Analysis of microbiota in rhizosphere, water and gut of grass carp (Ctenopharyngodon idella) in ponds treated with artificial floating beds

Abstract

With the increasing demand for environment friendly aquaculture, artificial floating beds have been now widely applied. However, there are few data available on the effect on microbiota in ponds. This study assessed the rhizobacteria community of artificial floating beds with three different kinds of aquatic plants [water spinach (Ipomoea aquatic), water hyacinth (Eichhornia crassipes) and alligator weed (Alternanthera philoxeroides)]. We used Polymerase Chain Reaction‐Denaturing Gradient Gel Electrophoresis to assess whether artificial floating beds would result in changes in microbiota of pond water and gut of grass carp (Ctenopharyngodon idella). The results showed that there existed no significant differences in rhizobacterial composition, and artificial floating beds would not greatly affect the microbiota of pond water. The dominant microbiota in the guts of grass carp changed from Aeromonas jandaei to Paenibacillus sp. Our results indicated that artificial floating beds may serve as a candidate of modulating fish gut microbiota.