• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.17-21
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• 1991

A gene coding for ${\beta}-xylosidase$ in alkalophilic Bacillus sp. YC-335 isolated from soil was cloned into Escherichia coli HB101 using plasmid pBR322. The recombinant plasmid pYK40 was isolated, and the cloned HindIII fragment was 15 kilobases (kb). To reduce the size of the inserted DNA fragment of pYK40, the 15 kb HindIII fragment was subjected to a series of subclonings. A 6 kb subfragment was found to code for ${\beta}-xylosidase$ activity, and the recombinant plasmid was named pYK44. Southern hybridization analysis revealed that the cloned gene hybridized with 3.5 kb, 1.5 kb, and 1.0 kb of HindIII cleaved chromosomal DNA from Bacillus sp. YC-335. ${\beta}-xylosidase$ activity produced by recombinant E. coli was found to be 11 times higher than that produced by Bacillus sp. YC-335. Xylan was required to induce the production of ${\beta}-xylosidase$ in Bacillus sp. YC-335.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.224-231
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• 1993

The nucleotide sequence of the xylanase gene (xynY) from alkalophilic Bacillus sp. YC-335 was determined and analyzed. An open reading frame of 1, 062 base pairs for xynY gene was observed and encoded for a protein of 354 amino acids with a molecular weight of 38, 915. S1 nuclease mapping showed that the transcription initiation sites of the xynY gene were different in Bacillus sp. YC-335 and Escherichia coli HB101 (pYS55). S1 mapping also showed that -10 region of the xynY gene recognized by RNA polymerases of E. coli and Bacillus sp. YC-335 were TACAGT and TATGAT , respectively. A ribosome binding site sequence with the free energy of -17.0 Kcal/mol was observed 9 base pairs upstream from the unusual initiation codon, TTG. The proposed signal sequence consisted of 27 amino acids, 2 of which were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YC-335 xylanase showed more than 50% homology with xylanases from B. pumilus, B. subtilis, and B. circulans.

• 자연과학논문집
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• 제5권1호
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• pp.47-52
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• 1992

$\beta$-galactosidase를 강력하게 생산하는 호알칼리성, 고온성 세균 TA-11를 부엽토에서 분리하여 Bacillus sp. TA-11로 동정 하였다. Bacillus sp. TA-11에 의한 $\beta$-galactosidase 생산은 lactose 1.5%, peptone과 yeast ext. 각각 0.4%, $MgSO_4$ 0.2%, $NH_4$CL 0.05% 및 NaCl 0.2% 등을 함유한 배지의 pH를 10.0으로 하여 시험균을 접종한후 $50^{\circ}C$에서 2일간 진탕배양 하였을 때 가장 좋았다.

• 생명과학회지
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• 제7권2호
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• pp.95-106
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• 1997

전분의 효율적인 이용을 목적으로 토양으로부터 균체외 플루탄아제효소를 대량분비하는 약알칼리성균주 Bacillus sp. S-1를 분리하였다. 본 균주의 풀루란아제효소 생샨의 최적 pH는 6-10 사이였으며, 조효소의 가용성전분과 플루란에 대한 주요반응 최종산물은 말토트리오스로, 본 효소가 ${\alpha}$-1,6-glycosidic 결합에 특이적임을 알 수 있었다. 본 균주는 지금까지 알려진 알칼리성균주들의 플루란아제 생산성보다 월등히 높은 7.0U/ml를 생산하였으며, 정제효소의 최적 pH와 온도는 각각 8.0-10.0와 50-60$^{\circ}$C로서 알칼리성 및 호열성의 특성을 나타났었다. 또한 정제효소는 pH12에서도 약 10%의 활성을 유지하며, 넓은 pH범위에서도 안정하였다. 이러한 결과들은 본 균주가 플루란아제 생산균주로서의 이용가능한 잠재력을 보유하고 있음을 시사하였다.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.213-218
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• 1989

Cloning을 위한 host와 vector의 이용 가능성을 타진하기 위해 호알칼리성 Bacillus속 K-17을 host로, pUB110과 pBD64를 vector로 사용하여 Bacillus속 K-17의 protoplast 형질전환조건을 검토하였다. 원형질체의 형성은 200$\mu\textrm{g}$/$m\ell$의 Iysozyme 을 처리하였으며, 원형질체 형성의 최적 온도, PH및 배양시간은 각각 4$0^{\circ}C$, 7.0 및 4시간으로 나타났다. 원형질체는 DM3 재생배지에서 재생시켰으며 0.8% agar, 0.5M sodium succinate 농도에서 가장재생이 좋았다. 형질전환시 PEG의 농도는 40%(w/v) PEG 6,000 30%(v/v)가 최적으로 나타났다. 형질전환체의 특성을 조사한 결과, plasmid 안정성은 pUB110이 pBD64보다 더 안정하였으며, 최대 효소활성은 비슷하였지만 효소 분비시간은 pUB110 은 2.5일, pBD64의 경우는 3일로 Bacillus속 K-17의 2일에 비해 약간 지연되었다.

• 한국식품영양학회지
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• 제15권2호
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• pp.126-130
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• 2002

고온성이며 호알칼리성인 Bacillus sp. TA-11이 생성하는 Invertase의 생합성 조절 기작을 규명하고자 먼저 이들의 유도와 억제에 관하여 검토하였다. Invertase는 10mM sucrose을 함유한 생합성 조절배지에서 3시간에 효율적으로 유도되었고 glucose는 sucrose에 의한 invertase 유도를 inducer exclusion 방식으로 억제시켰다. CAMP의 첨가로 glucose에 의한 catabolic repression이 다소 줄어들었다.

• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.45-49
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• 1991

The complete nucleotide sequence of alkalophilic Bacillus sp. K-17 $\beta$-xylosidase gene and its flanking regions were established. A 1263-bp of an open reading frame for $\beta$-xylosidase was observed. The molecular weight (50, 521 dalton), deduced from the nucleotide sequence of $\beta$-xylosidase gene, agreed with the result obtained by SDS-polyacrylamide gel electrophoresis of the purified enzyme (51, 000 dalton). The Shine-Dalgarno sequence, 5'-GAGGAGG-3', was found 8 bp upstream of the initiation codon ATG. The -10 sequence (TAAAAT) in the promoter region for $\beta$-xylosidase gene was similar to the consensus sequence for Bacillus subtilis RNA polymerase, whereas the -35 sequence (TCGATCA) different from all the known -35 regions in the promoter for Bacillus subtilis RNA polymerase.

• Journal of Microbiology and Biotechnology
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• 제1권2호
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• pp.102-110
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• 1991

Alkalophilic Bacillus sp. YJ-451, which was isolated from soil at several area in Korea, produced a novel type of bacteriolytic enzyme (cell wall peptidoglycan hydrolase) extracellulary. The cell wall hydrolytic activity was identified as a clear zone on sodium dodecyl sulfate polyacrylamide gel electrophoresis containing 0.2% (w/v) cell wall of Bacillus sp. as substrate. This enzyme was successively purified 66 fold with 3.2% yield in culture broth by ammonium sulfate precipitation, CM-cellulose column chromatography, and gel filtration, followed by hydroxylapatite column chromatography. The molecular weight of the purified enzyme was estimated to be 27,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration column chromatography. The optimum pH and temperature for the activity of the enzyme were pH 10.0 and $50^{\circ}C$, respectively. The enzyme was stable between pH 5.0 and 10.0 and up to $40^{\circ}C$. Among the microorganisms used in this experiment the enzyme was active against most of gram negative strains and the genus Bacillus such as B. megaterium, B. licheniformis, B. circulans, B. pumilus, B. macerans, B. polymyxa. The release of dinitrophenylglutamic acid but not reducing group from cell wall peptidoglycan digested by the enzyme suggested that the enzyme is a kind of peptidase which hydrolyzes the peptide bond at the amino group of D-glutamic acid in the peptidoglycan.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1550-1553
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• 2007

The functional characteristics of a ${\beta}$-cyclodextrin glucanotransferase (CGTase) excreted from alkalophilic Bacillus sp. BL-31 that is highly specific for the intermolecular transglycosylation of bioflavonoids were investigated. The new ${\beta}$-CGTase showed high specificities for glycosyl acceptor bioflavonoids, including naringin, rutin, and hesperidin, and especially naringin. The transglycosylation of naringin into glycosyl naringin was then carried out under the conditions of 80 units of CGTase per gram of maltodextrin, 5 g/l of naringin, 25 g/l of maltodextrin, and 1 mM $Mn^{2+}$ ion at $40^{\circ}C$ for 6 h, resulting in a high conversion yield of 92.1%.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.524-528
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• 1989

토양으로부터 분리한 호알카리성 Bucillus sp. YS-309는 $\beta$-galactosidase 생산력이 강력하였으며 중성배지 보다도 알카리배지 중에서 균체생육 및 효소생산량이 많았다. 이 분리균의 최적 배양조건은 lactose 0.5%, yeast extract 0.5%, defatted soybean meal extract 0.6%(v/v)가 함유된 PH9.9의 알카리 배지를 사용하였을 때 얻어졌다. 이 때의 배양온도는 4$0^{\circ}C$, 배양시간은 24-30시간의 바람직한 것으로 나타났다. 또 IPTG와 lactose에 의해 효소생산이 유도적으로 증가하였으며 전자는 후자의 3배 효과가 있었다. Lactose 농도도 균체생육 및 효소생산에 영향을 미쳤으며 그 농도가 1.5% 이상 배지 중에 첨가되면 균체생육 및 효소생산이 모두 감소하였다.