Mesoporous silica nanoparticles (MSN) are widely used as pesticide carriers to enhance their effective utilization, since it can promote the solubility and absorption of pesticides by plants. For plants, the particle size of pesticides influences their absorption and efficacy. Herein, is our research work of the size effect of MSN on the loading, release, and delivery behavior of pyraoxystrobin (Pyr) in cucumber plants. The well-ordered Pyr-loaded carbon quantum dots-MSN (Pyr@M) with sizes of 15, 100, and 200 nm were prepared. A comparative study among different particle sizes of Pyr@M was carried out on the aspects of control release performance, loading content, uptake, and transportation performance in cucumber plants. It was found that the loading content increased as the particle size increased. The nanoparticles as carriers increased the solubility of insoluble Pyr, but the nanoparticle size had no clear difference impact on the release rate. The efficiency of the cellular uptake strongly depended on the particle size. The smaller the MSN size, the easier it was to be absorbed and transmitted by cucumber plants. Compared to the free Pyr, the upward transportation rate of Pyr from Pyr@M in plant increased by 3.5 times. These findings provide new theoretical basis to design the MSN pesticide delivery system.

A bacterial strain QH-12 isolated from activated sludge was identified as Gordonia sp. based on analysis of 16S rRNA gene sequence and was found to be capable of utilizing dibutyl phthalate (DBP) and other common phthalate esters (PAEs) as the sole carbon and energy source. The degradation kinetics of DBP under different concentrations by the strain QH-12 fit well with the modified Gompertz model (R² > 0.98). However, strain QH-12 could not utilize the major intermediate product phthalate (phthalic acid; PA) as the sole carbon and energy source, and only a little amount of PA was detected. The QH-12 genome analysis revealed the presence of putative hydrolase/esterase genes involved in PAEs-degradation but no phthalic acid catabolic gene cluster was found, suggesting that a novel degradation pathway of PAEs was present in Gordonia sp. QH-12. This information will be valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs-degrading Gordonia sp. strains.

Pyraoxystrobin is a novel strobilurin fungicide that is widely used on many crops. The high log K_ow of pyraoxystrobin implies that it tends to accumulate in aquatic organisms. This study optimized the sorbents of QuEChERS (quick, easy, cheap, effective, rugged, and safe) using ¹³ Wu, W. Z. ; Jian, H. E. ; Xu, J. ; Kong, D. Y. ; Shan, Z. J. Determination of Pyraoxystrobin Residues in Water and Fish by UPLC-MS/MS. Agrochemicals 2016, 55, 681–683. [Google Scholar] C-labelled pyraoxystrobin as the internal standard (IS). It has been established a QuEChERS-LC-MS/MS IS method to study the bioconcentration and elimination of pyraoxystrobin in zebrafish (Danio rerio). The results indicated that the method had satisfactory linearity between 0.234 and 15 μg L⁻¹ (R² = 0.9996). The limits of detection (LOD) and quantification (LOQ) for pyraoxystrobin were 0.01 and 0.03 μg L⁻¹, respectively. The LOQs of the method for water and zebrafish were 0.05 μg L⁻¹ and 0.01 mg/kg, respectively. The mean recovery of pyraoxystrobin in zebrafish and water at fortification levels of 0.01–0.3 mg kg⁻¹ and 0.05–1.5 μg L⁻¹ ranged from 98.31 to 105.61% and 101.87 to 108.48%, respectively, with a % RSD (relative standard deviation) of 0.94–3.57%. The bioconcentration has been evaluated. The bioconcentration factors for pyraoxystrobin in zebrafish were 1,792 and 3,505 after exposure to 0.5 μg L⁻¹ for 168 h and 0.05 μg L⁻¹ for 216 h, respectively. The half-life of pyraoxystrobin in zebrafish was 9.0–9.5 d.

Sphingobium yanoikuyae TJ is a halotolerant di- n -butyl-phthalate-degrading bacterium, isolated from the Haihe estuary in Bohai Bay, Tianjin, China. Here, we report the 5.1-Mb draft genome sequence of this strain, which will provide insights into the diversity of Sphingobium spp. and the mechanism of phthalate ester degradation in the estuary.