| Benthic diatom is very important for abalone breeding, and becomes more and more widely used in aquiculture and biopharmacy. It excretes large quantity of exopolysaccharides which proved to be of numerous pharmacological activies, such as anti-tumor, anti-virus and enhancing immunity. It contains relatively high percent of polyunsaturated fatty acids which plays a conspicuous role in the prevention of cardiovascular disease, hyperlipemia, tumor, inflammation. A Navicula species named Navicula tenera Kützing was carried to the space by"Shen zhou 5"spacecraft in 2003, then the optimal combination of the four inorganic minerals(KNO3, Na2HPO4, FeCl3, Na2SiO3·9H2O) for the growth, yields of exopolysaccharides and contains of unsaturated fatty acids of the spaceflight and nonspaceflight Navicula tenera Kützing were assayed by the design of orthogonal test L16(45)on the basis of optimal concentration of the four single mineral nutrients. And then, we detected effects of different light-dark cycles on the growth, accumulation of Exopolysaccharides (EPS) and Polyunsaturated fatty acids (PUFAs) of spaceflight and nonspaceflight Navicula tenera Kützing. The effects of autotrophic, mixotrophic and heterotrophic culture mode on the growth, accumulation of EPSs and PUFAs of Navicula tenera Kützing were investigated. Meanwhile, the effects of acetate, glucose and malonate concentrations on the growth and exopolysacchrides production were determined in heterotrophic culture mode. The results are summarized as follows:1.The species of marine algae can be selected and isolated by dilution, micro-picking and streaking in the culture medium.The last method is the best one for us to get high purity target-algaes and eliminate mixed-algae, bacterium contamination. It is suitable for all unicell marine algae.2.The optimal combinations of the four inorganic minerals(KNO3,... |
