Meeting Abstract

62.2  Friday, Jan. 6  Elevated growth rate and hepatic IGF-1 expression in Oreochromis niloticus (Nile Tilapia), the case for Eubacterium cellulosolvens 5494 as a possible aquaculture probiont KELLY, J.E.*; BLAIR, B.G.; MEADE, M.E.; MURDOCK, C.A.; Jacksonville State University, Alabama; Jacksonville State University, Alabama; Jacksonville State University, Alabama; Jacksonville State University, Alabama

The use of probiotics has demonstrated the ability to increase growth rates in some aquaculture species. However, most studies have utilized facultative anaerobes. In this study, the effects of Eubacterium cellulosolvens 5494, a gram positive, cellulolytic, strict anaerobe isolated from bovine rumen was tested. Commercial feed was supplemented with E. cellulosolvens and presented to Oreochromis niloticus fry on three separate occasions over the course of the first 10 days of the experiment. Tilapia fry were maintained in 37.8 L tanks (at a density of 25 fish per tank) for a total of 45 days. Fish that received the E. cellulosolvens supplemented feed were significantly larger (3.66g ± 0.29g) than the control fish (2.76g ± 0.51g). Liver tissue samples were also collected from these fish for comparisons of insulin-like growth factor 1 (IGF-1) expression patterns, using quantitative real-time PCR methodology, in response to probiotic treatments. IGF-1 is an important hormone within the somatotropic axis and is essential for stimulating maximal growth. Treated tilapia had significantly higher expression (6.31 ± 0.22 pg/ug total RNA) than the control fish (4.85 ± 0.08 pg/ug total RNA). These data may help establish links between growth, molecular mechanisms of growth signals and anaerobic bacteria in the digestive tracts of aquaculture species.