Abstract
The energy on the Earth is relatively limited. Therefore, in recent years everybody pay attention to the application and development of renewable resource gradually. Microalga that have a wide range of application are renewable resource. The biomass of microalga include abundant protein, vitamin and other materials that can provide to increase in the food, animal feed, medicine, health care food etc. Easier cultivation and faster growth would the advantage of microalga. Besides, microalga had the special features that never compete in farming ground with traditional farm crop.This research would aim at the heterotrophic cultivation of Chlorella NC64A with virus PBCV-1 infection for hyaluronic acid production. In the result of our experiment, we discovered that NC64A could cultivate in high cell density with heterotrophic conditions and the cell number was 3×108 cells/L. Compare heterotrophic with autotrophic NC64A, the cell concentration of former could reach 55 times of the latter. The high concentration NC64A were infected with virus PBCV-1(m.o.i.: 0.0014) in 24hours. The molecular weight and concentration of hyaluronic acid, collected from Chlorella NC64A, were 1.6×106 Da and 12.6 mg/L-broth respectively. We observed a phenomenon that Chlorella NC64A would been inhibited by an unclear mechanism when EDTA and monosaccharide were exist in the medium at the same time. In addition, the weight percentage of algae cell triglyceride(TG) has risen to 11% of dry cell weight when alga cultured with MSG as nitrogen source of medium.In the future, this research would intend and continue the directions of proceeding:(1) Increase the cell concentration of NC64A continuously by using the strategy of fed- batch carbon source.(2) Culture algae cell with organic wastes to low the production cost.(3) Rise the TG content of algae cells with the biphasic strategy.(4) Study the effect upon the production of hyaluronic acid under using different infection conditions.(5) Try to understand that how EDTA and monosaccharide induce the inhibition of NC64A growth.