Effect of pH on the bacterial community present in larvae and spat of Crassostrea gigas

Abstract

Marine environmental changes, including pH changes have been correlated to alterations in the physiology and susceptibility to diseases in cultured organisms at the early stages of development. Metagenomic analysis 16S rRNA was done to evaluate the biodiversity of pediveliger larvae and spat of Crassostrea gigas under acidic pH stress compared to that of larvae at normal pH. The evaluation was carried out in an experimental system with continuous water flow and pH manipulation by CO 2 bubbling to simulate acidification (pH 7.384 ± 0.039), taking as reference the current ocean pH conditions (pH 8.116 ± 0.023). The results indicated that a modulation of the bacterial community is present in both pediveliger larvae and spat subjected to acidic conditions. The Rhodobacteraceae and Campylobacteraceae were the most affected families by the change of pH, with increases of Vibrionaceae in pediveliger larvae and of Planctomycetaceae and Phyllobacteriaceae in spat. In summary, this study demonstrates that bacterial communities associated with pediveliger larvae and spat of C. gigas are responsive to changes in acidification.