• 한국식품영양과학회지
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• 제32권3호
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• pp.381-387
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• 2003

본 연구에서는 생 전분 분해효소를 이 용한 비 열처리 현미식초 제조방법 확립과 초산발효 중 성분변화를 조사하였다. 초기 알콜농도별, 초기 산도별로 각각 실험한 결과 pH는 초기 알콜농도별 실험치와 초기 산도별 실험치 모두 발효 초기 3.44~4.06에서 발효가 진행됨에 따라 점점 감소하여 총산이 가장 높은 수치를 나타낸 시점에서 각각 2.90~3.44로 가장 낮은 수치를 나타낸 후 증가하는 경향이었다. 총산은 알콜농도가 높을수록 총산함량도 각각 4.23, 5.46, 5.79, 6.50 및 7.18로 점점 높게 나타났으며, 초기 산도별 실험에서는 모두 발효 1일째부터 서서히 증가하여 각각 4.78, 5.88, 5.79및 5.21로 최고치를 나타낸 후 감소하는 경향이었다. 초산 수율은 알콜농도 5%와 6%에서 60%이상으로 높게 나타났으며, 초기 산도 1.0에서 62%로 가장 높게 나타났다. 또한 초산발효과정 중 성분변화를 조사한 결과 pH는 발효초기 3.67에서 발효가 진행됨에 따라 점점 감소하여 3.16으로 나타났으며, 총산은 발효초기 1.02로 발효 1일째부터 총산이 서서히 증가하여 발효 2일에 1.54, 발효 12일에 5.53으로 가장 높은 수치를 나타낸 후 감소하는 경향이었다. 유기산 조성은 oxalic, malic, acetic, citric 및 succinic acid가 검출되었으며, 유기산 중 acetic acid가 가장 높은 함량으로 나타났다. 유리 아미노산은 1,121.09mg%이었으며, ${\gamma}$-aminobutyric acid, $\alpha$-aminoadipic acid, alanine이 주된 아미노산으로 나타났으며, 특히 ${\gamma}$-aminobutyric acid는 539.05 mg%로 아미노산중에서 가장 높은 함량으로 나타났다. 무기질함량은 P와 K함량이 유사하게 높은 함량으로 나타났으며, 다음으로 Mg, Na, Ca순으로 나타났다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.40-45
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• 2001

Raw starch-digesting amylase (BF-2A, M.W. 93, 000 Da) from Bacillus circulans F-2 was converted to two components during digestion with subtilisin. Two components were separated and designated as BF-2A' (63, 000 Da) and BF-2B (30, 000 Da), respectively. BF-2A' exhibited the same hydrolysis curve for soluble starch as the original amylase (BF-2A). Moreover, the catalytic activities of original and modified enzymes were indistinguishable in $K_{m}$, Vmax for, and in their specific activity for soluble starch hydrolysis. However, its adsorbability and digestibility on raw starch was greatly decreased. Furthermore, the enzymatic action pattern on soluble starch was greatly different from that of the BF-2A. A smaller peptide (BF-2B) showed adsorb ability onto raw starch. By these results, it is suggested that the larger peptide (BF-2A') has a region responsible for the expression of the enzyme activity to hydrolyze soluble substrate, and the smaller peptide (BF-2B) plays a role on raw starch adsorption. A similar phenomenon is observed during limited proteinase K, thermolysin, and endopeptidase Glu-C proteolysis of the enzyme. Fragments resulting from proteolysis were characterized by immunoblotting with anti-RSDA. The proteolytic patterns resulting from proteinase K and subtilisin were the same, producing 63- and 30-kDa fragments. Similar patterns were obtained with endopeptidase Glu-C or thermolysin. All proteolytic digests contained a common, major 63-kDa fragment. Inactivation of RSDA activity results from splitting off the C-terminal domain. Hence, it seems probable that the protease sensitive locus is in a hinge region susceptible to cleavage. Extracellular enzymes immunoreactive toward anti-RSDA were detected through whole bacterial cultivation. Proteins of sizes 93-, 75-, 63-, 55-, 38-, and 31-kDa were immunologically identical to RSDA. Of these, the 75-kDa and 63-kDa proteins correspond to the major products of proteolysis with Glu-C and thermolysin. These results postulated that enzyme heterogeneity of the raw starch-hydrolysis system might arise from the endogeneous proteolytic activity of the bacterium. Truncated forms of rsda, in which the gene sequence encoding the conserved domain had been deleted, directed the synthesis of a functional amylase that did not bind to raw starch. This indicates that the conserved region of RSDA constitutes a raw starch-binding domain, which is distinct from the active centre. The possible role of this substrate-binding region is discussed.d.

• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.371-380
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• 2019

Termites are pests that cause serious economic and cultural damage by digesting wood cellulose. Termites are arthropods and have an epidermis surrounded by a chitin layer. To maintain a healthy epidermis, termites have chitinase (${\beta}$-1,4-poly-N-acetyl glucosamidinase, EC 3.2.1.14), an enzyme that hydrolyzes the ${\beta}$-1,4 bond of chitin. In this study, the amino acid sequence of the gene, which is presumed to be termite chitinolytic enzyme (NCBI accession no. KC477099), was obtained from a transcriptomic analysis of Reticulitermes speratus KMT001 in Bukhan Mountain, Korea. An NCBI protein BLAST search confirmed that the protein is a glycoside hydrolase family 18 (GH18). The highest homology value found was 47%, with a chitinase from Araneus ventricosus. Phylogenetic analysis indicated that the KC477099 protein has the same origins as those of arthropods but has a very low similarity with other arthropod chitinases, resulting in separation at an early stage of evolution. The KC477099 protein contains two conserved motifs, which encode the general enzymatic characteristics of the GH18 group. The amino acid sequences $Asp^{156}-Trp^{157}-Glu^{158}$, which play an important role in the enzymatic activity of the GH18 group, were also present. This study suggests that the termite KC477099 protein is a new type of chitinase, which is evolutionarily distant from other insect chitinases.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1164-1173
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• 2006

Cellulase from Aspergillus niger, (${\alpha}$-amylase from Bacillus sp. and protease from Bacillus globigii were used as enzyme sources in this study to examine how their respective substrates protect them in two kinds of simulated gastrointestinal tract digesting processes. Avian total digest tract simulation test showed that filter paper, Avicel and cellulose resulted in 7.7, 6.4 and 7.4 times more activity than of unprotected cellulose, respectively. Protease with addition of casein, gelatin or soybean protein showed no significant protection response. Starch protected amylase to be 2.5 times activity of the unprotected one. Monogastric animal total tract digestion simulation test showed that filter paper, Avicel and cellulose resulted in 5.9, 9.0 and 8.8 times activity of unprotected cellulase, respectively. Casein, gelatin and soybean protein resulted in 1.2, 1.3 and 2.0 times activity of unprotected protease, respectively. Starch did not protect amylase activity in monogastric animal total tract simulation. Protection of mixed enzymes by substrates in two animal total tract simulation tests showed that filter paper in combination with soybean protein resulted in 1.5 times activity of unprotected cellulose, but all substrates tested showed no significant protection effect to protease. Soybean protein and starch added at the same time protected the amylase activity to be two times of the unprotected one. Test of non-purified substrate protection in two animal total digest tract simulation showed that cellulase activity increased as BSA (bovine serum albumin) concentration increased, with the highest activity to be 1.3 times of unprotected enzyme. However, BSA showed no significant protection effect to protease. Amylase activity increased to 1.5 times as BSA added more than 1.5% (w/v). Cellulase activity increased to 1.5 times as soybean hull was added higher than 1.5%. Amylase had a significant protection response only when soybean hull added up to 2%. Protease activity was not protected by soybean hull to any significant extent.

• 대한미생물학회지
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• 제22권4호
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• pp.463-471
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• 1987

The genomes of leptospiral field isolates from Korea belonging to serogroup Icterohaemorrhagiae (21 strains) and serogroup Canicola (1 strain) were analysed and compared by restriction enzyme analysis with EcoRI and HindIII as digesting enzymes. One isolate belonging to serogroup Canicola showed the same pattern as serovar portlandvere. All 21 isolates belonging to serogroup Icterohaemorrhagiae showed almost same patterns as Leptospira serovar lai from China, But with very slight differences 21 isolates could be classified into 8 subtypes and these grouping seems to reflect the differences in epidemiological niche. And also the geographical data consisted with the grouping into 8 subtypes. According to our results, we concluded that the restriction endonuclease analysis of chromosomal DNA will be an accurate and reliable method to compare and classify pathogenic leptospires.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.13-17
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• 1993

만다린 오렌지 과피를 기질로 하여 Asp. niger의 구연산 발효를 행하여 관련된 일련의 효소적 활성을 합성배지와 비교한 결과 만다린 오렌지 과피배지에서는 괴피에 함유된 Pectin이나 조섬유 등의 자화로 인하여 Polygalacturonase와 Pectin의 활성 뿐만 아니라 CMCase, xylannase 및 amylase의 활성이 높게 나타났다.

• 한국균학회지
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• 제15권3호
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• pp.175-182
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• 1987

1. $(NH_4)_2SO_4$침 전, DEAE-cellulose column chromatography, CM-Sephadex C-50 및 Sephadex G-75 gel filtration에 의하여 정제된 효소는 조효소보다 18배가 높았으며 회수율은 13.40%였다. 2. 겉보기 분자량은 약 40,000dalton이었다. 3. 최적 pH와 온도는 4.0, $40^{\circ}C$일 때이며, 안정범위는 pH2.0에서 pH5.0, 온도는 $60^{\circ}C$ 이하이었다. 4. 금속이온 첨가에 의한 영향은 $10^{-2}M$ $BaCl_2$첨가시 효소활성이 증가되었으며, $10^{-2}M$ $Pb(NO_3)_2$, $K_3Fe(CN)_6$, $AgSO_4$와 $ZnSO_4$첨가시는 효소활성이 완전히 저해되었다. 5. 각종 유기화합물 첨가에 의한 효소의 영향은 citric acid 첨가시 효소활성이 현저히 저해되었다. 6. 기질 특이성을 보면 dextrin과 glycogen을 기질로 하였을 때는 효소활성이 증가하였으나 saccharose 첨가시에는 현저히 저하되었다. 7. COD 제거율을 측정한 결과는 67에서 68% 정도이었다.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.183-188
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• 1992

A soil bacterium which produces raw starch-digesting $\beta$-amylase in culture medium, has been screened from soils. One strain, isolated and identified as Bacillus polymyxa No. 26, was selected as a $\beta$-amylase producing bacterium. Morphological and biological characteristics of the strain were found to be similar to those of a strain belonging to B. polymyxa. The electron microscopic observations of the bacterial vegetative cells and sporulated cells were extensively done to know the corelation between the enzyme synthesis and sporulation. When the bacterium was cultured on the appropriate media (3% dextrin, 0.3% beef extract, 0.5% polypeptone, 1% yeast extract and 0.3% NaCl at pH 7.0 for 4 days) raw starch-digestible $\beta$-amylase was produced extracellularly. This strain produced 130 units of $\beta$-amylase per ml in a culture medium containing 3% dextrin at $30^\circ{C}$. This value is compared to those of other $\beta$-amylase-producing strains. The optimum pH and temperature for crude enzymes were pH 6.5 to 7.0 and $50^\circ{C}$, respectively. The enzymes were stable between pH 5.5 and 9.0 for 30 min at $45^\circ{C}$.

• Molecules and Cells
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• 제21권3호
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• pp.411-417
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• 2006

We have developed a polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) marker that can distinguish male-fertile (N) and male-sterile (S) cytoplasm in onions. The PCR-RFLP marker was located in a chloroplast psbA gene amplicon. Digesting the amplicons from different cytoplasm-containing varieties with the restriction enzyme MspI revealed that N-cytoplasm plants have a functional MspI site (CCGG), whereas the S-cytoplasm plants has a substitution in that site (CTGG), and thus no MspI target. The results obtained using this PCR-RFLP marker to distinguish between cytoplasmic male sterile factors in 35 onion varieties corresponded with those using a CMS-specific sequence-characterized amplified region (SCAR) marker. Moreover, the PCR-RFLP marker can identify N- ot S-cytoplasms in DNA sample mixtures in which they are in up to a 10-fold minority, indicating that use of the marker has high diagnostic precision. We also demonstrated the usefulness of the SNP detected in the psbA gene for high-throughput discrimination of CMS factors using Real-time PCR and a TaqMan probe assay.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.264-271
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• 2006

Two fibrinolytic enzymes were purified from the culture supernatant of Fomitella fraxinea mycelia by ion-exchange and gel filtration chromatographies, and were designated as F. fraxenia proteases 1 and 2 (FFP1 and FFP2). The apparent molecular masses of the enzymes were estimated to be 32 kDa and 42 kDa, respectively, by SDS-PAGE and gel filtration chromatography. Both enzymes had the same optimal temperature ($40^{\circ}C$), but different pH optima (10.0 and 5.0 for FFP1 and FFP2, respectively). FFP1 was relatively stable at pH 7.0-9.0 and temperature below $30^{\circ}C$, whereas FFP2 was very stable in the pH range of 4-11 and temperature below $40^{\circ}C$. FFPI activity was completely inhibited by phenylmethylsulfonyl fluoride (PMSF) and aprotinin, indicating that this enzyme is a serine protease. The activity of FFP2 was enhanced by the addition of $CO^{2+}$ and $Zn^{2+}$ and inhibited by $Cu^{2+},\;Ni^{2+}$, and $Hg^{2+}$. Furthermore, FFP2 activity was strongly inhibited by EDTA and 1,10-phenanthroline, implying that the enzyme is a metalloprotease. Both enzymes readily hydrolyzed fibrinogen, preferentially digesting the $A{\alpha}$- and $B{\beta}$-chains of fibrinogen over ${\gamma}$-chain. FFP1 showed broad substrate specificity for synthetic substrates, but FFP2 did not. $K_{m}$ and $V_{max}$ values of FFP1 for a synthetic substrate, N-succinyl-Ala-Ala-Pro-Phe-pNA, were 0.213 mM and 39.68 units/ml, respectively. The first 15 amino acids of the N-terminal sequences of both enzymes were APXXPXGPWGPQRIS and ARPP(G)VDGQ(R,I)SK(L)ETLPE, respectively.