• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1092-1100
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• 2012

Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to $80^{\circ}C$. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.333-340
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• 1998

Streptomyces griseus trypsin (SGT) is an extracellular proteinase produced by S. griseus. The sprT gene, which encodes premature SGT protein, was cloned into the plasmid pWHM3, a Streptomyces-E. coli shuttle vector. When the recombinant plasmid was introduced into Streptomyces lividans TK24, two proteins with molecular weights of 28 kDa and 42 kDa were detected. The 28-kDa protein was a SGT protein while the larger 42-kDa protein is thought to have been a premature form of the SGT protein. The SGT protein was purified to homogeneity via ammonium sulfate fractionation and many column chromatographies, including CM -sepharose chromatography, Mono-S chromatography, and Superose-12 chromatography, from the culture broth of S. lividans TK24 harboring the sprT gene. The N-terminal amino acid sequence, isoelectric points, and stabilities at various conditions of the SGT proteins purified from the Pronase and transformant were almost identical. The amount of the expressed SGT in S. lividans TK 24 was determined to be 5 times more than that of S. griseus based on the enzymatic activity against artificial substrate.

• Journal of Dairy Science and Biotechnology
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• v.38 no.1
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• pp.53-57
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• 2020

Culture concentrate of probiotic Lactobacillus johnsonii PF01 inhibited the growth of Staphylococcus aureus, which was confirmed by agar well diffusion method. Protease treatment of PF01 culture concentrate indicated that the antimicrobial substance of PF01 was a bacteriocin. Investigation of PF01 genome revealed the existence of a gene similar to that of helveticin, which showed 34.9% and 41.0% identity with those of L. helveticus 481 and L. crispatus K313, respectively, thereby suggesting that the bacteriocin produced by strain PF01 is a helveticin homolog.

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.254-261
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• 1996

A potent immuno-stimulating activity was detected from the watersoluble and ethanol-precipitated crude extract (AG-1) of the root of Angelica gigas Nakai. The crude extract was fractionated into two fractions, an acidic AG-2 and a neutral AG-3 fraction by DEAE-cellulose adsorption. The two fractions contained polysaccharides of which M.W. were 10 Kdal and >2,000 Kdal respectively, proteins, and various inorganic components. The immunostimulating activities of two fractions were not reduced by proteinase K, acid or alkali treatment. The polysaccharides obtained from the root of A. gigas were mainly composed of arabinose, galactose, and galacturonic acid. These results indicated that immuno- stimulating components of the root of A. gigas was a kind of pectic polysaccharides or arabinogalactans.

• Natural Product Sciences
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• v.13 no.2
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• pp.169-173
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• 2007

Luteolin is a major flavonoid of Lonicera japonica and has anti-inflammatory effect. The activation of proteinase-activated receptor (PAR)-2 and -4 by trypsin appears to play a role in inflammation, In the present study, we examined the inhibitory effects of luteolin on activation of trypsin-induced human leukemic mast cells (HMC-1). HMC-1 cells were stimulated with trypsin, PAR-2 and PAR-4 agonist, in the presence or absence of luteolin. The level of TNF-${\alpha}$ secretion was measured by enzyme-linked immunosorbent assay (ELISA). The expression of tryptase and phosphorylated-extracellular signal-regulated kinase (ERK) were assessed by Westem blot analysis. Moreover, trypsin activity was measured by the substrate Bz-DL-Arg-p-nitroanilide (BAPNA). TNF-${\alpha}$ secretion and Tryptase expression in trypsin-stimulated HMC-1 cells were markedly inhibited by pretreatment of luteolin. Furthermore, the pretreatment of luteolin resulted in the reduction of ERK phosphorylation and trypsin activity. These results suggest that luteolin might has the inhibitory effects on the PAR-2 and -4-dependent inflammation.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.294-300
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• 2011

Proteolytic bacteria were isolated from Myeolchi-jeotgal and Saeu-jeotgal using high-salt-content media and their growths in the media containing 25% NaCl were monitored to draw the role of bacteria in the ripening of jeotgal. The most populous genus in Myeolchi-jeotgal detected on agar media with 15% NaCl was Bacillus and its relatives, while the most populous in Saeu-jeotgal was Staphylococcus. Among the isolates, Virgibacillus halodenitrificans from Myeolchi-jeotgal and Halobacillus trueperi from Saeu-jeotgal showed proteinase activities. The species from Myeolchi-jeotgal showed proteinase activity on the agar media with 8% NaCl were similar to those isolated from the media with 15% NaCl. The dominant of Myeolchi-jeotgal isolated at the 15% NaCl concentration may be involved in the proteolysis. The proteolytic species from Saeu-jeotgal on the agar media with 8% NaCl were the genera Bacillus, Salinicoccus, and Salimicrobium those were not the dominants at 15% NaCl condition. The dominant isolates from Saeu-jeotgal on agar media with 15% NaCl may not be involved in the proteolysis of Saeu-jeotgal. Vb. halodenitrificans and Staphylococcus equorum, the dominant species from Myeolchi-jeotgal and Saeu-jeotgal, showed growths at the nutrient broth containing 25% NaCl. They may play a significant role in the ripening of jeotgal and have a high possibility to be used as the starter.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.33-38
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• 2019

Ochratoxin A (OTA), one of mycotoxins produced mainly by Aspergillus is a common contaminant of stored grains, posing health hazards to human and livestock. The aim of this study is to explore ability of isolated bacteria Bacillus subtilis AF13 and Streptomyces shenzhenensis YR226 to remove OTA. AF13 and YR226 could remove 94.23 and 97.73% of OTA ($100{\mu}g/L$), respectively during 24 h incubation in NB medium. When cultures of two strains were separated into washed cells and cell-free supernatant, the supernatant of both strains removed more than 90% of $100{\mu}g/L$ OTA, and 98.88% of OTA could be also removed by the washed cells of YR226. OTA removal occurred in a few second by the supernatant of both strains, and treatments of autoclaving, proteinase K and chymotrypsin did not affect the OTA removal by the culture supernatants, which indicate that some thermostable and non-proteinaceous substances secreted by these bacteria may be involved in OTA removal in these two bacteria. These results suggest that AF13 and YR226 can be used to remove OTA from OTA-contaminated grains and feeds, and therefore decrease economic damage in agriculture and feed industry.

• Journal of Life Science
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• v.31 no.1
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• pp.47-51
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• 2021

In today's society, functional whitening cosmetics are important to beauty. Fungi are known to produce a variety of whitening-related metabolites. In this study, we searched for tyrosinase inhibitors with metabolic products derived from Trichoderma atroviride supernatant in order to apply a material for whitening functional cosmetics. In addition, the inhibitory effect was compared to arbutin, which has already been approved as a whitening raw material by the Korea Ministry of Food and Drug Safety (KMFDS). The metabolites from the T. atroviride supernatant showed higher tyrosinase inhibitory activity than that of arbutin. Some of the tyrosinase inhibitors were stable to heat, whereas some were unstable. The heat unstable material was exhibited in the case of samples treated with little amounts, such as 0.02~0.2%. They were very unstable in acidic and alkali pHs, especially under acidic conditions. However, it was found that a weakly-acidic to neutral pH range was the optimal working pH, especially neutral pH. Since the activity of the inhibitory substances in the T. atroviride supernatant was maintained regardless of proteinase K treatment, it was assumed that the metabolites, but not the bioactive peptides, were involved in the activity. In summary, we propose that the metabolites derived from T. atroviride supernatant have strong potential as whitening raw material.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.99-108
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• 2023

Several challenges arise in DNA extraction and gene amplification for airborne fungal metagenome analysis from a particulate matter (PM) samples. In this study, various conditions were tested to optimize the DNA extraction method from PM samples and polymerase chain reaction (PCR) conditions with primer set and annealing temperature. As a result of comparative evaluation of DNA extraction under various conditions, chemical cell lysis using buffer and proteinase K for 20 minutes and bead beating treatment were followed by using a commercial DNA extraction kit to efficiently extract DNA from the PM filter samples. To optimize the PCR conditions, PCR was performed using 10 primer sets for amplifying the ITS2 gene region. The concentration of the PCR amplicon was relatively high when the annealing temperature was 58℃ with the ITS3tagmix3/ITS4 primer set. Even under these conditions, when the concentration of the PCR product was low, nested PCR was performed using the primary PCR amplicon as the template DNA to amplify the ITS2 gene at a satisfactory concentration. Using the methods optimized in this study, DNA extraction and PCR were performed on 15 filter samples that collected PM2.5 in Seoul, and the ITS2 gene was successfully amplified in all samples. The optimized methods can be used for research on analyzing and interpreting the fungal metagenome of atmospheric PM samples.

• Mycobiology
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• v.36 no.1
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• pp.74-76
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• 2008

To obtain basic information on the biochemical property of basidiospores of shiitake mushroom (Lentinula edodes), the ability of producing extracellular enzyme was assessed using a chromogenic plate-based assay. For the aim, amylase, avicelase, $\beta$-glucosidase, CM-cellulase, pectinase, proteinase, and xylanase were tested against monokaryotic strains generated from forty basidiospores of two different parental dikaryotic strains of shiitake mushroom, Sanjo-101Ho and Sanjo-108Ho. These two parental strains showed different degree of extracellular enzyme activity. No identical patterns of the degree of enzyme activity were observed between monokaryotic strains and parental strains of the two shiitake cultivars. The degree of extracellular enzyme activity also varied among monokaryotic strains of the two shiitake cultivars. Our results showed that dikaryotic parental strains of shiitake mushroom produce monokaryotic basidiospores having very diverse biochemical properties.