Isolation and identification of xylanase-producing yeast, Pichia kudriavzevii used in the food industry

Today, among 400 types of identified enzymes, approximately 200 types are used in industry. The global enzyme market depict a major portion for xylanase, cellulase and pectinase at around 20%. Xylanase enzyme is used in different industries such as food industry, animal and poultry feed, paper industry and pharmaceutical industry. The aim of this study was to identify xylanase-producing yeast. Effluents from factories and poultry farms in Isfahan were sampled. In order to isolate the xylanase-producing yeasts, the samples were cultured on YPG medium containing beech wood using streak plate method. The enzyme activity was measured by DNS method and protein assay was done by Laurie method. The molecular identification of the best xylanase-producing isolate was performed using PCR followed by sequencing and blasting procedures. The yeast Pichia kudriavzevii strain SBN-IAUF-2 was isolated as the best xylanase producing yeast with the maximum enzyme activity of 1317.56 (u/ml) and maximum specific enzyme activity of 3272/3271 (u/mg) after 48 hours at 30 degree Celsius and aeration speed of 120 rpm. The 18s-rDNA partial sequence of the isolated yeast was deposited in GenBank, NCBI under the accession number of MZ816945. This is the first report of isolation and identification of xylanase-producing yeast Pichia kudriavzevii strain SBN-IAUF-2 conducted in Iran and it is recommended to be applied for optimal production of xylanase.