, conferring tolerance to glufosinate. The bar gene was not detected from genomic DNAs extracted at different time intervals from the soil samples, which had been treated with the leaf tissue of either transgenic or non-transgenic potato for 2 to 8 weeks. In addition, the level of glufosinate-resistant bacteria isolated from the soil samples treated with the leaf tissue of transgenic potato was similar to that of the samples treated with non-transgenic potato after 4 months of incubation at
. The bar gene was not detected in the genomic DNAs extracted from colonies growing on the plate containing glufosinate, indicating that the bacteria could acquire the resistant phenotype to glufosinate by another mechanism without the uptake of the bar gene from glufosinate-tolerant potato.
Biodegradation of Phenanthrene by Psychrotrophic Bacteria from Lake Baikal
AHN TAE-SEOK ; LEE GEON-HYOUNG ; SONG HONG-GYU ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1135~1139
Psychrotrophic phenanthrene-degrading bacteria were identified in the sediment samples collected from Lake Baikal, Russia. Among 70 phenanthrene-degrading isolates, the seven that had the highest phenanthrene-degradation rates were identified by 16S rDNA sequencing. Isolate P25, identified as the Gram-positive rod-shaped organism Rhodococcus erythropolis, had the highest growth and degradation rate at
. It could remove
of 100 mg
phenanthrene in 20 days at
, and degradation was less at
. The addition of surfactants to enhance degradation was tested. Brij 30 and Triton X-100 inhibited degradation at all surfactant concentrations tested, but Tween 80 stimulated phenanthrene degradation, especially at low concentrations. When
CMC (critical micelle concentration) of Tween 80 was added,
of 100 mg
phenanthrene was degraded in 12 days at
. This psychrotrophic phenanthrene-degrading bacterium is a candidate for use in bioremediation of polycyclic hydrocarbon contamination in low temperature environments.
Kitasatospora sp. MJM383 Strain Producing Two Antitumor Agents, Streptonigrin and Oxopropaline G
JIN YING-YU ; YOON TAE-MI ; KIM WON-KON ; KIM KYOUNG-ROK ; SONG JEA-KYOUNG ; KIM JONG-GWAN ; LIU JING ; YANG YOUNG-YELL ; KWON HYUNG-JIN ; SUH JOO-WON ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1140~1145
MJM383, a rare actinomycete sp. strain originated from Chinese soils, was isolated through an antimicrobial screening system. The analysis of 16S rDNA sequences and biochemical characterization determined the strain to belong to genus Kitasatospora. Both NMR and ESI mass data of its purified bioactive compounds revealed Kitasatospora sp. MJM383 to produce two antitumor agents, streptonigrin and oxopropaline G, which have been known to be produced from Streptomyces species. This is the first report to demonstrate the presence of antitumor agents produced by genus Kitasatospora.
cDNA Cloning of Farnesoic Acid-Induced Genes in Candida albicans by Differential Display Analysis
CHUNG SOON-CHUN ; LEE JI-YOON ; OH KI-BONG ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1146~1151
The yeast Candida albicans has a distinguishing feature, dimorphism, which is the ability to switch between two morphological forms: a budding yeast form and a multicellular invasive filamentous form. This ability has been postulated to contribute to the virulence of this organism. Previously, we reported that the yeast-to-hypha transition in this organism is suppressed by farnesoic acid, a morphogenic autoregulatory substance that accumulates in the medium as the cells proliferate. In this study, using a differential display reverse transcription polymerase chain reaction (DDRT-PCR) technique, we have identified several genes induced in C. albicans by farnesoic acid treatment. These observations indicate that farnesoic acid can alter the expressivity of multiple genes, including the DNA replication machinery and cell-cycle-control proteins.
The Effect of Carbon Sources on Nisin Z Biosynthesis in Lactococcus lactis subsp. lactis A164
CHEIGH CHAN-ICK ; LEE SANG-JAE ; PYUN YU-RYANG ; AN DUEK-JUN ; HWANG YOUNG-SUP ; CHUNG YOOJIN ; PARK HOON ;
Journal of Microbiology and Biotechnology, volume 15, issue 5, 2005, Pages 1152~1157
The effect of carbon sources on nisin Z biosynthesis in Lactococcus lactis subsp. lactis A164 was studied in batch culture using M17 broth containing different carbon sources. Among the eleven carbon sources tested, glucose, sucrose, and lactose were suitable carbon sources for cell growth of L. lactis A164. In particular, cells grown on lactose produced at least 3-fold greater amount of nisin Z than those on other carbon sources. Galactose resulted in less amount of cell mass than did sucrose or glucose, but gave a higher level of nisin Z activity. Northern blot analysis revealed. that lactose increased the transcription of the nisZ pre-peptide gene. Although galactose was less efficient than lactose, it increased the transcription of nisZ along with a higher level of nisin Z than did sucrose and glucose. These results suggest that the increased nisin Z production is correlated with the induction of nisZ by lactose and galactose. Among all the carbon sources tested, no remarkable differences were observed in nisRK and nisFEG transcripts, indicating that the lactose- or galactose-mediated induction is unique to the nisZ promoter.