• Journal of Environmental Science International
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• v.16 no.10
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• pp.1203-1208
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• 2007

Feathers are produced in huge quantities as a waste product at commercial poultry processing plants. Since feathers are almost pure keratin protein, feather wastes represent an alternative to more expensive dietary ingredients for animal feedstuffs. Generally they become feather meal used as animal feed after undergoing physical and chemical treatments. These processes require significant energy and also cause environmental pollutions. Therefore, biodegradation of feather by microorganisms represents an alternative method to prevent environment contamination. The aim of this study was to investigate cultural conditions affecting keratinolytic protease production by Bacillus pumilus RS7. We also assessed the nutritive value of microbial and alkaline feather hydrolysates, The composition of optimal medium for the keratinolytic protease was fructose 0.05%, yeast extract 0.3%, NaCl 0.05%, K2HPO4 0.03%, KH2PO4 0.04% and MgCl2 6H2O 0.01%, respectively. The optimal temperature and initial pH was $30^{\circ}C$ and 9.0, respectively. The keratinolytic protease production under optimal condition reached a maximum after 18 h of cultivation. Total amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $113.8\;{\mu}g/ml$ and $504.9\;{\mu}g/ml$, respectively. Essential amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $47.2\;{\mu}g/ml$ and $334.0\;{\mu}g/ml$, respectively. Thus, feather hydrolysates have the potential for utilization as an ingredient in animal feed.

• Journal of Life Science
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• v.16 no.1
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• pp.141-147
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• 2006

The effect of traditional Doenjang supplemented with the extracts of herb medicines (refer as DHM) on the taste component and microbial properties was investigated. The DHMs were divided to four group. Fatty acid compositions were similar between DHMs and control as ratio of each fatty acid to total fatty acids. Concentration of total free amino acid from groups II , III and IV was higher than that of control. Major organic acids were phytic acid, lactic acid, and butyric acid. In isoflavone of DHMs, free daidzein and genistein contents were mostly similar among the groups, and groups m and W were slightly higher as compared with control. Viable cell count of DHMs was shown to be $2.5\times10^7\;CFU/ml$, a similar trend of control. Protease activity of DHMs was higher than that of control(67.65 units), but amylase activity between DHMs and control was almost identical Sensory scores of group II and IV were shown to be brighter than those of group I and II, and decreasing off-odor was more effective. In over all eating-quality, group III and IV were evaluated to be favorable as compared with control and the other DHMs because of supplementing the sweet taste of extracts to Korean indigenous Doenjang.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.71-79
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• 1988

For the purpose of producing low salt fermented anchovy by accelerated method with a strong proteolytic bacteria, in this study, a strong proteolytic bacterium was isolated from low salt fermented anchovy and its bacteriological characteristics and properties of protease were experimented. The results obtained were as fellows : three proteolytic bacteria, Aeromonas anaerogenes Barillus subtilis and Staphylococcus saprophyticus were isolated from low salt fermented anchovy($4\%\;of\;salt,\;4\%\;of\;KCl,\;0.5\%\;of\;lactic\;acid,\;6\%$of sorbitol and $4\%$ of alcohol extract of red pepper) after 40 days fermentation. Among these strains, which grow best at $30^{\circ}C$, pH 7.0, B. subtilis was found the best proteolytic strain and benefit for industrial use as shown $0.95\;hr^{-1}$ of specific growth rate, $89{\mu}g-Tyr/hr.ml$ of maximum activity after 12 hrs culture in TPY broth. The protease produced by by B. subtilis showed maximum activity at $35^{\circ}C$, pH 7.0, and molecular weight was estimated to be 23,000 by Sephadex G-100 filtration, and it was supposed to be a kind of metal chelator sensitive neutral protease from the results of strong sensitivity against EDTA, o-phenanthroline and metal ions such as $Cu^{2+},\;Ni^{2+},\;Fe^{2+}.Km$ value of that by method of Lineweaver-Burk was determinded to be $0.73\%$ for casein as a substrate.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.189-195
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• 1997

The structural basis of Iysine specificity of Achromobacter protease I (API) was investigated by means of site-directed mutagenesis. The precursor protein in which Glu190, one of the two candidates for determining Iysine specificity, was substituted by glutamine, aspartic acid or leucine was processed autocatalytically to attaln full pretense activity with lysine specificity. The substitution of the other candidate, Asp225, for asparagine or leucine produced no mature active forms of pro-API. The precursor protein of the mutant D225E slowly matured autocatalytically. The lysylendopeptidase activity of the mature D225E was 0.25% of that of native API, and this reduced activity is mainly due to a decrease in the affinity of the enzyme for lysine. These results suggest that Asp225 plays a critical rol in restricted substrate specificity as a lysylendopeptidase. However, D225E exhibited no measurable activity for synthetic ornithine substrate. Since the hydroxyl group of Ser194 in this mutant retained essentially the same reactivity to DFP or PMSF as that in native API, it can be noted that a methylene unit longer side chain of residue 225 is not compensated by a methylene unit shorter side chain at subsite P1 in the bound substrate.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.65-74
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• 1996

Treatment of regenerating amphibian limbs with retinoic acid (RA) is known to induce paftern duplication, which is closely related to the extent of dedifferentiation. In the present study, the activities of trypsin- and chymotrypsin-like proteases are examined to delineate a possible role in the process of dedifferentiation in the regenerating limbs of urodeles, the Korean salamander (Hynobius leechii) and the Mexican axolod (Ambystoma mexicanum). Specifically, we were interested to know if there is any correlation between trypsin- and chymotrypsin-like protease activities and the state of dedifferentiation which is augmented by RA treatment. We were also interested in expoloring if there is any species-specific difference in the profile of enzyme activities during limb regeneration. The results showed that the activities of these two enzymes reached a peak level at dedifferentiation stage, and RA treatment caused elevation of their activities, especially in the case of trypsin-like protease. The increase of trypsin-like protease activity after RA treatment was pronounced in the Korean salamander, which might reflect a species-specific responsiveness to RA. The present results imply that trypsin and chymotrypsin or similar proteases may play an active role in the process of dedifferentiation in regenerating limbs, and that trypsin or trypsin-like eryrymes might be involved in the RA-evoked enhancement of dedifferentiation which precedes overt pattern duplication.

• Analytical Science and Technology
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• v.24 no.2
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• pp.78-84
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• 2011

The fragmentation patterns of a serine protease inhibitor, camostat, and its degradation product, 4-(4-guanidinobenzoyloxy)phenylacetic acid (GBPA), were for the first time investigated by a triple quadrupole tandem mass spectrometry equipped with an electrospray source (ESI-MS/MS) in positive and/or negative ion mode under collision-induced dissociation (CID). The positive CID spectrum of camostat showed distinctly that the single bond (C-O) cleavage between carbonyl group and oxygen atom of the ester bonds of the compound favorably occurred and then the loss of N,N-dimethylcarbamoylmethyl group was more susceptible than that of guanidine moiety. In the positive ion CID spectrum of GBPA, the initial cleavage between the carbonyl group and oxygen atom of 4-guanidinobenzoyloxy group also occurred, yielding the most abundant fragment ion at m/z 145. On the other hand, the negative CID spectrum of GBPA characteristically showed the occurrence of the most abundant peak at m/z 226 resulting from the sequential neutral losses of $CO_2$ and HN=C=NH from the parent ion at m/z 312.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.39-44
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• 2010

The process of the preparation of branched-chain amino acid (BCAA)-enriched hydrolysates from corn gluten was optimized through the parameters of pre-treatment (heating and cellulosic hydrolysis), hydrolysis method (acid, protease, and microbe plus protease), concentration, and spray drying condition. The protein yield of corn gluten was increased by heating and cellulase treatments. Among three different hydrolysis methods, the combined use of microbes and protease was the most effective in terms of free amino acid (FAA) and BCAA content of the corn gluten hydrolysates. In addition, the FAA and BCAA content in the hydrolysates prepared by microbial and enzymatic combined treatment were improved by a concentration process. Spray drying conditions for the preparation of the powder from the hydrolyzed reactant were an inlet temperature of $185^{\circ}C$, outlet temperature of $80^{\circ}C$, and the use of maltodextrin as an anticaking agent. Thus, this study established an economical process for preparation of value-added hydrolysates of excellent productivity and quality, in terms of high BCAA content and product stability.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.303-310
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• 2016

In this study, doenjang samples were prepared with different types of salts (12%, w/w): purified salt (PS), 3-year aged solar salt (SS3), 1-year aged solar salt (SS1), and bamboo salt melted 3 times (BS). Whole-soybean mejus were fermented with starters consisting of 2 Bacillus strains, a yeast, and a fungus (starter doenjang), and control mejus were fermented with organisms present naturally in rice straw (non-starter doenjang). The whole-soybean mejus were dried, and then mixed with cooked soybeans and the respective salts. The doenjang samples were fermented for 13 weeks at 25℃. The protease (acid, neutral, and alkaline) activities, fibrinolytic activities, and antioxidant capacities of the samples were examined every week. BS doenjang showed the highest acid protease (6.46 ± 0.20 unit/g) and fibrinolytic activities (0.61 unit/ml). Among the starter doenjang samples, those made with SS and BS showed the highest total phenolic contents after 91 days of fermentation. For antioxidant activities, SS3 doenjang showed higher activities than the other doenjang samples, as evaluated by ABTS, DPPH, and FRAP assays. These results suggest that solar salt, especially aged for 3 years, is better than purified salt in terms of producing better functionalities of doenjang.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.291-296
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• 1994

A bacterial strain NO. AM-28, showing proteolytic activity against defatted soybean was isolated from domestic soil. The isolated strain was identified as Aeromonas hydrophila by both the biochemical tests using API kit and the analysis of cellular fatty acid profile with MIDI system. The protease production from A. hydrophila AM-28 was highly enhanced when it was cultivated in the medium containing glycerol as a carbon source, tryptone or $(NH_4)_2HPO_4$ as a nitrogen source, and $CaCl_2$ as a mineral source. The optimal pH and temperature for the enzyme was 8.0 and $65^{\circ}C$, respectively. The enzyme was stable up to $55^{\circ}C$ and at pH values ranging from 7.0 to 13.0. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride and EDTA, indicating that serine residue and metal ions be involved in enzyme activity.

• Korean Journal of Food Science and Technology
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• v.9 no.1
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• pp.31-35
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• 1977

As a study on the acid protease production by Rhizopus japonicus S-62, the culture conditions for the enzyme production and characteristics of the crude enzyme were investigated. The results are summarized as follows: 1. The optimum conditions for solid culture on wheat bran were 48 hrs of culture period and $100{\sim}120%$ addition of tap water. 2. Of the several media, wheat bran medium was the most excellent in the enzyme production. 3. The addition of sucrose, fructose, $NH_4Cl$ and $NaH_2PO_4$ on wheat bran, respectively, increased largely the enzyme production. 4. The optimum pH for the enzyme action was pH $2.4{\sim}2.6$, the optimum temperature was about $40^{\circ}C$, and the stable pH range was $pH\;2.5{\sim}5.0$, the enzyme was stable below $40^{\circ}C$ and was inactivated abruptly above $40^{\circ}C$.