In this study, protoplasts were successfully isolated from Kappaphycus alvarezii using snail enzymes, abalone enzymes and cellulase. The optimum enzymic ratio was fixed to be 20% of abalone enzyme, 12% of cellulase and the osmotic stabilizer was 2.0 mol/L glucose. The optimum enzymic hydrolysis conditions were found to be dark enzymolysis at 30℃ continuing for 4.0 h. The resultant density and yield of protoplasts achieved 32.60×10⁴ mL^-1, 65.20×10⁴ g^-1 tissue for Kappaphycus alvarezii. Finally, under the temperature of 20℃, light intensity of 1 500-2 000 lx and photoperiod of 12 h/d, two developmental pathways were investigated: (1) callus-like cell mass and regenerated plantlet occurred on protoplast; (2) young shoots and calluslike cell mass occurred in tissue blocks after enzymolysis.

Optimal conditions for protoplasts formation of marine Actinomycete sp.isolate M048 were described, dense and disperse mycelia were cultured in SGGP medium, 0.5% glycine, lysozyme exposure (2 mg/cm³, 37℃, 40 min), and the concentration of sucrose in protoplast buffer was 0.4 mol/dm3 for keeping the balance of osmotic pressure.Using PEG-mediated protoplasts transformation, the transformation frequency was 89 transformants per microgramme of pIJ702.Meanwhile, an effective transformation procedure was established based on intergeneric conjugation from E.coli ET12567 (pUZ8002) using shuttle vectors pPM801, pPM803 and a (ψ)C31-derived integration vector pIJ8600 containing ori T and att P fragments.Transformation frequencies were 5.30×10^-4±0.26×10^-4, 8.92×10^-4±0.19×10^-4 and 6.38×10^-5±0.41×10^-5, respectively.Further, the heterologous expression of the allophycocyanin gene (apc) in the strain M048 was used to demonstrate this transformation system.SDS-PAGE and Western blot analysis confirmed the expression of recombinant APC (rAPC).

Comparative ultrastructural investigations on twenty-three isolates of Tetraselmis from the South China Sea, East China Sea and Huanghai Sea, have revealed that these isolates belong to:(1) Tetraselmis chui Butcher; (2) T. cordiformis (H. J. Carter) Stein; (3) T. helgolandica Kylin; (4) T. suecica (Kylin) Butcher; (5) T. guangdongensis sp. nov. Except T. helgolandica,the others are new records in China. T. guangdongensis sp. nov. is a new species. Its external and anatomical features closely resemble those of T. impellucida McLachlan et Parke. As in that species the pyrenoid is penetrated from many directions by cytoplasmic channels delimited by a double membrane.The protoplast withdraws from the apical portion of the theca, that portion which overlaid the trough inverts and pops out in the form of a teat. But unlike that species a starch sheath is present; pyrenoid matrix is surrounded by thylakoids which intervenes between the matrix and the starch sheath surrounding pyrenoid; the theca is stratified.