SCREENING OF THE LYTIC ENZYME FOR THE RED YEAST PHAFFIA-RHODOZYMA CELL-WALL AND EXTRACTION OF ASTAXANTHIN

Screening was conducted for a lytic enzyme-producing microorganism wit h the aim of achieving efficient extraction of astaxanthin from Phaffi a rhodozyma cells. The actinomycete Streptomyces rochei strain PHA-34 was found to produce the lytic enzyme, which mainly contained beta-1,3 glucan-and beta-1,6 glucan-hydrolyzing activities and which was stabl e within a wide pH range. The enzyme was induced by the addition of Ph affia cell wall into the culture broth. It was capable of lysing not o nly P. rhodozyma cells but also ascomycete and imperfecti yeasts in th e logarithmic phase, as well as many basidiomycete yeasts regardless o f the growth phase. Using the enzyme from S. rochei PKA-34, the extrac tion of astaxanthin was superior in yield to that obtained by physical or chemical treatments or by using other commercially available lytic enzymes. The astaxanthin obtained using the PHA-34 enzyme was similar to synthetic astaxanthin on high performance liquid and thin layer ch romatographies.