Synbiotic containing Kappaphycus alvarezii, Spirulina sp., and Halomonas alkaliphila improves survival, growth, and vibriosis resistance in whiteleg shrimp (Litopenaeus vannamei) post-larval culture

The high losses in shrimp production due to mortality caused by Vibrio opportunistic pathogens still constitute a significant challenge in the shrimp industry. Synbiotic feed supplementation appears to be a promising control strategy to maintain healthy shrimp stock. In this study, the effects of synbiotic-containing prebiotic seaweeds Kappaphycus alvarezii and Spirulina sp. as well as probiotic Halomonas alkaliphila were evaluated on the survival, growth, and vibriosis of Litopenaeus vannamei during the post-larval stage. Five different feeds were tested: commercial feed, prebiotics K. alvarezii and Spirulina sp.-supplemented feed, and synbiotic-supplemented feed using K. alvarezii, Spirulina sp. and probiotic H. alkaliphila with different concentrations of 10(8), 10(9), and 10(10) CFU.kg(-1). Following 14 days after the feeding test, the highest shrimp survival (91.46 +/- 0.05%) was obtained in the treatment group fed with synbiotic-supplemented feed containing 0.375% K. alvarezii, 0.125% Spirulina sp., and H. alkaliphila at 10(9) CFU.kg(-1) (p < 0.05). A 7-day challenge test against opportunistic bacteria Vibrio harveyii was then performed using three treatment groups: (1) synbiotic, containing 0.375% K. alvarezii, 0.125% Spirulina sp., and H. alkaliphila at 10(9) CFU.kg(-1); (2) prebiotic, with 0.375% K. alvarezii, 0.125% Spirulina sp.; and (3) control, using commercial feed. The highest shrimp survival of (79.9 +/- 0.05%) was found in the synbiotic treatment group, followed by the prebiotic and control treatment groups (p < 0.05). Overall results suggested that synbiotic-supplemented feed containing 0.375% K. alvarezii, 0.125% Spirulina sp., and H. alkaliphila at 10(9) CFU.kg(-1) significantly improved shrimp survival even when challenged with V. harveyii. Thus, this synbiotic can be potentially applied as an alternative biocontrol strategy against vibriosis in intensive shrimp post-larval culture.

Automated summary

The study found that synbiotic feed supplementation containing prebiotic seaweeds and probiotic Halomonas alkaliphila significantly improved shrimp survival and resistance against Vibrio infection, showing promising potential as an alternative biocontrol strategy in shrimp post-larval culture.