Microorganisms as production strains or direct-fed strains are widely used in health food, novel food, special food, food additives, new feed, new feed additives and other industries. The safety evaluation of microorganisms has received more attention from international and domestic government supervision, and the relevant regulatory requirements are constantly updated. The European Union issued “Guidance on the characterisation of microorganisms used as feed additives or as production organisms (EFSA Journal 2018;16(3):5206)” in 2018, and issued the guideline for safety evaluation of production strains of food enzymes “Characterisation of microorganisms used for the production of food enzymes (EFSA Journal 2019;17(6):5741)” in 2019. The Ministry of Agriculture and Rural Affairs of the People's Republic of China officially released “Requirements for application of new feed additives” by announcement No. 226 in 2019, which stipulated that: "To comprehensively evaluate the pathogenicity, toxic metabolite production ability, antimicrobial resistance of the proposed strains, through microbial phenotype test, molecular biology test and whole genome sequence analysis, combined with relevant literature". CICC has been tracking the domestic and foreign regulatory standards on strain safety evaluation for a long time, accumulated extensive technical experience, and is providing microbial strain safety evaluation services for whole industrial enterprises.