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Interactive effects of biochar amendment and lead toxicity on soil microbial community
Citation:
Wan, Y., R. Devereux, S. George, J. Chen, B. Gao, Matthew Noerpel, AND K. Scheckel. Interactive effects of biochar amendment and lead toxicity on soil microbial community. JOURNAL OF HAZARDOUS MATERIALS. Elsevier Science Ltd, New York, NY, 425:127921, (2022). https://doi.org/10.1016/j.jhazmat.2021.127921
Impact/Purpose:
The purpose of this study was to determine if microbial communities change in the near term (<1y) upon Pb and biochar exposure in a phytoremediation experiment and, if so, to identify the most responsive members of the community. The controlled greenhouse study is unique in providing a framework for microbial community assessment of Pb and biochar effects singly and in combination. Sequences of 16S ribosomal RNA genes were used tp assess changes within a phylogenetic/hierarchical taxonomic context. Results from statistical analyses demonstrated divergence of communities exposed to Pb or biochar, and interactive effects of both including an apparent mitigation of Pb toxicity from biochar. Effects were significant at bacterial taxonomic levels of genus through phylum. Further, biochar promoted formation of highly insoluble Pb-containing pyromorphite during the experiment. This study highlighted the effectiveness of biochar for Pb bioremediation and demonstrated that soil microbial communities may offer an avenue for rapid assessment of Pb bioavailability in soils.
Description:
This study determined the interactive effects of biochar and lead toxicity on the soil microbial community in a phytoextraction experiment. Arranged with a completely randomized design in a greenhouse, banana liners were planted singly in a sandy soil spiked with Pb(NO3)2 at 0, 400 and 1200 mg kg−1 and amended with bamboo biochar (pyrolyzing at 600 °C) at 0, 1, 3%. Soil samples were taken from triplicated pots five months after planting and measured for (i) content of lead and organic carbon; (ii) lead speciation; and (iii) microbial community composition through 16S rRNA gene sequencing. DNA sequencing results showed that lead and biochar treatments had significant individual and interactive effects on soil microbial dissimilarities from taxonomic levels of phyla to genera. While some specific taxa were lead resistant, biochar addition apparently alleviated lead toxicity and increased their richness (e.g., Alkanibacter, Muciaginibacter, Burkholderiaceae, and Beggiatoaceae). Soil analysis data indicated that biochar not only helped retain more lead in the soil matrix but created a soil environment inducive for transformation of lead into highly insoluble pyromorphite. This study highlights the effectiveness of biochar for lead remediation and the sensitivity of soil microorganisms in sensing changes in soil environment and lead bioavailability.
URLs/Downloads:
DOI: Interactive effects of biochar amendment and lead toxicity on soil microbial community
https://pubmed.ncbi.nlm.nih.gov/34986562/