کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
33436 44978 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
CTAB, Triton X-100 and freezing–thawing treatments of Candida guilliermondii: Effects on permeability and accessibility of the glucose-6-phosphate dehydrogenase, xylose reductase and xylitol dehydrogenase enzymes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
CTAB, Triton X-100 and freezing–thawing treatments of Candida guilliermondii: Effects on permeability and accessibility of the glucose-6-phosphate dehydrogenase, xylose reductase and xylitol dehydrogenase enzymes
چکیده انگلیسی

Cells of Candida guilliermondii (ATCC 201935) were permeabilised with surfactant treatment (CTAB or Triton X-100) or a freezing–thawing procedure. Treatments were monitored by in situ activities of the key enzymes involved in xylose metabolism, that is, glucose-6-phosphate dehydrogenase (G6PD), xylose reductase (XR) and xylitol dehydrogenase (XD). The permeabilising ability of the surfactants was dependent on its concentration and incubation time. The optimum operation conditions for the permeabilisation of C. guilliermondii with surfactants were 0.41 mM (CTAB) or 2.78 mM (Triton X-100), 30 °C, and pH 7 at 200 rpm for 50 min. The maximum permeabilisation measured in terms of the in situ G6PD activity observed was, in order, as follows: CTAB (122.4 ± 15.7 U/gcells) > freezing–thawing (54.3 ± 1.9 U/gcells) > Triton X-100 (23.5 ± 0.0 U/gcells). These results suggest that CTAB surfactant is more effective in the permeabilisation of C. guilliermondii cells in comparison to the freezing–thawing and Triton X-100 treatments. Nevertheless, freezing–thawing was the only treatment that allowed measurable in situ XR activity. Therefore, freezing–thawing permeabilised yeast cells could be used as a source of xylose reductase for analytical purposes or for use in biotransformation process such as xylitol preparation from xylose. The level of in situ xylose reductase was found to be 13.2 ± 0.1 U/gcells.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: New Biotechnology - Volume 29, Issue 2, 15 January 2012, Pages 192–198
نویسندگان
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