Biodegradation of Malachite Green in Milkfish Pond Sediments

Malachite green (MG) is usually applied as a biocide in aquaculture worldwide. The microbial degradation of MG and changes in the microbial community composition of milkfish (Chanos chanos) culture pond sediments were assessed in this study. Three MG-degrading bacteria strains-M6, M10, and M12-were isolated, identified, and characterized. Strains M6, M10, and M12 are closely related to Zhouia amylolytica, Tenacibaculum mesophilum, and Enterobacter cloacae, respectively. The bacterial strains M10 and M12 showed good ability to degrade MG in the sediment. The MG degradation rate was increased after adding MG three more times. The microbial community in the sediment changes with different treatments. The bacterial strains M10 and M12 provide a potential solution for the treatment of sediment of saline aquaculture ponds with MG contamination.