title: An extremely thermostable xylanase from the thermophilic eubacterium Thermotoga.

authors: Simpson, H.D.

subjects: biology

abstract: Endo-1,4-beta-xylanase (EC 3.2.1.8) was isolated from the culture supernatant of Thermotoga sp. strain FjSS3-B.1, an extremely thermophilic anaerobic eubacterium which grows optimally at 80 degrees C. Activity was purified 165-fold by anion-exchange and hydroxyapatite chromatography. The enzyme has an Mr of 31,000 as determined by SDS/PAGE and 35,000 by analytical gel filtration. The optima for activity and stability for purified xylanase were between pH 5.0 and 5.5. At pH 5.5, which is the optimum pH for thermostability, t1/2 (95 degrees C) is 90 min. The thermostability was improved by immobilization of the xylanase on to porous glass beads; t1/2 (105 degrees C) is 10 min. Several additives, such as sorbitol and xylan, were also found to increase the thermostability. At 130 degrees C, the half-life of immobilized xylanase in the presence of 90% sorbitol was 1.3 min. At 130 degrees C in molten sorbitol half of the enzyme denatured rapidly, but the remainder appeared to have a half-life of about 60 min.

text: An extremely thermostable xylanase from the thermophilic eubacterium Thermotoga. Endo-1,4-beta-xylanase (EC 3.2.1.8) was isolated from the culture supernatant of Thermotoga sp. strain FjSS3-B.1, an extremely thermophilic anaerobic eubacterium which grows optimally at 80 degrees C. Activity was purified 165-fold by anion-exchange and hydroxyapatite chromatography. The enzyme has an Mr of 31,000 as determined by SDS/PAGE and 35,000 by analytical gel filtration. The optima for activity and stability for purified xylanase were between pH 5.0 and 5.5. At pH 5.5, which is the optimum pH for thermostability, t1/2 (95 degrees C) is 90 min. The thermostability was improved by immobilization of the xylanase on to porous glass beads; t1/2 (105 degrees C) is 10 min. Several additives, such as sorbitol and xylan, were also found to increase the thermostability. At 130 degrees C, the half-life of immobilized xylanase in the presence of 90% sorbitol was 1.3 min. At 130 degrees C in molten sorbitol half of the enzyme denatured rapidly, but the remainder appeared to have a half-life of about 60 min.

year: 1991

title: The effect of SDS and TEG on chain mobility and secondary structure of decolored bloodmeal

authors: Hicks, Talia

subjects: IR spectroscopy

abstract: The effect of sodium dodecyl sulfate (SDS) and triethylene glycol (TEG) on secondary structure of decolored bloodmeal (DBM) during heating was examined via synchrotron-based Fourier transform infra-red spectroscopy (FT-IR) and wide angle X-ray scattering (WAXS). Both additives homogenize secondary structure distribution; SDS increases α-helices and decreases β-sheets and β-turns, while SDS–TEG reduces α-helices and β-sheets and increase random coils. Short heat cycles only change the composition of SDS-TEG treated DBM, implying TEG is responsible for chain mobility. Prolonged heating slowly increases β-sheets and suddenly increases α-helices at 55–75 °C in SDS-TEG treated DBM and 100 °C in SDS-treated DBM. Finally, WAXS shows that structural change due to heating is reversible for SDS-TEG treated DBM

text: The effect of SDS and TEG on chain mobility and secondary structure of decolored bloodmeal The effect of sodium dodecyl sulfate (SDS) and triethylene glycol (TEG) on secondary structure of decolored bloodmeal (DBM) during heating was examined via synchrotron-based Fourier transform infra-red spectroscopy (FT-IR) and wide angle X-ray scattering (WAXS). Both additives homogenize secondary structure distribution; SDS increases α-helices and decreases β-sheets and β-turns, while SDS–TEG reduces α-helices and β-sheets and increase random coils. Short heat cycles only change the composition of SDS-TEG treated DBM, implying TEG is responsible for chain mobility. Prolonged heating slowly increases β-sheets and suddenly increases α-helices at 55–75 °C in SDS-TEG treated DBM and 100 °C in SDS-treated DBM. Finally, WAXS shows that structural change due to heating is reversible for SDS-TEG treated DBM

year: 2014-11

title: The Pirates of Parihaka: Parody as a Response to Violence

authors: Moffat, Kirstine

abstract: This paper originates from my archival exploration of Gilbert and Sullivan, specifically Frank Rolleston's adaptation of Pirates of Penzance, a discovery pivotal for my chapter on Gilbert and Sullivan in colonial New Zealand. This led to a broader investigation into literary and musical responses to Parihaka, contemplating the appropriateness of capturing its essence. In 2019, reflecting on our national journey, I align with Ihimaera's perspective, acknowledging the justified anger at injustice but also embracing the optimism and hope—a new dawn after the dark night, symbolizing death, resurrection, and new life. The Maori proverb "Ko te poo e teiwi te kai hari te raa" encapsulates this sentiment, emphasizing that the night brings the day, and "Ko te mate te kai hari i te orange e au" asserts that death brings life.

text: The Pirates of Parihaka: Parody as a Response to Violence This paper originates from my archival exploration of Gilbert and Sullivan, specifically Frank Rolleston's adaptation of Pirates of Penzance, a discovery pivotal for my chapter on Gilbert and Sullivan in colonial New Zealand. This led to a broader investigation into literary and musical responses to Parihaka, contemplating the appropriateness of capturing its essence. In 2019, reflecting on our national journey, I align with Ihimaera's perspective, acknowledging the justified anger at injustice but also embracing the optimism and hope—a new dawn after the dark night, symbolizing death, resurrection, and new life. The Maori proverb "Ko te poo e teiwi te kai hari te raa" encapsulates this sentiment, emphasizing that the night brings the day, and "Ko te mate te kai hari i te orange e au" asserts that death brings life.

year: 2019-11-26