Roles of surface layer proteins in the regulation of Pediococcus pentosaceus on growth performance, intestinal microbiota, and resistance to Aeromonas hydrophila in the freshwater prawn Macrobrachium rosenbergii

Maintaining the balance of intestinal microbiota is vital for the growth and health of crustaceans. The current study explored the influences of the surface layer proteins (SLPs) of Pediococcus pentosaceus on the growth performance, disease resistance, and gut microbial community of the freshwater prawn Macrobrachium rosenbergii. After 28 days of feeding, obvious enhancements in the growth performance were found in the PF (a commercial basic diet + intact P. pentosaceus) group compared to the CF (a commercial basic diet, control) and RF (a commercial basic diet + LiCl-treated P. pentosaceus) groups. Meanwhile, the relative percent survival (RPS) of the PF group was found to be 82.1%, higher than the RF group (RPS = 63.2%) in the challenge test. There were noteworthy differences in the relative richness of Aeromonas among different treatments, and the PF group was the lowest. Whereas the relative abundance of Lactococcus between the CF and RF group did not markedly differences, which was obviously lower than the PF group. The prediction of bacterial phenotype indicated that the pathogenic potential of intestinal microbiota was decreased by increasing dietary SLPs-carrying P. pentosaceus. The results suggested that SLPs-carrying P. pentosaceus can improve growth, modulate intestinal microbiota, and increase the resistance of prawns against Aeromonas hydrophila infection.