Latilactobacillus curvatus KP3-4 isolated from fermented foods produces putrescine

Polyamines are aliphatic hydrocarbons with amino groups at both ends of their molecular structure, and are essential for biological activities. It has been reported that polyamines have health-promoting effects on animals, such as polyamine intake extending lifespan. If a bacterium that produces high levels of polyamines is isolated from foods, it could be utilized as a new probiotic. We aimed to screen high polyamine-producing bacteria, and isolated and collected bacteria from vegetables and fermented foods produced in Japan. We have successfully screened Latilactobacillus curvatus KP3-4 isolated from Kabura-zushi as a putrescine producing lactic acid bacteria. Comparing the polyamine synthesis capacity of L. curvatus KP3-4 with that of typical probiotic lactic acid bacteria and L. curvatus strains available from Japan Collection of Microorganisms, it was found that only L. curvatus KP3-4 was capable of producing high levels of putrescine. Whole-genome analysis of L. curvatus KP3-4 suggested that putrescine is synthesized via ornithine decarboxylase. Administration of L. curvatus KP3-4 to germ-free mice increased the concentration of putrescine in the feces.