• Korean Journal of Microbiology
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• v.45 no.4
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• pp.377-384
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• 2009

Among 27 Bacillus sp. isolated from Meju, a traditional Korean soybean fermented food, a strain MJ-226 was selected due to its strong fibrinolytic activity, and it was identified to be Bacillus subtilis MJ-226 according to morphological and biochemical characterization and sugar utilization. The fibrinolytic enzyme of B. subtilis MJ-226 was maximally produced by cultivating in the Tryptic Soy Broth (TSB) for 24~26 h at $37^{\circ}C$, and the enzymes activity was promoted with adding glucose, fructose, peptone or yeast extract to TSB. The fibrinolytic enzyme was stable at the range of pH from 6.0 to 8.0, and between 35 and $40^{\circ}C$. Also, when the crude enzyme was exposed to various metal ions and chemical inhibitors for 12 h, the enzyme stability was maintained by $MnSO_4$, $CaCl_2$, KCl, and NaCl. However, the stability was destroyed by treatment with $CuSO_4$, $MgSO_4$, $ZnSO_4$, $FeSO_4$, and $BaCl_2$, and the enzyme was unstable in the presence of chemical inhibitors such as iodoacetic acid, leupeptin, phenylmethanesulphonyl fluoride (PMSF), sodium dodecyl sulfate (SDS), thiourea, trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA) and ethylenediaminetetraacetic acid (EDTA).

• Journal of Mushroom
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• v.19 no.4
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• pp.316-321
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• 2021

Ligninolytic enzymes were produced by Pleurotus ostreatus No.42, cultivated in a new kind of bioreactor that has a rotating draft tube with a helical ribbon. Maximum laccase (Lac) production (about 8,200 U/bioreactor) was reached after 3 days of incubation, then production decreased. Production of manganese peroxidase (MnP) in this fermenter reached a maximum level of about 8,400 U/bioreactor after 6 days of incubation. Lignin peroxidase (LiP) was not detected under these growth conditions. These results indicate that the rotary draft tube bioreactor (RTB) is compatible with large scale production of ligninolytic enzymes. MnP produced under these fermentation conditions was purified via a multistep process that included chromatography on Sepharose CL-6B, prep grade Superdex 75, and Mono-Q. This major isoenzyme was confirmed to have an apparent molecular weight of 36,400 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its isoelectric point (IEF) was determined to be 3.95. N-terminal sequencing of the major isoenzyme from this fermentation was identical to that reported for an MnP3 isoenzyme isolated under different cultivation conditions, including stationary and shaking culture.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.735-742
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• 2012

This study tried to find a suitable method for enhancing the foam stability of cationic surfactants that normally generate less foam or no foam. Several trials were made to enhance the foam stability: addition of anionic surfactant, colloids and polymer. Cationic starch (CA-ST) did not form foam at all, while the foam stability of two other cationic surfactant also showed low levels; methyl triethanol ammonium methyl sulfate distearyl ester (CEQ90) for 46 sec. and Cetyl trimethyl ammonium chloride (CM29) for 31 seconds. Foam stability of cationic surfactants were significantly affected by addition of anionic surfactant, sodium dodecyl sulfate (SDS). Foam stability of CA-ST was significantly enhanced by addition of SDS, while those of CEQ90 and CM29 were decreased. Addition of colloids ($SiO_2$, kaolin) and polyvinyl alcohol (PVA) enhanced foam stabilities of CEQ90 and CM29. However, CA-ST did not form foam even in the presence of colloids or PVA. Effect of simultaneous addition of colloids and anionic surfactant on foam stability of cationic surfactant showed that foam stability of cationic surfactant was more influenced by addition of anionic surfactant than colloids. Effect of simultaneous addition of PVA and anionic surfactant on the foam stability of cationic surfactant also showed that presence of anionic surfactant significantly affect the foam stability of cationic surfactant. Foam stability of CA-ST was greatly increased to 8,780 seconds by addition of SDS 0.14% and PVA 2.5%. The foam stability of CA-ST was 8 times higher than CEQ 90. This study suggested that cationic surfactants not forming foam can generate foam by addition of anionic surfactant and its stability can be additionally increased by addition of colloids and PVA. The study results showed that enhancement in foam stability of cationic surfactant was prominently affected by the concentration of anionic surfactant added.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.886-892
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• 1997

There are many methods to synthesize polystyrene latex. Emulsion polymerization technique is commonly used commercially, but it requires a new technology to replace a traditional polymerization method because of the disadvantage of chemical initiator for environmental pollution. Since free radicals can be produced by ultrasound energy effect, polystyrene latex was synthesized using ultrasound energy instead of chemical initiator. As the ultrasonic irradiation time was increased, average molecular weight was increased and polydispersity was decreased. The degree of polymerization was increased with the concentration of SDS and maximum degree of polymerization was shown at 2wt.% SDS concentration and the reaction temperature of $40^{\circ}C$. During the course of polymerization, molecular weight was repeatedly fluctuated because of occurrence of depolymerization. Narrow molecular weight distribution polystyrene latex having controlled molecular weight was synthesized by controlling ultrasonic irradiation time and the concentration of SDS.

• Journal of Microbiology
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• v.45 no.5
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• pp.402-408
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• 2007

A strain producing a potent protease was isolated from turban shell. The strain was identified as Bacillus sp. S17110 based on phylogenetic analysis. The enzyme was purified from culture supernatant of Bacillus sp. S17110 to homogeneity by ammonium sulfate precipitation, SP-Sepharose, and DEAE-Sepharose anion exchange chromatography. Protease activity of the purified protein against casein was found to be stable at pH 7 to pH 10 and around $50^{\circ}C$. Approximately 70% of proteolytic activity of the enzyme was detected either in the presence of 100 mM SDS or Tween 20. The enzyme activity was enhanced in the presence of $Ca^{2+},\;Zn^{2+},\;Mg^{2+}$, but was inhibited by EDTA, indicating that it requires metal for its activity. The purified enzyme was found to be a monomeric protein with a molecular mass of 75 kDa, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography. The purified enzyme was analyzed through peptide fingerprint mass spectra generated from matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and a BLAST search, and identified as immune inhibitor A (inhA) deduced from nucleotide sequence of B. cereus G9241. Since InhA was identified as protease that cleave antibacterial proteins found in insect, inhA-like protease purified from Bacillus sp. S17110 might be pathogenic to sea invertebrates.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.551-558
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• 1991

We investigated the physicochemical and functinal properties of rapeseed(Brassica napus var. Youngsan) protein prepared by combining various soluvent and purification procedures, such as ultrafiltration (UF) concentration and acid-washin. The lightness value(YCIE) of each protein was greadully improved and its hydrophobicity increased by the degree of purification. The analysis of each protein by sodium dodecyl sulfate-plyacrylamide gel electrophoresis (SDS-PAGE) had nine bands revealed without difference, the considerable portion of which were of $1.96~1.59{\times}10^4$ dalton molecular weight. The content of amino acid increased a little more in the other processed proteins than in the control, and decreased considerably in the proteins extracted by the mixed solvent of 1% sodium hexametaphosphate(SHMP) and 0.25M ethlene diamine tetraacetic acid (EDTA). The better proteins were purified, the lower the kinematic viscosities were in their values. The water absorption and foaming properties were scarcely different according to the processes. The oil absorption and the emulsion activity index normally increased according to the degree of purification. The properties of heat coagulation revealed high values only in the proteins processed by EDTA while they showed considerably low values the other proteins.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.439-446
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• 2021

Quercus infectoria (nutgall) has been reported to possess antimicrobial activities against a wide range of pathogens. Nevertheless, the biofilm removal effect of nutgall extract has not been widely investigated. In this study, we therefore evaluated the effect of nutgall extract in combination with cetrimonium bromide (CTAB) against preformed biofilm of Salmonella Typhimurium on polypropylene (PP) and stainless steel (SS) coupons in comparison with other sanitizers. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of nutgall extract and surfactants (CTAB and sodium dodecyl sulfate; SDS) were assessed. CTAB showed a more efficient antimicrobial activity than SDS and was selected to use in combination with nutgall extract for removing biofilm. To determine the biofilm removal efficacy, the PP and SS coupons were individually submerged in 2x MBC of nutgall extract (256 mg/ml) + 2x MBC of CTAB (2.5 mg/ml), nutgall extract alone (256 mg/ml), CTAB alone (2.5 mg/ml), distilled water, and 100 ppm sodium hypochlorite for 5, 15, and 30 min. The remaining sessile cells in biofilm were determined. Overall, the greatest biofilm removal efficacy was observed with nutgall extract + CTAB; the biofilm removal efficacy of sanitizers tended to increase with the exposure time. The SEM analysis demonstrated that S. Typhimurium biofilm on PP and SS coupons after exposure to nutgall extract + CTAB for 30 min displayed morphological alterations with wrinkles. This study suggests nutgall extract + CTAB may be an alternative to commonly used sanitizers to remove biofilm from food contact surfaces in the food industry and household.

• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.111-122
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• 1996

S. chibaensis J-59 produced an extracellular xylanase in a CSL medium composed of 1.5% com steep liquor, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, and 0.15% glucose containing xylan. but it did not produce in the culture medium containing xylose. The production of enzyme reached to a maximum level (0.83 uints/ml) when bacteria were cultured in 2.5 l jar fermentor for 48hrs at $30^{\circ}C$ and pH 7.0. Furthermore, S. chibaensis J-59 produced an intracellular glucose isomerase in a medium containing xylan and/or xylose. Xylanase was purified 29-fold over the culture supernatants of S. chibaensis J-59 by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50, and gel filtration on Sephadex G-200. The purified enzyme is a monomeric enzyme with a native molecular mass of 25 kDa and a subunit molecular mass of 25 kDa. The purified enzyme requires $Mg^{2+}$ for activity, $Ca^{2+}$, $Co^{2+}$ is not an inhibitor but inhibit by $Fe^{3+}$, $Hg^{2+}$, and $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down birchwood xylan at random giving xylobiose, xylotriose and xylotetrose as the main end products.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.90-94
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• 1988

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunodiffusion method were used for the species differentiation of yeasts, Saccharomyces cerevisiae, Candida utils, Candida tropicalis, and Kleuyveromyces fragilis. Comparing the electrophoretic patterns of soluble and membrane proteins, Saccharomyces cereνisiae was similar to Candida utilis but was different from Candida tropicalis and Kleuyveromyces fragilis. In immunochemical properties of soluble proteins, Saccharomyces cerevisiae was almost identical with Candido utilis. However, Saccharomyces cerevisiae or Candida utilis was quite different from Candida tropicalis and Kleuyveromyces fragilis in their immunoreactivities. In immunochemical properties of membrane proteins, almost the same results were obtained irrespective of four yeast species. By using SDS-PAGE and immunodiffusion methods, Saccharomyces cerevisiae and Candida utilis were difficult to differentiate but both species were easily differentiated from Candida tropicalis and Kleuyveromyces fragilis.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.414-421
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• 2011

Purpose: Recently, an increase in the number of patients sensitized to rice allergen with or without clinical symptoms has been reported. This study was designed to determine the major allergens in rice and their clinical significance. Methods: Twenty-four children (15 boys and 9 girls; mean age, 16.3 months) with allergic disease, who were sensitized to rice antigen (by UniCAP) in the Pediatric Allergy Respiratory Center at Soonchunhyang University Hospital, were enrolled in this study. The allergenicity of various types of rice (raw, cooked, and heat-treated, simulated gastric fluid [SGF], and simulated intestinal fluid [SIF]) was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoglobulin E (IgE) immunoblots. The patients' medical records, including laboratory data and allergy symptoms after ingestion of rice were reviewed. Results: Patients were sensitized to an average of 13.5 food antigens and their mean total IgE was 6,888.7 kU/L. In SDS-PAGE, more than 16 protein bands were observed in the raw rice, whereas only 14-16 kDa and 31-35 kDa protein bands were observed in cooked rice. The common SDS-PAGE protein bands observed in SGF-, SIF-, and heat-treated rice were 9, 14, and 31 kDa. In a heated-rice IgE immunoblot, protein bands of 9, 14, and 31-33 kDa were found in 27.8%, 38.9%, and 38.9% of all sera, respectively, and in 50%, 50%, and 75%, of ser a from the 4 symptomatic patients, respectively. Conclusion: The 9-, 14-, and 31-kDa protein bands appeared to be the major allergens responsible for rice allergy symptoms.