Characterization of phthalate-degrading bacteria from Asian carp microbiomes and riverine sediments

摘要

Phthalates are ubiquitous in the environment due to widespread production and distribution. The carcinogenic compounds dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP) are non-covalently bonded to plastics; thus prone to dispersal in various environments. Phthalates not only sorb to riverine sediments, but are also taken up by a variety of aquatic organisms. Asian carp species silver (Hypophthalmichthys molitrix) and bighead (Hypophthaltnichthys nobilis) are exposed to phthalates by ingestion and absorption.,The biodegradation of phthalates has been extensively investigated; however, no studies have isolated phthalate degrading bacteria from aquatic species. The purpose of this study was to characterize the growth and biodegradation kinetics of phthalate-degrading bacteria isolated from the gut, gill, and scale microbiomes of Asian carp, and riverine sediments. 16S rRNA sequencing identified similar genera in sediment and H. molitrix gut microbiome inoculated phthalate enrichments. Achromobacter aegrifaciens strain SKTGEO1 and Pseudomonas japonica strain SKEO1 were enriched from sediments; Bacillus subtilis strain SK18, Pseudomonas putida strain SKTG1, and Consortium SK-1 were enriched from Asian carp microbiomes. Each bacteria isolated was shown to eliminate phthalates from experimental systems. This is the first study documenting the biodegradation of phthalates by bacteria isolated from Asian carp gut and H. molitrix scale microbiomes.