The Influence Of Nutritional And Environmental Factors On The Growth And Lipid Accumulation Of Three Microalgae

Nannochloropsis oculata, Chlorella vulgaris and Phaeodactylum tricornutum are choosed as experimental materials to study the nutritional and environmental factors effection on three microalge growth and lipid accumulation, analyse the rule dynamic changing of their total lipid content. The results are as follows:(1)The biomass of three microagle increased with nitrogen concentrations rises at different nitrogen concentrations range. The maximum biomass of Nannochloropsis oculata, Chlorella vulgaris were 4.4 g/L and 3.7 g/L at nitrogen concentration of 14.4 mmol/L, the two microalge maximum total lipid content were respectively 54.6% and 39.1%. In the 4.4-17.6 mmol/L of nitrogen concentrations range, the biomass of Phaeodactylum tricornutum has little changed, from 1.6 to 2.4 g/L, the maximum total lipid content is 60.4%.(2)The biomass of Nannochloropsis oculata and Chlorella vulgaris change slightly as the phosphorus concentration rises, were respectively 2.6 g/L and 4.5 g/L. Phaeodactylum tricornutum biomass increased as phosphorus concentration rises, the maximum were 2.7 g/L at phosphorus concentration was 0.88 mmol/L. Phosphorus concentration in the range of 0.11-0.88 mmol/L, the total lipid content of three microalge were decreased as phosphorus concentration rises, Nannochloropsis oculata, Chlorella vulgaris and Phaeodactylum tricornutum total lipid content were respectively 37.7%,36.2% and 39.9% at lowest phosphorus concentration(0.11 mmol/L).(3)The biomass of Nannochloropsis oculata and Chlorella vulgaris increase as the light intensity rises, the effect of one side illumination was better than two sides illumination. Little effection of light intensity, one side and two sides illumination to the biomass of Phaeodactylum tricornutum. Total lipid content of Nannochloropsis oculata increased at first and then decreased as light intensity rises, in the final phase of culture, one side 300μmol photons/m2·s group was 47.4%, two sides 300μmol photons/m2·s group was 36.3%. Total lipid content of Chlorella vulgaris and Phaeodactylum tricornutum increased as light intensity rises, the maximum obtained in two sides 300μmol photons/m2·s light intensity, were respectively 50.8%,43.11%.