| The use of microalgae to produce bio-energy is a hot topic of algal biotechnology researchin recent years. Chlorella has many advantages, such as high photosynthetic efficiency,environmental adaptation ability, short growth cycle, high biological production and highproducing oil. In addition, Chlorella does not struggle for land and water with crop. Residue ofbio-diesel can also be used as feed for fishes or animals. Chlorella has a good study basis and itis an important material for biodiesel production.Medium of C. pyrenoidosa F-9and C. vulgarisHYS-2has been optimized in this paper. The cell dry weight,the lipid content and fatty acidscontent of Chlorella in four different medium and different media of N/P.The main research results are as follows:（1） f/2medium was more conducive to the rapid growth of Chlorella while Chlorellain MAV could accumclate more lipid among knop, Provasoli, f/2, MAV four kinds of mediums.The relative growth rates of C. pyreinodoisa F-9and C. vulgaris HYS-2in f/2medium whosecell dry weight were respectively0.19g/L and0.23g/L were0.16and0.17after cultured9days.The lipid content of cell dry weight of C. pyreinodoisa F-9in MAV was19.67%whereas thelipid content of C. vulgaris HYS-2reached21.98%. And the fatty acid content of C.pyreinodoisa F-9and C. vulgaris HYS-2in MAV media had increased to5.11%and8.71%biomass by dry weight.（2） When N/P is16:1, the f/2medium strongly promoted the growth of Chlorella withthe relative growth rates for0.23and0.24and brought about a increase of the biomass to0.11g/L and0.14g/L. The lipid content of C. pyreinodoisa F-9and C. vulgaris HYS-2under thecondition of N/P for16:1were up to20.40%and27.39%, while fatty acid content of the dryweight of algae were12.52%and16.94%.（3） C. pyreinodoisa F-9and C. vulgaris HYS-2are cutured in f/2medium with theconcentration of iron ions being respectively0ã€3.0×10-6mol/Lã€6.0×10-6mol/Lã€1.2×10-5mol/Lã€2.4×10-5 mol/L and the other components unchanged. The results showed that chlorellagrowing under the condition of the iron ion concentration of6.0×10-6mol/L is the best whilethe iron ion concentration of1.2×10-5 mol L-1is the most suitable for lipid accumulation, andthe lipid content of Chlorella F-9and HYS are up to19.92%and28.00%.（4） The growth rate, lipid accumulation and fatty acid composition of C. pyreinodoisa F-9and C.vulgaris HYS-2and their ability of removal of nitrogen and phosphorus from industrial wastewater, whilef/2medium were used as control, were investigated. Results showed that two species of Chlorella couldabsorb nitrogen and phosphorus from the industrial wastewater and the biomass were0.29g/L and0.27g/L.They were2.4and1.6fold than those in f/2medium. The highest total lipid content of C. vulgaris HYS-2in wastewater was36.22%and was1.42times of that in f/2medium, whereas the total lipid content of C.pyreinodoisa F-9in f/2medium was higher than that in wastewater. The removal efficiency of nitrogen andphosphorus from wastewater by two species of Chlorella were both over90.00%after15days’ culture. |
