• 제목/요약/키워드: bioproducts

검색결과 258건 처리시간 0.034초

Screening and Characterization of Microorganisms with Fibrinolytic Activity from Fermented Foods

  • Yoon, Seon-Joo;Yu, Myeong-Ae;Sim, Gwan-Sub;Kwon, Seung-Taek;Hwang, Jae-Kwan;Shin, Jung-Kue;Yeo, In-Hyun;Pyun, Yu-Rang
    • Journal of Microbiology and Biotechnology
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    • 제12권4호
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    • pp.649-656
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    • 2002
  • Fibrinolytic microorganisms were screened from 42 samples of Korean fermented food (7 kinds of Chungook-jang, 14 kinds of commercial Doen-Jang, 5 kinds of home-made Doen-jang, and 16 kinds of Jeot-gal), 15 samples of Japanese fermented food (5 kinds of home-made soybean paste, and 10 kinds of Natto), and 19 samples of Indonesian fermented food (Tempe) as well as starters of Meju (500 microflora from Korea, and 22 from China). Initially, 11 isolates with strong fibrinolytic activity were selected for further characterization. The fibrinolytic activity of the 11 isolates ranged from 89 to 199% of standard plasmin. Four strains, M5l from Korean fermented food (Meju), I 1-1, I 1-4, and I 5-1 from Indonesian fermented food (Tempe), were chosen based on the degree of activity and reproducibility, and identified as Staphylococcus sciuri, Citrobacter or Enterobacter, Enterococcus faecalis, and Bacillus subtilis, respectively. The first two isolates are pathogenic stains while the latter two are considered as GRAS (Generally Recognized As Safe). Fibrinolytic activity of E. faecalis, characterized and designated as BRCA-5, reached a maximum, when the producer was cultivated in Ml7 broth supplemented with 1.0% glucose for 5 h at 37$^{\circ}C$ with shaking at 180 rpm. Compared to commercial fibrinolytic enzymes, the cell-free culture supernatant of 5. faecaiis BRCA-5 showed stronger activity than plasmin and streptokinase, but similar degree of specific activity as nattokinase and urokinase, aud it also demonstrated anticoagulant and antiplatelet activity ex vivo. These features of E. faecalis make it an attractive agent as a biomaterial for health-promoting foods.

Production of D-Xylonic Acid from Hemicellulose Using Artificial Enzyme Complexes

  • Lee, Charles C.;Kibblewhite, Rena E.;Paavola, Chad D.;Orts, William J.;Wagschal, Kurt
    • Journal of Microbiology and Biotechnology
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    • 제27권1호
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    • pp.77-83
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    • 2017
  • Lignocellulosic biomass represents a potentially large resource to supply the world's fuel and chemical feedstocks. Enzymatic bioconversion of this substrate offers a reliable strategy for accessing this material under mild reaction conditions. Owing to the complex nature of lignocellulose, many different enzymatic activities are required to function in concert to perform efficient transformation. In nature, large multienzyme complexes are known to effectively hydrolyze lignocellulose into constituent monomeric sugars. We created artificial complexes of enzymes, called rosettazymes, in order to hydrolyze glucuronoxylan, a common lignocellulose component, into its cognate sugar ${\small{D}}$-xylose and then further convert the ${\small{D}}$-xylose into ${\small{D}}$-xylonic acid, a Department of Energy top-30 platform chemical. Four different types of enzymes (endoxylanase, ${\alpha}$-glucuronidase, ${\beta}$-xylosidase, and xylose dehydrogenase) were incorporated into the artificial complexes. We demonstrated that tethering our enzymes in a complex resulted in significantly more activity (up to 71%) than the same amount of enzymes free in solution. We also determined that varying the enzyme composition affected the level of complex-related activity enhancement as well as overall yield.

Characterization of Bacillus thuringiensis StrainBT-14 having Insecticidal Activity against Plutella xylostella

  • Bok, Song-Hae-Jung, Yong-Chul;Kim, Sung-Uk;Son, Kwang-Hee;Lee, Hyung-Hoan
    • Journal of Microbiology and Biotechnology
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    • 제4권4호
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    • pp.322-326
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    • 1994
  • Bacillus thuringiensis strain BT-14 was isolated from alfalfa dust in Korea. The strain BT-14 produced one bipyramidal crystal and one spore in the cell. The biochemical characteristics of the strain BT-14 were similar to those of Bacillus thuringiensis subsp. kurstaki HD-l. Examination of its antibiotic resistance revealed that while the strain BT-14 was less resistant than BTK HD-l to ampicillin, gentamycin, neomycin and tobramycin, it was more resistant to amikacin than BTK HD-l. The $\delta$-endotoxin crystal of strain BT-14 consisted of a single protein with a high molecular weight of ca 135 KD on a 10% SDS-PACE. The strain BT-14 contained at least nine different plasmids with sizes of 2.9, 5.3, 5.8, 6.2, 9.4, 15.1, 18.1, 23.1 and 79 Kb. In insect bioassay, the isolated strain BT-14 showed lethality of 67% against Plutella xylostella larvae at dilution of 5$\times$$l0^{-4}$ (5$\times$l0 to 3$\times$$l0^2$ spores/ml), which is, almost equivalent to that of BTK HD-l.

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Strain Improvement for Enhanced Production of Streptokinase and Streptodornase in Streptococcus sp.

  • HYUN, HYUNG-HWAN;YOON-BUM LEE;KYUNG-HWA SONG;JI-YOUNG JEON;HYUNE-HWAN LEE
    • Journal of Microbiology and Biotechnology
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    • 제7권2호
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    • pp.101-106
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    • 1997
  • Strain improvement for the enhanced production of streptokinase and streptodornase in Streptococcus sp. ATCC 12449 was performed. Strain UB111, a hyperproductive mutant which was isolated by use of nitrosoguanidine and selection of colonies with large clear zones on DNase test agar plates supplemented with $1{\%}$ glucose and $0.5{\%}$ ammonium chloride, produced about 3 fold more streptokinase and streptodornase than the wild type when tested in shake flask fermentations. The enhanced production of both streptokinase and streptodornase was achieved by cultivating the mutant in a pH-controlled fermentor containing fermentation medium enriched with yeast extract ($2.1{\%}$). Under these conditions, the mutant produced 7300 units/ml of streptokinase and 800 units/ml of streptodornase.

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