Inhibition of mussel settlement by calcined mussel shell powder through altering biofilms and bacterial community

Sustainability-driven innovations with non-toxic coating developing is essential. Here, we utilized the waste mussel shells as an alternative antifouling coating to test the potential impacts on biofilm formation and then Mytilus coruscus settlement. Compared with Natural Mussel Shell Powder (NMSP), the bacterial density of biofilm on 10 mg/mL Calcined Mussel Shell Powder (CMSP) coating was 63.09%, lowered significantly (p < 0.05). Further analysis of X-ray diffraction test showed the phase transformation appeared in the CMSP in comparison to NMSP. The biofilm bioassays showed that in 28-day-old natural biofilm, compared with Glass and PDMS, the bacterial density in 10 mg/mL CMSP decreased by 46.58 % and 34.60 %, respectively, and the diatom density decreased by 71.07 % and 42.99 %, respectively. Compared to Glass and PDMS, the relative abundance of Psychrobacter and Loktanella in the 28-day-old biofilms on CMSP coating was reduced, but that of Erythrobacter increased. Simultaneously, settlement on 10 mg/mL CMSP was reduced by 65.31 % and 72.13 %, respectively, compared to PDMS and Glass in the case of 28-day-old biofilms. These results demonstrate the viability of CMSP as a coating and provide a sustainable solution to against marine biofouling.