کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10160929 | 276 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Evaluation of porous glass and zeolite as cells carriers for xylitol production from sugarcane bagasse hydrolysate
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Evaluation of porous glass and zeolite as cells carriers for xylitol production from sugarcane bagasse hydrolysate Evaluation of porous glass and zeolite as cells carriers for xylitol production from sugarcane bagasse hydrolysate](/preview/png/10160929.png)
چکیده انگلیسی
Adsorbing carriers for immobilisation of Candida guilliermondii cells to use for xylitol production from sugarcane bagasse hemicellulose hydrolysate were tested. Biomass was immobilised in situ by natural adsorption, i.e. through direct contact between cells for the inoculum and carrier particles at the beginning of fermentations. The carriers employed were: Syrane porous glass beads with 2.53 mm diameter in average and pore diameter in the range 60-300 μm, supplied by Bioengineering (Wald, Switzerland), and NaX zeolite UOP WE 894 purchased from Plury QuÃmica S.A. (Diadema, SP, Brazil). At the end of the run with free cells taken as a reference test, xylitol concentration (Pf) achieved 35.5 g/l, corresponding to a xylose-to-xylitol yield factor (YP/S) of 0.72 g/g and a volumetric productivity (QP) of 0.49 g/l h, while final cell concentration (Xf) and productivity (Qx) were only 5.32 g/l and 0.048 g/l h, respectively. Both systems with immobilised cells exhibited lower xylitol productions (Pf = 28.8-29.5 g/l, YP/S = 0.52-0.53 g/g, QP = 0.32-0.33 g/l h) and higher cell growth, with particular concern to porous glass (Xf = 10.5 g/l, Qx = 0.10 g/l h). Electronic microscopy observations demonstrated that the excellent performance of porous glass as cell support was due to the development of a thick extracellular matrix either within the large pores or on the surface of this material. As a consequence, almost 50% of the cells resulted to be adsorbed to the carrier at the end of the run. This growth was also responsible for a decrease in the fraction of xylose available for xylitol production. Employing zeolite, a material with pore size smaller than cell size, immobilised cells represented only 30% of the final population and immobilisation was just observed on the carrier surface. The low cell attachment on this material can be explained by the stress exerted on the outer immobilised cells by the friction among beads.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical Engineering Journal - Volume 23, Issue 1, March 2005, Pages 1-9
Journal: Biochemical Engineering Journal - Volume 23, Issue 1, March 2005, Pages 1-9
نویسندگان
Júlio C. Santos, Solange I. Mussatto, Giuliano Dragone, AtÃlio Converti, SÃlvio S. Silva,