Agmatine-producing Hafnia spp. dairy strains: isolation, technological characterization and potential in functional food development

Owing to its wide range of health-promoting effects, particularly with respect to psychiatric and neurological disorders, agmatine (AGM) has earned much attention. The development of functional foods enriched in this compound has, however, not yet been explored. AGM is found in foods, albeit in very low concentrations, as a consequence of microbial activity. The search for AGM-producing microorganisms with good technological traits is thus essential if AGM-enriched functional foods are to be developed. This work reports the screening for AGM-producing bacteria in different dairy products; those detected belonged to the genus Hafnia and the species Citrobacter freundii . The Hafnia spp. isolates were subjected to technological characterization, the results of which revealed their adaptation to the dairy environment compared to Hafnia spp. type strains. Genome sequencing and safety analyses of Hafnia paralvei IPLA15029 confirmed its potential for use as an adjunct culture. Experimental cheese made with this strain showed the highest AGM concentration ever reported for dairy products (2.4 mmol/L equivalent to 312 mg/kg), highlighting its potential in the development of AGM-enriched functional dairy products. • Thirty-five agmatine (AGM) producing microorganisms were isolated from dairy samples. • Hafnia isolates showed good technological traits and adaptation to dairy environment. • Cheese made with H. paralvei IPLA15029 showed the highest AGM content described. • These results constitute the first step to develop AGM-enriched functional foods.