• Food Science of Animal Resources
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• v.22 no.3
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• pp.259-266
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• 2002

The egg shell membrane degrading isolated from soil was identified as Bacillus licheniformis by 16S rDNA identification method. A keratinase was isolated from the Baciilu licheniformis culture. DEAE-cellulose ion-exchange and Sephadex C-75 gel chromatograhies were used to purify the enzyme. The specific activity was increased 17.3-fold by the purification procedures. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and Sephadex G-75 chromatography indicated that the purified keratinase was monomeric and had a molecular weight of 65 kDa. The enzyme showed optimum activity at pH 9.0, and was stable above pH 9.0. The optimum temperature was 50$\^{C}$ and the enzyme was stable in the temperature ranges from 20$\^{C}$ to 50t. By the addition of 1 mM and 10 mM FeSO4, the activities of the enzyme were increased to 111$\pm$4.6% and 133$\pm$3.79%, respectively. The keratinase was an alkaline serine pretense because it was inhibited only by phenylmethylsulfonylfluorice (PMSF).

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.148-154
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• 2003

Moraxella sp. CK-l is known to inhibits the growth of Anabaena cylindrica, a cyanobacterium. It has been documented that the ability of this growth inhibition of Anabaena cylindrica was attributed to extracellular autolysin from Moraxella sp. CK-l. However, it remains to be elucidated identification and characterization of autolysin have yet been elucidated. In this study, we tried to purify and identify autolysin secreted from Moraxella sp. CK-l. Cells were grown in a complex liquid medium (BGC-11) and culture supernatants were collected, followed by ammonium sulfate fractionation. Fractions were further separated with anion exchange column, Mono-Q, in FPLC system and analyzed by SDS/PAGE. The fraction containing high autolysin activity showed a single distinct protein peak in anion column and molecular mass of about 17 kDa in SDS/PAGE. Nterminal amino acid sequencing of the protein was analyzed, of which result showed the homology with some proteases, including extracellular serine protease, Dichelobacter nodosus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.917-923
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• 2002

Inhibitory mechanism of the anticoagulant polysaccharide purified from Codium fragile was investigated. The anticoagulant compounds (Cf-30-IV-4-ii, CF-30-IV) prolonged the clotting time at both activated partial thrombo-plastin time (aPTT) and thrombin time (TT). The Inhibition factor assay of instrinsic coagulation pathway in the blood showed that the anticoagulant polysaccharide (CF-30-IV-4-ii) inhibited other factors such as Ⅷ, Ⅸ, Ⅵ and Ⅷ of the coagulation cascade, which did not affect the lupus anticoagulant AB activity. In the thrombin inhibition pattern the CF-30-IV-4-ii did not directly influence the fibrine formation mediated by thrombin but af-fected the anticoagulant activity through the activation of antithrombin III. Base on these result, the anticoaglant polysaccharide (CF-30-IV-4-ii) was considered to inhibit serine pretense involved in the blood coagulation cascade through the enhancing antithrombin III activity. The residual effects of anticoagulant activity and antithrombosis were tested with ICR mice. The anticoagulant polysaccharide (CF-30-W) kept its anticoagulant activitv for 6 hrs with 100% survival at a dose of 150 mg/kg in the antithromboisis test. The anticoagulant effect of CF-30-RF in ex vivo was proportional to the concentration of intravenously injected dose up to 100 mg/kg.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.255-260
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• 2007

This study was conducted to isolate and identify bacteria producing xylanase and cellulase from spent mushroom substrates and to determine the optimal medium conditions for their growth. Bacteria showing high xylanase and carboxymethyl cellulase activities and low protease and amylase activities were strain 201-3 and strain 206-3. Strain 201-3 was identified as Enterobacter ludwigii and named Ent. ludwigii KU201-3. 206-3 was identified as Bacillus cereus and named B. cereus KU206-3. The optimal medium condition of Ent. ludwigii KU201-3 was obtained when 1%(w/v) of soybean meal and 3%(w/v) of sucrose were used as nitrogen and carbon source, respectively. That of B. cereus KU206-3 was obtained when 3%(w/v) of soybean meal and 1%(w/v) of molasses were used as nitrogen and carbon sources, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.175-179
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• 1999

Processing conditions for dried condiments with oyster, pen shell and cockle shell were investigated. The enzymatic hydrolysis for 3 hours was more profitable than hydrothermal extraction to develop flavoring matters from oyster, pen shell and cockle shell. As a result of omission tests, nucleotides were predominated in the taste compounds of shellfish hydrolysates rather than free amino acids, and the contribution of nucleotides and free amino acids to the taste of shellfish hydrolysates was remarkable. The major flavoring components of shellfish hydrolysates were free amino acids and oligopeptides below 500 dalton. When shellfish hydrolysates were separated with membrane (molecular weight cutoff 500 dalton) for recovering flayer, recovering yields of amino type nitrogen were $92.1\~92.8\%$. Moisture contents of dried shellfish condiments prepared with pretense hydrolyzed oyster, pen shell and cockle shell were $3.5\%,\;3.8\%$ and $3.7\%$, respectively. Contents of total nitrogen were $69.4\%,\;78.8\%$ and $74.2\%$, and those of amino nitrogen were $45.5\%,\;48.9\%$ and $45.4\%$, respectively. Drying yield, solubility and absorption rates at Aw 0.88 were $11.7\%,\;78.4\%$ and $6.8\%$ in oyster, $8.2\%,\;73.6\%$ and $6.1\%$ in pen shell, $9.8\%,\;76.9\%$ and $6.6\%$ in cockle shell, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.296-308
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• 1996

Proteolytic enzymes responsible for post-mortem degradation of the fish tissues have been studied in regard with screening the proteases distributed in the fish body by reacting with the specific synthesized substrates. Activities of cathepsin L, B, H, G, and D like enzymes were detected in the muscle crude protease from the both kind of fish, dark fleshed fish (anchovy, Engraulis japonica, and gizzard-shad, Clupanodo punctatus) and white fleshed fish (seabass, Lateolabrax japonicus, and sole, Pleuronichthys cornutus), however, those of chymotrypsin, trypsin, pepsin, and peptidase like enzymes were observed 3n the viscera crude pretense from the fish. Proteolytic activities of the muscle crude protease at pH 6.0 were similar to those of the viscera crude protease at pH 8.0, but, those of the viscera crude protease at pH 8.0 were about 2 times higher than those at pH 6.0. The muscle and viscera crude protease from anchovy showed the strongest proteolytic activity among the four fish crude proteases and the proteolytic activity of the viscera crude protease was approximately 100 times higher than that of the muscle crude protease, which suggest that viscera proteases were more contributed on the development of post-mortem changes than muscle proteases. With the degradation patterns on SDS-polyacrylamide gel electrophoresis against yellowtail myofibrillar proteins, the muscle and viscera crude protease of the four fishes were primary responsible for the degradation of myosin heavy chain, and myosin light chain and actin, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.211-215
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• 2002

Pretense production and its characteristics were investigated for Rhizopus stolonifer, Rhizopus oryzae and Absidia corymbifera which were isolated from Korean traditional meju. The optimum culture conditions of the strains for the production of protease in basic medium [wheat bran : 1% glucose solution=1 : 1 (w/v)] were 3$0^{\circ}C$ and 4 days. The optimum pH and temperature for the enzyme activity of crude enzymes produced by Rhizopus sto-lonifer, Rhizopus oryzae and Absidia corymbifera were pH 6.0 and 5$0^{\circ}C$, respectively. The enzymes were relatively stable at pH 4.0~7.0, at temperature below 4$0^{\circ}C$, and at NaCl concentration lower than 16%. The $K_{m}$ value for Hammastein casein was 3.3$\times$10$^{-4}$ , 0.75$\times$10$^{-4}$ and 1.3$\times$10$^{-4}$ M, and $V_{max}$ value was 17.2$\mu\textrm{g}$/min, 9.4$\mu\textrm{g}$/min and 7.8$\mu\textrm{g}$/min, respectively.y.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.

• Food Science and Preservation
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• v.13 no.5
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• pp.603-610
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• 2006

Korean traditional soy paste (Doenjang) was fermented using Meju prepared by the culture of wild microorganisms in steamed soy beans. During the fermentation, changes in the physicochemical and several functional properties were monitored. Total acidity and amino acidity increased from 0.09 to 0.96, and 2.24% to 3.28% respectively, Amylase and protease activities increased and showed the maximal level after 60 days of fermentation, which were 4.03 and 7.29 units/ml, respectively. However, both enzyme activities decreased after then. The inhibitory activities against tyrosinase and angiotensin converting enzyme increased and reached 20.57 and 38.18% respectively. Antimutagenic activities against N-methyl-N'-nitro-N-nitiosoguanidine and 4-nitro-O-phenylenediamine (NPD) increased for 90 days and roached 70.21 and 60.01% in S. enterica serovar Typhimurium TA100, respectively. Against NPD and 4-nitroquinoline-1-oxide, the antimutagenic activities also increased and reached 50.91 and 46.35% in the strain TA98, respectively.

• Food Science and Preservation
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• v.13 no.1
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• pp.95-101
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• 2006

Quality characteristics of Cheongbukjangs with $1\~3\%$ desalted and dried sea tangle powder were investigated after fermentation for 48 hr at $40^{\circ}C$. Addition of sea tangle, irrespective of concentration, did not affect pH and slime content of Cheongbukjang. Color L* and a* values were generally decreased with increasing sea tangle concentration. There were no significant differences in total microbe, amino nitrogen content, and protease and amylase activity between control and Cheongbukjangs with up to $2\%$ sea tangle. However, addition of $3\%$ sea tangle resulted in decreased total microbe, amino nitrogen content, and enzyme activity compared with those of control. Fiber content increased with increasing sea tangle concentration and hardness increased by 1.5 times at $2\%$ sea tangle and by 2.6 times at $3\%$ sea tangle compared with that of control. Results for sensory evaluation revealed that addition of $2\%$ sea tangle was the optimum concentration in view of reducing bitter taste and odor, and improving overall acceptability.