PROTOPLAST FORMATION FROM SCHIZOPHYLLUM-COMMUNE BY A CULTURE FILTRATEOF BACILLUS-CIRCULANS KA-304 GROWN ON A CELL-WALL PREPARATION OF S-COMMUNE AS A CARBON SOURCE

From microorganisms growing on a cell-wall preparation (CWP) of Schizo phyllum commune as a carbon source, Bacillus circulans KA-304 was isol ated on the bases of activities in culture filtrate to decrease turbid ity of the CWP-suspension and to form protoplasts from S. commune. The culture filtrate was also active in hydrolyzing p-nitrophenyl (p-NP)- alpha-D-glucoside, p-NP-beta-B-glucoside, and p-NP-beta-D-N-acetylgluc osaminide. The protoplast-forming and the p-NP-glycoside-hydrolyzing a ctivities were increased by the addition of CWP of S. commune to the c ulture medium, and this was not observed for other bacteria tested (15 genera, 80 species), B. circulans KA-304 was shown on gel filtration to produce at least two enzyme species for hydrolyzing both p-NP-beta- D-glucoside and p-NP-alpha-D-glucoside. The protoplast-forming activit y was retained for at least 6 months at 5 degrees C as an ammonium sul fate (90% saturation) precipitate or at -20 degrees C as a freeze-drie d preparation (KA-preparation). The activity was stable at pH 6.5-7.0, and remained after 10 min of treatment at 40 degrees C. Protoplast fo rmation proceeded optimally at pH 6.5 with 50 mM potassium phosphate b uffer and 0.5 M mannitol as an osmotic stabilizer, B. circulans KA-304 seems to be a suitable strain producing enzyme(s) to prepare protopla sts from S. commune.