Location: Food and Feed Safety ResearchTitle: Evaluation of the dairy/yeast prebiotic, GroBiotic-A, in the diet of the juvenile Nile tilapia, Oreochromis niloticus) Author
Submitted to: Journal of the World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2014
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Tilapia production ranks among the highest worldwide due to their fast growth and ability to thrive under various culture conditions. However, tilapias are still susceptible to outbreaks of systemic disease caused by opportunistic bacterial pathogens such as Streptococcus inaie. These epizootic events are facilitated by high stocking densities, poor water quality, and inadequate nutrition. Various aspects of controlling disease through dietary supplementation of nutritive and non-nutritive compounds are becoming better understood and acknowledged in aquaculture. Significant attention has been generated about dietary prebiotic supplementation in aquaculture by numerous studies aimed at characterizing the physiological action of these compounds as they affect gastrointestinal health and the overall health and disease resistance of aquatic organisms. One of the primary roles of prebiotic intervention is to alter the microbial community within the intestine in such a way as to promote the growth of beneficial bacteria while decreasing the number of potentially pathogenic bacteria. Despite the increasing amount of information on prebiotic research in fish, relatively few studies have employed molecular methods to characterize the intestinal microbiota. In a previous study, supplementation of the commercial prebiotic, GroBiotic®-A, at 1% and 2% of diet to juvenile Nile tilapia proved to significantly alter the microbial community within the intestine based on denaturing gradient gel electrophoresis. The focus of the current project was to further characterize the effects of GBA supplementation on the microbial communities of fish fed the various diets. Digesta samples were collected from a total of six fish per dietary treatment in the aforementioned trial. Bacterial DNA was extracted using universal bacterial primers flanking the variable V3 region. Composite samples of lyophilized DNA, based on dietary treatment, were then sent to the Research and Testing Laboritories, LLC in Lubbock, TX, for pyrosequencing. Results indicated an increase in the beneficial bacteria Lactococcus sp. and Lactobacillus sp., but no changes in Bifidobacteria sp. abundance were detected.