Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Korean Journal of Microbiology
Journal Basic Information
Journal DOI :
The Microbiological Society of Korea
Editor in Chief :
Volume & Issues
Volume 50, Issue 4 - Dec 2014
Volume 50, Issue 3 - Sep 2014
Volume 50, Issue 2 - Jun 2014
Volume 50, Issue 1 - Mar 2014
Selecting the target year
Establishment of a Selection System for the Site-Specific Incorporation of Unnatural Amino Acids into Protein
Edan, Dawood Salim ; Choi, Inkyung ; Park, Jungchan ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 1~7
DOI : 10.7845/kjm.2014.4012
Site-specific incorporation of unnatural amino acids (SSIUA) into protein can be achieved in vivo by coexpression of an orthogonal pair of suppressor tRNA and engineered aminoacyl-tRNA synthetase (ARS) that specifically ligates an unnatural amino acid to the suppressor tRNA. As a step to develop the SSIUA technique in Escherichia coli, here we established a new 2-step screening system that can be used for selecting an ARS variant(s) that ligates an unnatural amino acid to a suppressor tRNA. A positive selection system consists of chloramphenicol acetyl transferase gene containing an amber mutation at the
residue, and efficiently concentrated amber suppressible ARS with a maximum enrichment factor of
. On the other hand, a negative selection system was constructed by adding multiple amber codons in front of a lethal gene encoding the control of cell death B toxin (ccdB) which acts as an inhibitory protein of bacterial topoisomerase II. Amber suppression of ccdB by an orthogonal pair of Saccharomyces cerevisiae tyrosyl-tRNA synthetase (TyrRS) and an amber suppressor tRNA significantly inhibits bacterial growth. This selection system was also able to efficiently remove amber suppressible ARS which could ligate natural amino acids to the suppressor tRNA. Thus, sequential combination of these two selection systems might be able to function as a powerful tool for selecting an ARS variant that specifically ligates an unnatural amino acid to the suppressor tRNA from an ARS mutant pool.
Studies on the Functional Properties of Lactic Acid Bacteria Isolated from Home-made Yogurt and Commercial Yogurt
Choi, Moon-Sup ; Yun, Hyun-Myoung ; Oh, Kye-Heon ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 8~14
DOI : 10.7845/kjm.2014.4005
The objective of this work is to investigate and compare several functional properties of lactic acid bacteria (LAB), Lactobacillus casei SK-7 isolated from home-made yogurt and Lactobacillus bulgaricus YK-11 from commercial yogurt. Initially, physiological and biochemical properties of SK-7 and YK-11 were characterized. Phylogenetic analysis using 16S rRNA sequencing were performed to identify the strains, and the strain could be assigned to Lactobacillus casei and Lactobacillus bulgaricus, designated as L. casei SK-7 and L. bulgaricus YK-11. Phylogenetic tree of SK-7 and YK-11 was plotted based on 16S rRNA sequence comparisons. Production of lactic acid and organic acid, and pH changes in the cultures of SK-7 and YK-11 were monitored during 72 h. During the incubation period, several functional properties of L. casei SK-7 and L. bulgaricus YK-11 were examined. L. casei SK-7 and L. bulgaricus YK-11 cultures eliminated 93.9% and 88.2% of nitrite, respectively. Antioxidant activity of cultural supernatants of SK-7 and YK-11 were 62.6%, 54.9%, and activity of
-galactosidase were 14.9 units/mg and 13.1 units/mg, respectively. The antimicrobial activities were examined with 20-fold concentrated culture supernatants from the cultures of SK-7 and YK-11. The activities of SK-7 supernatants were clearly observed against all microorganisms in this work, whereas no activities were observed in YK-11 supernatants. Although it might be conducted additional functional research, functional properties of LAB isolated from home-made yogurt have been shown to be better than those of commercial yogurt in this work.
Identification of Auxin from Pseudomonas sp. P7014 for the Rapid Growth of Pleurotus eryngii Mycelium
Kang, Young Min ; Cho, Kye Man ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 15~21
DOI : 10.7845/kjm.2014.3076
The promoting effect of Pseudomonas sp. P7014 on the mycelia growth of Pleurotus eryngii was investigated. An ethyl acetate fraction (F5) from the culture supernatant of the bacteria was confirmed to contain the growth promoting compound (GPC). The GPC was identified to be indole acetic acid (IAA) by TLC, HPLC, MS/MS, and NMR analyses. P. eryngii mycelia grew rapidly both on PDA and in PDB after the treatment of GPC. The promoting concentration of GPC was as low as 1.0 nM. Tryptophan, the aminated form of IAA, was confirmed to be the precursor of IAA. These results suggested that bacterial secreted compound was IAA and plays an important role in promoting growth of mushroom mycelia.
Effect of Interaction between Protocatechualdehyde Produced from Streptomyces lincolnensis M-20 and Copper Ions on Antioxidant and Pro-oxidant Activities
Kim, Kyoung-Ja ; Lee, Jae-Hun ; Yang, Yong-Joon ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 22~26
DOI : 10.7845/kjm.2014.4007
Protocatechualdehyde (PA) is phenolic compound having antioxidative and antitumor activities. PA was purified from supernatant of Streptomyces lincolnensis M-20. In the presence of copper ion, PA acted as pro-oxidant. The antioxidant activity was assessed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, and the pro-oxidant effect of PA on DNA damage as pBR322 plasmid DNA-cleaving agents in the presence of Cu(II) ions was investigated. The involvement of reactive oxygen species (ROS) in the DNA damage was confirmed by the inhibition of the DNA breakage by using glutathione (GSH), specific scavenger of ROS. When the increase in ROS reaches a certain level (the toxic threshold), it may trigger cell death. The formation of the PA/Cu(II) chelate complex was confirmed by reaction with ethylenediamine-tetraacetic acid (EDTA), a well-known chelating agent for metal ions, by using UV/Vis spectroscopic analysis.
Induced Autophagy Regulates Salmonella enterica serovar Typhimurium Infection in Murine Macrophage
Lee, Sunhye ; Kim, Ju-Young ; Lee, Hyo-Ji ; Jung, Yu-Jin ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 27~32
DOI : 10.7845/kjm.2014.4008
Autophagy is one of the lysosomal degradation pathways to maintain cellular homeostasis. The damaged proteins or organelles are uptaken through extra- and intra-cellular stress, starvation and infected pathogens, subsequently, autophagosomes are fused with lysosomes to break down the molecules. Salmonella enterica serovar Typhimurium (S. Typhimurium), intracellular bacteria, cause acute gastroenteritis and food poisoning. Given that autophagy induced by S. Typhimurium plays an important role in the cells to control the infection, we identify whether the induction of autophagy with rapamycin, chemical inducer of autophagy, before infection regulates S. Typhimurium infection. After treatment of rapamycin or 3-methyladenine (3-MA), autophagy inhibitor, RAW264.7 cells were infected with S. Typhimurium. Pretretment of rapamycin decreased the growth rate of S. Typhimurium in the cells; otherwise, pretreatment of 3-MA increased the growth rate of S. Typhimurium. The expression of autophagy-related genes was significantly increased in the S. Typhimurium-infected cells pretreated with rapamycin. To examine whether induced autophagy by rapamycin control the infection with increase the production of reactive oxygen species (ROS) and nitric oxide (NO), antibacterial radical substrates were measured in infected cells followed by the treatment with either rapamycin or 3-MA. NO production increased in RAW264.7 cells; otherwise, ROS production remained unchanged during the infection. These findings suggest that inducing autophagy with rapamycin reveals antimicrobial activity as producing NO against S. Typhimurium infection in mouse macrophages.
Characteristics of Biosurfactant Producing Pseudomonas sp. HN37
Jung, Da Hee ; Chang, Dong Ho ; Kim, Yeong Eun ; Jeong, Mi Rang ; Hahn, Kyu Woong ; Kim, Hyong Bai ; Park, Kyeong Ryang ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 33~39
DOI : 10.7845/kjm.2014.2054
One hundred forty four bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its emulsification activity, growth rate and surface tension activity, and this selected bacterial strain was identified as Pseudomonas sp. HN37 through physiological- biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. HN37 utilize the several aliphatic hydrocarbons, 3,5-dinitrosalicylic acid and 2,4-dichlorophooxyacetic acid as a sole carbon source. And this bacterial strain showed a high resistance to antibiotics such as ampicillin and chloramphenicol, as well as heavy metals such as Ba, Cr, Li and Mn. Also, it was found that the optimal pH and temperature for the cell growth, surface tension, and emulsification activity of Pseudomonas sp. HN37 were pH 6.0-9.0 and
, respectively. The emulsification and surface tension activity was reached the maximum to 1% (V/V) crude oil and 1% (W/V) NaCl concentration. The surface tension of the culture broth was decreased from 62 to 27 dyne/cm after fifteen hours of inoculation in LB media.
Growth Promotion of Tomato by Application of Immobilized Arthrobacter woluwensis ED in Alginate Beads
Kwon, Seung-Tak ; Song, Hong-Gyu ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 40~45
DOI : 10.7845/kjm.2014.4010
In order to increase the persistence of plant growth promoting rhizobacteria (PGPR) in rhizpsphere soil, the growth of tomato was examined after the application of Arthrobacter woluwensis ED immobilized in alginate bead, which was known as PGPR. When tomato seedlings were treated with A. woluwensis ED of
and incubated for 30 days in a plant growth chamber, the shoot length, root length, fresh weight and dry weight of the grown tomato plants treated with the suspended inoculants significantly increased by 36.2, 59, 51.1, and 37.5%, respectively compared to those of the uninoculated control. The treatment of the immobilized bacteria increased those by 42, 67.4, 62.5, and 60.4%, respectively compared to those of the uninoculated control. Therefore, the enhancement of tomato growth by the treatment of the immobilized bacteria was higher than those by the suspended inoculants. The effects of the inoculation on indigenous bacterial community and the fate of the inoculated bacteria were monitored by denaturing gradient gel electrophoresis analysis. The DNA band intensity of A. woluwensis ED in the tomato rhizosphere treated with the suspended inoculants continuously decreased after the inoculation, but the band intensity in the tomato rhizosphere soils treated with the immobilized inoculants showed the maximum at 1 week after inoculation and the decreasing rate was less than that of the suspended inoculants, which indicated the longer maintenance of the immobilized bacteria at rhizosphere soils. Therefore, encapsulation of PGPR in alginate beads may be more effective than liquid inoculant for the plant growth promotion and survival of PGPR at plant rhizosphere.
Antioxidant Activities and Monacolin K Production of Fermented Chinese Yam by Monascus sp. MK805
Jeon, Chun-Pyo ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 46~52
DOI : 10.7845/kjm.2014.4002
This study was carried out to investigate the characteristics of fermented chinese yam and rice (Dioscorea japonica, Dioscorea batatas, Dioscorea opposita, Rice, FCYR) using Monascus sp. MK805. The extracts from FCYR were measured to examine pigments, antioxidant activities were investigated through DPPH radical scavenging activity, total polyphenol and flavonoid contents, reducing power. Also it was investigated monacolin K productivity by FCYR. Pigments productivity (yellow, orange and red) were 26.2, 13.9, 17.3 at Dioscorea japonica, 41.9, 22.6, 53.2 at Dioscorea batatas, 12.5, 7.5, 9.7 at Dioscorea opposita and 10.1, 7.7, 10.2 at rice, respectively. DPPH radical scavenging activity of FCYR was about 69.7, 79.6, 57.8, and 42.3%, total polyphenol contents of FCYR was about 480.6, 658.7, 379.3, and 212.9 mg/kg, total flavonoid contents of FCYR was about 342.5, 448.4, 235.2, and 168.7 mg/kg, reducing power of FCYR was about 1.57, 2.14, 1.14, and 0.35 (OD at 700 nm), respectively. And then monacolin K productivity of FCYR was about 453.8, 509.5, 332.2, and 263.2 mg/kg, respectively.
Antioxidant Activities and Monacolin K Production on Solid-State Fermentation of Diverse Yam by Aspergillus Species Strain
Lee, Joon-Geol ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 53~59
DOI : 10.7845/kjm.2014.4004
This study was conducted to investigate the characteristics between non-fermented chinese yam and rice (non-FCYR) and fermented chinese yam and rice (FCYR). 1.1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, total polyphenol, flavonoid contents and reducing power were investigated to evaluate the anti-oxidation activities of FCYR. Also, productivity of monacolin K, major medicinal ingredient of FCYR, was investigated, using Aspergillus terreus KCCM 12225. In case of non-FCYR, DPPH radical scavenging activities for three kinds of yam (Dioscorea japonica, Dioscorea batatas, Dioscorea opposita) and rice were estimated about 51.8, 66.4, 42.2 and 7.5%, while in case of FCYR, those for three kinds of yam and rice were estimated to increased about 64.7, 74.7, 52.8, and 32.3%, respectively. Total polyphenol contents of non-FCYR were estimated to 196.9, 265.7, 160.1, and 91.6 mg/kg, while total polyphenol contents of FCYR were estimated to increase about 530.7, 708.3, 427.2, and 265.9 mg/kg, respectively. Total flavonoid contents of FCYR increased to 2.8-3.3 times higher than those of non-FCYR. Reducing power of non-FCYR was about 0.97, 1.28, 0.64, and 0.17 (OD at 700 nm), while, that of FCYR increased about 1.75, 2.38, 1.24, and 0.46. Remakable increase in monacolin K productivity of FCYR was observed. Monacolin K productivity of FCYR was estimated to 467.1, 514.8, 339.2, and 272.5 mg/kg, respectively. In this study, fermented chinese yam (Dioscorea batatas) was estimated to be effective biological activity material.
Characteristics of Fermented Omija (Schizandra chinensis Baillon) Sugar Treatment Extracts by Lactobacillus sp.
Park, Se-Cheol ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 60~66
DOI : 10.7845/kjm.2014.4006
This study was carried out to investigate the characteristics of FOST (fermented omija sugar treatment extracts) using Lactobacillus brevis HLJ59. Antioxidant activities of FOST were evaluated through viable cell number of L. brevis HLJ59, DPPH radical scavenging activity, reducing power and SOD-like activity, compared to non-FOST(non-fermented omija sugar treatment extracts). Also it was to evaluate Angiotensin Converting Enzyme (ACE) and Urease inhibitory activity of FOST. The viable cell number of L. brevis was about
dilution, respectively. DPPH radical scavenging activity of FOST was about 60.3%, 71.8%, and 44.5% at
dilution, respectively. The reducing power of FOST was about 0.92, 1.19, and 0.73 (OD at 700 nm) at
dilution, and SOD-like activity of FOST was about 50.4%, 53.7%, and 33.4% at
dilution, respectively. ACE and Urease inhibitory activity by FOST was about 47.4%, 78.2%, 56.4% and 58.1%, 83.4%, 63.2% at
dilution, respectively. The results indicated that the fermentation of omija sugar treatment extracts using Lactobacillus brevis HLJ59 increased the antioxidant activities campared to the non-fermented omija sugar treatment extracts.
Isolation and Characterization of Nicotine-Degrading Bacterium Arthrobacter sp. NU11 and NU15
Jeong, Yeonju ; Oh, Ji-Sung ; Roh, Dong-Hyun ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 67~72
DOI : 10.7845/kjm.2014.4009
Minimal broth containing nicotine as a sole carbon source (MB/N) was used to isolate novel nicotine-degrading bacterial strains from tobacco plants and field soils. Comparative analysis of 16S rRNA gene sequence, phenotypic test and morphological tests showed that the position of these isolates were in the genus Arthrobacter of the family Micrococcaceae. The highest 16S rRNA gene sequence similarity of the isolate NU11 and NU15 to type strains in the genus Arthrobacter were Arthrobacter equi (98.2%) which was presumably a novel strain and Arthrobacter nicotinovorans (99.8%), respectively. Both strain NU11 and NU15 showed rod shaped, Gram-positive characteristics and catalase activity, but did not show oxidase activity. The novel strain NU11 was found to degrade efficiently nicotine in MB/N medium by the analysis of UV absorption spectra and could be used as an organism in bioremediation technique.
Heterocyclic Amines Removal by Binding Ability of Lactic Acid Bacteria Isolated from Soybean Paste
Lim, Sung-Mee ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 73~83
DOI : 10.7845/kjm.2014.4011
The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.
Fermentation of a Potential Biocontrol Agent, Bacillus amyloliquefaciens SKU-78 Strain
Kim, Shin-Duk ; Cho, Hong-Bum ;
The Korean Journal of Microbiology, volume 50, issue 1, 2014, Pages 84~86
DOI : 10.7845/kjm.2014.3062
Mass production of biocontrol agent is an essential step for its commercial use. Media composition and culture conditions for production of Bacillus amyloliquefaciens SKU-78, a potential biocontrol agent against bacterial wilts, were optimized by a flask culture. Low cost media combining nitrogen and carbon sources were tested. Maximum cell growth (>
CFU/ml) was obtained in a medium of 5% soy flour combined with 3% corn starch after 24 h cultivation. The optimum initial pH, temperature and shaking speed was 5.5,
and 150-250 rpm, respectively. Fermentation of SKU-78 was scaled up in 30 L fermenter and the profiles of cell density, pH, dissolved oxygen and spore formation were recorded. After 8 h lag phase, exponential growth occurred and reached at maximum viable cell number (
CFU/ml) after 20 h. The SKU-78 strain grown in a low cost medium exhibited the high suppression of bacterial wilts. The results indicate that SKU-78 strain can be produced in a low cost medium and provide a basis for scaling up to industrial level.