A New Look at Xylanases: An Overview of Purification Strategies

Abstract

Interest in xylanases from different sources has increased markedly in the past decade, in part because of the application of these enzymes in the pulp and paper industry. Purity and purification costs are becoming important issues in modern biotechnology as the industry matures and competitive products reach the marketplace. Thus, new paths for successful and efficient xylanase recovery have to be followed. This article reviews the isolation and purification methods used for the recovery of microbial xylanases. Origins and applications of xylanases are described, highlighting the special features of this class of enzymes, such as the carbohydrate-binding domains (CBDs) and their importance in the development of affinity methodologies to increase and facilitate xylanase purification. Implications of recombinant DNA technology for the isolation and purification of xylanases are evaluated. Several purification procedures are analyzed, taking into consideration the sequence of the methods used in each and the number of times each method is used. New directions to improve xylanase separation and purification from fermentation media are described.

Purification and characterization of a new Xylanase from Humicola grisea var. Thermoidea

“…The ability of xylanases to penetrate an ultrafiltration membrane has been reported before (18,19,23). It is suggested to be due to xylanase compact structure and/or non-uniformity of membrane pore size (15,18). The retentate elution in DEAE-Sepharose chromatography resulted in the separation of two peaks of xylanase activity.…”

“…Furthermore, a small level of xylanase was present in the ultrafiltrate. Ultrafiltration procedure is reported to reduce xylanase recovery yields (15). Low purification yields for xylanase activities are often reported in the literature (7,15,18,22,23).…”

Immobilization of xylanase purified from Bacillus pumilus VLK-1 and its application in enrichment of orange and grape juices

“…The enzyme was purified 15.4-fold with 88.3 % recovery (Table 1). Purification of xylanase from various microorganisms involving different techniques and steps have been reported but with variations in specific activity, recovery % and fold purification (Sa-Pereira et al 2003). …”

Characterization of Enzymes Associated with Degradation of Insoluble Fiber of Soybean Curd Residue by Bacillus subtilis

“…Xylanases are produced from xylan by fungi, yeast and bacteria, including Bacillus sp. (Beg et al, 2001;Blanco et al,1995;Gallardo et al, 2004;Heck et al, 2005;Sa-Pereira et al, 2003) and physicochemical properties, structures and specific activities of these xylanases were diverse. In this study, two xylanase-active enzymes were isolated.…”