Thiobencarb 50%EC 90%EC Weedicide brown yellow Pesticide Agrochemical selective herbicide CAS No.28249-77-6

                                                                         Thiobencarb

Thiobencarb is a thiocarbamate. Flammable gases are generated by the combination of thiocarbamates and

dithiocarbamates with aldehydes, nitrides, and hydrides.

Thiocarbamates and dithiocarbamates are incompatible with acids, peroxides, and acid halides. Hazard Toxic.

Thiobencarb Preparation Products And Raw materials Raw materials

Thiobencarb is a thiocarbamate herbicide used in rice paddies worldwide.

Microbial degradation plays a crucial role in the dissipation of thiobencarb in the environment.

However, the physiological and genetic mechanisms underlying thiobencarb degradation remain unknown.

In this study, a novel thiobencarb degradation pathway was proposed in Acidovorax sp. strain T1.

Thiobencarb was oxidized and cleaved at the C-S bond, generating diethylcarbamothioic S-acid and 4-chlorobenzaldehyde (4CDA).

4CDA was then oxidized to 4-chlorobenzoic acid (4CBA) and hydrolytically dechlorinated to 4-hydroxybenzoic acid (4HBA).

The identification of catabolic genes suggested further hydroxylation to protocatechuic acid (PCA) and finally degradation through the

protocatechuate 4,5-dioxygenase pathway.

A novel two-component monooxygenase system identified in the strain, TmoAB, was responsible for the initial catabolic reaction.

TmoA shared 28 to 32% identity with the oxygenase components of pyrimidine monooxygenase from Agrobacterium fabrum, alkanesulfonate

monooxygenase from Pseudomonas savastanoi, and dibenzothiophene monooxygenase from Rhodococcus sp. TmoB shared 25 to 37%

identity with reported flavin reductases and oxidized NADH but not NADPH. TmoAB is a flavin mononucleotide (FMN)-dependent

monooxygenase and catalyzed the C-S bond cleavage of thiobencarb.

Introduction of tmoAB into cells of the thiobencarb degradation-deficient mutant T1m restored its ability to degrade and utilize thiobencarb.

A dehydrogenase gene, tmoC, was located 7,129 bp downstream of tmoAB, and its transcription was clearly induced by thiobencarb.

The purified TmoC catalyzed the dehydrogenation of 4CDA to 4CBA using NAD+ as a cofactor.

A gene cluster responsible for the complete 4CBA metabolic pathway was also cloned, and its involvement in thiobencarb degradation was

preliminarily verified by transcriptional analysis.

IMPORTANCE Microbial degradation is the main factor in thiobencarb dissipation in soil.

In previous studies, thiobencarb was degraded initially via N-deethylation, sulfoxidation, hydroxylation, and dechlorination. However, enzymes

and genes involved in the microbial degradation of thiobencarb have not been studied. This study revealed a new thiobencarb degradation

pathway in Acidovorax sp. strain T1 and identified a novel two-component FMN-dependent monooxygenase system, TmoAB. Under TmoAB-

mediated catalysis, thiobencarb was cleaved at the C-S bond, producing diethylcarbamothioic S-acid and 4CDA. Furthermore, the downstream

degradation pathway of thiobencarb was proposed. Our study provides the physiological, biochemical, and genetic foundation of thiobencarb

degradation in this microorganism.