Screening of yeasts capable of producing cellulase-free xylanase

Abstract

Xylanases have largely been obtained from filamentous fungi and bacteria; few studies have investigated the production of this enzyme by yeasts. The aim of this study was to isolate yeasts from different sources, such as vegetables, cereal grains, fruits, and agro-industrial waste and to obtain yeasts capable of producing celulase-free xylanase. Samples were enriched using yeast malt broth, and yeasts were isolated on Wallerstein nutrient agar. In all, 119 yeast strains were isolated and evaluated in terms of their ability to degrade xylan, which was found in the medium by using agar degradation halos, the basis of this polysaccharide, and Congo red dye. Selected microorganisms were grown in complex medium and the enzymatic activities of endo-xylanase, β-xylosidase, carboxymetilcellulase, and filter paper cellulose were determined over 96 h of cultivation; the pH and biomass concentration were also evaluated. The yeast strain 18Y, which was isolated from chicory and later identified as Cryptococcus laurentii, showed the highest endo-xylanase activity (2.7 U.mL-1). This strain had the ability to produce xylanase with low levels of cellulase production (both CMCase [0.11 U.mL-1 ] and FPase [0.10 U.mL-1 ]). This result gives this strain great biotechnological potential since this enzyme can be used for industrial pulp and paper bleaching.

Purification and characterization of an extracellular β-xylosidase from Pseudozyma hubeiensis NCIM 3574 (PhXyl), an unexplored yeast

“…However, no growth and enzyme production was observed at 35 °C. This is highest β-xylosidase activity reported so far from the yeast strains (Lara et al 2014 ; Otero et al 2015 ). C ryptococcus albidus produced 1.0 IU mL −1 of β-xylosidase on xylan (Peciavora and Biely 1982 ).…”

Evaluation of Multifarious Plant Growth Promoting Trials of Yeast Isolated from the Soil of Assam Tea (Camellia sinensis var. assamica) Plantations in Northern Thailand

“…Five replications were made for each enzyme. Endoglucanase and xylanase productions were investigated on carboxymethyl cellulose (CMC) agar [ 40 ] and xylan agar [ 41 , 42 ], respectively. One drop of yeast inoculum (5 µL) was dropped onto the tested media.…”

Process optimization for simultaneous production of cellulase, xylanase and ligninase by Saccharomyces cerevisiae SCPW 17 under solid state fermentation using Box-Behnken experimental design

“…To the best of the authors' knowledge, no studies have been carried out on the production of combined multienzyme – cellulase, xylanase and ligninase from yeasts from a mushroom farm. Studies reported in literature include production of xylanase using psychrophilic yeast Cryptococcus adeliae and Cryptococcus flavus isolate I-11 [ 11 , 12 , 13 ]. Gomes et al.…”