Production and purification of alkaline xylanases

Partial purification and properties of cellulase-free alkaline xylanase produced by Rhizopus stolonifer in solid-state fermentation

“…The optimum pH for xylanases cited in the literature varied between 4.0 and 5.5 (Uhlig, 1998); however, some bacterial xylanases showed optimum activity between pH 6.0 and 7.0. These results are interesting as the thermostable and alkaline xylanases have good scope because the enzymatic bleaching of kraft pulp needs these enzymes with such characteristics (Subramaniyan and Prema, 2000;Duarte et al, 1999;Christov et al, 1999). Thus, the alkaline xylanase studied in this work could be utilized with this purpose.…”

“…An increase of 55% in the xylanase specific activity was reached in the group P-II ( Table 1). Monti et al (1991) reported 169.35 U/mg protein for xylanase of Humicola grisea; Christov et al (1999), using several species of Aspergillus obtained 547.4 U/mL for a xylanase of A. foetidus (ATCC 14916); Duarte et al (1999) isolated several strain of bacteria, with 41.1 U/mg protein for a xylanase of the "B" strain; Ghanem et al (2000) used several forms for the purification of a xylanase of A. terreus and obtained a final specific activity of 183.29 U/mg protein. Heck et al (2002) reported 5.19 U/mg protein for xylanase of a strain of Bacillus subtilis; Damaso et al (2002), using Thermomyces lanuginosus (IOC-4145), obtained 85 U/mg protein for the xylanase activity in a filtered culture.…”

Use of Bacillus pumilus CBMAI 0008 and Paenibacillus sp. CBMAI 868 for colour removal from paper mill effluent

“…Bacillus pumilus CBMAI 0008 was isolated from wood decomposition material by Duarte et al (1) and was maintained in a culture medium containing birchwood xylan (6). Paenibacillus sp.…”

“…Bacillus pumilus CBMAI 0008 and Paenibacillus sp. CBMAI 868 previously isolated, respectively, from wood decomposition material and paper mill effluent were identified by the Coleção Brasileira de Microrganismos de Ambiente e Indústria -CBMAI and are able to produce alkaline enzymes under thermophilic conditions, including xylanases and manganese-dependent peroxidase (1,2,3,8,10). In this study we evaluated the ability of these bacteria for colour removal of the paper mill effluent.…”

Purification of α‐toxin from Clostridium perfringens type A in PEG‐phosphate aqueous two‐phase systems: a factorial study

“…Yield values above 100% are frequently reported for enzyme extraction using liquid-liquid systems. 18,19,20 It has been suggested that PEG is essentially an inert polymer that does not interact with proteins due to its steric and hydration properties. 21 However, several authors have found evidence of interactions between PEG and proteins.…”