Measurement of acetylxylan esterase in Streptomyces

Extracellular Carbohydrate Esterase from the BasidiomyceteCoprinopsis cinereaReleased Ferulic and Acetic Acids from Xylan

“…11,12) The release of acetic acid and ferulic acid from xylan was examined as follows: acetylated xylan was prepared from oat-spelt xylan as described previously. 13) The reaction was performed with purified rCcEst1 (8 ng/ml) in 200 ml of McIlvaine buffer (pH 7.0) containing acetylated xylan (10 mg/ml) in the absence and the presence of endo--1,4-xylanase from Thermomyces lanuginosus (Sigma, 2.9 ng/ml) at 37 C for 1 h. The reaction was terminated by adding 300 ml each of 0.3 M zinc sulfate and 0.3 M barium hydroxide. After 20 min of centrifugation, the supernatant was transferred to a new tube.…”

Purification and some characteristics of the acetylxylan esterase from Schizophyllum commune

“…Enzyme assays The acetyl esterase activity was assayed by the method of Johnson et al (1988a) with some modification. Aliquots (100 ,u) of the enzyme diluted in 20 mM sodium phosphate buffer, pH 7.0, were mixed with 800 ,u1 of distilled water, and the enzyme reaction was started by adding 100 ,ul of 10 mM 4-nitrophenylacetate dissolved in dimethyl sulphoxide.…”

Phylogeny, classification and metagenomic bioprospecting of microbial acetyl xylan esterases

“…Chemically acetylated alkali-extracted glucuronoxylan is an alternative substrate used in functional assays to confirm AcXE activity [35]. While the substrate specificity of AcXEs has been associated with whether xylan was naturally or chemically acetylated [36], it remains unclear whether the acetyl groups in chemically acetylated xylan are located on xylopyranosyl residues only.…”

“…The fact that acetylated xylan is not currently commercially available also represents a bottleneck in the AcXE screening technologies. Several researchers [29,36,90,101,120] report the in-house (and rather time-consuming) synthesis of this substrate using the method of [35], while others extract acetylated xylan from natural substrates using DMSO [34,66,78,121] or steam [33,58,62].…”