Mercury (Hg) is one of the most toxic metals and is not essential for any organism. In this study, the potential of maize plants in association with bacteria to treat oxisol contaminated with Hg (II) was evaluated. The experiment was conducted in a controlled environment, and pots with 2 kg of oxisol were contaminated with HgCl2 solution at a dose of 36 mg kg-1 of Hg in a 7x4 factorial scheme: control (soil without Hg(II) and microorganisms), T2= (soil with Hg(II) and without microorganisms), and T3= soil with Hg(II) + Enterobacter cloacae, T4= Hg(II) + Bacillus subtilis, T5= Hg(II) + Enterobacter sp., T6= Hg(II) + Staphylococcus epidermidis, and T7= Hg(II) + Bacillus sp. Total Hg quantification was performed by atomic absorption spectrophotometry. At the end of the experiment, the soil pH was significantly lower (0.3 to 0.4 pH unit) in the T2 (no inoculation), Enterobacter cloacae, Enterobacter sp. and Bacillus sp. treatments. Neither contamination of soil with Hg nor plant associations with bacteria led to differences in the root dry mass of maize plants. Maize plants associated with Staphylococcus epidermidis and Bacillus sp. bacteria had lower shoot biomass (71 and 50%) compared to the treatment 2. The best remedial effect was observed with the association of maize plants with Bacillus sp., which recovered 19.67% of Hg(II) in the soil when compared to control and treatment 2 and treatment with B. subtilis. The recommendation is the use of B. subtilis to decrease the toxicity caused by Hg(II).

Blossom-end rot (BER) is a physiological disorder related to calcium (Ca) deficiency in tomato fruits. However, adequate Ca supply is not sufficient to inhibit the BER incidence. The Ni-Ca interaction has increased the Ca content in Ni hyperaccumulators plants. However, studies with commercial plants are still incipient. The objective of this work was to evaluate the effect of Ni-Ca interaction in tomato plants, focusing on yield and incidence of BER. We carried out two trials. The first trial two Ca doses was used: sufficient Ca 0.70 g kg⁻¹ (Ca S) and deficient Ca 0,35 g kg⁻¹ (Ca D) and; four Ni doses applied via substrate (0.0; 0.5; 1.0 and; 2.0 mg kg⁻¹). In the second trial, the same Ca doses of the first trial and four doses of Ni (0.0; 0.08; 0.42 and; 0.84 mM) applied, via foliar, at the beginning of flowering were used. We verified that the Ni-Ca interaction increased the tomato fruits yield, the shoot calcium accumulation reduced the BER incidence and increased the time of fruit color change (green to red). Even under stressed conditions such as a low Ca availability. Both Ni application ways showed positive results for fruit yield and decreased BER incidence.

Vibratory ball milling enables the fast, solvent-free synthesis of gallate-based bioMOFs with preserved structure and Cr( vi ) adsorption performance.