Approximately 330 million tons of plastic were produced worldwide in 2015, and this figure continues to increase 1 . As a result, the contamination of our environment with plastics of all sizes is becoming one of the most widespread and long-lasting anthropogenic changes to the biosphere of our planet 2 . Microplastics (MPs) are generally defined as plastic particles in the size range of 100 nm to 5 mm, including submicrometre (100 nm to 1 μm) and micrometre (1 μm to 5 mm) plastics, and nanoplastics ranging from 1 nm to 100 nm (ref. 3 ). Furthermore, MPs are separated into primary MPs, which are originally manufactured in a particularly small size for specific applications, and secondary MPs, originating from the fragmentation of larger plastic debris by external forces 3 . Scientific research on MPs pollution is rapidly advancing. However, studies to date have focused almost exclusively on aquatic systems, especially the oceans 4-6 . The oceans represent the ultimate sink for most MPs, but the terrestrial environment is a major recipient of plastics of all sizes, owing to the large amounts of anthropogenic wastes derived from sewage sludges, organic fertilizers, plastic mulching, wastewater irrigation and other sources such as atmospheric particulate deposition [7][8][9] . On the basis of emissions data, it is estimated that 110,000 and 730,000 tons of MPs are added annually to farmlands in Europe and North America, respectively 10 . These figures exceed the estimated annual global burden of MPs in ocean surface waters of 93,000-236,000 tons 11 . Hence, there is a great need to understand and quantify the distribution, fate and transformation of MPs in the terrestrial compartment.Very little information exists on the accumulation and effects of MPs on soil biota 12,13 . Plants comprise a basic living component of terrestrial ecosystems and are an important source of human food.

No abstract

No abstract

The active sites of a mixed Cu/Ce material and the doping effect of typical element (iron, Fe) on the active species and the catalytic behavior of Cu/Ce for CO preferential oxidation in rich H2 (CO-PROX) were investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), in situ oxygen storage capacity measurement (OSC) combined with designed temperature-programmed reduction (TPR), along with Raman, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and temperature-programmed desorption/reduction of CO (CO-TPD/TPR). These results showed that two kinds of surface active center were involved in the CuCe- and Fe-doped CuCe systems, that is, Cu+ as adsorption sites for the chemisorption and the activation of CO molecules, the surface reactive oxygen (the highly dispersed oxygen and surface lattice oxygen) that directly participated in the whole CO oxidation process. The addition of Fe into CuCe sample resulted in the incorporation of Fe into CeO2 lattice forming Fe–O–Ce structure and generated more oxygen vacancies, which not only enhanced the interaction between Cu and Ce to form more Cu+ absorption sites but also trapped the gas-phase oxygen and promoted the release of subsurface lattice oxygen to supply more reactive oxygen. Thus, the turnover frequency (TOF) value was increased from 3.62 × 10–2 s–1 for CuCe to 4.50 × 10–2 s–1 for Fe-doped CuCe. Moreover, with the enhancement of the lattice oxygen migration combined with the promotional role of Fe on the water gas shift (WGS), the capacity of the resistance to CO2 and H2O was enhanced for Fe-doping CuCe, and the corresponding stability time was largely prolonged from 170 to 400 h, in the coexistence of CO2 and H2O.

Mathematical modelling study for water uptake of steadily growing plant root Science in China Series G-Physics, Mechanics & Astronomy 51, 184 (2008); The uptake diversity of soil nitrogen nutrients by main plant species in Kobresia humilis alpine meadow on the Qinghai-Tibet Plateau SCIENCE CHINA Earth Sciences 55, 1688 (2012); Alkali salts of heteropoly tungstates: Efficient catalysts for the synthesis of biodiesel from edible and non-edible oils

The extraction of K(+) and SiO(2 )from silicate minerals by Bacillus mucilaginosus in liquid culture was studied in incubation experiments. B. mucilaginosus was found to dissolve soil minerals and mica and simultaneously release K(+) and SiO(2) from the crystal lattices. In contrast, the bacterium did not dissolve feldspar. B. mucilaginosus also produced organic acids and polysaccharides during growth. The polysaccharides strongly adsorbed the organic acids and attached to the surface of the mineral, resulting in an area of high concentration of organic acids near the mineral. The polysaccharides also adsorbed SiO(2) and this affected the equilibrium between the mineral and fluid phases and led to the reaction toward SiO(2 )and K(+) solubilization. These two processes led to the decomposition of silicate minerals by the bacterium.

This research undertook the systematic analysis of the Klebsiella sp. D5A genome and identification of genes that contribute to plant growth-promoting (PGP) traits, especially genes related to salt tolerance and wide pH adaptability. The genome sequence of isolate D5A was obtained using an Illumina HiSeq 2000 sequencing system with average coverages of 174.7× and 200.1× using the paired-end and mate-pair sequencing, respectively. Predicted and annotated gene sequences were analyzed for similarity with the Kyoto Encyclopedia of Genes and Genomes (KEGG) enzyme database followed by assignment of each gene into the KEGG pathway charts. The results show that the Klebsiella sp. D5A genome has a total of 5,540,009 bp with 57.15% G + C content. PGP conferring genes such as indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, siderophore production, acetoin and 2,3-butanediol synthesis, and N2 fixation were determined. Moreover, genes putatively responsible for resistance to high salinity including glycine-betaine synthesis, trehalose synthesis and a number of osmoregulation receptors and transport systems were also observed in the D5A genome together with numerous genes that contribute to pH homeostasis. These genes reveal the genetic adaptation of D5A to versatile environmental conditions and the effectiveness of the isolate to serve as a plant growth stimulator.

No abstract