A gelatinized lipopeptide diet effectively modulates immune response, disease resistance and gut microbiome in Penaeus vannamei challenged with Vibrio parahaemolyticus.

Penaeus vannamei is one of the most economically vital shrimp globally, but infectious diseases have hampered its proper production and supply. As antibiotics pose a huge threat to the environment and humankind, it is essential to seek an alternative strategy to overcome infection and ensure proper culture and production. The present study investigates the effect of an anti-infective biosurfactant derivative lipopeptide MSA31 produced by a marine bacterium on the growth performance, disease resistance, and the gut microbiome of P. vannamei when challenged with pathogenic Vibrio parahaemolyticus SF14. The shrimp were fed with a commercial and lipopeptide formulated diet for 60 days and the growth performance was analyzed. The lipopeptide fed shrimp group showed enhanced growth performance and specific growth rate with improved weight gain than the control group. The challenge experiment showed that the survival rate was significant in the lipopeptide fed group compared to the control group. The results revealed 100% mortality in the control group at the end of 12 h of challenge, while 50% of the lipopeptide diet-fed group survived 24 h, which indicates the enhanced disease resistance in shrimp fed with a lipopeptide diet. The test group also showed higher levels of digestive and immune enzymes, which suggests that the lipopeptide diet could positively modulate the digestive and immune activity of the shrimp. The gut microbiome profiling by Illumina high-throughput sequencing revealed that the most abundant genera in the lipopeptide diet-fed group were Adhaeribacter, Acidothermus, Brevibacillus, Candidatus, Mycobacterium, Rodopila, and Streptomyces, while opportunistic pathogens such as Streptococcus, Escherichia, Klebsiella, Neisseria, Rhizobium, and Salmonella were abundant in the control diet-fed shrimp. Also, lipopeptide diet-fed shrimp were found to have a high abundance of ammonia and nitrogen oxidizing bacteria, which are essential pollutant degraders. Therefore, the study reveals that the dietary supplementation of lipopeptide in shrimp aquaculture could positively modulate the gut microbiome and enhance the shrimp's overall health and immunity in an eco-friendly manner.