THE STATUS AND PROBLEMS IN STUDY OF BLUE-GREEN ALGAE SPHEROPLASTS Isolation of Blue-Green Algal Spheroplasts by Penicillin-Lysozyme Method Regeneration of Spheroplasts in a N2-Fixed Filamentous Blue-Green Alga Anabaena cylindrica Complemental Effect of Osmotic Stabilizers and Their Roles in Degradation Cell Walls of Blue-Green Algae Isolation and Photosynthesis of Spheroplasts in Spirulina platensis EFFECT OF MANNITOL ON THE CELLS OF BLUE-GREEN ALGAE A NEW METHOD TO ISOLATE THE SPHEROPLASTS FROM BLUE-GREEN ALGAE; PENICILLIN-LYSOZYME METHOD SPONTANEOUS SPHEROPLAST FUSION IN A BLUE-GREEN ALGA ANABAENA CYLINDRICA