Study On Semi-continuous Culture And Lipid Accumulation Of Chlorococcum Pamirum In Outdoor

With the oil energy diminishing,the use of fossil energy increasingly makes environmental problems serious.It is very important to develop sustainable and environmentally friendly energy.Microalgae have the advantages of high photosynthetic efficiency,biomass productivity,lipid productivity and environmental adaptability.It is considered as an ideal raw material for producing biodiesel.This paper focuses on semi-continuous culturing C.pamirum under outdoor conditions in different thickness bioreactor?length×thickness×height=500 cm×20 cm×60 cm,500 cm×10cm×60 cm?of the whole year.It is arm to study the biomass productivity,lipid productivity and the change of growth in four seasons in different thickness of the whole year.This paper also emphasizes on culturing C.pamirum under nitrogen limitation in outdoor.It is arm to study the effect of initial cell concentrations on growth,Chl-a,lipid content,protein contend and fatty acid distribution of C.pamirum.The results show that:?1?The change of biomass productivity in different period of the whole year,the max biomass productivity in the thickness of 20 cm is 50 mg L^-1 d^-1 and in the thickness of 10 cm is 67 mg L^-1 d^-1.In different thickness of bioreactors,the biomass productivity in the thickness of 20 cm is less than in the thickness of 10 cm.But the output in the thickness of 20 cm is higher than in the thickness of 10 cm.The highest biomass productivity is acquired in the period from September 26 to October 11.The average biomass productivity of the whole year is 28 mg L^-1 d^-1?20 cm?and 44 mg L^-1 d^-1?10cm?.The total biomass of the whole year is 5110 g?20 cm?and 4015 g?10 cm?.?2?The change of lipid productivity in different period of the whole year,the max lipid productivity in the thickness of 20 cm is 13.9 mg L^-1 d^-1 and in the thickness of 10cm is 19.1 mg L^-1 d^-1.In different thickness of bioreactors,the lipid productivity in the thickness of 20 cm is less than in the thickness of 10 cm.The average lipid productivity of the whole year is 7.5 mg L^-1 d^-1?20 cm?and 11.6 mg L^-1 d^-1?10 cm?.The total lipid of the whole year is 1369 g?20 cm?and 1059 g?10 cm?.?3?The biomass productivity of four seasons from high to low is spring,autumn,summer and winter.The Chl-a content in the thickness of 20 cm is less than in the thickness of 10 cm.The Chl-a content from high to low is spring,winter,autumn and summer.The higher ability of photosynthetic oxygen evolution in four seasons is spring and winter.?4?The biomass productivity of C.pamirum is increased with initial cell concentration increase.The max biomass productivity is 45.55 mg L^-1 d^-1.With increasing initial cell concentrations,the lipid content declined.The max lipid content is45.48%.The lipid periodicity is increased with initial cell concentrations increase.The max lipid productivity is 16.65 mg L^-1 d^-1.In the culture process,the Chl-a form rise to unchanged,the protein content declined gradually,the unsaturations of fatty acid distribution declined.These results suggest that,C.pamirum has a potential to product biodiesel.