Breeding Of A Chlorella Strain And The Enlargement Culture With A Built-in Light Source Photobioreactor

Microalgae can be divided into the prokaryotic and eukaryotic algae,itcan not only be used as a bioenergy to alleviate the shortage of fossil energy,andreduced the damage to the ecosystem caused by the use of fossil energy,but also to purify various industrial waste gas,such as wastewaterand living Sewage,and to reduce the environmental pollution caused by the discharge of organic waste,it is an ideal bioenergy and has high research value.The cost of existing microalgae bioreactors is is too high,which severely hinders the development of microalgae related industries,Therefore,it is of great significance to reduce the production cost of the bioreactor and improve the production efficiency of the reactor for promoting the industrialized production of microalgae.In this study,a strain of algae stored in the laboratory was used as a starting point to perform UV mutagenesis to increase its biomass and oil content.The obtained positive mutant algae species were optimized for their cultivation conditions to obtain higher biomass and Oil production.Pre-experimental cultivation of a strain of microalgae obtained after mutagenesis was performed using 8 L PBR.60 L PBR was used to cultivate algae species.In this paper,a microalgae preserved in the laboratory of the College of Biological Science and Engineering of Hebei University of Economics and Trade was activated,separated and purified by the algae species number CS-510 and identified as Chlorella by cell morphology observation and 18S rDNA in molecular biology.The algal strain CS-510 was subjected to ultraviolet mutagenesis.,under 38 W of ultraviolet light with 20 cm mutation distance.In the final,the biomass was 1.245 g/L,which was 11.3%higher than the starting algae biomass and the fat content was 0.086.g/L ratio increased by 34.3%compared to the starting algae strain,which was an improvement over the starting algae strain.It was used as a test algae strain for later expansion culture.The mutagenic excellent algae strain was cultured by single factor and response surface method The conditions were optimized,and the best heterotrophic medium components were finally obtained:sucrose10 g/L,NaNO₃ 1.2 g/L,K₂HPO₄ 3H₂O 100 mg/L.Through the 8 L PBR pre-experiment,the changes in biomass and pH during algal cell culture were measured.The analysis of the data revealed problems in the algal culture,avoiding risks in the later expansion of the culture,and determined the best experimental material for 60L PBR.60 L PBR was purchased and assembled by itself.Using OD₆₈₀ or biomass as an indicator,the effects of different culture conditions on the growth of algal cells were investigated to improve yield.Finally,the optimal light-dark ratio was 18:6?h:h?.The best CO2 flow rate is 4 mL/h,and the best way to feed sucrose is:start feeding on the second day,every 12 h,5 g each time.