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Lead (Pb) contamination in soils is becoming one of the most serious environmental issues in recent years. For this reason, amendment induced immobilization of Pb in contaminated soils has been considered as an eco-friendly and cost-effective technique to minimize soil Pb availability. This study aims at evaluating efficacy of the newly discovered Aspergillus niger strain, SANRU in bioimmobilization of Pb in contaminated mine soil. To conduct bioimmobilization, phosphate rock (PR) at various P/Pb ratios of 0 (T 1 ), 2 (T 2 ), 4 (T 3 ), or 6 (T 4 ) molars was inoculated with the A. niger strain SANRU and subsequently introduced into the soil. The soil sample inoculated with A. niger SANRU and P/Pb molarity ratio of 0 (T 1 ) in this study showed the highest Pb bioimmobilization efficiency, as well as a significant reduction up to 65 % in the unimmobilized Pb concentration and an increase in residual Pb fraction. Our in-depth Fourier transform infrared spectra (FTIR) and X-ray diffraction (XRD) studies revealed that the successful Pb bioimmobilization in this sample was attributed to Pb oxalate formation in the soil. In T 2 treated soil with A. niger and P/Pb molarity ratio of 2, the Pb oxalate was precipitated solely as Pb minerals in spite of the presence of available phosphate. In the samples with A. niger and higher amounts of PR (T 3 and T 4 ) the Pb bioimmobilization efficiency was significantly lower than T 1 but hydroxypyromorphite was formed in these samples. Our data thus propose that A. niger SANRU alone suffice to bioimmobilize Pb in contaminated soil., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

[Objectives] This paper was aimed to study the remediation effects of phosphate-solubilizing fungi and bone char in different soils. [Methods] Three different types of lead-contaminated soils (neutral yellow brown soil, alkaline sand soil and acidic red soil)were mixed with the bone char sintered at different temperatures. We measured the contents of phosphorus and lead, and the remediation differences of different soils. The Pb bioavailability of lead-contaminated soil was then determined by planting non-heading Chinese cabbage. The application potential of compound remediation materials was confirmed by adding compound remediation agents to the soil with the best remediation effect. [Results] The bone char had the best effect of promoting the release of phosphorus in yellow brown soil, and the available phosphorus content was 64 times higher than that of the control, showing a high potential of lead remediation. The pH of yellow brown soil was neutral, and the available P in the soil would not be fixed by Ca, Fe, Al, etc., thus increasing the probability of its reaction with Pb. When bone char was solely used, the material treated at 200-300 ℃ had qualified remediation effect. We planted non-heading Chinese cabbage to verify the bioavailability of lead in yellow brown soil after bone char application. It was observed that addition of a certain proportion of bone char to yellow brown soil (the initial mass ratio of bone char to lead was over 0.5:1) could not only increase the absorption of phosphorus by 2.0 to 3.5 times, but also reduce the absorption of lead by non-heading Chinese cabbage(content of lead in pakchoi leaves was reduced by 70% to 80% compared with blank treatment). A composite of bone char and Aspergillus niger was further applied to yellow brown soil, and the effective lead was reduced to 14.36 mg·kg-1. In particular, the growth of the A. niger proved the remediation potential of the composite. [Conclusions] The composite of bone char and A. niger was suitable for lead remediation in neutral soils, and the suitable heating temperature for preparing bone char was 200-300 ℃. [ABSTRACT FROM AUTHOR]

Objective: The present study aims to isolate and diagnose of fungi from soil polluted with oils and investigate their ability to produce a-amylase. Methods: Soil samples were collected from different areas of oil-polluted soils in Karbala, Iraq for the period from October to November 2019. 0.5 g of each sample was diluted with distilled water and cultured on potato dextrose agar (PDA). A week later, the purification processes were carried out to obtain pure colonies of isolated fungi. The isolated fungi were diagnosed and their own codes were given. The fungal isolates were then implanted in the nutrient broth to determine the susceptibility of these isolates to produce of a-amylase. After 10 days of incubation, the filtration and centrifuge processes were measured for production media. The amount of the enzyme was measured by using kit of a-amylase in the Reflatron. Results: Four fungal genera were obtained in this study and are belong to five fungal species (45 Isolates), including: Aspergillus niger (20 isolates), Aspergillus flavus (8 isolates), Rhizopus stolonifera (5 isolates), Phoma medicaginis Malbra var. pinodella (9 isolates) and Mucor sp. (3 isolates). Twelve isolates were found in the production of a-amylase produced. The two isolates, Phoma medicaginis Malbra var. pinodella (D7) and Aspergillus niger(A19), were the most productive a-amylase, with the amount of enzyme produced (746 and 321) U/L, respectively. Conclusions: The fungal species found in the soil polluted with oils in the city of Karbala are five fungal species including Aspergillus niger, Rhizopus stolonifer, Phoma medicaginis Malbra var. pinodella, Aspergillus flavus and Mucor sp. The highest production of a-amylase was through the fungal isolation of Phoma medicaginis Malbra var. pinodella D7. [ABSTRACT FROM AUTHOR]