Xylanase

About: Xylanase is a research topic. Over the lifetime, 7099 publications have been published within this topic receiving 163793 citations.

Simultaneous application of phytase and xylanase to broiler feeds based on wheat: in vitro measurements of phosphorus and pentose release from wheats and wheat-based feeds†

Abstract: An in vitro procedure that simulated digestion in growing broilers was tested to predict phosphorus availability and arabinoxylan hydrolysis in samples of nine wheat varieties and in a wheat-based diet. Amounts of dialysable phosphorus freed from wheat samples correlated with activities of endogenous phytase (R = 0.913; p < 0.0001), whereas amounts of pentoses released were correlated with viscosities of the digested samples (R = 0.899; p < 0.0001). Differences in phosphorus release resulting from graded levels of microbial phytase added to feeds that were either autoclaved or not autoclaved revealed a decreasing role of endogenous phytase in dephosphorylation as levels of microbial phytase supplementation grew. Amounts of pentoses released from feeds containing two different xylanase preparations reflected literature data on different in vivo efficacies of those preparations. Simultaneous addition of phytase and xylanase affected phosphorus release in a manner that depended upon the form of xylanase preparation used (liquid or powder). There was a positive influence of acid protease on both phytate and arabinoxylan hydrolysis in feeds supplemented with phytase. Effects observed by the in vitro procedures corresponded to in vivo phenomena described in the literature. © 1999 Society of Chemical Industry

β-Xylosidase and xylanase characterization and production by Streptomyces sp. CH-M-1035

Abstract: Extracellular xylanase activity and cell-bound β-xylosidase production by a selected strain of Streptomyces sp. CH-M-1035 was characterized during growth on three xylans, sugar cane bagasse pith and lemon peel as sole carbon source. The cell-bound β-xylosidase and extracellular endoxylanase had pH optima of 6·0 and 5·0, and temperature optima of 50°C and 60°C, respectively. The highest level of β-xylosidase activity was obtained when Streptomyces sp. CH-M-1035 was grown on larchwood xylan, whereas the maximal endoxylanase production was found on lemon peel. Reducing sugars accumulated in the culture media when Streptomyces sp. CH-M-1035 was grown on xylans, but not on agroindustrial residues.

A xylanase produced by the rumen anaerobic protozoan Polyplastron multivesiculatum shows close sequence similarity to family 11 xylanases from Gram-positive bacteria

Abstract: We report for the first time the cloning and characterisation of a protozoal enzyme involved in plant cell wall polysaccharide degradation. A cDNA library was constructed from the ruminal protozoan Polyplastron multivesiculatum and a stable clone expressing xylanase activity was isolated. The encoded enzyme belongs to the glycoside hydrolase family 11, and phylogenetic analysis indicates a closer relationship with catalytic domains from Gram-positive bacteria than the other fibrolytic eukaryotes from the rumen, the anaerobic fungi.