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

Abstract

Changes in marine environments, including pH changes, have been correlated to alterations in the physiology and disease susceptibility of cultured organisms at the early stages of development. In this study, high-throughput sequencing of the V3-V4 region of the 16S rRNA gene was performed to evaluate the bacterial biodiversity of Crassostrea gigas pediveliger larvae and spat under acidic stress compared to that of larvae at normal pH value. The evaluation was performed in an experimental system with continuous water flow and pH manipulation by CO2 bubbling to simulate acidification (pH 7.38 ± 0.039), using the current ocean pH conditions (pH 8.116 ± 0.023) as a reference. The results indicated that the bacterial communities associated with both pediveliger larvae and spat were modified in response to acidic conditions. The families Rhodobacteraceae and Campylobacteraceae were the most affected by the change in pH, with increases in Vibrionaceae in pediveliger larvae and Planctomycetaceae and Phyllobacteriaceae in spat detected. The results of this study demonstrate that the bacterial communities associated with C. gigas pediveliger larvae and spat are responsive to changes in ocean acidification.

Symbiotic microbiome and metabolism profiles reveal the effects of induction by oysters on the metamorphosis of the carnivorous gastropod Rapana venosa

“…The microbiome plays an important role in the digestive system. Rhodobacteraceae has been reported to exist in the intestines of many aquatic organisms [41] , [42] , [43] ; in addition, feeding with β-glucan can promote the growth of Rhodobacteraceae and activate the NF-ΚB signaling pathway via the PHB gene in Rhodobacteraceae in the intestine of Apostichopus japonicus [44] , [45] . In our results, the significant change and high correlation with other species may suggest that Rhodobacteraceae play an important role in food habit transition and metamorphosis induced by juvenile oysters.…”

In Vivo Mercury (De)Methylation Metabolism in Cephalopods under Different pCO2 Scenarios

“…This absence of perturbation in microbiota diversity could be explained by the environmental levels of Hg­(II) and MeHg used along the exposure period. The cuttlefish microbiota also did not seem specifically sensitive to decreasing pH/increasing p CO 2 , whereas ocean acidification induced changes in microbial communities of oyster larvae. , This seems to confirm a certain plasticity of cuttlefish facing climate change …”

“…The observed variability seemed to be individual-specific and unrelated to Hg exposure or rearing under lowered seawater pH or both combined stressors (for example, the diversity of Burkholderiaceae in the digestive gland shows high variability for replicates of the T10_Hg condition = 41.8 ± 32.6%, n = 3). Nevertheless, it is recognized that Hg could create a dysbiosis on intestinal microbiota, 65,66 which was not observed in this study. This absence of perturbation in microbiota diversity could be explained by the environmental levels of Hg(II) and MeHg used along the exposure period.…”