Search

Pyrolysis of animal manure at high temperature is necessary to effectively immobilize heavy metals, while the available phosphorus (P) level in biochar is relatively low, rendering it unsuitable for use as fertilizer. In this study, the pretreatment of swine manure with different potassium (K) sources (KOH, K2CO3, CH3COOK and C6H5K3O7) was conducted to produce a biochar with enhanced P availability and heavy metals immobility. The addition of all K compounds lowered the peak temperature of decomposition of cellulose in swine manure. The percentage of ammonium citrate and formic acid extractable P in biochar increased with K addition compared to undoped biochar, with CH3COOK and C6H5K3O7 showing greater effectiveness than KOH and K2CO3, however, water- extractable P did not exhibit significant changes. Additionally, the available and dissolved Si increased due to the doping of K, with KOH and K2CO3 having a stronger effect than CH3COOK and C6H5K3O7. X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that K addition led to the formation of soluble CaKPO4 and silicate. In addition, the incorporation of K promoted the transformation of labile copper (Cu) and znic (Zn) into the stable fraction while simultaneously reducing their environmental risk. Our study suggest that the co-pyrolysis of swine manure and organic K represents an effective and valuable method for producing biochar with optimized P availability and heavy metals immobility. [ABSTRACT FROM AUTHOR]

The decomposition of returned straw is increasing facing the negative impacts by metal nanoparticles (NPs), however, which may be modulated by soil fauna and this modulation effect is unclear. Here, the interactive effects of ZnO NPs with soil fauna on wheat straw decomposition were investigated in a potted rice cropping system. The results showed that ZnO NP below middle concentrations did not significantly influence straw decomposition, and mass loss was mainly driven by microfauna and microbes. High concentrations of ZnO NPs significantly impeded decomposition, mainly by reducing the complexity of fungal communities. This negative effect was ascribed to the promotion of Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes. ZnO NPs had a greater impact on soil microorganisms than on fauna, reduced microbial activity, promoted the released straw nutrients entering into the soil by damaging nutrient transferring microorganisms and dominated the effects on soil stoichiometry. However, soil fauna significantly increased the activities of C- and N-releasing enzymes, decreased the activity of P-releasing enzymes, regardless of ZnO NP concentration, and promoted straw C decomposition. ZnO NPs altered soil microbial community composition, but these changes were modulated by soil fauna. Nonetheless, nutrient transport by fungi such as Ascomycota and Zygomycota and grazing by fauna were the predominant modulators on straw stoichiometry. The results of this study revealed that rational control of soil fauna will be helpful for promoting straw decomposition and efficient recycling of straw nutrients by crops under ZnO NP contamination.Article Highlights: High ZnO NP concentrations inhibit straw decomposition mainly by reducing diversity of fungal community. The negative effects of ZnO NPs are ascribed to Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes. ZnO NPs have greater impact on soil microorganisms than on fauna, reduce microbial activity, promote the released nutrients into soil and dominate the effects on soil stoichiometry. Fungal transport (e.g., Ascomycota and Zygomycota) and fauna grazing are the predominant modulators on straw stoichiometry. [ABSTRACT FROM AUTHOR]

A new cis-caffeoyl coumarin glycoside, cichorigenin-5-O-(4′-cis-caffeoyl)-β-D-glucopyranoside (1), wasisolated from the stem barks of Fraxinus depauperata, together with two known coumarins, cichorigenin (2) and esculin (3). The chemical structures of compounds 1-3 were elucidated through spectroscopic and chemical analysis, as well as by comparison with the literature. Compounds 2 and 3 are reported from this species for the first time. [ABSTRACT FROM AUTHOR]

Galanthamine is used as a strong reversible inhibitor of cholinesterase to increase acetylcholine sensitivity. Here, we sought to determine the effect of nitrogen (N) application on physiological and proteomic properties of Lycoris aurea ( L. aurea) in order to explore the factors that influence galanthamine biosynthesis. A marked increase in plant growth was observed under absent nitrogen condition (0 mmol L N), while a clear stunting of growth was seen under high nitrogen condition (3.57 mmol L N). Levels of photosynthetic pigments also showed a preference for the absent nitrogen condition. The leaves and roots of absent nitrogen plants had significantly higher galanthamine content and lower contents of free amino acids and proline compared with those of control (0.75 mmol L N). On the other hand, galanthamine content in L. aurea was significantly reduced with high nitrogen treatment. However, the contents of free amino acids and proline were increased with high nitrogen application, suggesting that these play important roles in the storage of nitrogen in L. aurea. Next, we carried out proteomic analysis of the leaves, bulbs and roots of L. aurea treated with nitrogen by two-dimensional gel electrophoresis. Using comparative proteomic strategies, we found 11 proteins that showed significant differences among the three groups. These proteins are involved in a variety of cellular processes including energy metabolism, scavenging oxygen free radicals, cytoskeleton stabilization, galanthamine biosynthesis and cellular homeostasis. Out of the 11 proteins, the level of phenylalanine ammonia-lyase was found to correlate with that of galanthamine biosynthesis. [ABSTRACT FROM AUTHOR]