• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 1986년도 추계학술대회
• /
• pp.532.2-532
• /
• 1986

Alkaline protease which is an important enzyme used in detergents, leather tanning and food industry was produced by alkalophilic bacterium, Bacillus sp. KCTC 1723 isolated from soil. The maximum productivity of the enzyme in alkaline medium containing 1% sodium bicarbonate was obtained by incubating for 3 days at 37$^{\circ}C$. The optimum pH of the enzyme was 11.5 and calcium ion was effective on stabilization of the enzyme at high temperature. The enzyme was not inhibited by metal chelating agent such as El)TA but inhibited by diisopropyl fluorophosphate. Purification of the enzyme was carried out DEAE- and CM-cellulose column chromatographies and molecular weight of the purified enzyme was determined

• 한국미생물·생명공학회지
• /
• 제23권6호
• /
• pp.687-694
• /
• 1995

Alkalophilic Bacillus sp. HJ-12 producing $\beta $-1, 4-D-arabinogalactanase was isolated from soil in the alkalic condition, pH 10.0. $\beta $-1, 4-D-arabinogalactanase was maximaly produced in the medium consisting of 2% soybean arabinogalactan (SAG), 0.5% yeast extract, 0.5% polypeptone, 0.5% NaCl, 0.1% K$_{2}$HPO$_{4}$, 0.02% MgSO$_{4}$$\cdot $7H$_{2}$O, 0.1% Na$_{2}$CO$_{3}$ under the aerobic condition (pH 8.2). $\beta $-1, 4-D-arabinogalactanase is inducible enzyme so that its activity has been increased 10 fold in the SAG medium than in the glucose medium. Through the ammonium sulfate precipitation, DEAE- Sephadex A-50 ion chromatography, and Sephadex G-75 gel chromatography procedures, this enzyme was purified with a single protein of 11% vield and 110 fold's purity. $\beta $-1, 4-D-arabinogalactanase is endo type enzyme producing ollgosaccharide from SAG.

• Journal of Microbiology and Biotechnology
• /
• 제12권1호
• /
• pp.153-156
• /
• 2002

The characterization of a partially purified, cellulase-free, thermostable alkaline xylanase from thermoalkalophilic Bacillus sp. JB-99 was investigated. The xylanase production was the highest when birchwood xylan was added to a medium containing finely powdered rice bran, showing 4,826 IU$ml^-1$ of activity for 15 h of incubation. The partially purified xylanase exhibited an optimum temperature and pH at $70^C{\circ}$ and 10, respectively. The enzyme was stable at pH 5-11 at $50^C{\circ}$. The xylanase activity was strongly inhibited by $Hg^2+$, while dithiothreitol, cysteine, and ${\beta}$-mercaptoethanol enhanced the activity.

• 한국미생물·생명공학회지
• /
• 제23권5호
• /
• pp.544-549
• /
• 1995

The alkaline elastase is an extracellular serine protease of the alkalophilic Bacillus strain Ya-B. To increase the gene copy number and the production level of the alkaline elastase Ya-B, we designed, on the B. subtilis chromosome, a gene amplification of the 10.6 kb repeating unit containing amyE, aleE (alkaline elastase Ya-B gene) and tmrB. The aleE was inserted between amyE and tmrB, and B. subtilis APT119 strain was transformed with this amyE-aleE-tmrB-junction region fragment. As a result, we succeeded in obtaining tunicamycin-resistant (Tm$^{r}$) transformants (Tf-1, Tf-2) in which the designed gene amplification of 10.6 kb occurred in chromosome. The transformants showed high productivity of $\alpha $-amylase and alkaline elastase Ya-B. The copy number of the repeating unit (amyE-aleE-tmrB) was estimated to be 25, but plasmid vector (pUC19) was not integrated. The amplified aleE of chromosome was more stable than that of plasmid in absence of antibiotics.

• 한국미생물·생명공학회지
• /
• 제11권3호
• /
• pp.187-192
• /
• 1983

Three kinds of xylanases, X-C, X-I, and X-II, were separated from culture filtrate of an alkalophilic bacteria, Bocillus licheniformis OR-1. Their molecular weights were estimated to be 29, 000, 50, 000, and 34, 000, respectively. They were most active at pH 6.0-6.5, and at temperature of 5$0^{\circ}C$. Mercurc ion and p-chloromercurybenzoate inhibited the xylanase activity of X-C and X-II remarkably, whereas X-I was not affected. Xylanase X-I hydrolyzed barley straw xylan liberating xylose, xylobiose, and arabinose, while X-C and X-II produced only xylobiose and xylotriose.

• Journal of Microbiology and Biotechnology
• /
• 제14권4호
• /
• pp.751-758
• /
• 2004

The NCS(Non-Cariogenicity Sugar) from Bacillus sp. S-1013 was purified by cold acetone and methanol precipitation, and DEAE-cellulose ion-exchange and Sephadex G-100 column chromatographies, to yield an amorphous yellow syrup. The melting point and $[\alpha]_D^{20}$ were 155-$157^{\circ}C$ and +53, respectively. Instrumental analyses such as FT-IR, $^1H-NMR, and ^{13}C-NMR$ showed that the NCS contained an O-H group, C-H, C=O, $NH_2$, anomeric carbon, anomeric proton, N-acetylgalactose, fucose, and neuramic acid, thus, the NCS was determined to be a trisaccharide of Fuc($1\longrightarrow4$)GalNAc($2\longrightarrow6$) NeuAc.

• Journal of Microbiology and Biotechnology
• /
• 제11권3호
• /
• pp.534-538
• /
• 2001

The xynA gene encoding an alikali-tolerant endo-1,4-${\beta}$-xylanase (XYN) was cloned from the alkalophilic Bacillus pumilus A-30. The nucleotide sequence of a 974-bp DNA fragment containing the xynA was determined. An ORF of 684 nucleotides that encoded a protein of 228 amino aicds was detected. Asparagine-71 of XYN from B. Pumilus A-30 showed to be highly conservative in alkaline xylanases of family G/11, upon comparing the amino acid sequences of 17 family G/11 xylanases. Site-directed mutation of N71D of the xynA gene resulted in a decrease of 12.4% in the specific acitivity and a significant decline in the enzyme activity in the alkaline pH range.

• Journal of Microbiology and Biotechnology
• /
• 제2권1호
• /
• pp.7-13
• /
• 1992

A moderately thermophilic, alkalophlic and powerful crystalline cellulose-digesting bacterium, Bacillus K-12, was isolated from filter paper wastes and found to be similar to Bacillus circulans or Bacillus pumilis, except for its ability to grow at a moderately high pH and temperature. The isolate grew at a pH ranging from 6 to 10 and at a temperature ranging from 35 to $65^{\circ}C$ and produced a large amount of cellulase components containing avicelase, xylanase, CMCase, and FPase when grown in avicel medium for 5 to 7 days at $50^{\circ}C$. The crude enzyme preparation from the culture broth hydrolyzed xylan, raw starch, pullulan and ${\beta}-1,3$ glucan such as laminarin. Furthermore, the enzyme hydrolyzed crystalline cellulose to cellobiose and glucose and had a broad pH activity curve (pH 6~9). The enzyme was stable up to $70^{\circ}C$.

• 한국식품과학회지
• /
• 제23권1호
• /
• pp.31-36
• /
• 1991

고온, 알칼리성 Bacillus sp. F204의 CMCase 유전자를 pUC19의 HindIII부위에 연결하여 전이된 E.coli 형질전환체 중 2개의 재조합 플라스미드 즉, pBC191과 pBC192를 선발하였는데, 이들은4.6 Kb와 5.8 Kb HindIII 절편을 각각 함유하고 있었다. pBC191의 4.6 Kb HindIII 절편을 BamHI, EcoRI, KpnI, PvuII 부위가 각각 1개씩 존재하였다. Dioxigenin-labeled deoxyuridin-triphosphate에 4.6 Kb 절편을 표식한 것을 probe로 하여 상동성을 검정한 결과 모균주와 강한상동성이 없었고, 면역학적 실험에서도 Bacillus sp. F204 유래임이 인정되었다. pBC191의 4.6 Kb 절편을 E.coli의 발현 벡타인 pKK223-3과 Bacillus vector인 pGR71에 연결시켜 구축한 pKC231과 pGC711은 각각 pBC191에 비하여 효소활성이 3.2배와 2.8배정도 증가되었으며, 그리고 E.coli에서는 대부분 세포내와 periplasmic 분획에서 검출되었다. 기질 특이성을 조사한 결과에 의하면 pBC191과 pBC192는 CMCase gene을 코딩하고 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제21권8호
• /
• pp.861-868
• /
• 2011

A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at $55^{\circ}C$ and was thermostable at $50^{\circ}C$ and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent $K_m$ and $V_{max}$ values were 1.18 mg/ml and 1,961 ${\mu}mol$/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.