کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
17734 | 42692 | 2008 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Bleaching of kraft pulp by a commercial lipase: Accessory enzymes degrade hexenuronic acids Bleaching of kraft pulp by a commercial lipase: Accessory enzymes degrade hexenuronic acids](/preview/png/17734.png)
The potential of a commercial lipase for bleaching kraft pulp was investigated. Enzymatic treatment of hardwood and softwood kraft pulps before and after oxygen delignification resulted in a significant reduction of kappa number and hexenuronic acid content. Pretreatment of unbleached hardwood kraft pulp followed by a DE bleaching sequence gave the same kappa number as a control sequence but with considerably less chlorine dioxide. Two enzyme fractions containing high accessory enzyme activities were purified by size exclusion chromatography. These fractions demonstrated a high bleaching efficiency as well as a high selectivity, with a significant reduction in sugar released in the filtrate compared to commercial xylanase bleaching. This work provides the first evidence that the accessory enzymes from a commercial enzyme preparation can degrade hexenuronic acids and bleach kraft pulp.
Journal: Enzyme and Microbial Technology - Volume 43, Issue 2, 5 August 2008, Pages 130–136