Gold Biomineralization on Bacterial Biofilms for Leaching of Au³⁺ Damages Eukaryotic Cells

Abstract

Heavy metals not only pollute the environment but also are health and environmental hazard. Bacteria constitute inexpensive and eco-friendly material to eliminate and recycle heavy metals via biomineralization and biosorption. However, the effect of metal biomineralization in bacterial biofilms on the ecological balance of bacteria and infectious diseases is unclear. This study aimed to explore the interaction between a eukaryotic cell line HEK293T and mineralized Escherichia coli, using a model of gold biomineralization on E. coli biofilms (E. coli-Au). In our present model, bacterial activity was not disrupted and bacterial adhesion and invasion were enhanced. E. coli-Au invaded the cytoplasm and nuclei of HEK293T cells and damaged them via intracellular growth and multiplication. The present findings indicate that metal biomineralization in bacterial biofilms for leaching of heavy metal ions is hazardous to eukaryotic cells and even human health.

Forced Biomineralization: A Review

“…Gold of microbial origin, which occurs in nano-particulate, spheroidal, and bacteriomorphic forms [ 40 , 41 , 42 , 43 ], has been reported as a biological response to highly toxic gold-complexes [ 44 ]. Both the geomicrobiology and the biogeochemistry of gold have been described by Reith et al [ 40 , 41 ] and Southam et al [ 42 ], respectively.…”

Biosynthesis of Bimetallic Au–Ag Nanoparticles Using Escherichia coli and its Biomedical Applications

“…In recent years, more and more studies on the biosynthesis of metallic nanoparticles, mainly including noble metals and transition metal elements, have been reported in bacteria, fungi, plant extracts, and yeast. − Unfortunately, most of the studies are concentrated on the biosynthesis of a single element. Even though multielement nanoparticles have been obtained via biosynthesis in some studies, the highly ordered and homogeneous shape of nanocomposites is still difficult to be synthesized. − In addition, these papers focused on the method and process of biosynthesis while often neglected the advantages of the multielement nanoparticles in application prospects.…”

Design and applications of self-assembled soft living materials using synthetic biology

“…In this study, the amino, thiol, carboxyl, and phenolic groups in bacterial biofilms are of paramount interest due to their ability to bind and effectively immobilize heavy metal ions and reduce them to zerovalent nanoparticles. Rooting from this property of biofilms, they developed a model of gold biomineralization and gold nanoparticle formation on E. coli biofilms and they investigated if this model causes any alterations in bacterial biological aspects and its effect on eukaryotic cells (Jiang et al, 2019). There are further examples for nanoparticle synthesis via biofilms.…”