Renewable natural resources such as xylans are abundant in many agricultural wastes. Penicillium sp. AHT-1 is a strong producer of xylanolytic enzymes. The sequential activities of its xylanase, alpha-L-arabinofuranosidase, and beta-xylosidase on model hemicellulose oat-spelt xylan was investigated. Optimum production of the enzymes was found in culture containing oat-spelt xylan at 30 degrees C and initial pH 7.0 after 6 days. The enzymes were partially purified by ammonium sulphate fractionation and anion-exchange chromatography on DEAE-Toyopearl 650 S. The apparent molecular mass was 21 kDa, and the protein displayed an "endo" mode of action. The xylanase exhibited glycotansferase activity. It synthesized higher oligosaccharides from the initial substrates, and xylotriose was the shortest unit of substrate transglycosylated. Xylanolytic enzymes (enzyme mixture) produced by this Penicillium sp. interacted cooperatively and sequentially in the hydrolysis of oat-spelt xylan in the following order: alpha-L-arabinofuranosidase --> xylanase --> beta-xylosidase. All three enzymes exhibited optimal activity under the same conditions (temperature, pH, cultivation), indicating that they alone are sufficient to completely depolymerize the test xylan. Results indicate that the xylanolytic enzyme mixture of Penicillium sp. AHT-1 could be useful for bioconversion of xylan-rich plant wastes to value-added products.
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http://dx.doi.org/10.1139/w02-114 | DOI Listing |
Int J Biol Macromol
November 2024
Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil; Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, SP, Brazil. Electronic address:
Acetylxylan esterases (AXEs) are essential enzymes that break down the acetyl groups in acetylated xylan found in plant cell walls polysaccharides. They work synergistically with backbone-depolymerizing xylanolytic enzymes to accelerate the degradation of complex polysaccharides. In this study, we cloned the gene axeA, which encodes the acetylxylan esterase from Aspergillus nidulans FGSC A4 (AxeAN), into the pEXPYR expression vector and introduced it into the high protein-producing strain A.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
November 2024
Graduate School of Bioresources, Mie University, Tsu, Japan.
Paenibacillus xylaniclasticus strain TW1 is a promising tool for decomposing xylan-containing lignocellulosic biomass, since this strain possesses various genes encoding cellulolytic/hemicellulolytic enzymes. In this study, PxRex8A from the TW1 strain was found to be a reducing-end xylose-releasing exo-oligoxylanase of glycoside hydrolase family 8, which cleaves xylose from xylooligosaccharides of corn core xylan. In a synergistic assay, the efficient decomposition of oat spelt xylan (OSX) and beech wood xylan was exemplified in the combination of endo-β-1,4-xylanase (PxXyn11A) and PxRex8A from the TW1 strain in a molar ratio of 4:1.
View Article and Find Full Text PDFInt J Biol Macromol
May 2024
College of Life Sciences, Capital Normal University, Beijing 100048, China. Electronic address:
Carbohydrate-binding module (CBM) family 91 is a novel module primarily associated with glycoside hydrolase (GH) family 43 enzymes. However, our current understanding of its function remains limited. PphXyl43B is a β-xylosidase/α-L-arabinofuranosidase bifunctional enzyme from physcomitrellae patens XB belonging to the GH43_11 subfamily and containing CBM91 at its C terminus.
View Article and Find Full Text PDF3 Biotech
January 2024
Programa Multicêntrico de Pós-Graduação em Bioquímica e Biologia Molecular, Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), Universidade Federal de Mato Grosso do Sul, Campo Grande, MS Brazil.
J Fungi (Basel)
March 2023
Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
A endo-1,4-β-mannanase (CcMan5C) gene was cloned from and heterologously expressed in , and the recombinant enzyme was purified by Ni-affinity chromatography and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). CcMan5C hydrolyzed only locust bean gum galactomannan (LBG) but not α-mannan from or Avicel cellulose, oat spelt xylan, or laminarin from . CcMan5C exhibited distinctive catalytic features that were different from previously reported β-mannanases.
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