• The Journal of Natural Sciences
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• v.5 no.2
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• pp.13-17
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• 1992

Regulation of $\beta$-galactosidase biosynthesis was studied with alkalophilic, thermophilic Bacillus sp. TA-11. Biosynthesis of the enzyme was effectively induced by lactose and some low level by isoprophyl-$\beta$-D-thiogalactopyranoside(IPTG). When 30mM glucose was added at the different intervals to the culture that had been in contact with lactose, the different levels of the enzyme synthesis were observed. So, this suggests that glucose interfered with the entry of the lactose into the cells.The glucose inhibitory effect was not relieved by adding cAMP to the culture.

• The Journal of Natural Sciences
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• v.18 no.1
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• pp.29-38
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• 2007

Regulation of invertase biosynthesis was studied with alkalophilic and thermophilic Bacillus cereus TA-11. Biosynthesis of invertase in Bacillus cereus TA-11 was effectively induced in the presence of 10 mM of sucrose for 180 min and 25 mM of raffinose for 90 min, respectively. Glucose repressed the invertase induction by sucrose and as late addition time of glucose, invertase formation was increased, indicating that glucose repression was occurred by inducer exclusion. Catabolite repression was not reduced by the addition of cAMP for 180 min of induction.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.501-506
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• 1992

An alkalophilic Vibrio sp. RH530 showing high proteolytic activity was isolated form soil samples by enrichment culture. The activity staining using gelatin SDS- polyacrylamide gel electrophoresis (PAGE ) revealed that the strain produced an alkaline major protease (Apr B) with a size of 27 kDa, and at least six minor proteases. The apparent sizes of four of the minor proteases were approximately 45, 28, 22 and 19 kDa. Apr B and five of the minor proteases were inhibited by serine protease inhibitors including PMSF and DFP, suggesting that they are serine proteases. One of the minor proteases was inhibited by metalloprotease inhibitors, not by serine protease inhibitors, indicating it to be a metalloprotease. Furthermore, the activities of Apr B and Prt 3 were not inhibited by SDS in the reaction mixture. The production of Apr B and some of the minor proteases was specifically affected by culture temperature (30 to 37.deg.C) and pH (7 to 10). The production of Apr B. Prt 2, Prt 5 and Prt 6 was mainly affected by culture temperature, while Prt 4 by culture pH. Prt 1 and Prt 3 were not affected by neither of these factors.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.608-613
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• 1993

Production of cyclodextrin (CD) by cyclodextrin glycosyltransferase (CGTase) isolated from alkalophilic Bacillus sp. was carried out to determine optimal reaction conditions. The maximum initial rate of CD production from amylose was obtained at dextrose equivalent 10.5. The CD production yield showed inverse proportionality to DE values over the range from 0.5 to 37.7. Even though the deactivation constant of CGTase at $60^{\circ}C$ was higher than those at lower temperatures, the production rate and yield at $60^{\circ}C$ were still higher. These results suggest thermal stabilization of CGTase by binding with starch.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.11-17
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• 2015

In an attempt to shift the optimal pH of the xylanase B (XynB) from Aspergillus niger towards alkalinity, target mutation sites were selected by alignment between Aspergillus niger xylanase B and other xylanases that have alkalophilic pH optima that highlight charged residues in the eight-residues-longer loop in the alkalophilic xylanase. Multiple engineered XynB mutants were created by site-directed mutagenesis with substitutions Q164K and Q164K+D117N. The variant XynB-117 had the highest optimum pH (at 5.5), which corresponded to a basic 0.5 pH unit shift when compared with the wild-type enzyme. However, the optimal pH of the XynB-164 mutation was not changed, similar to the wild type. These results suggest that the residues at positions 164 and 117 in the eight-residues-longer loop and the cleft's edge are important in determining the pH optima of XynB from Aspergillus niger.

• KSBB Journal
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• v.9 no.4
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• pp.400-405
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• 1994

The conditions for ${\beta}$-galactosidase production from alkalophilic, thermophilic Bacillus sp. TA-11 were investigated. The maximal enzyme production was obtained when the strain was cultured at $50^{\circ}C$ for 5 days with fed-batch culture in the optimal medium containing 1.5% lactose, 0.6% yeast extract 0.15% $K_2HP0_4$and initial pH 9.5, and then final enzyme activity under the above conditions was 5200 unit/ml of cell free extract.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.91-100
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• 1997

Production of alkaline carboxymethyl cellulase (CMCase) and xylanase by batch and fed-batch cultures of alkalophilic Cephalosporium sp. RYM-202 was investigated. Of carbon sources tested, wheat bran gave the highest production of those enzymes. The high levels of CMCase on carboxymethyl cellulose and xylanase on birchwood xylan suggest that the biosynthesis of CMCase and xylanase in Cephalosporium sp. RYM-202 is regulated separately at the level of enzyme induction. The temperature and pH for maximal production of those enzymes was $20^{\circ}C$ and 9.0, respectively. High concentration of wheat bran in batch fermentation resulted in the lower and delayed production of the enzymes by catabolite repression. In fed-batch fermentation with controlled feeding of 5% final wheat bran concentration, the highest activities of CMCase and xylanase were 0.39 and 9.2 units/ml, respectively, and 1.22 and 1.36 times higher respectively than those in batch fermentation on 5% wheat bran.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.283-288
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• 1989

To reduce the size of 5.0kb HindIII fragment containing $\beta$-xylosidase gene, the 5.0kb insert of pAX278 which was previously cloned was reduced by various deletions and thus 1.4kb EcoRI-Xbal fragment was subcloned into pUC19, and the recombinant plasmid was named pAK208. The $\beta$-xylosidase acnivity of E. coli harboring pAK208 was higher about 1.3times than that of pAX278. For the improvement of $\beta$-xylosidase activity, we cloned and expressed the $\beta$-xylosidase gene in E. coli using vector pKK223-3 containing a potent tac-promoter, and enzyme activity of the transformant harboring pKHR212 was increased about 3.3 and 1.8 times than that of E. coli(pAX278) and Bacillus sp. K-17, respectively. To obtain better expression of $\beta$-xylosidase gene, the whole 5.0kb HineIII fragment was recloned into pC194, and the Bacillus sp. K-17 transformant harbor-ing the recombinant plasmid pCX174 showed higher activity than that of the E. coli (pAX278) and Bacillus sp. K-17, respectively. The characteristics of enzyme purified from transformants were consistent with those front alkalophilic Bacillus sp, K-17.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.503-509
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• 1991

Action of a cyclodextrin glycosyltransferase (CGTase) produced from alkalophilic Bacillus sp. No.4 was studied in a solution containing starch and sucrose to prepare glycosyl sucrose syrup with good sweetness and antidecaying properties of teeth. In the initial stage of the reaction the CGTase produced cyclodextrin, however, the cyclodextrin disappeared and glycosyl sucrose was formed with the lapse of reaction time. The best proportion of sucrose to starch for prodution of glycosyl sucrose was about 1 : 1. The optimum pH and temperature of the coupling reaction was pH 6.0 and $60^{\circ}C$, respectively. Main composition of glycosyl sucrose syrup prepared with 20% starch and 20% sucrose was sucrose 18%, glucosyl sucrose ($G_{2}F$) 15.3% and maltosyl sucorse ($G_{3}F$) 11.3%. And glucose, maltose and maltotriose were produced very little. Smaller amounts of acid and insoluble glucan were formed in the syrup by Streptococcus mtans OMZ176 than in the sucrose. Therefore, the prepared glycosyl sucrose sucrose syrup is expected to prevent teeth from decaying.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.301-309
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• 1993

An alkalophilic Cephalosporium sp. RYM-202 capable of producing cellulase components was isolated from soil. This organism grew best at an initial pH 9.0 and produced cellulase maximal at an initial pH 9.5-10.0. Three carboxymethyl cellulases(CMCases), P-I-I, P-I-II and P-II-I, were partially purified by DEAE-Sephadex A-50 ion exchange column followed by Sephadex G-150 gel filtration. The optimum pH values for activity were 7.5 for P-I-I, 8.0-9.5 for P-I-II and 7.5-10.0 for P-II-I. All CMCases were stable between pH 4.5 and 12.0. Temperature optima for activity ranged between 40 and $60^{\circ}C$ and more than 50% of the maximum activity was observed at $20^{\circ}C$ for both of P-I-I and P-II-I. The activity of CMCases was significantly stable in the presence of various laundry components, such as, surfactants, chelating agents and alkaline proteinases.