• 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.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.235-243
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• 2006

The study was performed to identification of producing microbe Non-Cariogenicity Sugar (NCS; Fuc($1{\to}4$) gaINAc($2{\to}6$)NeuAc) with anti-caries activity, and to optimization of production condition. A typical strain which produced the NCS was identified alkalophilic Bacillus sp. S-1013 through the results of morphological, biochemical and chemotaxonomic characteristics and 16S rDNA sequencing. The optimal medium composition for the maximal production of the NCS from alkalophilic Bacillus sp. S-1013 was as follow: soluble starch 30 g, dextrin 15 g, yeast extract 5 g, peptone 10 g, $K_{2}HPO_4$ 2 g in a liter of distilled water. Optimal temperature and pH were 25 and 11.0, respectively. The highest production of NCS was shown 60 hrs cultivation using the optimal medium, and then NCS productivity and dry cell weight of culture broth increased 4.24 and 2.67 time than initial medium, respectively.

• The Korean Journal of Food And Nutrition
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• v.1 no.2
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• pp.68-75
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• 1988

A strain of alkalophilic Bacillus sp. YS-309 has been isolated from domestic soil. It belongs to genus Bacillus from its morphological and biochemical characteristics. The strain grows better in the alkaline media rather than in the neutral media. The optimum pH and temperature for growth were observed at 8.5 and 4$0^{\circ}C$, respectively. Glucose, lactose and maltose were appeared as good carbon source but soluble starch and fructose were utilized uneffectively for growth. Concentrations of lactose had affected both the cellular growth and the enzyme productions. The maximum growth and the highest enzyme productions were obtained at 0.5%(w/e) of lactose added in the media. B-Galactosidase from Bacillus sp. YS-309 was produced inducibly into the cell and total enzyme activities per ml were gradually decreased when the concentration of glucose increased.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.128-134
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• 1991

To study the reduced growth and synthesis, proeviously reported, of ${\beta}$-galactosidase of alkalophilic Bacillus sp. YS-309 at the higher lactose concentration of 0.5% (w/v) in the medium, lactose transport and utilization were examined. The results showed that lactose transport was influenced by the addition of four kinds of antibiotics, and tetracycline stimulated most but not valinomycin. PEP-potentials of the cells grown on lactose was estimated lower than the cells on glucose and on galactose. Thus, the transport of lactose was independent of intracellular PEP and phosphorylation reactions, and was thought to be uptaked directly or oxidized in part in the transport process. In the other hand, once lactose was uptaked into the cells, it was hydrolyzed by ${\beta}$-glactosidase to glucose and galactose. The former was metabolized fast but the latter was accumulated. Galactose and lactose were not utilized until glucose was mostly depleted in the medium. The ${\beta}$-galactosidase synthesis decreased in the presence of glucose over 0.2% and galactose over 0.05 to 0.1%, respectively. In conclusion, it was considered for glucose as a repressor and galactose as a inducer for ${\beta}$-galactosidase synthesis even though the mechanisms were not elucidated. Catabolite repression of glucose on the enzyme synthesis was not relieved by the addition of exogeneous cAMP.

• 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.

• 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.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.436-439
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• 1989

The chromosomal DNA fragments of thermophilic alkalophilic Bacillus sp, K-17, a potent xylanhydrolyzing bacterium, were ligated to a vector plasmid pBR322 and transformed into Escherichia coli HB101. The plasmid pAX278, isolated from a transformant forming yellow color on the LB agar plate containing 1 mM p-nitrophenyl- $\beta$-xylopyranoside, was found to enable the transformants to produce p-xylosidase. The 5.0 kilobase insert of pAX278 had single sites for EcoRI, PstI, XbaI, and PvuII, and 2 sites for BglII. Biotinylated pAX218 was hybridized to 0.9 kb as well as 5.0 kb fragment from Bacillus sp. K-17 DNA on nitrocellulose filter. pGX718 was constructed by inserting the 5.0 kb HindIII fragment of pGX278 at the HindIII site of pGR71, E. coli and B. subtilis shuttle vector. The enzymatic properties of $\beta$-xylosidase from E. coli HB101 carrying recombinant plasmid were the same those of $\beta$-xylosidase from Bacillus sp. K-17.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.333-340
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• 2016

An alkaline protease was purified and characterized from an alkalophilic microorganism, Bacillus sp. DK1122, isolated from soil in central Korea. The optimum temperature and pH for the growth of the producer strain were 40℃ and pH 9.0, respectively. The protease was produced aerobically at 40℃ after 24 h incubation in modified Horikoshi I medium (pH 9.0) containing 0.5% (w/v) glucose, 0.8% (w/v) yeast extract, 0.5% (w/v) polypeptone, 0.1% (w/v) K₂HPO₄, 0.02% (w/v) MgSO₄·7H₂O, 1% (w/v) Na₂CO₃, and 3% (w/v) NaCl. The alkaline protease was purified by 70% ammonium sulfate precipitation of the culture supernatant of Bacillus sp. DK1122, followed by CM-Sepharose chromatography. The molecular weight of the enzyme was estimated to be 27 kDa on the basis of SDS-PAGE. The optimum temperature and pH for the protease activity were 60℃ and pH 9.0, respectively. Addition of CaCl₂ increased the thermal stability of the purified protease, where 90% of protease activity was retained at 60℃ for up to 3 h. Consequently, it is expected that the alkaline protease from this study, exhibiting stability at pH 7–9 and 60℃, may be promising for application in the food and detergent industries.

• Microbiology and Biotechnology Letters
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• v.28 no.5
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• pp.243-250
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• 2000

The study was performed to investigated the excellent microbial anticaries substance which is more effective than the chlorohexidine in the dental caries treatment. For the screening of alkaliphilic microorganism, more than 1200 bacterial strains were isolated from sea soil sample. A typ-ical strain which produced the most excellent antimicrobial substance was selected. The strain was identified novel alkalophilic Bacillus sp. through the results of morphological, biochemical and chemotaxonomical characteristics and 16S rDNA sequencing and designated as Bacillus alkalophilshaggy JY-827.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.545-551
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• 1989

Thermostable alkaline protease of alkalophilic Bacillus sp. No. 8-16 has been purified, and the properties of the enzyme investigated. The characteristic point of the organism used is especially good growth in alkaline and thermal condition. The alkaline protease of the strain No. 8-16 was purified from crude enzyme by acetone precipitation, CM-cellulose ion exchange chromatography, Sephadex G-100 and Sephadex G-75 gel filtration. Through the series of chromatograpies, the enzyme was purified to homogeneity with specific activity of 37 fold higher than that of the crude broth. Characteristics of the purified enzyme were as follow; $K_m$ value for the enzyme was 1.3 mg/ml, the alkaline protease showed a maximal activity at 7$0^{\circ}C$ and from the pH 6.0 through 12.0, and stable for 1 hr. at 6$0^{\circ}C$. The moleclar weight of the enzyme was estimated to be 33,000 by Sephadex G-100 gel filtration. The activity of the alkaline protease was inhibited by iodoacetic acid and Ag$^+$, Hg$^+$, PMSF (phenylmethylsulfonyl fluoride), and activated by $Ca^{2+}$ and Mn$^{2+}$.