Xylanase

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

Characteristics of Enzymes Produced by Ruminococcus flavefaciens which Degrade Plant Cell Walls

Abstract: Summary: Enzyme preparations active against crystalline cellulose, marble-milled filter paper, carboxymethyicellulose (CM-cellulose), hemicellulose and xylan were obtained from cultures of Ruminococcus flavefaciens. These preparations also contained swelling factor, pectin methylesterase, pectin lyase and low levels of aryl β-glucosidase and aryl β-xylosidase. CM-cellulase and xylanase activities were present in a high molecular weight complex, but substrate competition studies showed that different active sites were probably responsible for each activity. Analysis of products and viscosity changes during enzymic hydrolysis of CM-cellulose and xylan indicated that the most active enzymes were of the exo-1, 4-β-glycosidase type. A variety of reducing sugars were released from cell walls of Lolium perenne (perennial ryegrass) by enzyme preparations.

Invertase and xylanase activity of bulk soil and particle-size fractions during maize straw decomposition

Abstract: The activity of invertase and xylanase during maize straw decomposition was investigated in an incubation experiment (14°C, 52 weeks) with two treatments: (i) straw mixed with soil (mixed) and (ii) straw placed on the soil surface (surface) A soil without straw was included as reference (ref soil) The particle-size fractions (2000–200 μm, 200–63 μm, 63–2 μm, 2–01 μm and 250 μm) Invertase and xylanase in the bulk soils with straw applied were mainly influenced by a highly variable activity in the >200 μm fraction, which contained most of the added organic matter during the incubation Enzyme activity associated with particles <63 μm was less affected by maize straw Invertase activity clearly differed between the mixed and surface treatment, particularly in the early phase of incubation This difference seemed to be linked to different microbial communities Xylanase activity was mainly located in the coarser fractions throughout the incubation and did not differ between treatments After an initial lag phase, xylanase activity increased steadily, showing highest values when 30–40% of the maize straw was released as CO2 In conclusion, the separation of differently sized organo-mineral particles yielded enzyme pools which differ significantly in size and stability, both factors strongly depending on enzyme type and substrate localisation

Ileal amino acid digestibility and performance of growing pigs fed wheat-based diets supplemented with xylanase.

Abstract: Two experiments were conducted to determine the effect of supplementation of xylanase to a wheat-based diet on the apparent ileal digestibility (AID) of AA and the performance of growing pigs fed diets limiting in AA. In Exp. 1, eight pigs (average initial BW = 20.5 ± 1.2 kg) fitted with a simple T-cannula at the distal ileum, were fed four diets according to a repeated 4 x 4 Latin square design. Diet 1 was a basal diet that contained 97.6% wheat. Diets 2, 3, and 4 were the basal diet supplemented with xylanase at rates of 5,500, 11,000, and 16,500 units of xylanase activity (XU), respectively (as-fed basis). There were linear and quadratic effects (0.062 < P < 0.001) of xylanase supplementation on the AID of CP and most of the AA. The largest increases in AID of CP and AA were obtained when xylanase was supplemented at a rate of 11,000 XU; no further increases were observed with xylanase supplementation at a rate of 16,500 XU. In Exp. 2, 30 pigs (average initial BW 21.4 ± 1.8 kg) were randomly allotted to six dietary treatments. Diets 1 to 4 were similar to those used in Exp. 1. Diet 5 was the same as Diet 1, but supplemented with 0.53% lysine, 0.12% threonine, and 0.05% methionine. Diet 6 (positive control diet) was a wheat-soybean meal diet that contained 18.2% CP (as-fed basis). The total contents of lysine, threonine, and methionine were similar for Diets 5 and 6. There was a linear effect of xylanase supplementation on ADG (P = 0.093) and feed:gain ratio (P = 0.089), and a quadratic effect on ADG (P = 0.067) and feed:gain ratio (P = 0.074). But, the greatest response was obtained with the supplementation of 11,000 XU. The supplementation of lysine, threonine, and methionine to Diet 1 increased (P = 0.001) ADG and ADFI and improved (P = 0.01) feed:gain ratio. There was no difference (P = 0.508) in the performance of pigs fed the AA-supplemented or control diet. In conclusion, the supplementation of xylanase to a diet in which wheat provided the sole source of protein and energy improved the AID of AA, ADG, and feed:gain ratio; however, this improvement was very small compared with that obtained with the supplementation of synthetic amino acids.

Using Amazon forest fungi and agricultural residues as a strategy to produce cellulolytic enzymes

Abstract: The successful strategy to produce cellulolytic enzymes includes both microorganism selection and improved fermentation process conditions. This work describes the isolation, screening and selection of biomass-degrading fungi species from the Amazon forest and analyzes the enzymatic complex produced by a selected strain of Aspergillus fumigatus cultivated using different agro-industrial residues (wheat bran, sugarcane bagasse, soybean bran, and orange peel) as substrate in solid state fermentation (SSF). The profile of endoglucanase (CMCase), FPase, β-glucosidase and xylanase enzymatic activities obtained during 120 h of cultivation is presented. Enzyme activities up 160.1 IU g−1 for CMCase, 5.0 FPU g−1 for FPAse, 105.82 IU g−1 for β-glucosidase and 1055.62 IU g−1 for xylanase were achieved. The enzymatic extract with higher CMCase activity was used to run a zymogram analysis that showed 3 bands of endoglucanase activity. Characterization studies of this extract showed that the CMCase was most active at either 65 °C or pH 3–3.5, indicating that this microorganism produces a thermophilic and acid endoglucanase. These data demonstrate that the fungal isolates from the Amazon forest are a potential source of cellulases and xylanases, providing support to further studies related to the use of these microorganisms to obtain the enzymes needed for biomass conversion.