Isolation of xylanase-producing yeast Pseudozyma tsukubaensis from chrysanthemum

Yeast strains showing xylanase activity were explored from various natural sources, such as flowers and soil. A yeast strain showing high xylanase activity on the Remazol Brilliant Blue-xylan plate was isolated from the flower of yellow chrysanthemum and identified as Pseudozyma tsukubaensis through analysis of the nucleotide sequence of the internal transcribed spacer region of 18S ribosomal RNA. P. tsukubaensis MBY/L1662 exhibited higher tolerance to fermentation inhibitors than the control strain. The maximum xylanase activity of 3,244.11 ± 210.01 U/mg protein was obtained for P. tsukubaensis MBY/L1662 grown at pH 5 and 10 g/L xylose. The ability of P. tsukubaensis MBY/L1662 to degrade xylan will be a critical stepping stone for its various applications.