{Reference Type}: Journal Article
{Title}: Cooperative improvement in growth rate, red-colour score and astaxanthin level of white-leg shrimp by Bacillus strains originating from shrimp gut.
{Author}: Nguyen TT;Nguyen HT;Pham HTT;Nguyen AH;Phan TN;Hara T;Takatsuka Y;Nguyen ATV;
{Journal}: J Appl Microbiol
{Volume}: 129
{Issue}: 1
{Year}: Jul 2020
{Factor}: 4.059
{DOI}: 10.1111/jam.14603
{Abstract}: <B>OBJECTIVE: </B>We investigated the potential cooperative effects of carotenoid-producing Bacillus aquimaris SH6 and nonpigmented Bacillus subtilis SH23 on white-leg shrimp growth and health.<BR><B>RESULTS: </B>SH6, SH23 and a combination of both spores (1 × 106  CFU per g pellet) were administered in shrimp. The growth rate (2·36% day-1 ), red-colour score (25) and astaxanthin concentration (3·5 µg g-1 shrimp) were maximum in two-spore-administered shrimp. Immune-related Rho mRNA expression level and phenoloxidase and superoxidase dismutase activities were higher in two-spore-administered shrimp than in control shrimp, with Rho mRNA expression level being 55-fold higher in two-spore-administered shrimp than in SH6-administered shrimp and phenoloxidase activity being 1·2-fold higher in two-spore-administered shrimp than in SH23-administered shrimp. Although live SH6 count was 2·7-fold lower, SH6 germination level was 3·5-fold higher in the combination group than in SH6 group.<BR><B>CONCLUSIONS: </B>When both SH6 and SH23 spores were administered, SH6 spore germination was enhanced and cooperative improvement was seen in growth, astaxanthin level and red-colour score of white-leg shrimp; however, immune-related parameters were induced in a noncooperative manner.<BR><B>CONCLUSIONS: </B>This is the first report showing the cooperative probiotic activities of Bacillus strains and their possible mechanisms in a shrimp model.