کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6289536 1301752 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Identification of Paenibacillus sp. 2S-6 and application of its xylanase on biobleaching
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست علوم زیست محیطی (عمومی)
پیش نمایش صفحه اول مقاله
Identification of Paenibacillus sp. 2S-6 and application of its xylanase on biobleaching
چکیده انگلیسی
A Paenibacillus sp. strain 2S-6 was isolated from the black liquor of the first brownstock washing stage of kraft pulping process and identified by its 16S rDNA sequence. This bacterial strain utilized a variety of saccharides and polysaccharides as carbon source, but neither lignin nor lipids. Crude xylanase from Paenibacillus sp. 2S-6 was produced in a 5 L laboratory fermenter at 37 °C, pH 7. After 24 h, up to 10.5 IU xylanase per mg of protein in the crude extract of fermentation broth was obtained. After two-stage ultrafiltration, the optimal activity of partially purified xylanase reached 60.51 IU/mg at 50 °C, pH 6. A major band indicating molecular weight of 33 kDa was shown on SDS-PAGE for the partially purified xylanase. After 4 h at 60 °C, 48.99% and 31.25% residual xylanase activities were demonstrated at pH 7 and 9, respectively. Efficacy of its xylanase on the bleaching agent saving was demonstrated by using 5 IU xylanase per gram oven-dried pulp prior to bleaching, referred as biobleaching. Identical levels of brightness and higher levels of viscosity were obtained for the xylanase pretreated eucalypt kraft pulps followed by a 20% reduction of the bleaching agent dosage in the first step of a commercial C70/D30-Eo-D bleaching sequence.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Biodeterioration & Biodegradation - Volume 65, Issue 2, March 2011, Pages 334-339
نویسندگان
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