Optimization on synthesis of lipid from pueraria residue hydrolysate by Parachlorella kessleri Z6
[Objective]The lignocellulosic materials suitable for the utilization of Parachlorella kessleri Z6 were screened,and the culture conditions of Parachlorella kessleri Z6 were optimized by single factor and response surface method in order to improve its lipid yield.[Method]In order to obtain the optimum lignocellulosic material,the changes of biomass and lipid production of Parachlorella kessleri Z6 under four hydrolysate culture conditions of caraway residue,bagasse,straw and fungus bran were investigated.The optimal culture technology of Parachlorella kessleri Z6 was obtained through single factor test,PB test and centre combination test,and the fatty acid composition of Parachlorella kessleri Z6 before and after optimization was analyzed by GC-MS technique.[Result]The highest biomass and lipid production of Parachlorella kessleri Z6 were obtained when pueraria residue hydrolysate was used as the ferment.PB test showed that pueraria residue hydrolysate,sodium nitrate,dipotassium hydrogen phosphate and citric acid were the components which significantly affected the lipid production of Parachlorella kessleri Z6.Furthermore,the CCD central combination test showed that the optimal culture conditions for Parachlorella kessleri Z6 were 70%PS hydrolysate,0.70 g/L sodium nitrate,0.02 g/L dipotassium hydrogen phosphate,0.008 g/L citric acid,0.075 g/L magnesium sulphate,and 0.04 g/L calcium chloride,and the other components were consistent with the BG11 medium.When Parachlorella kessleri Z6 was cultivated under the optimal conditions,the lipid production of 2.22 g/L were obtained at the end of cultivation process,which was 43.23%and 12.69%higher than that of the initial PS hydrolysate culture medium and the heterotrophic culture medium.[Conclusion]The hydrolysate of pueraria can be used as the ferment of Parachlorella kessleri Z6,and the total lipid production of Parachlorella kessleri Z6 was significantly improved after optimization by response surface method.The results of this study can provide reference for the utilization of other lignocellulosic materials and the improvement of microalgae oil production performance.
Parachlorella kessleri Z6lignocelluloseresponse surface optimizationlipid production