Plant Microbiome and Mycorrhizal Fungi

In this paper, the research results on the synergy between mycorrhizal fungi and plant microorganisms in China and abroad were summarized. The purpose of this paper was to elaborate the effects of the synergy mechanism between mycorrhizal fungi and plant microorganisms on crop growth and stress resistance, soil physical and chemical properties, and soil microbial diversity and to analyze the contribution of the interaction between mycorrhizal fungi and plant microorganisms in agriculture and forestry, so as to provide theoretical basis for the further preparation of composite microbial agents, the healthy and green improvement of crop yield, and the ecological restoration of forestry stress resistance. The main directions of future research in this field were also analyzed

Release and Transformation of BTBPE During the Thermal Treatment of Flame Retardant ABS Plastics

Thermal scenarios inevitably occur during the lifecycle of engineering plastics laden with brominated flame retardants (BFRs). However, little information on the fate of embedded BFRs during the thermal processes is available. In this study, we measured the release and transformation of a typical BFR, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), during the thermal treatment of acrylonitrile butadiene styrene (ABS) plastics. The possible thermal scenarios were simulated by varying the heating temperature and atmosphere. The maximum release rate of BTBPE was observed at 350 degrees C. A release kinetic model was developed to explore the mechanism of BTBPE release while heating ABS. Material phase diffusion was found to be the rate-determining step during release. According to the developed release model, it was estimated that 0.04-0.17% of embedded BTBPE could be released to air during the industrial processing of ABS plastics. When the heating temperature was >= 350 degrees C, approximately 15-56% of embedded BTBPE decomposed to bromophenols (BPs) and 1,3,5-tribromo-2-(vinyloxy) benzene (TBVOB), and the decomposition followed a first-order kinetics at 350 degrees C. Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) were also significantly formed at >= 350 degrees C from BPs and TBVOB via a precursor mechanism. A higher temperature (>= 450 degrees C) was favorable for the formation of PBDFs

Dispersion of Short- and Medium-Chain Chlorinated Paraffins (CPs) from a CP Production Plant to the Surrounding Surface Soils and Coniferous Leaves

Chlorinated paraffin (CP) production is one important emission source for short- and medium-chain CPs (SCCPs and MCCPs) in the environment. In this study, 48 CP congener groups were measured in the surface soils and coniferous leaves collected from the inner and surrounding environment of a CP production plant that has been in operation for more than 30 years to investigate the dispersion and deposition behavior of SCCPs and MCCPs. The average concentrations of the sum of SCCPs and MCCPs in the in-plant coniferous leaves and surface soils were 4548.7 ng g^–1 dry weight (dw) and 3481.8 ng g^–1 dw, which were 2-fold and 10-fold higher than those in the surrounding environment, respectively. The Gaussian air pollution model explained the spatial distribution of CPs in the coniferous leaves, whereas the dispersion of CPs to the surrounding surface soils fits the Boltzmann equation well. Significant fractionation effect was observed for the atmospheric dispersion of CPs from the production plant. CP congener groups with higher octanol–air partitioning coefficients (<i>K</i>_OA) were more predominant in the in-plant environment, whereas the ones with lower <i>K</i>_OA values had the elevated proportion in the surrounding environment. A radius of approximately 4 km from the CP production plant was influenced by the atmospheric dispersion and deposition of CPs

Concentrations of short- and medium-chain chlorinated paraffins in indoor dusts from malls in China: Implications for human exposure

Levels and distribution of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) were measured in indoor dusts from malls in China. The concentrations of SCCPs and MCCPs in dustfalls from a building material mall ranged from 6.0 to 361.4 mu g g(-1) and from 5.0 to 285.9 mu g g(-1), respectively. Much heavier contamination was found in central air conditioner filter (CACF) dusts from a newly opened shopping mall, with SCCP concentrations of 114.7-707.0 mu g g(-1) and MCCP concentrations of 89.0 -1082.9 mu g g(-1). The C-13- and C-14-CP5 were the dominant congeners, while the Cl-7 and Cl-8 groups were the major chlorine congeners in both kinds of dust samples. Significant correlation relationships (p <= 0.05) were found between ESCCPs and EMCCPs in CACF dusts and dustfalls. Varied exposure pathways including dust ingestion and dermal permeation have been evaluated. The average daily exposure doses of SCCPs and MCCPs for the adult in CACF dusts and dustfalls were estimated to be 0.394 and 0.150 mu g kg(-1) day(-1), respectively. The toddler had higher exposure risks with 5.918 and 2.658 mu g kg(-1) day(-1) in the shopping and building material malls, respectively. Dermal permeation was the predominated exposure pathway for the adult, while dust ingestion was suggested to be more important for the toddler due to hand-to-mouth contact. (C) 2017 Elsevier Ltd. All rights reserved

Pontibacter brevis sp. nov., isolated from rhizosphere soil of Tamarix ramosissima

Osman, Ghenijan, Gao, Yan, Wang, Ning, Mahmud, Otkur, Sun, Jian, Zhang, Tao, Zhan, Faqiang, Zhang, Zhidong, Lou, Kai (2018): Pontibacter brevis sp. nov., isolated from rhizosphere soil of Tamarix ramosissima. International Journal of Systematic and Evolutionary Microbiology 68 (1): 81-86, DOI: 10.1099/ijsem.0.002455, URL: http://dx.doi.org/10.1099/ijsem.0.00245

Release and Gas-Particle Partitioning Behaviors of Short-Chain Chlorinated Paraffins (SCCPs) During the Thermal Treatment of Polyvinyl Chloride Flooring

Chlorinated paraffin (CP) mixture is a common additive in polyvinyl chloride (PVC) products as a plasticizer and flame retardant. During the PVC plastic life cycle, intentional or incidental thermal processes inevitably cause an abrupt release of short-chain CPs (SCCPs). In this study, the thermal processing of PVC plastics was simulated by heating PVC flooring at 100–200 °C in a chamber. The 1 h thermal treatment caused the release of 1.9–10.7% of the embedded SCCPs. A developed emission model indicated that SCCP release was mainly controlled by material–gas partitioning at 100 °C. However, release control tended to be subjected to material-phase diffusion above 150 °C, especially for SCCP congeners with shorter carbon-chain lengths. A cascade impactor (NanoMoudi) was used to collect particles of different sizes and gas-phase SCCPs. The elevated temperature resulted in a higher partition of SCCPs from the gas-phase to particle-phase. SCCPs were not strongly inclined to form aerosol particles by nucleation, and less present in the Aitken mode particles. Junge-Pankow adsorption model well fitted the partitioning of SCCPs between the gas-phase and accumulation mode particles. Inhalation exposure estimation indicated that PVC processing and recycling workers could face a considerably high risk for exposure to SCCPs

Analysis of the virulence, infection process, and extracellular enzyme activities of Aspergillus nomius against the Asian corn borer, Ostrinia furnacalis guenée (Lepidoptera: Crambidae)

ABSTRACTThe control of Ostrinia furnacalis, a major pest of maize in Xinjiang, is challenging owing to the occurrence of resistant individuals. Entomopathogenic fungi (EPF) are natural insect regulators used as substitutes for synthetic chemical insecticides. The fungus Aspergillus nomius is highly pathogenic to O. furnacalis; however, its virulence characteristics have not been identified. This study aimed to analyse the lethal efficacy, mode of infection on the cuticle, and extracellular enzyme activity of A. nomius against O. furnacalis. We found that the mortality and mycosis of O. furnacalis were dose-dependent when exposed to A. nomius and varied at different life stages. The egg-hatching and adult emergence rates decreased with an increase in conidial suspension. The highest mortality (83.33%, 7 d post-infection [DPI]) and mycosis (74.33%, 7 DPI) and the lowest mortality response (8.52 × 103 conidia mL−1) and median lethal time (4.91 d) occurred in the 3rd instar larvae of O. furnacalis. Scanning electron microscopy indicated that numerous conidia germination and infection structure formation may have contributed to the high pathogenicity of A. nomius against O. furnacalis. There were significant correlations between O. furnacalis mortality and the activities of extracellular protease, lipase, and chitinase of A. nomius. This study revealed the infection process of the highly pathogenic A. nomius against O. furnacalis, providing a theoretical basis and reference for strain improvement and field application of EPF