The invention belongs to the technical field of microbial
engineering, and discloses a method for producing
eicosapentaenoic acid (EPA) with high yield by
schizochytrium limacinum based on
random mutation and low-temperature screening and application, and the method comprises the following steps: driving overexpression of a G418 resistance
gene through a P2520
promoter, constructing a random
insertion mutant library, and screening to obtain a
schizochytrium limacinum
mutant strain with a randomly mutated
genome;
coating in a culture medium containing G418 resistance for culturing, and screening out strains which are resistant to low temperature and good in growth state at 15 DEG C; and inoculating into a
fermentation culture medium, adding MgSO4 with the final
mass concentration of 0.1% at the initial stage of
fermentation, supplementing MnCl2 with the final
mass concentration of 0.05% when
fermentation is performed for 72 hours, and culturing to obtain a
mutant strain. According to the invention, the G418 resistance
gene carried by the
plasmid is randomly inserted into the
schizochytrium limacinum
genome, and low-
temperature induced screening is combined, so that the target limitation of traditional
homologous recombination is broken through, and a stable strain with multiple
mutation superposition can be obtained through enrichment.