• 한국식품과학회지
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• 제23권4호
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• pp.503-509
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• 1991

Strach와 sucrose의 혼합액에 호알칼리성 Bacillus sp. No.4가 생산하는 cyclodextrin glycosyltransferase(CGTase)를 작용시켜 감미가 우수하고 항우식성이 있는 glycosyl sucrose syrup을 만들기 위한 조건을 검토하였다. 설탕과 전분의 혼합액에 CGTase를 작용시키면 반응 초기에는 cyclodextrin을 생성하지만 반응시간의 경과에 따라 점차 cyclodextrin은 소실되고 glycosyl sucrose가 생성되었다. 이 반응은 설탕과 전분의 비율이 1 : 1 부근이 좋았으며, pH6.0, 온도 $60^{\circ}C$가 최적이었다. 20% starch와 20% sucrose의 혼합액으로부터 제조된 glycosyl sucrose syrup의 주성분은 sucrose 18%, glucosyl sucrose($G_{2}F$) 15.3%, maltosyl sucrose($G_{3}F$) 11.3%이었으며 glucose, maltose, maltotriose는 거의 생성되지 않았다. 제조된 syrup은 Sucrose에 비하여 충치균 Streptococcus mutans OMZ 176에 의한 산생성량이 적고 불용성 glucan의 생성량도 적어 충치 예방효과가 기대되었다.

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

• Food Science and Biotechnology
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• 제16권4호
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• pp.509-514
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• 2007

In this study, we optimized the production of ${\gamma}-polyglutamic$ acid (PGA) in soybean milk cakes (SMC) fermented with Bacillus subtilis GT-D and B. subtilis KU-A, to be utilized as a functional food ingredient. PGA production was dependent upon the glutamate content, fermentation time, and type of Bacillus sp. The consistencies of the SMCs fermented by B. subtilis GT-D and B. subtilis KU-A were highest after 36 hr of fermentation, and then decreased gradually. The SMC fermented by B. subtilis KU-A had a higher consistency than the SMC fermented by B. subtilis GT-D. In the presence of 10% defatted soy flour (DFS), 5% glutamate in the SMC was efficiently converted into polyglutamic acid (PGA) for 24 hr, indicating a conversion yield above 96%, but its conversion then decreased with higher concentrations of glutamate. The soluble solid content (mucilage) of the SMC fermented with B. subtilis KU-A was 9.5%(w/w), and composed of 65.6% PGA (Mw 1,536 kDa) and some polysaccharides. However, the SMC fermented with B. subtilis GT-D had a mucilage content of 7.8%(w/w), and was composed of 66.4% PGA (Mw 1,409 kDa), 11.5% levan, and some polysaccharides. The viscoelastic values of the mucilage obtained using B. subtilis KU-A were much higher than those of mucilage obtained using B. subtilis GT-D. Also, the G'-value (elastic modulus) was higher than the G"-value (viscous modulus).

• Applied Biological Chemistry
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• 제39권5호
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• pp.333-337
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• 1996

갈락토올리고당의 연속 생산을 위하여 Bacillus sp. A4442가 생산하는 갈락토스 전이활성이 높은 $\beta-galactosidase$를 균체제거 후 농축, 탈염하여 $Diaion^{TM}$ HPA 75(styrene-divinylbenzene resin)에 고정화하였다. 고정화 수율 및 고정화 효소의 활성을 높이기 위하여 효소 고정화에 영향을 주는 변수들을 최적화하였다. 고정화 시간은 실온에서 3시간, Tris 완충액의 농도는 30mM, pH는 8이 적당하였다. 단백질부하가 증가할수록 효소는 다른 단백질과 경쟁적이며 가역적으로 담체에 결합하였으며, 최적부하는 약 25 mg Protein/g resin 이었다. 가교제로서 glutaraldehyde 0.5%를 사용하였을 때 효소의 열 안정성 및 운전 안정성이 현저히 증가하였다. 이러한 실험조건하에서 고정화를 실시하였을 때 고정화 수율은 40% 이상이었으며 그 활성이 약 200 U/g resin인 고정화 효소를 얻을 수 있었다. Packed-bed reactor에서 유당을 갈락토올리고당으로 연속적으로 전환 가능하였고, 이때 고정화 효소 1 g으로 갈락토올리고당 약 300 g을 생산할 수 있었다.

• 미생물학회지
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• 제45권2호
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• pp.185-192
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• 2009

Bacillus subtilis 028-1 균주는 청국장 발효에 사용하는 균주로 Staphylococcus sp. LS2 뿐만 아니라 여러 yeast 균주의 생장을 억제하는 항생물질을 생산하며, soybean meal 2%와 maltose와 같은 이당류를 1% 첨가하여 15~18시간 진탕 배양하였을 때 최대의 항생물질 생산을 보였으며 배지의 pH는 6.5 이하였다. 항생물질의 활성은 약염기성 조건에서 극대화되었으며, $100^{\circ}C$에서 20분간 가열하여도 활성은 크게 감소하지 않았고, 실온 보관 시 한 달 이상 효과가 지속되며 chymotrypsin과 papain 같은 단백질 분해효소 처리에 의해 서서히 활성이 줄어들었다. 투석에 의해 항생물질의 분자량을 측정한 결과 1,000에서 500 dalton 사이인 것으로 나타났으며 항미생물 효과는 있으나 fibrin 분해 능력이 없으므로 surfactin이 아닌 iturin 계열의 peptide성 항생물질로 보인다.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.32-36
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• 1997

An adenosine deaminase inhibitor-producing bacterium was isolated from soil. An isolate exhibiting high adenosine deaminase inhibitory activity, was designated J-89, and classified as a strain of Bacillus subtilis on the basis of its morphological, phenotypic characteristics, the menaquinone content and cellular fatty acid composition. To confirm the taxonomic position of the strain we need more information such as DNA-DNA homology and other chemotaxonomic characteristics. In this paper we provisionally named strain J-89 as Bacillus sp. J-89 pending further chemotaxonomic study and analysis of adenosine deaminase inhibitor.

• 한국미생물·생명공학회지
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• 제19권2호
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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.

• 한국미생물·생명공학회지
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• 제52권3호
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• pp.335-338
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• 2024

Bacillus sp. strain hwrm1, isolated from the rumen of Korean native cattle Hanwoo (Bos taurus coreanae), exhibit phytic acid-degrading, cellulose-degrading and antimicrobial activities. The complete genome of strain hmrw1 consists of a circular chromosome in the size of 4,141,581 bp with a GC content of 46.1% GC contents. The genome contains 3,976 genes, including genes encoding a phytase, various glycoside hydrolases, and antibiotic peptides, aligning with its activities. The genomic information is crucial for further characterization and application of the strain as a probiotic.

• 미생물학회지
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• 제45권2호
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• pp.193-199
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• 2009

오징어 젓갈로부터 호염성 균주를 분리하여 형태적, 생리 생화학적 특성 및 분자계통학적 분석을 통하여 동정하였고, 이 균주가 세포외로 생산하는 호염성 protease를 정제하여 그 특성을 분석하였다. 본 균주는 NaCl 0~14%, $20\sim55^{\circ}C$ 및 pH 5~8에서 성장하였으며, $35{\pm}5^{\circ}C$, pH 7 및 5% NaCl에서 최적으로 성장하였다. 주요 지방산 조성은 anteiso-$C_{15:0}$ (44.70%), anteiso-$C_{17:0}$ (15.76%) 및 $C_{16:0}$ (13.91%)이었고, menaquinone은 MK-7이었으며, DNA G+C 함량은 50.58 mol%였다. 16S rRNA 유전자 염기서열을 통한 계통분석 결과 Bacillus이었으며 Bacillus sp. SJ-10으로 명명하였다. SJ-10 균주 배양액으로부터 40% 황산암모늄 침전과 Mono Q 컬럼크로마토그래피 과정을 거쳐 collagen과 gelatin을 특이적으로 분해하는 약 40 kDa의 세포외 protease를 정제하였다. 이 효소는 $35{\pm}5^{\circ}C$, NaCl $5{\pm}1%$ 및 pH 8에서 최적 활성을 나타냈으며, pH 5~10 범위에서 안정하였다.

• Journal of Microbiology
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• 제40권1호
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• pp.26-32
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• 2002

From the culture supernatant of the psychrotrophic strain of Bacillus amyloliquefaciens an extracellular serine protease was purified to apparent homogeneity by successive purification steps using QAE-Sephadex, SP-Sephadex and Sephacryl S-100 column chromatography. The pretense is monomeric, with a relative molecular mass of 23,000. It is inhibited by the serine protease inhibitor phenylmethylsulfonyl fluoride, but not by EDTA. The enzyme is most active at pH 9-10 and at $45^{\circ}C$, although it is unstable at $60^{\circ}C$.