Effect of seafood peptones on biomass and metabolic activity by Enterococcus faecalis DM19

- The influence of SPHs on survival and metabolic activities was investigated.
- Hydrolysates from squid and shrimp stimulated Enterococcus faecalis DM19 growth.
- Enterococcus faecalis DM19 produced lactic acid with excellent efficiency.
- Antimicrobial activity increased in media with higher amounts of SPHs.

Eight seafood protein hydrolysates (SPHs) obtained from squid, shrimp and fish gelatin were incorporated as substitutes of peptones in culture media in order to evaluate its effect on survival and metabolic activity (lactic acid, acetic acid and bacteriocins production) of Enterococcus faecalis DM19. The substitution of commercial peptones in culture media by either a shrimp hydrolysate prepared with Protamex, or by squid protein hydrolysates prepared with Esperase or Alkaline protease, stimulated E. faecalis DM19 growth up to 16%. The incorporation of SPHs, mainly from shrimp, in the culture media significantly increased production of lactic and acetic acids in more than 60%. Furthermore, the media containing SPHs stimulated antimicrobial activity by E. faecalis DM19. The inhibitory activity was observed against both Gram-positive and Gram-negative microorganisms, but it was remarkably observed against Listeria monocytogenes. SPHs incorporated in culture media render properties of bio-technological interest, which, together with their low price, make them suitable for industrial use.