• Title/Summary/Keyword: Halobacterium

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Studios on the Processing of Low Salt Fermented Sea Foods 3. Changes of Microflora during Fermentation of Low Salted Sardine (저염수산발효식품의 가공에 관한 연구 3. 저염정어리젓의 미생물상의 변화)

  • CHA Yong-Jun;CHUNG Su-Yeol;HA Jae-Ho;JEONG In-Cheol;LEE Eung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.3
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    • pp.211-215
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    • 1983
  • The changes of microflora during fermentation of low salted sardine were observed. The viable cell count in the low salt fermented sardine with $8\%\;or\;10\%$ salt showed lower than that of control ($20\%$ salt) during the fermentation period and it was considered that the microbial growth was controlled by adding ethanol, sorbitol and lactic acid. Among 48 strains isolated, 7 genus of bacteria and 1 genus of yeast were identified during the fermentation of sardine. The changes of microflora also occurred during fermentation depending on the salt levels in the product. Brevibacterium, Pseudomonas, Flavobacterium and Baciilus were detected at early stage of fermentation and they disappeared after 50 days fermentation from the product with $20\%$ salt and Halobacterium, Micrococcus, Pediococcus and Torulopsis were isolated, whereas Brevibacterium, Micrococcus and Pediococcus were isolated from the product with $8\%\;or\;10\%$ salt.

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Optical Switchies based on Bacteriorhodopsin Thin Film (박테리아로돕신 박막 소자의 광 스위칭 특성)

  • 유연석;김남훈;신정록;조현일
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.114-115
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    • 2000
  • Halobacterium halobium에서 추출한 Bacteriorhodopsin(bR)을 고분자 물질에 첨가해 박막화하였다. 이 단백질 박막 소자의 photodynamic특성을 이용하여 광 switching system을 구성하였다. 광 switch system은 pump광을 이용해 B상태와 M상태에서 축퇴4광파 혼합방식으로 구성했다. Red, blue, violet 광원을 사용하여 B상태와 M상태 격자를 형성하고 on-off되는 위상공액신호를 측정했다. (중략)

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The Effect of S130A Mutant of pharaonis Halorhodopsin on Ability of Chloride Binding and Photocycle

  • Sato, Maki;Kikukawa, Takashi;Araiso, Tsunehisa;Okita, Hirotaka;Shimono, Kazumi;Kamo, Naoki;Demura, Makoto;Nitta, Katsutoshi
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.308-310
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    • 2002
  • Bacteriorhodopsin (bR) and halorhodopsin (hR), which exist in the membrane of Halobacterium salinarum, are light-driven ion pumps. In spite of high similarity of primary and tertiary structures between bR and hR, these membrane proteins transport different ions, proton and chloride, in the opposite direction. From alignment of the amino acid sequences, Thr-89 of bR is homologous to Ser-l15 of hR from Halobacterium salinarum (shR). X-ray structure of shR has revealed that OH group of this residue directly interacts with CI$\^$-/ Thus, Ser-lI5 of shR is expected to play an important role in CI$\^$-/ binding and transport. In this study, we expressed wild type hR from Natronobacterium pharaonis (PhR) and Sl30A, which corresponds to Ser-l15 of shR, in E. coli in order to clarify binding affinity of chloride ion and photocycle reactions. From the titration with CI$\^$-/, affinity of Sl30A became quite lower than that of WT (WT 6 mM, Sl30A 89 mM). Furthermore, from the flash photolysis with pulse laser of λ$\_$max/ at 532 nm, the reaction rate of SI30A from 0 intermediate to hR ground state was found to become apparently slower than that of WT. The singular value decomposition (SVD) and global fitting analyses of the photocycles were performed to identify all photointermediates and determine the reaction rates.

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The Effect of Acidic pH on the Spectral Properties of Bacteriorhodopsin (산성 pH가 박테리오로돕신의 분광학적 성질에 미치는 효과)

  • Quae Chae
    • Journal of the Korean Chemical Society
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    • v.23 no.5
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    • pp.320-324
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    • 1979
  • Purple membrane from Halobacterium halobium was incorporated into 7.5% polyacrylamide gels. Absorption and circular dichroic spectra of purple membrane incorporated with gels were obtained at various pH. The spectra of these gels measured at pH 7.0 were essentially identical with those obtained in the aqueous suspension of purple membrane. Acid titration of the gels showed the transition to a form absorbing at 605nm $(bR_{605}^{acid}$) at pH 2.6, and to a second form at 565nm $(bR_{565}^{acid})$ at pH 0.8. Dark-adapted gels showed an isosbestic point for each transition whereas light-adapted gels did not. Visible CD spectra of $bR_{570}^{LA},\;bR_{305}^{acid}\;and\;bR_{565}^{acid}$ all showed the typical bilobed pattern. CD spectra measured at UV wavelength region were also independent of the variation of pH in terms of molar ellipticity and spectral shape. The protonated species $bR_{605}^{acid}$ may be one of the intermediates formed during the normal photochemical cycle of purple membrane. Most probably, the species $bR_{605}^{acid}$ is considered to be $O^{640}$ in the cycle.

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Glu-56 in Htrl is Critical for Phototaxis Signaling in Halobacterium salinarum

  • Choi, Ah-Reum;Kim, So-Young;Yoon, Sa-Ryong;Jung, Kwang-Hwan
    • Animal cells and systems
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    • v.9 no.3
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    • pp.139-144
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    • 2005
  • The attractant (orange light) or repellent (white light) signal is transmitted from SRI (Sensory Rhodopsin I) via protein-protein interaction with its transducer Htrl (Halobacterial Transducer for Sensory Rhodopsin I) which in turn controls a cytoplasmic phospho-transfer pathway that modulates flagella motor switching in Halobacterium salinarum. Some mutations in both SRI and Htrl showed an unusual mutant phenotype called inverted signaling, in which the cell produces a repellent response to normally attractant light. Twelve mutations at the Glutamate 56 (E56) position in the second transmembrane helix of Htrl were introduced by site-specific random mutagenesis. Almost all E56 mutants showed orange-light inverted responses in pH and temperature-dependent manners except E56D and E56Y. Except for these two mutants, all mutants accelerated the $S_{373}$ decay compared to wild-type at $18^{\circ}C$. This supported that there is an interaction between SRI and the second transmembrane of Htrl. Also a structural model of Htrl based on the Tar crystal structure and the secondary structure prediction program proposed the E56 residue to be in the middle of the proton channel. The most important observation is that the E56 mutant provides the evidence that this residue is very sensitive for signal relay, which can be explained by the open and closed conformations of the channel (A and R conformations) in SRI, as was postulated by the unified conformational shuttling model for transport and signaling.

HYDRATION DEPENDENCE OF DRIED ORIENTED PURPLE MEMBRANE FILMS ACTIVITY

  • Lee, Ki-Hwan;Boucher, Francois;McIntosh, Alan R.
    • Journal of Photoscience
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    • v.2 no.2
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    • pp.69-72
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    • 1995
  • Dry orderly oriented purple membrane from Halobacterium halobium was obtained by a new technique of preparation. This oriented purple membrane film was very stable, nearly permanently, and showed long term reproducibility with respect to its photochemical behavior. In addition, we have investigated the photooptical properties in terms of the M$_{412}$ intermediate of the bacteriorhodopsin photocycle with respect to the humidity of the film. The relative optical density, i.e. its apparent concentration of the M$_{412}$ intermediate was decreased with the humidity increase as a function of the intensity of the exciting flash within our experimental range. It is suggested that the bound water molecules play an important role in the structure of the bacteriorhodopsin.

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호염성 세균의 생리적 특성

  • Song, Kyung-Sook;Lee, Jung-Im;Bae, Moo
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.517.3-518
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    • 1986
  • 국내 염장식품 및 염전으로부터 세균을 분리하여, 호염성 세균의 NaCl 농도에 따른 성장범위, 생리적 및 효소학적 특성을 조사하고자 했다. 염전으로부터 NaCl 20%배지에서 14주와 총 16종류의 젓갈류에서 NaCl 10% 배지로 56균주의 호염성 세균을 분리하여 0, 5, 10, 15, 20, 25% NaCl농도에서 성장률을 조사하고 최적온도 및 배지조성과 함께 동정에 필요한 생리실험을 하였다. 또한 세포의 효소로서 Lactate dehydrogenase, Glucokinase, Glucose-6-phosphate dehydrogenase, Alanine dehydrogenase, Isocitrate dehydrogenase 등의 특성도 조사하였다. 선별한 균주중 Acinetobacter sp, 등이 관찰 조사되었으며 최적 성장 NaCl농도는 10%이고, 최적온도는 3$0^{\circ}C$이며, 25% NaCl, 45$^{\circ}C$에서 자란 Halobacterium sp. 등이 분리되었다. 그중 Acinetobacter strain H6는 단백분해효소와 탄수화물 분해효소의 생성능이 15>10>20% NaCl순이며, 특히 Lactate dehydrogenase 활성은 2>3>1>OM NaCl 순으로 나타났고, NaCl 대신 KCl을 사용했을 때는 3>2>1> OM순으로 활성이 나타났다.

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A Study on Change of Excess Volume in Membrane of Holobacterium Holobium (Halobacterium Halobium의 Membrane에서 잉여부피 변화에 관한 연구)

  • Kim, Ki-Jun;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.2
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    • pp.247-250
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    • 2011
  • The excess volumes of mixing of benzyl alcohol and halothane in vesicle and in suspensions of several lipids have been determined at $25^{\circ}C$ it using a excess volume dilatometer. The potency of general anesthetics has long been known to correlate with lipid solubility. Denaturations of the vesicle, which is a sole membrane protein in the purple membrane of Halobacteriun Halobium, were studied by absorption changes at 280 nm and fluorescence changes at 330 nm and excess volume dilatometer. The particle size analysis of viscous polymer solutions by diffusional interchange is the key step by measurement. The excess volume of mixing in chitosan was found to be negative, whereas them of purple membrane, Halobacteriun Halobium and red membrane were positive in benzyl alcohol and halothane. This result was confirmed as Miller's supposition.

A Multi-microbial Biofungicide for the Biological Control against Several Important Plant Pathogenic Fungi (진균성 식물병해 방제를 위한 항생물질 생산 길항미생물의 복합제제화)

  • Jung, Hee-Kyoung;Ryoo, Jae-Cheon;Kim, Sang-Dal
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.40-47
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    • 2005
  • In order to develop a multi-microbial biofungicide against several important plant pathogenic fungi, strains were isolated from the phtophthora blight suppressive red-pepper field soil of Gyeongsangbuk-do, Korea. Strains AY1, AY6, AB1, BB2 and F4, which had strong antagonistic ability against Phytophthota capsici and Fusarium oxysporum, were selected for their involvement with strains of biocontrol fungicide. There were no antagonism among the selected strains and were compatible for making the biofungicide. Their antagonistic mechanisms, except for strain BB2, were an antibiosis by the production of antibiotic, while BB2 produced not only an antibiotic but also cellulase as an antagonistic mechanism against blight causing P. capsici. They were identified as Halobacterium sp. AB1, Xenorhadus sp. AY1, Bacillus sp. AY6, Bacillus sp. BB2, Zymomonas sp. F4 by various cultural, biochemical test and $Biolog^{TM}$ System 4.0. The highest levels of antifungal antibiotic could be produced after 48 hrs of incubation under the optimal medium which were 0.1% galactose, 0.1% $NaNO_2$, 5 mM $Na_2{\cdot}HPO_4$ (pH 5.5). The cultured multi-microbial biofungicide showed strong biocontrol activity against bacterial wilt disease and fusarium wilt disease in cucumber and tomato fields.

Isolation and characterization analysis of the halophilic archaea isolated from solar saltern, Gomso (곰소 염전에서 분리한 호염성 고세균의 특성 분석)

  • Koh, Hyeon-Woo;Kim, So-Jeong;Rhee, Sung-Keun;Park, Soo-Je
    • Korean Journal of Microbiology
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    • v.51 no.4
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    • pp.427-434
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    • 2015
  • Most of halophilic archaea are found in the various hypersaline environments including solar saltern, salt lake with very high salt concentration. The present study is about isolation and characterization of halphilic archaea from Gomso solar saltern known as a representative high salt environment in Korea. In order to isolate the halophilic archaea, we prepared and used high salt medium. Finally, total 7 strains obtained were tentatively identified based on comparative similarity analysis for 16S rRNA gene sequence and physiological traits. All halophilic archaea belonged to Haloruburm, Halogeometriucm, Halobacterium, and Haloarcula genera. These isolates were all Gram-staining negative, and growth was not observed using nitrate as an alternative electron acceptor under anaerobic conditions. In addition, all isolates required about 12-30% (w/v, NaCl) salt. This case study might provide basic information on microbial isolation technologies and related research in halophilic microorganisms from domestic halophilic environments, and contribute to obtaining useful indigenous halophilic archaea in a variety of extreme environmental conditions.