Filamentous Somatic Cells Of Haitanensis Nutrition Proliferation In The Photobioreactor

As an economical macroalga, Porphyra is of great economical and biological importance,and can be used as experimental system in the research of marine biology. Here we usebiochemical engineering technology of photobioreactors for suspended cultivation ofconchocelis, in order to offer fine seeds to the seed-breeding, and to produce materials forfundamental and applied research, and also to establish techniques for cell cultivation.Photobioreactors suitable for macroalga cell cultivation must offer five fundamental factors:illumination, controllable temperature, air transfer, nutrients transfer, and mixing. In thisthesis, we cultivated Porphyra haitanensis conchocelis within the photobioreactorsdesigned by our lab. The main results are as follows:1) Conchocelis was cultured in a shaken flask, the growth characteristics ofconchocelis were found that the filamentous cells can grow into a big cell clump.2) A bubble-column photobioreactor with a working column of 300 mL had beendesigned and manufactured. The result showed that the bioreactor was very favorable toculture the conchocelis of P. haitanensis and it could be operated easily. Through theexperiment of optimizing the process conditions, a maximum final dry cell weight of 4000mg DCW/L was obtained in the batch culture with an initial dry cell weight of 700 mgDCW/L, light intensity of 40 μmol m^-2s^-1, aeration rate of 1.2 L air min^-1L^-1 (vvm), nitrateof 15 mM and phosphate of 0.6 mM during a 20-day period.3) The bubble-column culture system scaled up to 2500 mL and effects of differentlevels of illuminance and light/dark cycles on the growth of conchocelis were investigated,the result showed an optimized growth with an illuminance of 80 μmol m-2s-1 and aphotoperiod of 14 h light/10 h dark, the final biomass was 4350mg DCW/L.4) In order to improve the photobioreactor cultivation system, a 2500 mL airliftphotobioreactor was designed and manufactured. We evaluated both the bubble-column andairlift bioreactor comparatively. The results showed the final biomass density in the airliftsystem were 4850 mg DCW/L, increased by 22.8% compared with that in the bubble-column, and was more suitable for the growth of P. haitanensis conchocelis.