Jeong, S.-M.; Khosravi, S.; Cho, M.-U., and Lee S.-M., 2023. Rhodobacter sphaeroides supplementation enhances growth performance and immunity in rainbow trout (Oncorhynchus mykiss). In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 543-547. Charlotte (North Carolina), ISSN 0749-0208.

Rhodobacter sphaeroides (RB), a purple non-sulfur bacteria, has high protein content and a large number of bioactive substances, such as carotenoids and CoQ10. To investigate its efficacy as a feed additive in aquaculture, we added graded levels of RB in rainbow trout feed and examined the changes in growth, whole-body biochemical composition, blood chemistry, and antioxidant gene expression. This study found that the weight gain and specific growth rate showed a significant response to the increasing dietary RB levels up to 1.5 % (quadratic, P < 0.05). Total bilirubin content decreased with the increasing level of RB in the diet (linear, P < 0.05). Thus, RB can be an effective additive for enhancing growth in the aquaculture of rainbow trout.