Isolation and Characterization of the Pymetrozine-Degrading Strain Pseudomonas sp. BYT-1

Abstract

In this study, we isolated and characterized the bacterial strain Pseudomonas sp. BYT-1, which is capable of degrading pymetrozine and using it as the sole carbon source for growth. Strain BYT-1 could degrade 2.30 mM pymetrozine within 20 h under the optimal conditions of 30 °C and pH 7.0. Investigation of the degradation pathway showed that pymetrozine was oxidatively hydrolyzed to 4-amino-6-methyl-4,5-dihydro-2H-[1,2,4]triazin-3-one (AMDT) and nicotinic acid (NA). The former accumulates as the end product in the culture, whereas the latter was hydroxylated to 6-hydroxynicotinic acid (6HNA) and subjected to further degradation. The transformation of pymetrozine to AMDT and NA by the cell-free extracts of strain BYT-1 also supported that the oxidative hydrolysis of the CN double bond in pymetrozine was the initial degradation step. This is the first report on a pure bacterial culture with the ability to degrade pymetrozine. These findings enhance our understanding of the microbial degradation mechanism of pymetrozine.

A novel hydrolase PyzH catalyses the cleavage of C=N double bond for pymetrozine degradation in Pseudomonas sp. BYT‐1

“…1F). This was different from the catabolism pathway reported previously in the degradation of pymetrozine by strain BYT‐1 (Sun et al ., 2019), in which pymetrozine was hydrolyzed to AMDT and nicotinic acid instead of nicotinaldehyde. The reason for this difference was explained below.…”

“…In this study, PyzH hydrolyzed pymetrozine to nicotinaldehyde and AMDT (Fig. 4B), which is different from the catabolism pathway previously proposed for the degradation of pymetrozine by strain BYT‐1, in which pymetrozine was metabolized to nicotinic acid and AMDT (Sun et al ., 2019). We speculate that the nicotinaldehyde is rapidly converted to nicotinic acid by dehydrogenase in strain BYT‐1 and, therefore, cannot be detected by HPLC.…”

“…strain BYT‐1, which was isolated by our lab, is the only reported strain capable of degrading pymetrozine (Sun et al ., 2019). Strain BYT‐1 could degrade pymetrozine to produce nicotinic acid and 4‐amino‐6‐methyl‐4,5‐dihydro‐2 H ‐[1,2,4]triazin‐3‐one (AMDT), the former could be used as a carbon source for growth, while the latter cannot be further degraded (Sun et al ., 2019). However, the functional genes or enzymes involved in pymetrozine degradation have not been unveiled.…”

Covalent Organic Framework‐Semiconductor‐Based Heterostructures for Photocatalytic Applications

“…The holes and ⋅O 2− played dominant roles in enhancing the photocatalytic activity for the degradation of BPA, which was confirmed by radicals trapping experiments [140] . Chemical products such as fertilizers and pesticides, which were widely used in agriculture, have been increasingly threatening to the health of humans [141] . Pymetrozine (PYM) pesticide is stable in different environmental waters and has become a representative pollutant.…”

“…[140] Chemical products such as fertilizers and pesticides, which were widely used in agriculture, have been increasingly threatening to the health of humans. [141] Pymetrozine (PYM) pesticide is stable in different environmental waters and has become a representative pollutant. The Ag 3 PO 4 /TpPa-1-COF heterojunction was prepared by integrating 2D COF with nanosphere-shaped Ag 3 PO 4 via π-π stacking for the photocatalytic degradation of PYM and Rhodamine B (RhB) under visible-light irradiation.…”