Improvement and screening of astaxanthin producing mutants of newly isolated Coelastrum sp. using ethyl methane sulfonate induced mutagenesis technique

Natural astaxanthin is known to be produced by green microalgae, a potent producer of the most powerful antioxidant. To increase the productivity of astaxanthin in microalgae, random mutagenesis has been extensively used to improve the yield of valuable substances. In the presented work, a newly isolated Coelastrum sp. was randomly mutagenized by exposure to ethyl methane sulfonate and further screened using two approaches; an approach for high growth mutant and an approach for high astaxanthin producing mutant with a high-throughput screening method using glufosinate. Among these, mutant G1-C1 that was selected using glufosinate showed the highest of total carotenoids (45.48±1.5 mg/L) and astaxanthin (28.32±2.5 mg/L) production, which was almost 2-fold higher than that of wild type. This study indicates that random mutagenesis via chemical mutation strategy and screening using glufosinate successfully expedited astaxanthin production in a mutated strain of a Coelastrum sp.