BackgroundGlycoside hydrolases (GHs) are enzymes that hydrolyze polysaccharides into simple sugars. To better understand the specificity of enzyme hydrolysis within the complex matrix of polysaccharides found in the plant cell wall, we studied the reactions of individual enzymes using glycome profiling, where a comprehensive collection of cell wall glycan-directed monoclonal antibodies are used to detect polysaccharide epitopes remaining in the walls after enzyme treatment and quantitative nanostructure initiator mass spectrometry (oxime-NIMS) to determine soluble sugar products of their reactions.ResultsSingle, purified enzymes from the GH5_4, GH10, and GH11 families of glycoside hydrolases hydrolyzed hemicelluloses as evidenced by the loss of specific epitopes from the glycome profiles in enzyme-treated plant biomass. The glycome profiling data were further substantiated by oxime-NIMS, which identified hexose products from hydrolysis of cellulose, and pentose-only and mixed hexose-pentose products from the hydrolysis of hemicelluloses. The GH10 enzyme proved to be reactive with the broadest diversity of xylose-backbone polysaccharide epitopes, but was incapable of reacting with glucose-backbone polysaccharides. In contrast, the GH5 and GH11 enzymes studied here showed the ability to react with both glucose- and xylose-backbone polysaccharides.ConclusionsThe identification of enzyme specificity for a wide diversity of polysaccharide structures provided by glycome profiling, and the correlated identification of soluble oligosaccharide hydrolysis products provided by oxime-NIMS, offers a unique combination to understand the hydrolytic capabilities and constraints of individual enzymes as they interact with plant biomass.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-017-0703-6) contains supplementary material, which is available to authorized users.

Antibiotic pollution via wastewaters has led to many environmental problems. In this work, to remove ciprofloxacin which is an antibiotic from water, foil photocatalyst of zinc oxide nanowires doped with copper and cerium oxides was applied under UV light irradiation. An empirical model was developed to determine the photocatalyst activity using response surface methodology. The independent variables were the concentrations of precursors, copper and cerium nitrates in the coating solution. The F‐value and p‐value of the model showed the accuracy of the model. The statistical analysis indicated that copper oxide had larger effect on the response than cerium oxide. The optimized catalyst was determined and characterized using ICP, XRD, SEM and MIP techniques. The results of this work which are comparable to those of the previous studies have the advantage of easy separation of the photocatalyst from water without using a centrifuge.