Preparation of bacterial enzymes capable of degrading the cell wall of red alga Porphyra yezoensis.

The authors isolated three bacteria from natural habitats which were able to produce β-1, 4-mannanase, β-1, 3-xylanase and porphyranase. They were cultivated in a fiuid media, stirring for 4 days at 25°C. Each enzyme produced was partially purified from the culture fluid by ammonium sulfate precipitation and chromatography on a Sephadex G-200 column. The thallus of Porphyra yezoensis was treated with a 0.5% papain solution, and then it was put in a mixture solution of 0.1M acetate buffer, pH 6.0, 0.1 unit each of β-1, 4-mannanase, β-1, 3-xylanase and porphyranase, and 0.7M mannitol as an osmoticum. After 1 h-gentle shaking of the mixed solution, a number of protoplasts were released from the thallus. When the thallus was treated with the mixture solution which lacked in the above three enzymes, no protoplast was observed. These results indicate that the bacterial enzymes obtained were quite useful to degrade the cell wall of red aigae, and an of β-1, 4-mannanase, β-1, 3-xylanase and porphyranase were essential for the release of protoplast from the thallus of P. yezoensis.