Optimization Of Condition Of Chlorella Sp. And Dunaliella Salina Cultured In Oil-contaminated Seawater

Due to the crisis of the global energy,the microalgae biodiesel as a new bioenergy.The area of the global seawater is very large,and the coastal waters are generally subject to the oil pollution.So combining the seawater contaminated by oil and the cultivation of microalgae can both provide nutritional ingredients and a lot of seawater for the cultivation of microalgae and feedstock for microalgae biodiesel,but also can improve the rate of biodegradation of oil pollution.In this paper,by using the Chlorella sp.And Dunaliella salina as two common marine microalgae contained high lipid as research subjects,choosing the seawater and F/2 as medium,utilizing the standard oil to simulate the oil pollution in the sea,then by using the method of spectrophotometer to analyze the growth and the content of Chlorophy II,using the Soxhlet extraction method to analyze the total lipid content of cell of microalgae cultured in the seawater contaminate by oil under different physical conditions,organic conditions and growth factor conditions,and suing the Imaging-PAM to study the response of photosynthetic system of the two microalgae under the oil stress.For large-scale cultivation of Marine microalgae using oil pollution sea conditions optimization laid a solid foundation.Specific results are as follows:(1)Optimization of culture conditions(1)optimization of environmental factorsThe results based on the orthogonal experimental designed:The best condition of Chlorella sp.cultured under the target of high density of cells:Light intensity is 2500 lx,photoperiod is 24h:0h(light:dark),pH value of 7.5;The best condition of Dunaliella salina:Light intensity is 1500 lx,photoperiod is 18h:6h(light:dark),pH value of 7.5;The best condition of Chlorella sp.cultured under the target of high content of Chlorophy II:Light intensity is 2500 lx,photoperiod is 24h:0h(light:dark),pH value of 6.5;The best condition of Dunaliella salina:Light intensity is 1500 lx,photoperiod is 18h:6h(light:dark),pH value of 6.5;The best condition of Chlorella sp.cultured under the target of high content of lipid:Light intensity is 1000 lx,photoperiod is 18h:6h(light:dark),pH value of 7.5;The best condition of Dunaliella salina:Light intensity is 1000 lx,photoperiod is 18 h:6h(light:dark),pH value of 7.5.(2)Optimization of organic carbon and growth factorsThe best condition of Chlorella sp.cultured under the target of high density of cells:sodium acetate is 100mg/L,sucrose is 10mg/L,glucose is 30mg/L,GA3 is 5.0mg/L;The best condition of Dunaliella salina:sodium acetate is 50mg/L,6-BA is 0.5mg/L,NAA is 3.0mg/L,IBA is 5.0mg/L;The best condition of Chlorella sp.cultured under the target of high content of Chlorophy II:sodium acetate is 800mg/L,sucrose is 100mg/L,glucose is 30mg/L,GA3 is3.0mg/L;The best condition of Dunaliella salina:sodium acetate is 50mg/L,6-BA is0.5mg/L,NAA is 3.0mg/L,IBA is 20.0mg/L;The best condition of Chlorella sp.cultured under the target of high content of lipid:sodium acetate is 100mg/L,sucrose is 100mg/L,glucose is 30mg/L,GA3 is 5.0mg/L;The best condition of Dunaliella salina:sodium acetate is 50mg/L,6-BA is 0.5mg/L,NAA is3.0mg/L,IBA is 20.0mg/L.(2)The response of photosynthetic system of microalgae under oil stressBy the analysis of the minimum fluorescence(F_o)and the maximal efficiency of PSII in a dark-adapted state(F_v/F_m)of two microalgae,we can draw the Chlorella sp.Own photosynthetic ability is better than Dunaliella salina;by the analysis of non-regulatory energy dissipation in the quantum yield Y(NO),the nonphotochemical quenching parameter(NPQ)and the effective quantum yield of PSII[Y(II)]of the two microalgae,we can draw photosynthesis stability under the oil pollution of Chlorella sp.Is better than Dunaliella salina.Therefore,we can draw that the oil stress has less effect for the photosynthesis system of Chlorella sp.,and the Chlorella sp.Is more appropriate than the Dunaliella salina cultured in oil-pollution waters.