| Abstrakt: |
Abstract: A yeast strain, CO-2, was isolated as a producer of extracellular protease from a sample of bamboo by-product. The cells were spherical- to ovoid-shaped and 3.7-4.2×4.1-4.8µm in size. The isolated strain grew at 20–45°C, in the pH range of 3.0–12.0. Optimal growth conditions were 35°C and pH of 6.0 for 14 h. The isolate was able to grow in up to 8.0%(w/v) NaCl and 9.0%(v/v) ethanol. Biochemical data obtained using the VITEK system were close to those of Pichia farinose (exhibiting a 97% matching level). Based on molecular phylogenetic analysis of the 18S rDNA sequences and restriction enzyme analysis of the 18S rDNA-ITS1 region, this strain was identified as P. farinosa. Optimum pH and temperature of the crude protease preparation of P. farinose CO-2 were pH 3.0 and 40°C, respectively. The enzyme retained more than 80% of its stability at pH ranging from 3.0 to 8.0. After heating at 60°C for 1 h, the enzyme exhibited 71% of its original activity. |
