Table 1.

Molecular pathways leading to microbial herbicide metabolism/cometabolism

Herbicide	Genes/pathway	Reference
	Metabolism by free‐living microbes
2,4‐D (glycolate)	tfdA‐like genes (α‐ketoglutonate‐dependent dioxygenase pathway), producing 2‐chloromaleylacetate	62
Atrazine (triazine)	Oxidative–hydrolytic and hydrolytic pathways, producing cyanuric acid	63
Glyphosate (organophosphorus)	Several microbial pathways documented:	20, 27, 64, 65
	enzyme EPSPS (5‐enol‐pyruvylshikimate‐3‐phosphate synthase) from Agrobacterium sp. strain CP4‐associated target‐site resistance degradation by the C–P lyase pathway/phosphonatase pathway (phosphonate‐degrading enzymes), producing aminomethyl phosphonic acid amino‐methyl phosphonic acid pathway by Penicillium notatum glyphosate N‐acetyltransferase (GAT) acetylation, producing N‐acetylglyphosate (NAG)
Molinate (thiocarbamate)	Several pathways by diverse bacterial and fungal isolates, either:	13
	oxidation: (a) of the ethyl moiety of molinate, with the formation of molinate alcohol and molinate acid: (b) of the azepane ring, with the formation of hydroxyl‐ and oxo‐molinate derivatives; (c) of the sulphur atom and subsequent cleavage of the C–S bond, with the formation of hexamethyleneimine and an S‐ethyl derivative hydrolysis: cleavage of the thioester bond of molinate by molinate hydrolase (MolA), producing ethanethiol and azepane‐1‐carboxilate (ACA)
Sulfonylureas	Hydrolysis of the sulfonylurea linkage (pH dependent) via either acid‐catalysed cleavage or base‐catalysed contraction/rearrangement. Produces CO2 + corresponding aryl sulphonamide and aminoheterocyclic portions	66
	Cometabolism by plant‐associated microbes
Alachlor (chloroacetanilide)	Glutathione S‐transferase (GST)‐mediated metabolism	67
2,4‐D, atrazine, aminotrizole, pentanochlor (anilide)	BphKLB400‐mediated metabolism (dechlorination). Note: similarity of BphKLB400 protein sequence to GST	33