Paper Published on Environmental Science & Technology

A research team led by Associate Prof. Li Nan from the School of Environmental Science & Engineering, published a paper titled Geobacter Autogenically Secretes Fulvic Acid to Facilitate the Dissimilated Iron Reduction and Vivianite Recovery in Environmental Science & Technology, a world-famous and impactful research journal in the field. The first author is Wang Shu, a doctoral student, and the corresponding author is Associate Prof. Li Nan. The link to the paper is https://pubs.acs.org/doi/10.1021/acs.est.0c01404.

Phosphorus undergoes a one-way flow from minerals to soil and to water, creating a phosphorus crisis as well as aquatic eutrophication. Dissimilatory metal reduction bacterial (DMRB) - induced vivianite recovery from wastewater is a promising way to solve these problems synthetically. Biosynthetic organic matters, such as humus, play important roles in iron and phosphorus cycling in soil and aquatic systems. As an important member of humus, fulvic acid (FA) is ubiquitous in different environmental media.

The research team fabricated the network among phosphate supply, metabolism pathway of FA, iron reduction, and vivianite recovery at the batch scale. Both the vivianite recovery performance and the content of biosynthetic FA were positively related to the phosphorus dosage.

Metabolome analysis revealed that FA biosynthesis was mainly relevant to tricarboxylic acid (TCA) cycle, amino acid metabolism, and purine metabolism, with glutamate and aspartate as the precursors. Sufficient phosphate stimulated the FA biosynthesis by modulating the biosynthesis and transformation of glutamate and aspartate. After adding trace FA, the maximal iron reduction rate as well as the vivianite formation efficiency were improved significantly. Transcriptome revealed that FA promotes iron reduction and vivianite recovery by upregulating the expression of metal ion binding-, flagella-, and electron transfer activity-related genes.

The research was supported by the National Natural Science Foundation of China.

By Wang Shu from the School of Environmental Science and Engineering

Editor: Eva Yin