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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Microbiology and Biotechnology Letters
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 38, Issue 4 - Dec 2010
Volume 38, Issue 3 - Sep 2010
Volume 38, Issue 2 - Jun 2010
Volume 38, Issue 1 - Mar 2010
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Importance of Weissella Species during Kimchi Fermentation and Future Works
Lee, Kang-Wook ; Park, Ji-Yeong ; Chun, Ji-Yeon ; Han, Nam-Soo ; Kim, Jeong-Hwan ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 341~348
Weissella species are one of the most common lactic acid bacteria isolated from kimchi during kimchi fermentation but few researches have been done on this group of organisms. Its recent establishment as a separate genus is one reason for the few studies. Another reason is probably poor resolution of identification methods based on biochemical properties. Currently, 14 species are registered in the genus of Weissella but new members are reported continuously. It is important to understand at detail the properties and roles of Weissella species during kimchi fermentation if desirable properties of Weissella species are fully utilized for the production of high quality kimchi with good taste and enhanced biofunctionalities.
Carbon Metabolism and Its Global Regulation in Corynebacterium glutamicum
Lee, Jung-Kee ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 349~361
In this review, the current knowledge of the carbon metabolism and global carbon regulation in Corynebacterium glutamicum are summarized. C. gluamicum has phosphotransferase system (PTS) for the utilization of sucrose, glucose, and fructose. C. glutamicum does not show any preference for glucose when various sugars or organic acids are present with glucose, and thus cometabolizes glucose with other sugars or organic acids. The molecular mechanism of global carbon regulation such as carbon catabolite repression (CCR) in C. glutamicum is quite different to that in Gram-negative or low-GC Gram-positive bacteria. GlxR (glyoxylate bypass regulator) in C. glutamicum is the cyclic AMP receptor protein (CRP) homologue of E. coli. GlxR has been reported to regulate genes involved in not only glyoxylate bypass, but also central carbon metabolism and CCR including glycolysis, gluconeogenesis, and tricarboxylic acid (TCA) cycle. Therefore, GlxR has been suggested as a global transcriptional regulator for the regulation of diverse physiological processes as well as carbon metabolism. Adenylate cyclase of C. glutamicum is a membrane protein belonging to class III adenylate cyclases, thus it could possibly be a sensor for some external signal, thereby modulating cAMP level in response to environmental stimuli. In addition to GlxR, three additional transcriptional regulators like RamB, RamA, and SugR are also involved in regulating the expression of many genes of carbon metabolism. Finally, recent approaches for constructing new pathways for the utilization of new carbon sources, and strategies for enhancing amino acid production through genetic modification of carbon metabolism or regulatory network are described.
Pretreatment of Waste-activated Sludge for Enhancement of Methane Production
NamKung, Kyu-Cheol ; Jeon, Che-Ok ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 362~372
Although different disposal routes of waste-activated sludge are possible, anaerobic digestion plays an important role for its abilities to further transform organic matter into methane. The potential of using methane as energy source has long been widely recognised and the present paper extensively reviews the principles of anaerobic digestion, the process parameters and hydrolysis. Hydrolysis is recognised as rate-limiting step in the complex digestion process. To accelerate the digestion and enhance the production of biogas, various pre-treatments can be used to improve the rate-limiting hydrolysis. These treatments include mechanical, thermal, chemical and biological interventions to the feedstock. All pre-treatments result in a lysis or disintegration of sludge cells, thus releasing and solubilizing intracellular material into the water phase and transforming refractory organic material into biodegradable species. The reader will finally be guided to extensive discussion for anaerobic digestion processes.
Screening and Characteristics of Useful Fungi for Brewing from Commercial Nuruk in Chungcheong Provinces
Baek, Seong-Yeol ; Yun, Hye-Ju ; Choi, Hye-Sun ; Hong, Seung-Beom ; Koo, Bon-Sung ; Yeo, Soo-Hwan ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 373~378
Studies on standardization and quality upgrade of nuruk which is a basic component in brewing are required to increase the quality level of Korean traditional rice wines and to develop the technology for practical use of it. It is important to isolate best strains, to improve the properties and effectively preserve them for brewing industry. In this study, 16 commercial nuruk samples were obtained from the commercial markets located in Chungcheong areas in Korea. 174 fungal strains were isolated from the samples on DG18 medium using a dilution plating method and then screened for enzyme activity and acid production. The active strains were identified based on the morphological characteristics and ITS sequence analysis. Out of 174 strains, 12 strains showed high amylase activity. Especially, Rhizopus sp. CN084, CN174, Aspergillus sp. CN161 and Mycocladus sp. CN042 showed high saccharogenic power and dextrinogenic enzyme activity on cooked wheat bran medium. On the other hand, Aspergillus sp. CN010, CN161, Rhizopus sp. CN105, CN168 and Rhizomucor sp. CN088 produced high acid production on the same medium. Our results showed that the active strains may be used as microbial sources for nuruk starter with good quality in brewing.
Isolation and Physiological Characteristics of Microorganisms Producing Extracellular Enzymes from Korean Traditional Soybean Sauce and Soybean Paste
Baek, Seong-Yeol ; Yun, Hye-Ju ; Choi, Hye-Sun ; Koo, Bon-Sung ; Yeo, Soo-Hwan ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 379~384
We isolated microorganisms presenting high enzymatic activities for amylase, cellulase, protease, lipase or fibrinolysis from Korean traditional soybean sauce and paste. Then, the physiological properties and 16S rRNA sequences of isolated microorganisms were analyzed. All of the isolated 13 strains possessing high extra cellular enzyme activities have higher amylase and cellulase activities than Bacillus subtilis KACC 10114. All the selected strains have protease activities except for D2-14. Except D8-8 and K4-1, other strains have lipase activity. D2-7, D8-8 and K4-1 strains have higher fibrinolytic activities than others, while D8-2 strain has no activity. Most of the selected strains showed antibacterial activity even in gram positive and gram negative bacteria and yeast. Gene sequence analysis of 16S rRNA from isolated strains revealed that all the selected strains were member of Bacillus species.
Medium Optimization for the Protease Production by Bacillus licheniformis Isolated from Cheongkookjang
Yoon, Ki-Hong ; Shin, Hye-Young ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 385~390
Bacillus licheniformis fermenting soybean product with highest score in consumer acceptance had been isolated from homemade Cheongkookjang. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon sources, metal ions and phosphate were examined for protease production of the isolate. Potato starch increased the protease productivity, while glucose repressed it. Yeast extract was the most effective nitrogen source for enzyme production. The calcium was found to increase protease activity slightly while cell growth and enzyme production was completely inhibited by divalent ions such as
. The maximum protease productivity was reached approximately 800 unit/mL in the optimized medium consisting of potato starch (1.5%), yeast extract (1.5%),
(0.03%). The protease activity of culture filtrate was gradually decreased after incubation for 28 h.
Efficacy of Antibacteriocidal Yeast That Producing Bacteriocin OR-7 in Chicken
Cho, Dong-In ; Kang, Sang-Mo ; Lee, Jae-Hwa ; Lee, Sang-Hyeon ; Kim, Nam-Young ; Kim, Ki-Seuk ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 391~398
This study was conducted to investigate the effects of feeding probiotics(gene modified yeast) on the egg quality in laying hens. The laboratory method of this study is as follow: In hens, 300, 36 weeks old ISA brown commercial layer, were employed in 13weeks feeding trial with a 7 days adjustment period. Dietary treatments are 1) control (basal diet) 2) Y0.3 (basal diet+0.3% probiotics), 3) Y0.5% (basal diet+0.5% probiotics), 4) PY0.3% (basal diet+0.3% plasmid modified probiotics), 5) PY0.5% (basal diet+0.5% plasmid modified probiotics). For overall period, hen-day egg production, egg weight (p<0.05) by dietary probiotic supplementation were recorded. Eggs were collected and weighed every day. Egg production number and egg production rate, egg weight, failure egg ratio and trouble egg ratio were recorded for 13weeks days. Diets PY0.3 and PY0.5 improved Egg production rate, egg production number and egg weight, compared to control diet (linear effect. p<0.05). And, diets PY0.3 and PY0.5 improved Egg production rate, egg production number, compared to Y0.3 and Y0.5 (linear effect. p<0.05). But, in Inferior egg and cracked egg, diets PY0.3 and PY0.5 did not tended to increase by dietary probiotic supplementation compared to control diet and Y group (0.3, 0.5) (linear effect. p<0.05). The productivity enhance on the egg quality in laying hens is considered from the effects of feeding probiotics(gene modified yeast).
Isolation and Culture Conditions of Hydrogen Producing Bacterium Enterobacter sp. ES392
Jeon, Sung-Jong ; Lee, Eon-Seok ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 399~404
A hydrogen-producing bacterium (strain ES392) was isolated from pond water located in the Dong-Eui University, Busan, Korea. The cell was long-rod type (
) of about (
) in diameter, and not formed flagellum and spore. Phylogenetic analysis based on the 16S rRNA sequence and biochemical studies indicated that ES392 belonged to the genus Enterobacter sp. The optimum pH and temperature for hydrogen production was 7.5 and
, respectively. The optimization of medium compositions which maximize hydrogen production from Enterobacter sp. ES392 was determined. As a result, the maximum hydrogen production was obtained under the conditions of 4% (w/v) sucrose, 0.5% (w/v) yeast extract and 50 mM potassium phosphate buffer (pH 7.5). Under batch culture conditions, the maximal hydrogen production and yield were obtained as 3481 mL/L and 1.33 mol/mol sucrose, respectively.
Synergistic Antibacterial Activity of Fig (Ficus carica) Leaves Extract Against Clinical Isolates of Methicillin-resistant Staphylococcus aureus
Lee, Young-Soo ; Cha, Jeong-Dan ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 405~413
Fig (Ficus carica L.) belongs to the mulberry tree (Moraceae) which is one of the oldest fruits in the world. It has been used as a digestion promoter and a cure for ulcerative inflammation and eruption in Korea. The present study investigated the antimicrobial activity of methanol (MeOH) extract of fig leaves against methicillin-resistant Staphylococcus aureus (MRSA) isolated in clinic. The MeOH extract (MICs, 2.5 to 20 mg/mL; MBCs, 5 to 20 mg/mL) was demonstrated as antibacterial activity in isolates MRSA 1-20. The administration of the MeOH extract in combination with oxacillin or ampicillin induced a reduction of
4-8-fold in all tested bacteria, which was considered to be synergistic based on a FICI of
0.375-0.5. Furthermore, time-kill study was found that a combination of MeOH extract with oxacillin or ampicillin produced a more rapid decrease in the concentration of bacteria CFU/mL than MeOH extract alone. The results suggest that fig leaves could be employed as a natural antibacterial agent in MRSA infection care products.
Anti-Oxidant Property and Inhibition of Melanin Synthesis of Eight Plant Extracts
Kim, Jae-Young ; Lee, Jin-Young ; Lee, Wi-Young ; Yi, Yong-Sub ; Lim, Yoong-Ho ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 414~419
Plants extracts are good resources to find functional compounds for human health. The following eight plants were collected and total phenolic contents were determined. Acer psedo-siebolianum showed the highest phenolic contents, 16.4 mg/g, whereas Cercidiphyllum japonica showed the lowest contents, 1.9 mg/g. The DPPH free radical scavenging capacities of the plant extracts showed high activity in following order : Acer ginnala (
) > Cornus walteri (
) > Distylum racemosum (
) > Castanopsis cuspidata var. Thunbergii (
) > Acer psedo-siebolianum (
) > Thuijopsis dolabrata cv. Aurea (
) > Cercidiphyllum Japonica (
). Also the mushroom tyrosinase inhibitory activities of total extracts were determined at different concentration. D. racemosum extract showed highest (49.1% at 1,000 mg) in inhibitory activity than other seven extracts. The ethanol fraction
) from D. racemosum showed more inhibitory activity than ethyl acetate fraction (
). The ethanol fraction on showed no significant cytotoxicity in B16/F1 cells line up to
of ethanol fraction showed cytotoxicity in B16/F1 cells. The melanin contents of cells were significantly attenuated by ethanol fraction in a dose-dependent manner. The
value of ethanol fraction was
Process Development of a Virally-Safe Acellular Bovine Amniotic Membrane for Biological Dressing
Bae, Jung-Eun ; Kim, Chang-Kyong ; Kim, Sung-Po ; Yang, Eun-Kyung ; Kim, In-Seop ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 420~427
A process for manufacturing virally-safe bovine amniotic membrane(BAM) has been developed for biological dressing. BAM was harvested from a healthy bovine placenta, and then the epithelium was removed. The remaining stromal layer was consecutively disinfected with 70% ethanol and 0.05% sodium hypochlorite. The stromal layer was incubated in a decellularization solution containing 0.25%(w/v) trypsin to remove the cellular components. The resulting acelluar BAM was lyophilized to preserve its biochemical and structural integrity. The BAM was packed and exposed to 25 kGy of gamma irradiation for sterilization purpose. Histological, electron microscopical, and biochemical observations showed that the acellualr BAM had intact structural integrity of three dimensional collagen fibers and contained several growth factors, accelerating wound healing, such as EGF (Epidermal growth factor), KGF (Keratinocyte growth factor), and FGF (Fibroblast growth factor). Bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), bovine parainfluenza virus type 3 (BPIV-3), and bovine parvovirus (BPV) were chosen as the biological indicators for validation of viral safety of the acellular BAM. Samples from relevant stages of the production process were spiked with each virus and subjected to viral inactivation processes. Viruses were recovered from the samples and then titrated immediately. All the viruses tested were completely inactivated to undetectable levels within 1 h of 70% ethanol treatment. Enveloped viruses such as BHV, BVDV, and BPIV-3 were more effectively inactivated than BPV by 0.05% sodium hypochlorite treatment. BHV, BVDV, and BPIV-3 were completely inactivated to undetectable levels by 25 kGy of gamma irradiation. Also BPV was effectively inactivated by 25 kGy of gamma irradiation. The cumulative log reduction factors of BHV, BVDV, BPIV-3, and BPV were
7.57, respectively. These results indicate that the production process for acelluar BAM has a sufficient virus-reducing capacity to achieve a high margin of the virus safety.
Characterization of Agarose Produced by Yeast Cell Surface Displayed-Arylsulfatase
Cho, Eun-Soo ; Kim, Jeong-Hwan ; Kim, Yeon-Hee ; Nam, Soo-Wan ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 428~433
Enzymatic hydrolysis of sulfate groups in agaropectin or agar simplifies the production process of high-quality or low sulfate-content agarose. This study was investigated that cell surface displayed arylsulfatase can be applied to desulfatation of agar for production of agarose. Sulfate content of agarose prepared by treatment of yeast surface-displayed arylsulfatase was decreased in a enzyme dosedependent manner. Especially, 35 unit/mL of yeast surface arylsulfatase attenuated sulfate content of agarose up to 0.2%. In the 0.6% agar(Junsei), 35 unit/mL enzyme treated at
for 3 h showed the lowest content of sulfate. Therefore, this result was determined to be the optimal condition to desulfatation of agar for production of agarose. In addition, the gel strength of yeast surface arylsulfatase treated agar and commercial agarose were compared. Agarose prepared by treatment of yeast surface arylsulfatase showed
of gel strength, and it is a similar compared to the commercial agarose.
Anti-oxidant and Anti-inflammation Activity of Fractions from Aster glehni Fr. Schm.
Kim, Han-Hyuk ; Park, Gun-Hye ; Park, Kang-Soo ; Lee, Jin-Young ; An, Bong-Jeun ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 434~441
The Plants and their extracts containing polyphenol have been shown to be associated with decreased the cause of aging and variety of disease such as reaction oxygen species (ROS) and reactive nitrogen species (RNS) in several recent studies. We conducted to investigate whether the extracts and fractionation isolated from Aster glehni Fr. Schm. has an inhibitory effect association with oxidation or inflammation. The Aster glehni Fr. Schm. 70% aq. MeOH was fractioned according to polarity with n-hexane layer, EtOAc layer, n-BuOH layer and water layer. The electron donating ability of EtOAc, n-BuOH solvent fraction from Aster glehni Fr. Schm. was about 58.0%, 46.4% at
, respectively. The superoxide anion radical inhibitory effect of EtOAc extracts was about 64.65% at
, and n-BuOH extracts was 35.66% at
. EtOAc layer to the inhibition activity of hyaluronidase and lipoxygenase were inhibited about 24.37%, 29.5% at
. In the anti-inflammation effect of EtOAc layer inhibited the generation of nitric oxide. also, these results showed that EtOAc extract inhibited 81.5% at
on the expressions of iNOS protein in Raw264.7 cell line.
Analysis of Differentially Expressed Genes by Allicin in Human Colorectal Cancer Cell
Kim, Kyung-Ho ; Kim, Min-Jung ; Kim, Jong-Sik ; Pyo, Suhk-Neung ; Kim, Byung-Oh ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 442~447
We investigated anti-cancer and anti-proliferative activity of allicin and analyzed global gene expression changes by allicin treatment in human colorectal HCT116 cells. As a result, allicin decreased cell viabilities in a dose and time-dependent manner and induced apoptosis. Oligo DNA microarray analysis, we found that 7,840 genes were up-regulated more than 2-folds, whereas 10,010 genes were down-regulated more than 2-folds by
allicin treatment. To confirm specific gene expressions, we performed RT-PCR. Consistent with the results of DNA microarray analysis, allicin dramatically induced ATF3 and NAG1 gene expression. Interestingly, NAG-1 protein expression was dependent on p53 presence. Taken together, our present results increase the knowledge of the molecular mechanism of anti-cancer and anti-proliferative activity mediated by allciin in human colorectal cancer cell.
Analysis of Microbial Community during the Anaerobic Dechlorination of PCE/TCE by DGGE
Kim, Byung-Hyuk ; Cho, Dae-Hyun ; Sung, Youl-Boong ; Ahn, Chi-Youg ; Yoon, Byung-Dae ; Koh, Sung-Cheol ; Oh, Hee-Mock ; Kim, Hee-Sik ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 448~454
This study investigated the effect of PCE and TCE as electron acceptors on the bacterial composition of dechlorinating communities. The enrichment cultures reductively dechlorinating PCE and TCE were developed from three environment samples using acetate as electron donor. The cultures were prepared by sequential enrichment, which was seeded with sediment and dredged soil. Denatured gradient gel electrophresis (DGGE) of 16S rRNA gene fragment was used to compare the microbial communities of these three enrichment cultures. After incubation for 4 weeks, the removal efficiencies of PCE and TCE were highest from Yeocheon site (87.37% and 84.46%, respectively). PCE and TCE as electron acceptors affected the bacterial diversity and community profiles in the enrichment cultures. DGGE analysis showed that the dominant bacteria in PCE and TCE enrichment were belonged to Clostridium sp., Desulfotomaculum sp., and uncultured bacteria.
Application of 16S rDNA PCR-RFLP Analysis for the Rapid Identification of Weissella Species
Lee, Myeong-Jae ; Cho, Kyeung-Hee ; Lee, Jong-Hoon ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 455~460
A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis was applied to detect and identify ten Weissella spp. frequently found in kimchi. The previously reported genus-specific primers designed from 16S rDNA sequences of Weissella spp. were adopted but PCR was performed at the increased annealing temperature by
. The sizes of amplified PCR products and restricted fragments produced by AluI, MseI, and BceAI endonucleases were well correspond with the expected sizes. W. kandleri, W. koreensis, W. confusa, W. minor, W. viridescens, W. cibaria, and W. soli were distinguished by AluI and MseI and W. hellenica and W. paramesenteroides were identified by BceAI. W. thailandensis was distinguished when restriction pattern of other species was compared but identified by the single use of MspI.
Studies on a Feasibility of Swine Farm Wastewater Treatment using Microbial Fuel Cell
Jang, Jae-Kyung ; Kim, Se-Hee ; Ryou, Young-Sun ; Lee, Sung-Hyoun ; Kim, Jong-Gu ; Kang, Young-Goo ; Kim, Young-Hwa ; Choi, Jung-Eun ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 461~466
In this study the feasibility of simultaneous electricity generation and treatment of swine farm wastewater using microbial fuel cells (MFCs) was examined. Two single-chamber MFCs containing an anode filled with different ratio of graphite felt and stainless-steel cross strip was used in all tests. The proportion of stainless-steel cross strip to graphite felt in the anode of control microbial fuel cell (CMFC) was higher than that of swine microbial fuel cell (SMFC) to reduce construction costs. SMFCs produced a stable current of 18 mA by swine wastewater with chemical oxygen demand (COD) of
after enriched. The maximum power density and current density of SMFCs were
, respectively. In the CMFC, power density and current density was lower than that of SMFC. CODs decreased by the SMFC and CMFC from
, achieving 72.7% and 70.6% COD removal, respectively. The suspended solid (SS) of both fuel cells was also reduced over 99% (
). The concentration of nutritive salts,
, dropped by 65.4%, 57.5%, and 73.7% by the SMFC, respectively. These results were similar with those of CMFC. These results show that the microbial fuel cells using electrode with mix stainless-steel cross strip and graphite felt can treat the swine wastewater simultaneously with an electricity generation from swine wastewater.
Changes in the Functionality of Cheonggukjang During Fermentation Supplemented with Angelica gigas, Rehmanniae Radix, and Red ginseng
Choi, Eun-Ji ; Lee, Jung-Sook ; Chang, Hung-Bae ; Lee, Mee-Sook ; Jang, Hae-Dong ; Kwon, Young-In ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 467~474
Cheonggukjang is one of the traditional fermented soy-based foods in Korean diets. Studies in cell cultures, humans have revealed anti-hypertension, anti-stress, anticancer, antioxidant, immune enhancing effects. Angelica gigas, Rehmanniae radix, and Red ginseng are popular medicinal plants and widely used for oriental medicine. In this study a strategy had been developed to mobilize beneficial phenolics from Angelica gigas, Rehmanniae radix, and Red ginseng combined with fermented soy by Cheonggukjang fermentation for antioxidant and Type II diabetes management. The quality and functional characteristics of Chenggukjang fermented with Angelica gigas, Rehmanniae radix and Red ginseng. Cheonggukjang (CKJ), Angelica gigas Cheonggukjang (CKJ-DD), Rehmanniae radix Cheonggukjang (CKJ-RG), Angelica gigas and Rehmanniae radix Cheonggukjang (CKJ-DD+RG) and Red ginseng Cheonggukjang (CKJ-RED) were evaluated. The mobilized phenolic profile was evaluated for antioxidant activity and the potential to inhibit
-amylase linked to hyperglycaemia. This research has important implications for the development of functional soy-based-fermented foods enriched with Angelica gigas, Rehmanniae radix and Red ginseng phenolics for oxidative stress - induced diabetic complications. Furthermore, Hunter's color values of 5 types cheonggukjang, lightness (L-values), redness (a-values) and yellowness (b-values) were evaluated. Free amino acid content of CKJ-RED (0.993 mg/gd. w.) showed higher than that of CKJ (0.205 mg/g-d.w.).
Improvement of Cyclosporin A Hydroxylation in Sebekia benihana by Conjugational Transfer of Streptomyces coelicolor SCO4967, a Secondary Metabolite Regulatory Gene
Kim, Hyun-Bum ; Lee, Mi-Jin ; Han, Kyu-Boem ; Kim, Eung-Soo ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 475~480
Actinomycetes are Gram-positive soil bacteria and one of the most important industrial microorganisms due to superior biosynthetic capabilities of many valuable secondary metabolites as well as production of various valuable bioconversion enzymes. Among them are cytochrome P450 hydroxylase (CYP), which are hemoproteins encoded by a super family of genes, are universally distributed in most of the organisms from all biological kingdoms. Actinomycetes are a rich source of soluble CYP enzymes, which play critical roles in the bioactivation and detoxification of a wide variety of metabolite biosynthesis and xenobiotic transformation. Cyclosporin A (CyA), one of the most commonly-prescribed immunosuppressive drugs, was previously reported to be hydroxylated at the position of 4th N-methyl leucine by a rare actinomycetes called Sebekia benihana, leading to display different biological activity spectrum such as loss of immunosuppressive activities yet retaining hair growth-stimulating side effect. In order to improve this regio-selective CyA hydroxylation in S. benihana, previously-identified several secondary metabolite up-regulatory genes from Streptomyces coelicolor and S. avermitilis were heterologously overexpressed in S. benihana using an
promoter-containing Streptomyces integrative expression vector. Among tested, SCO4967 encoding a conserved hypothetical protein significantly stimulated region-specific CyA hydroxylation in S. benihana, implying that some common regulatory systems functioning in both biosynthesis and bioconversion of secondary metabolite might be present in different actinomycetes species.
Characteristics of Bacteriocin Produced by a Lactobacillus plantarum Strain Isolated from Kimchi
Chung, Jae Hyuk ; Bae, Yun-Sook ; Kim, Yeon-Joo ; Lee, Jong-Hoon ;
Microbiology and Biotechnology Letters, volume 38, issue 4, 2010, Pages 481~485
Lactobacillus plantarum strain KK3 with tannase activity was isolated from Gochunipkimchi (red pepper leaf kimchi) and showed a high antagonistic activity against five kinds of food pathogens. Strain KK3 secreted antibacterial compound into culture medium and 24-h culture in MRS broth at
was enough for the antibacterial compound production. The crude antibacterial compound prepared from culture supernatant inhibited the growth of some Gram-negative bacteria and Bacillus cereus but not Listeria monocytogenes. The antibacterial activity was sensitive to proteinase K treatment, confirming its proteinaceous nature (bacteriocin). The crude bacteriocin was active in the pH range 3.5-8.5 and extremely stable after 15 min of heat treatment at
. The strain KK3 produced equally active bacteriocin in Chinese cabbage juice as it produced in MRS broth.