Seedling production using enzymatically isolated thallus cells and its application in Porphyra cultivation

On the basis of previous achievements in Porphyra seedling production using enzymatically isolated thallus cells, we have investigated the influences of water content of thallus before freezing, storing temperature and enzymes on the viability of isolated cells. We have also tried outdoor cultivation of seedlings produced enzymatically in different seasons. It has been found that survival rate of isolated cells of thallus stored for two months can reach 90% if water content is 30% before freezing and storing temperature is constant at - 20°C. The 80% cell survival rate can be reached after two years of storage under this condition. The fluctuation of storing temperature causes drastic decrease of cell survival rate. 84% of the cells have survived digestion of sea snail enzyme I, which is the highest among five enzymes used. Outdoor cultivation of seedlings produced on the first ten days of January can reach lengths of more than 20 cm upon harvesting in the middle of May. In addition, seedlings produced in spring can be stored frozen and cultivated in autumn. The harvesting date will advance 15 days in comparison with the conventional seedling producing approach. This promises multiple rounds of cultivation of Porphyra within a year.