• Title/Summary/Keyword: MOLECULAR WEIGHT

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Purification and Properties of a Novel Extracellular Agarase from Marine Bacterium, Sphingomonas paucimobilis AS-1 (해양미생물 Sphingomonas paucimobilis AS-1이 생산하는 새로운 extracelluar agarase의 정제 및 특성)

  • Jung, Il-Sun;Kim, Yu-Jung;Song, Hyo-Ju;Gal, Sang-Wan;Choi, Young-Ju
    • Journal of Life Science
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    • v.18 no.1
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    • pp.103-108
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    • 2008
  • An agar-degrading marine bacterium, strain AS-1 was isolated from the seawater. The strain AS-1 was identified as Sphingomonas paucimobilis (90% probability) by VITEK. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 104-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The molecular weight of the purified enzyme was estimated to be 80 kDa by SDS-PAGE. The optimum pH and temperature for activity were 7.0 and $40^{\circ}C$, respectively. Antioxidative activity of the strain AS- was 72% in the supernatant cultured for 12 h. The culture supernatant of the strain AS-1 showed antibacterial activity against bacteria causing putrefaction and food poisoning such as Escherichia coli, Staphylococcus aureus and Proteus vulgaris. However, the cell growth of the lactic aicd forming strain, Lactobacillus plantarium was promoted by the treatment of 10% culture supernatant of an agar-degrading strain.

Optimal Production of Xylooligosaccharide by Using Recombinant Endoxylanase from Bacillus subtilis (Bacillus subtilis 유래 재조합 endoxylanase를 이용한 xylooligosaccharide의 최적 생산)

  • Kim, Yeon-Hee;Heo, Sun-Yeon;Kim, Mi-Jin;Lee, Jae-Hyung;Kim, Young-Man;Nam, Soo-Wan
    • Journal of Life Science
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    • v.18 no.1
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    • pp.52-57
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    • 2008
  • Xylan is a major hemicellulose component of the cell walls of monocots and hardwood, representing up to 30% of the dry weight of these plants. To efficiently hydrolyze xylan, the endoxylanase gene from Bacillus sp. was expressed in B. subtilis DB431 by introducing the plasmid pJHKJ4. The total activity of the recombinant endoxylanase reached about 857 unit/ml by batch fermentation of B. subtilis DB431/pJHKJ4 in LB maltose medium. The majority (>92%) of endoxylanase was efficiently secreted into the culture medium. The recombinant endoxylanase hydrolyzed more the birchwood xylan efficiently than the other xylans. When 4 % concentration of xylan was used, the highest production of xylooligosaccharide was observed, and xylobiose and xylotriose were the major products. Optimal amount of enzyme and reaction time for producing xylooligosaccharide were found to be 10 unit and 1 hr, respectively. In addition, the temperature of $40^{\circ}C{\sim}50^{\circ}C$ gave the highest production of xylooligosaccharide. Consequently, the optimized conditions for the production of xylooligosaccharide through the hydrolysis of xylan were determined as follows: 10 unit endoxylanase, $50^{\circ}C$, 4% birchwood xylan, 1 hr reaction.

Purification and Characterization of the Bacteriocin Produced by Lactococcus sp. KD 28 Isolated from Kimchi (김치에서 분리한 Lactococcus lactis가 생산하는 박테리오신의 정제 및 특성)

  • Lee, Ji-Young;Choi, Nack-Shick;Chun, Sung-Sik;Moon, Ja-Young;Kang, Dae-Ook
    • Journal of Life Science
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    • v.25 no.2
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    • pp.180-188
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    • 2015
  • The bacterial strain isolated from Kimchi showed antibacterial activity against Micrococcus luteus IAM 1056. The selected strain was identified as Lactococcus lactis by 16S rRNA nucleotide sequence analysis and named as Lactococcus sp. KD 28. The treatment of culture supernatant with proteinase K removed antibacterial activity, indicating its proteinaceous nature, a bacteriocin. This bacteriocin was sensitive to hydrolytic enzymes such as ${\alpha}$-chymotrypsion, trypsin, proteinase K, lipase, ${\alpha}$-amylase and subtilisin A. The bacteriocin was highly thermostable and resistant to heating at $80^{\circ}C$ for up to an hour but 50 % of the total activity was remained at $100^{\circ}C$ for 30 min. The pH range from 2.0 to 8.0 had no effect on bacteriocin activity and it was not affected by solvents such as acetonitrile, isopropanol, methanol, chloroform and acetone up to 50% concentration. The bacteriocin showed antibacterial activity against M. luteus IAM 1056, Lactobacillus delbrueckii subsp. lactis KCTC 1058, Enterococcus faecium KCTC 3095, Bacillus cereus KCTC 1013, B. subtilis KCTC 1023, Listeria ivanovii subsp. ivanovii KCTC 3444, Staphylococcus aureus subsp. aureus KCTC 1916, B. megaterium KCTC 1098 and B. sphaericus KCTC 1184. The bacteriocin was purified through ammonium sulfate concentration, SP-Sepharose chromatography and RP-HPLC. The molecular weight was estimated to be about 3.4 kDa by tricine-SDS-PAGE analysis.

Induction of Metallothionein Gene by Laminin in Normal and Malignant Human Prostate Epithelial Cells (악성 단계별 인간 전립선 암세포에서 라미닌에 의한 metallothionein 유전자 발현유도 현상 연구)

  • Ock, Mee-Sun;Cha, Hee-Jae
    • Journal of Life Science
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    • v.21 no.4
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    • pp.529-533
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    • 2011
  • Metallothioneins (MT) are a group of low-molecular weight, cysteine-rich, intracellular proteins that are encoded by a family of genes containing at least 10 functional isoforms in human. The expression and induction of these proteins is associated with protection against DNA damage, oxidative stress, and apoptosis. Many studies have shown increased expression of MT in various human tumors, whereas MT is down-regulated in certain tumors such as hepatocellular carcinoma and liver adenocarcinoma. Hence, the expression of MT is not universal to all human tumors but may depend on the differentiation status and proliferative index of tumors, along with other tissue factors and gene mutations. Using Northern blot analysis, we found that laminin induced expression of MT-1 in HSG and PC12 cells, which can be differentiated by laminin, but had no effect on MB-231, MDA-435, and PC-3 cells, which cannot be differentiated by laminin. In addition, we analyzed the expression level of the MT-1 gene in five prostate cancer cell lines possessing different metastatic potential. The expression of MT-1 in normal and less malignant cells (RWPE-1 and WPE1-NA22) was high and up-regulated by laminin, whereas the expression of MT-1 in WPE1-NB14, WPE1-NB11, and WPE1-NB26 cells (malignant) was extremely low and not elevated by laminin. These results suggest that the MT-1 gene is involved in laminin-mediated differentiation and affects the metastatic potential of tumor cells.

Toxicity and Characteristics of Antifungal Substances Produced by Bacillus amyloliquefaciens IUB158-03 (Bacillus amyloliquefaciens IUB158-03이 생산하는 항진균물질의 생화학적 특성 및 독성)

  • Kim, Hye-Young;Lee, Tae-Soo
    • Journal of Life Science
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    • v.19 no.11
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    • pp.1672-1678
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    • 2009
  • The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

Comparison of Arylphorin of Antheraea pernyi with Those of Several Lepidopteran Wild Silkmoths by Western Blot Analysis. (작잠(Antheraea pernyi) arylphorin의 항체를 이용한 수종의 나비목 야생 견사곤충들 간의 면역학적 비교)

  • Park, Nam-Sook;Kim, Mi-Ae;Park, Hyun-Chul;Kim, Keun-Ki;Jin, Byung-Rae;Lee, Sang-Mong
    • Journal of Life Science
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    • v.18 no.3
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    • pp.409-413
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    • 2008
  • The occurences of proteins relating to Antheraea pernyi arylphorin in haemolymph, fat body, integument, midgut and silkgland of the wild silkmoths, Antheraea yamamai, Antheraea pernyi, Samia cynthia pryeri and Actias gnoma in the 5th larval instar were investigated by immunoblot analysis using mouse polyclonal antibody against A. pernyi arylphorin as probe. In A. yamamai, A. pernyi, S. cynthia pryeri and A. gnoma, the major immunoreactive antigenic proteins with a molecular weight of 80 KDa against the antisera of the A. pernyi arylphorin were clearly observed in the haemolymph, but in the integument, fat body, midgut and silkgland of the corresponding wild silkmoths the presence of the immunoreactive proteins were very variable. These results suggest that the A. pernyi arylphorin has almost same immunological identity with those of the wild silkmoths, A. yamamai, S. cynthia pryeri and A. gnoma though the distribution of the corresponding antigenic arylphorins is different according to the tissues of the wild silkmoths.

밀배아 분말첨가가 식빵의 품질특성에 미치는 영향

  • 김래영;전순실;서재수
    • Proceedings of the Korean Journal of Food and Nutrition Conference
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    • 2000.12a
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    • pp.51-51
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    • 2000
  • 식생활의 서구화로 제빵 산업이 발달하고, 빵을 주식으로 하는 인구가 늘고 있다 또한 기존의 재료보다는 기능성이 첨가된 부재료를 활용한 건강 지향적인 식품의 수요가 증가하고 있는 추세이다. 최근 밀배아의 용도 다양화를 위하여 팔은 연구가 진행되고 있으며, 상업적으로 이용되고 있다. 소맥의 제분과정에서 부산물로 얻어지는 밀배에는 식물 중에서 가장 많은 천연 비타민 E 복합체가 이상적인 상태로 함유되어 있다. 밀배아에 들어 있는 비타민 E는 천연 비타민 E 복합체와 합성 비타민 E로 구분되어진다. 천연비타민E는 8가지 이성체를 가진 자연 비타민 E를 말하며, 4종류의($\alpha$$\beta$${\gamma}$$\delta$)의 토코페롤과 4종의 토코페롤의 복합체이다. 비타민 E는 사람을 포함한 고등동물에 필수적인 영양소로 식물성기름, 곡류, 배아 등에 많이 들어 있으며, 여러 이성질체중 $\alpha$-토코페롤이 체내에서 가장 생물학적 활성이 큰 것으로 알려졌으며, 생체막조직에서 인지질의 천연항산화제 역할을 하여 체내대사를 정상으로 유지하는데 큰 기능을 하는 것으로 보고되고 있다. 우리나라에서 식용으로 소비되는 밀은 거의가 수입에 의존하고 있으며, 밀배아는 거의 전량이 가축의 사료용으로 사용되고 있고 근래에 와서는 배아유, 배아떡, 복합 조미료, 쿠키, 배아를 첨가한 국수 등에 이용되고 있다. 따라서 본 실험에서는 식빵제조시 밀배아 분말을 0, 2, 4, 6, 8, 10%씩 첨가하여 기능성 식빵을 제조하였을 때의 반죽의 물성, 호화특성을 살펴보고 빵으로 제조하였을 때의 식빵의 품질 특성으로서 1차 발효 손실률, 굽기 손실률, 부피, 질감, 노화도, 관능적 특성 및 mould-free shelf life를 측정하였다.te, ferric citrate가 유제품에 사용하기에 적합한 것으로 나타났다. 생이용성을 평가하기 위하여 우유에서 low molecular weight components(ILC)를 분리하고 철분과 복합체를 형성시킨 다음, 철분 결핍된 쥐의 소장에서 loop을 형성시켜 ILC-철분 복합체를 injection하여 철분 흡수도를 조사하였다. Ferrous lactate 100ppm에서 약 25.6%흡수되었고 ferric citrate 100ppm은 24.7%, ferrous sulfate는 19.7%흡수되었다. ILC를 첨가하지 않은 100ppm 철분염 용액은 ferrous sulfate를 제외하고는 흡수도가 감소되었다. 철분 결핍된 쥐에게 gavage 방법에 의하여 철분강화우유를 투여하였을 때 철분 25ppm 시료에서는 ferrous sulfate가 12.5%로 가장 높았고 ferrous lactate는 8.1%, ferric citrate는 6.5% 흡수되었다. 철분 100ppm수준에서는 흡수율이 낮아져 ferrous sulfate는 25ppm 시료보다 절반이하 수준이었다. Ferric citrate는 차이가 거의 없었으며 ferrous lactate는 70%수준이었다. 이상의 결과에서 철분강화우유에 사용하기 적합한 철분염은 ferrous lactate, ferric citrate였는데 특히 ferrous lactate는 제품의 이화학적 품질, 생이용성 측면 모두에서 가장 좋은 것으로 나타났다.다 높았으며, 1회당 평균 8.1$\pm$5.1개의 난포란을 회수하였다. investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the inves

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Purification and Characterization of a Keratinase from Bacillus licheniformis Strain for Degradation of Egg Shell Membrane (낙각막 분해를 위한 Bacillus licheniformis로 부터 Keratinase의 정제 및 특성)

  • 전태욱;박기문
    • Food Science of Animal Resources
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    • v.22 no.3
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    • pp.259-266
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    • 2002
  • The egg shell membrane degrading isolated from soil was identified as Bacillus licheniformis by 16S rDNA identification method. A keratinase was isolated from the Baciilu licheniformis culture. DEAE-cellulose ion-exchange and Sephadex C-75 gel chromatograhies were used to purify the enzyme. The specific activity was increased 17.3-fold by the purification procedures. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and Sephadex G-75 chromatography indicated that the purified keratinase was monomeric and had a molecular weight of 65 kDa. The enzyme showed optimum activity at pH 9.0, and was stable above pH 9.0. The optimum temperature was 50$\^{C}$ and the enzyme was stable in the temperature ranges from 20$\^{C}$ to 50t. By the addition of 1 mM and 10 mM FeSO4, the activities of the enzyme were increased to 111$\pm$4.6% and 133$\pm$3.79%, respectively. The keratinase was an alkaline serine pretense because it was inhibited only by phenylmethylsulfonylfluorice (PMSF).

Characterization of Endoglucanase (F-I-III) Purified from Trichoderma sp. C-4 (새로운 섬유소분해 균주 Trichoderma sp. C-4에서 분리한 Endoglucanase (F-I-III)에 대한 연구)

  • Sul Ok Ju;Chung Dae Kyun;Han In Seob;Jeong Choon Soo
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.81-86
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    • 2005
  • One of the endoglucanases, F-I-III, was purified from the culture filtrate of T. sp. C-4 through procedures including chromatography on Sephacryl S-200, DEAE-Sepharose A-50, and Chromatofocusing on Mono-P (FPLC). The molecular weight of the enzyme was determined to be about 56,000 Da by SDS-PAGE, and pI of 4.9 by analytical isoelectric focusing. F-I-III showed the highest enzyme activity at $55^{\circ}C$, and the pH optimum of the enzyme was 5.0. There was no loss of activity when the enzyme was incubated at $50^{\circ}C$ for 24 hours. The specific activity of the enzyme F-I-III toward the CMC was 315.4 U/mg. The Km value for $PNPG_2$ of F-I-III was 2.69 mM. N-terminal sequence of F-I-III was analyzed to be QPGTSTPEVHPKKLTTYK. It showed $95\%$ of homology to that of EGI from T. reesei. The presence of some metal ions (1 mM) had only a little effect on CMCase activity. The treatment of the reducing agents resulted in the increase of endoglucanase activity.

Origin of Flavor Compounds in Canned Tuna and Their Relation to Quality (참치 통조림 중 향미 물질의 기원과 품질)

  • Kim, Mu-Nam;Lindsay, R.C.
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.6
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    • pp.731-737
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    • 1992
  • The specific attributes of aroma quality of canned tuna meat were investigated before and during refrigerated storage. Fresh, cooked tuna, beefy and meaty flavor notes of canned tuna meat were changed to card-boardy(1 week storage), oxidized fat-like(2 weeks storage), fatty acid-like and heavy oxidized fat-like(3 weeks storage), and then moldy and painty(4 weeks storage) flavor notes during storage in refrigerator at $4^{\circ}C.$ More than 126 peaks of volatile compounds collected from canned tuna meat were separated on Carbowax 20M capillary column of gas chromatographic analysis. Of the peaks, 54 compounds were identified by mass spectral data, matching $I_E$ values, and sniffing the effluent of each peak from GC detector. The contents of many low molecular weight compounds eluted with early retention times were decreased, whereas some other new compounds eluted with longer retention time were formed during storage. The compounds increased up to 3 weeks of storage and then decreased at extended storage time(4 weeks) were 1-penten-3-ol, 3-penten-2-ol, heptanal, limonene, 1-pentanol, octanal, 1-hexanol, nonanal, 2-octanone, 2-nonanone, 1-heptanol, benzaldehytde and some methyl substituted benzenes. p-Thiocresol, 2-chlorophenol, and 2-heptylthiophene were formed after 4 weeks of storage, but not detected in fresh canned tuna. Therefore, these compounds could be used as indicators for the quality changes during refrigerated storage.

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