• Korean Journal of Microbiology
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• v.51 no.2
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• pp.141-147
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• 2015

Four halophilic bacteria were isolated from a salt water tank of more than 25% above salinity used for production of salt. HJS1 and HJS6 strains were identified as having ${\beta}$-glucosidase producing capabilities at high salinity. ${\beta}$-Glucosidase produced from these bacterial strains showed the best activity at 56-79 U/ml in NaCl (0-5%), showing the highest ${\beta}$-glucosidase activity at NaCl 3%. A salt tolerant ${\beta}$-glucosidase can maintain at least 75% activity of the enzyme in 0-20% NaCl concentration. The 16S rRNA gene sequences of strains HJS1 and HJS6 shows 99.8% similarity with Roseivivax roseus $BH87090^T$. Those sequences were registered as AB971835 and AB971836 in the NCBI GenBank. DNA-DNA hybridization test revealed that both strains showed 90.1 to 90.3% hybridization values with R. roseus $BH87090^T$, which was the closest phylogenetic neighbor. Major Cellular fatty acids of strains HJS1 and HJS6 were $C_{16:0}$, $C_{18:1}$ ${\omega}7c$, $C_{19:0}$ cyclo ${\omega}8c$ and 11-methyl $C_{18:1}$ and the major quinone was Q-10. Their fatty acid composition and quinone were very similar to Roseivivax roseus $BH87090^T$. Meanwhile, Roseivivax roseus $BH87090^T$ did not produce any ${\beta}$-glucosidase. Based on the molecular and chemotaxonomic properties, strains HJS1 and HJS6 were identified as members of Roseivivax roseus.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.140-146
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• 2015

The increase in resistance by pathogenic bacteria to multiple antimicrobial agents has become a significant treat, as the effective antimicrobial agents available for the patients infected by such resistant bacteria are reduced, or even eliminated. Several natural plant extracts have exhibited antibacterial and synergistic activity against various resistant microorganisms. Houttuynia cordata is frequently used by many traditional medicine practicioners for its antimicrobial, antiviral, and anti-inflammatory properties. This study investigated the antibacterial effects of H. cordata extract against clinical multi-resistant bacteria, and compared the two methods used for the antimicrobial susceptibility testing. Thirty isolates of Methicillin-resistant Staphylococcus aureus (MRSA, 10), Vancomycin-resistant Enterococcus faecium (VRE, 10), Carbapenem-resistant Acinetobacter baumannii (CRAB, 10) were included in this study. The antibacterial effect of H. cordata was tested by disk diffusion and microbroth dilution methods as per CLSI guidelines. In disk diffusion, all isolates (30) showed no inhibition to 30,000 ug/mL of H. cordata. But in the microbroth dilution method, $MIC_{90}$ of H. cordata was 4,096 ug/mL, 8,192 ug/mL and 4,096 ug/mL in MRSA, VRE and CRAB, respectively. These results demonstrate that H. cordata exhibits antibacterial activity against MRSA, VRE and CRAB. Moreover, the microbroth dilution method is a more effective method than disk diffusion to evaluate the antibacterial activity of natural products. The Disk diffusion method used to evaluate the antibacterial activity of natural products required new standard guidelines including inoculum concentration of bacteria.

• Journal of Life Science
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• v.27 no.7
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• pp.783-789
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• 2017

Malus melliana (Hand.-Mazz.) Rehder (M. melliana) is a Chinese plant that belongs to the Rosaceae family. There have been no previous reports regarding its bioactivity. In this study, the anti-oxidative and anti-inflammatory activities of M. melliana ethanol extract (MMEE) were evaluated using a 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity assay, reactive oxygen species (ROS) scavenging activity assay, nitric oxide (NO) inhibitory activity assay, and the analysis of related protein expressions through Western blot hybridization. MMEE showed potent scavenging activity against DPPH, similar to ascorbic acid, a well-known anti-oxidative agent, which was used as a positive control. MMEE also inhibited hydrogen peroxide-induced ROS in RAW 264.7 cells. Moreover, MMEE induced the expression of an anti-oxidative enzyme, heme oxygenase 1, and its upstream transcription factor, nuclear factor E2-related factor-2, in a dose-dependent manner. On the other hand, MMEE was associated with a reduction in NO production, which was induced by the lipopolysaccharide treatment of RAW 264.7 cells. The expression of inducible nitric oxide synthase, which is the upstream regulator of NO production, was also inhibited. Taken together, these results suggest that MMEE has anti-oxidative and anti-inflammatory properties, thus appearing to be a potential anti-oxidant and anti-inflammatory agent. The further identification of active compounds that confer the biological activities of MMEE may be necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.398-406
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• 1992

In order to develop a new flavourant using the fish skin gelatin, the proteolytic renditions for the gelatin hydrolysate of the alkali (B-type) and Alcalase (E-type) pretreated flounder (Limanda aspera) skin gelatin were investigated, and some physical properties, molecular weight and amino acid compositions of the hydrolysates were, also, compared with each other. The proteolytic conditions of the gelatins (B-type and E-type) by trypsin were as follows : reaction temperature, 55$^{\circ}C$ : pH, 9.0 : enzyme concentration, 0.1% : re-action time, 4hrs for B-type and 1 hr for E-type. The degrees of hydrolysis of the B-type and E-type gelatin un-der the renditions stated above were 63% and 82%, respectively. The rnajor molecular weights of the hydrolysates were 15,000 dalton for B-type and 12,400 dalton for E-type. Among the amino acids in the hydrolysates, glycine, alanine, proline, hydroxyproline and serine having a sweet taste were responsible for 57% of the total amino acid. But valine, leucine, phenylalanine, tyrosine, methionine, arginine and histidine having a bitter taste were only 18%.

• Applied Biological Chemistry
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• v.7
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• pp.1-13
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• 1966

1) Three ${\beta}-1$, 4-mannanases were isolated from germinated guar bean through extraction, ammonium sulfate fractionation, column chromatography on cellulose derivatives and gel filltration on Sephadex G-100. They were designated as ${\beta}-1$, 4-mannanase A,B and C, respectively, in the order of isolation. 2) These enzymes were different in several aspects such as pH optimum, effect of metal ions, adsorbability on cellulose derivatives, molecular weight, Michaelis constant toward reduced ivory nut mannan A, mode of action and extent of hydrolysis of the mannan. 3) ${\beta}-1$, 4-Mannanases A and C were proposed to be two different endo-enzymes of random-splitting type producing a series of oligosaccharides from ${\beta}-1$, 4-mannans. ${\beta}-1$, 4-Mannanase B was suggested to be possibly an exe-type enzyme catalyzing a stepwise splitting from the non-reducing end of ${\beta}-1$, 4-mannans to produce mannose. 4) Guaran was subjected to hydrolysis by the purified enzymes and the consequence was discussed in connection with structural requirements of the enzymes toward substituted ${\beta}-1$, 4-mannans and their role in germinating guar seeds.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.147-153
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• 2004

Protein modification by N-acetyl-${\beta}$-D-glucosamine (O-G1cNAc) on the hydroxyl groups of Ser or Thr ubiq-uitously occurs in eukaryotic cells and is involved in many cellular phenomena. The level of O-G1cNAc-mod-ified protein is regulated by OGT and O-GlcNAcase enzymes. We have tried to produce recombinant O-GlcNAcase in E. coli as an effort to establish in vitro screening system for modulators of O-GlcNAcase. The culture conditions for improvement of O-GlcNAcase productivity, were as follows: induction temperature, $30^{\circ}C$; the concentration of L-arabinose, 0.02% and induction time, 5 hr. Under these culture conditions, E. coli cells containing O-GlcNAcase gene had no enzyme activity until up to 3 hr culture. However, O-GlcNAcase activity dramatically increased from 3 to 5 hr culture. It almost maintained the same level after 5 hr culture. Western blot analysis verified the amount of expressed O-GlcNAcase increased with culture time, being con-sistent with activity data. The optimal reaction condition determined in this study was as follows: protein quan-tity, $5{\mu}g$; reaction time, 30 min; reaction temperature, $45^{\circ}C$; substrate concentration, 2 mM; reaction pH, 6.5. Methanol had little effect on O-GlcNAcase activity and 90% of activity were retained at 10%. Only 15% resid-ual activity were detected at 5% of chloroform.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.143-152
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• 2013

Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the central nervous system of animals, has several physiological effects including anti-hypertensive, diuretic, tranquilizing, and anti-stress properties, in humans. The purpose of this study was to investigate Lactobacillus plantarum K74, which was isolated from kimchi and selected as a strain with a high ability to produce GABA, to develop a new starter culture for fermented milk production. L. plantarum K74 produced $134.52{\mu}g/mL$ GABA in MRS broth containing 1% MSG, $212.27{\mu}g/mL$ GABA in MRS broth containing 2% MSG, and $234.63{\mu}g/mL$ GABA in MRS broth containing 3% MSG. The optimum growth temperature of L. plantarum K74 was $34^{\circ}C$, reaching a pH of 4.4 after 18 hours of growth. L. plantarum K74 was most sensitive to novobiocin out of 16 different antibiotics tested, and was most resistant to kanamycin and polymyxin B. L. plantarum K74 did not produce ${\beta}$-glucuronidase, a carcinogenic enzyme, and was comparatively tolerant to bile juice and low pH. Furthermore, it displayed resistance to Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus at rates of 54.9%, 46.3%, and 0.7%, respectively.

• Journal of Life Science
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• v.19 no.12
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• pp.1724-1730
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• 2009

The mannanase-producing bacteria, designated CS47, was isolated from the fresh feces of three horses (from a farm in Jinju National University). The isolate CS47 was facultatively anaerobic and grew at temperatures ranging from $20^{\circ}C$ to $50^{\circ}C$ with an optimal temperature of $38^{\circ}C$. The DNA G+C content of the isolate CS47 was 44 mlo%. The major fatty acids were anteiso-15:0 (39.6%), 17:0 (7.6%), and iso-15:0 (37.8%). The 16S rRNA gene sequence similarity between the isolate CS47 and other Bacillus strains varied from 93% to 98%. In the phylogenetic analysis based on these sequences, the isolate CS47 and Bacillus amyloliquefaciens clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate CS47 was classified within the genus Bacillus as Bacillus amyloliquefaciens CS47. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens CS47 were pH 6.0 and $50^{\circ}C$, respectively. The thermal stability of mannanase from B. amyloliquefaciens CS47 is valuable when using this enzyme in industrial application.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.742-746
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• 2011

To increase the quality of Korean traditional yakju, we prepared seed cultures by fermentation at $20^{\circ}C$ for 2 days after addition of 140% water, 3% nuruk and 1.5% yeast into cooked rice. After the 200% cooked rice, 120% water and 0.08% commercial saccharifying enzyme were added to seed cultures and fermented for 2 days at $20^{\circ}C$, wild ginseng was added and then further fermented for 5 days. Physicochemical properties of traditional yakju were investigated. Ethanol was produced (18.5%) by the addition of 1.2% wild ginseng. However, ethanol content was not increased by addition of microwave treated-wild ginseng and rice (either cooked rice or raw). The traditional yakju obtained by fermentation at $20^{\circ}C$ for 5 days, after 90 sec of microwave treated-wild ginseng was added into main fermentation broth, showed good total acceptability and also contained 791 ppm saponin.

• KSBB Journal
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• v.11 no.6
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• pp.718-725
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• 1996

Old newsprint was deinked with endoglucanase, exoglucanase and their various compositions from Trichoderma viride. The yield decreased with an increase in enzyme concentration. Especially, it was the lowest in the treatment of endo-exo mixture(1:1). It may be regarded as a synergistic actions of the cellulase components. The brightness was the highest in pulp deinked with endo-exo mixture(1:1). Maximum brightness was observed when 0.5mg/mL of the endo-exo mixture was used. The physical strength increased with increasing concentration in exoglucanase. But, it decrease with increasing concentration in endoglucanse and endo-exo mixture(1:1). Also, we investigated the yield, brightness and physical strength of endoglucanase in combination with exoclucanase(12:1, 8:1, 4:l, 1:1, 1:4, 1:8, 1:12). Maximal deinking conditions, obtained at a specific optimal ratio of endoglucanase to exoglucanse are as follow ; 12:1 for yield, 12:1 for brightness, 4:1 for tensile strength, 12:1 for bursting strength, and 8:1 for tearing strength. These results indicated that the deinking depended largely upon the action of endoglucanase. Exoglucanase was occupying more than 60% of the total crude cellulase contents. Therefore, the most effective deinking must repress the action of exoglucanase.