• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.228-233
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• 2017

The aim of the current study was to examine genotoxicological safety of purified bee venom (Apis mellifera L.) The bacterial reverse mutation in Salmonella typhimurium (TA100, TA1535, TA98, and TA1537) and Escherichia coli (WP2 uvrA) were evaluated with purified bee venom at concentrations of 0, 1.5, 5, 15, 50, 150, and $500{\mu}g/plate$. Purified bee venom was negative in Ames test with both in the presence and absence of rat liver microsomal enzyme. According to these results, we concluded that purified bee venom did not cause bacterial reverse mutation. The safety of the purified bee venom at practical doses needs to be further evaluated in in vivo genotoxicity assays.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.157-162
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• 2009

An agar-liquefying bacteria (SC-22), which produces a diffusible agarase that caused agar softening around the colony was isolated from Daecheong lake in Korea. Chemotaxanomic and phylogenetic analyses based on 16S rRNA gene sequences revealed the strain was classified as Cellvibrio mixtus SC-22. The isolate SC-22 showed maximal extracellular agarase activity with 58.5 U/mL after 48 h cultivation in the presence of 0.2% agar. It was observed that the isolate produced two kinds of extracellular and three kinds of intracellular isoenzymes. The major agarase was purified from the culture filtrate of agarolytic bacteria by ammonium sulfate precipitation, anion exchange and gel filtration column chromatographic methods. The molecular mass of the purified enzyme was estimated to be 25 kDa by SDS-PAGE. The optimum pH and temperature of the purified enzyme were pH 7.0 and $50^{\circ}C$, respectively. The agarase activity was activated by $Fe^{2+}$, $Na^+$ and $Ca^{2+}$ ions while it was inhibited by $Hg^{2+}$, $Mn^{2+}$ and $Cu^{2+}$ at 1 mM concentration. The predominant hydrolysis product of agarose by the enzyme was galactose and disaccharide on TLC, indicating the cleavage of $\beta$-1,4 linkage in a random manner. The enzyme showed high substrate specificity for only agar and agarose among various polysaccharides.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.68-74
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• 2015

Based on the genomic analysis of Thermococcus pacificus P-4, we identified a putative GH1 ${\beta}$-glucosidase-encoding gene (Tpa-glu). The gene revealed a 1,464 bp encoding 487 amino acid residues, and the deduced amino acid residues exhibited 77% identity with Pyrococcus furiosus ${\beta}$-glucosidase (accession no. NP_577802). The gene was cloned and expressed in Escherichia coli system. The recombinant protein was purified by metal affinity chromatography and characterized. Tpa-Glu showed optimum activity at pH 7.5 and $75^{\circ}C$, and thermostability with a half life of 6 h at $90^{\circ}C$. Tpa-Glu exhibited hydrolyzing activity against various pNP-glycopyranosides, with kcat/Km values in the order of pNP-${\beta}$-glucopyranoside, pNP-${\beta}$-galactopyranoside, pNP-${\beta}$-mannopyranoside, and pNP-${\beta}$-xylopyranoside. In addition, the enzyme exhibited exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharide (laminarin) and ${\beta}$-1,3- and ${\beta}$-1,4-linked oligosaccharides. This is the first description of an enzyme from hyperthermophilic archaea that displays exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharides and could be applied in combination with ${\beta}$-1,3-endoglucanase for saccharification of laminarin.

• Journal of Life Science
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• v.30 no.7
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• pp.581-591
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• 2020

This study investigated the probiotic properties and physiological activities of Korean fermented foods such as sikhae, young radish kimchi, and bean-curd dregs. Among the isolated lactic acid bacteria, Pediococcus inopinatus BZ4, Lactobacillus plantarum SH1, Lactobacillus brevis SH14, Pediococcus pentosaceus YMT1, and Leuconostoc mesenteroides YMT6 demonstrated a greater than 60% survival rate at pH 2.5, along with an excellent survival rate even at 0.3% bile acid. These five bacteria showed strong flocculation ability in autoaggregation and coaggregation tests, indirectly clustering useful micro-organisms and inhibiting the attachment of pathogenic bacteria. In a cell surface hydrophobicity test, these bacteria showed adhesion to three solvents (ethyl acetate, chloroform, and xylene) and high hydrophobicity, thereby indicating excellent indirect cell adhesion to intestinal cells. The cell-free supernatants and intracellular extracts of the five lactic acid bacteria showed antioxidative activity in the form of 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability and lipid peroxidation inhibition. Antimicrobial activities were also observed in four pathogenic bacteria, namely E. coli KCTC 2571, H. pylori HPKCTC B0150, L. monocytogenes KCTC 13064, and S. aureus KCTC 1916. These results demonstrate that these five lactic acid bacteria could be used as probiotics with antioxidant and antimicrobial properties.

• Journal of Life Science
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• v.27 no.4
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• pp.430-434
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• 2017

Essential oils are fragrant oils extracted from the leaves, stems, peels, petals and roots of aromatic plants cultivated by natural means or using organic agricultural techniques. Essential oils have commonly been used as antibacterial and antifungal agents. In the present study, essential oil was extracted from lisianthus (Eustoma grandiflorum [Raf.] Shinn.) and tested for antifungal activities against three eumycetes (Penicillium pinophilum, Chaetomium glogosum and Aspergillus niger). Lisianthus essential oil showed high antifungal activities against three eumycetes, especially against Aspergillus niger, for which the resulting minimum inhibitory concentration (MIC) was 0.005 mg/ml. In addition, the extracted essential oil was shown to have antimicrobial activity against ten intestinal pathogenic bacteria (Escherichia coli, Salmonella typhimurium, Klebsiella pneumonia, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Bacillus subtilis, Enterococcus faecalis and Vibrio parahaemolyticus) according to the disc diffusion method and was also shown to exhibit strong antibacterial activity against an additional three pathogenic bacteria (Bacillus subtilis, Listeria monocytogenes and Vibrio parahaemolyticus). These results indicate that lisianthus essential oil could be used as an antibiotic against harmful bacteria that produce intestinal illnesses. From the present study, we suggest that lisianthus extracts can be utilized as potential antifungal and antibacterial agents and for the development of pharmaceutical and cosmetic products.

• Food Science and Preservation
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• v.19 no.3
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• pp.406-412
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• 2012

The purpose of this research is to develop functional food with garlics(Allium sativum var. pekinense) as a healthy food. Fermented garlic broth(FGB)s were prepared with whole bulb of garlics preserved in sugar and sugar syrup, then fermented and aged at room temperature for 36 months. Biological activities of FGBs were tested antibacterial, antioxidative, fibrinolytic activities and analyzed for polyphenol contents. The total polyphenol contents of FGBs in 12~36 month fermented broth(870~885 mg/100 mL of broth) had significantly higher than those of 1~6 months fermented broths(p<0.001). The electron donating abilities(EDAs) and SOD-like activities of 24~36 month fermented broth had significantly higher than those of 1~6 months fermented broths(p<0.05). FGBs had shown strong antibacterial activities against four kinds of pathogenic bacteria(L. monocytogenes, S. aureus, E. coli O157:H7, and Sal. typhimurium). The fibrinolytic activities of 24~36 months fermented broth had more than twice of the fibrinolytic activity of plasmin. FGBs had increasing activities in antibacterial, antioxidative and fibrinolytic activity as the progress of fermentation period. FGBs can be used as natural antioxidant to prevent oxidative damage on normal cells probably because of their antibacterial, antioxidative and fibrinolytic activities.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.117-121
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• 2012

Biological activities of the hot water and ethanol extracts from Opuntia humifusa cladodes were investigated. 1,1-diphenyl-2-picryl hadrazyl (DPPH) electron donating ability of hot water and ethanol extracts was 79.07 and 82.54%, respectively. Hot water extract generally showed better cytotoxic activity than ethanol extract against each cell line. HeLa and AGS cell lines treated with hot water extract had more than 50% cytotoxic activities. Based on the antimicrobial activities against four microbial strains, both extracts inhibited growth of Staphylococcus aureus KCCM 11593, whereas affected cell growth of three other microorganisms, Escherichia coli (KCCM 11234), Pseudomonas aeruginosa (ATCC 27853), and Salmonella typhimurium (ATCC 11862), in proportion to the concentration of extracts. The inflammatory activities against hot water extract (34.31%) showed higher than that of ethanol extract (25.59%). The effect of extracts on 3T3-L1 preadipocytes differentiation showed that differentiation of treated group with 80 and 100 ${\mu}g/mL$ of hot and ethanol extracts were increased more than treated group with isobutyl methyl xanthine (IBMX) + dexamethasone. These results indicate that the O. humifusa cladodes extracts can be used as a functional material due to their effective biological activities.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.884-888
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• 2005

An agar-degrading bacterium was isolated from north-eastern sea of Jeju island and cultured in marine agar 2216 media. Biochemical and morphologicl characteristics and 165 rRNA gene revealed that isolated strain was member of Agarivorans genus, and named Agarivorans sp. JA-1. Agarase was produced as growth-related and expressed regardless of agar presence. Optimal pH was 8 at 50 mM Clycine-NaOH buffer, and activity was maximum at $40^{\circ}C$E Enzymatic activity was maintained over $80\%$ at $60^{\circ}C$t and $70\%$ at $80^{\circ}C$ which is thermotolerant. Hence isolated novel Agarivorans sp. JA-1 strain and its beta-agarase could be used for the production of functional oligosaccharide from agar in solution state.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.299-305
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• 2006

In this study, we have isolated and identified a proteolytic bacterium from conventional Cheongkukjang. We also characterized several bioactivity of Cheongkukjang, which was fermented by an isolated strain. One strain out of about $10^4$ strains obtained from Cheongkukjang showed relatively high proteolytic activity was selected and named as a Bacillus subtilis LSH805 strain. White soy-bean Cheongkukjang possessed less odor and more viscous substance than black soy-bean Cheongkukjang. Cheongkukjang showed fibrinolytic activity, and about 1,500 mg fibrin was degraded after 20 h incubation. Although nitric oxide (NO) assays of soy-bean and Cheongkukjang were almost the same, their activities were significantly higher than that of no treatment. Activity of water fraction of Cheongkukjang was somewhat higher than that of soy-bean. Fibrinolytic and NO assays of Cheongkukjang suggest that Cheongkukjang, which was fermented by an isolated strain may be a useful candidate for natural fibrinolytic and macrophage-stimulating agents.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.796-800
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• 2013

Soybean-based fermented foods have been used as traditional condiments in Korea, Japan and China. Thirteen Korean types of soybean sauce that had been manufactured and sold in China were examined to evaluate their quality. The pH, salinity, and moisture content of the samples were pH 5.17-6.86, 8.0%-23.0%, and 46.446-70.40%, respectively. The amino-type nitrogen content was in the range of 199.18 to 736.46 mg%. The total aerobic bacterial counts were 4.83-7.89 Log CFU/g. The coliform count of gochujang (CNH-2) was 2.31 Log CFU/g, but none were detected in the other samples. Moreover, Bacillus cereus counts from samples of doenjang and gochujang were in the range 2.00-4.09 Log CFU/g. The protease and amylase activity of samples were 379.02-781.36 unit/g and 5.29-63.27 unit/g, respectively.