npj Emerging Contaminants - Microbial remediation of microplastic-contaminated soil, focusing on mechanisms, benefits, and research gaps

Bisphenol F (BPF) is a widely used alternative to bisphenol A and poses a growing threat to ecosystems and human health due to its environmental persistence and endocrine-disrupting effects. Although microbial degradation pathways for BPF have been reported, the key enzymes involved and their catalytic mechanisms remain unclear. This work reports the isolation of a Sphingobium strain capable of mineralizing BPF and the genetic basis for the catabolic pathway. Three enzymes—a two-component oxidoreductase, a Baeyer–Villiger monooxygenase, and an α/β hydrolase—were biochemically characterized and shown to catalyze the three critical steps in BPF degradation. These findings provide insights into the biochemical processes involved in the microbial degradation of BPF.

The presence of low-density polyethylene (LDPE) in agricultural soils poses significant ecological risks due to its resistance to biodegradation. Desp…

Plastic pollution has emerged as a pervasive global threat to ecosystems, with rising production and ineffective waste management accelerating environ…

Biodegradation of toxic cyanobacterial cyclic peptides microcystins (MCs) by heterotrophic bacteria isolated from freshwater has gained global interest as an eco-friendly approach for water treatment....

Biodegradation of toxic cyanobacterial cyclic peptides microcystins (MCs) by heterotrophic bacteria isolated from freshwater has gained global interest as an eco-friendly approach for water treatment. This study focused on elucidating the structures of MC-LR breakdown products generated by a group of five bacteria previously isolated from Lake Erie. Three isomers of a tetrapeptide NH2-Adda-Glu-Mdha-Ala-OH (Adda-TetraP-1, 2, and 3) and a cyclic tripeptide NH2-Adda-Glu-Mdha-OH (Adda-TriP) were identified during the MC-LR degradation process. Of these peptides, only linear Adda-TetraP-1 was described previously. UHPLC-high-resolution (HR)-MS and MS/MS data acquired for tetrapeptides and the tripeptide and their thiol derivatization showed that Adda-TetraP-2, Adda-TetraP-3, and Adda-TriP were cyclic peptides that contained modified Mdha and Adda moieties. The experimental evidence suggests that the Adda amine group of Adda-TetraP-1 underwent intramolecular aza-Michael reaction with the Mdha double bond to form a cyclic tetrapeptide, which appeared in two diastereomeric forms, of which Adda-TetraP-2 was formed faster than Adda-Tetra-P-3. The Mdha-Ala peptide bond of Adda-TetraP-2 appeared to be hydrolyzed by bacteria to form Adda-TriP. Independent of our laboratory cultures, Adda-TetraP-1, 2, and 3 were detected in Lake Erie water during cyanobacterial blooms, and identifying them will assist in elucidating biodegradation pathways of MC congeners and genes relevant to MC degradation.