For immobilization of puerarin glycosidase from Microbacterium oxydans CGMCC 1788 on DEAE-52 cellulose, the optimal amount of enzyme protein was 12 mg protein: 1 g DEAE-52 cellulose; the optimal pH was 6.5; and the optimal immobilization time was 6 hr. The specific activity of immobilized enzyme was 36.67 mU.g-1 carrier with an immobilization yield of 98.87% and an enzyme recovery yield of 92.43%. The molar transformation rates of puerarin by immobilized enzyme and by the relative bacterial cell amount equal to the same amount of enzyme were 53.3% and 2.2%, respectively, after 1 hr of transformation. The former molar transformation rate, which was similar to that for free enzyme, was more than 24-fold greater than the latter. The immobilized puerarin glycosidase showed improved enzymatic properties and stability. The immobilized puerarin glycosidase retained 88% of its initial activity after being reused 10 times.

Identification of commercially important fungi, such as the valuable edible fungus Boletus edulis can be difficult considering visual or metabolic approaches. Based on phylogenetic analysis of the rDNA ITS sequence, a pair of specific primers was designed for differentiating B. edulis from other mushrooms by PCR. PCR was performed with total DNA as a template at an annealing temperature between 56-60ºC. Positive amplicons were obtained from B. edulis with all DNA templates from fruit bodies and cultured mycelium, but not from other fungal species at an annealing temperature of 60ºC. The result indicated that B. edulis could be clearly distinguished from other fungi by PCR, and there were no misidentifications under the reaction conditions used. The primers were also successfully employed to identify various tissues of B. edulis.