Screening of three Chlorella mutant strains with high lipid production induced by 3 types of lasers

Abstract

There are many studies on the use of lasers as a special mutation-breeding method to select microorganisms and plant seeds. In this study, we screened 72 microalgal mutants from the Chlorella samples irradiated using three types of laser (He-Ne, Nd:YAG and SC). Finally, 2 mutants N2 and S3 from wild Chlorella pyrenoidosa, and 1 mutant, N3 from Chlorella pacifica having high potential for biodiesel applications with high yield and stability, were obtained after comprehensive comparison and systematic screening. The average total lipid productivities of the 3 mutants were 19.90 ± 2.46 mg L−1 day−1 for N2, 29.82 ± 4.45 mg L−1 day−1 for S3 and 20.56 ± 5.69 mg L−1 day−1 for N3, respectively. The 3 mutants were proved they could display higher lipid productivity, lipid content, growth rate and transcriptional expression trends of 7 genes relevant to fatty acid biosynthesis than the wild strain in 10 continuous generation subcultures.