Chlortetracycline ELISA Kit

Rhizosphere is a crucial site for the proliferation of antibiotic resistance genes (ARGs) in agricultural soil. Pesticide contamination is ubiquitous in soil, such as chlorpyrifos as one of the most commonly used pesticides. However, limited knowledge is reported about ARGs profiles changes and the driving mechanism of ARGs prevalence in rhizosphere soil after adding pesticide. In this study, irrespective of chlorpyrifos presence, the abundances of ARGs (tetM, tetO, tetQ, tetW, tetX, sul1 and sul2) and intI1 in rhizosphere soil of wheat were obviously higher than those in bulk soil. 20.0 mg center dot kg(-1) chlorpyrifos significantly increased the abundance of total ARGs and intI1 in bulk soil, respectively, at day 50 and 100, but not in rhizosphere soil. Rhizosphere influence on ARGs was far greater than chlorpyrifos. ARGs and intI1 abundances were higher at day 50 than ones at day 100. C/N ratio and NO3--N content, which were affected by rhizosphere and cultivation time, significantly explained the increased ARGs. Compared to bulk soil, rhizosphere shifted host bacteria of tetracycline resistance genes (TRGs), intI1 at genus level, and host bacteria of sul1, sul2 at phylum level. Rhizosphere simplified the linkage of ARGs, host bacteria and metabolites. Bacterial communities played important roles in the variation of ARGs and intI1, and the difference in the distribution of potential hosts between bulk and rhizosphere soil was related to metabolites abundance and composition. These results provide valuable information for understanding the linkage of ARGs, associated bacteria communities and metabolites in the wheat rhizosphere soil. (c) 2020 Elsevier B.V. All rights reserved.

Construction of heterojunction photocatalyst is a very useful approach to enhance photocatalytic activity. In particular, the coupling of narrow-band-gap semiconductor and wide-band-gap semiconductor can solve their inherent drawbacks, simultaneously optimizing the photoabsorption and redox capabilities. In this work, a series of BiOI/Bi2O2[BO2(OH)] heterojunction photocatalysts were synthesized by an in-situ precipitation method. The crystal structure, morphology and surface chemical composition were analyzed to confirm the heterojunction formation. BiOI/Bi2O2[BO2(OH)] heterojunctions show increased specific surface area, which can provide more absorptive and catalytic sites for pollutants. Particularly, the recombination of photogenerated electrons and holes in BiOI/Bi2O2[BO2(OH)] was severely inhibited. Compared to the pristine BiOI and Bi2O2[BO2(OH)], the BiOI/Bi2O2[BO2(OH)] heterojunctions demonstrated substantially enhanced visible-light driven photocatalytic activity for degradation of various contaminants, including methyl orange, methylene blue and tetracycline hydrochloride. The superoxide radicals (O-center dot(2)-) and holes (h(+)) were determined as the main active species and played crucial role in the photodegradation process, which also verified the formation of type II heterojunction between BiOI and Bi2O2[BO2(OH)]. This work provides an efficient heterojunction photocatalyst for environmental remediation.