Engineering bacteria for biogenic synthesis of chalcogenide nanomaterials

Abstract

SummaryMicrobes naturally build nanoscale structures, including structures assembled from inorganic materials. Here, we combine the natural capabilities of microbes with engineered genetic control circuits to demonstrate the ability to control biological synthesis of chalcogenide nanomaterials in a heterologous host. We transferred reductase genes from both Shewanella sp. ANA‐3 and Salmonella enterica serovar Typhimurium into a heterologous host (Escherichia coli) and examined the mechanisms that regulate the properties of biogenic nanomaterials. Expression of arsenate reductase genes and thiosulfate reductase genes in E. coli resulted in the synthesis of arsenic sulfide nanomaterials. In addition to processing the starting materials via redox enzymes, cellular components also nucleated the formation of arsenic sulfide nanomaterials. The shape of the nanomaterial was influenced by the bacterial culture, with the synthetic E. coli strain producing nanospheres and conditioned media or cultures of wild‐type Shewanella sp. producing nanofibres. The diameter of these nanofibres also depended on the biological context of synthesis. These results demonstrate the potential for biogenic synthesis of nanomaterials with controlled properties by combining the natural capabilities of wild microbes with the tools from synthetic biology.

Simulations to Aid in the Design of Microbes for Synthesis of Metallic Nanomaterials

“…In studies of arsenic sulfide biosynthesis, changing the host strain changed the resultant nanomaterial geometry from spheres to wires. 19 Furthermore, heavy-metal resistant strains like Klebsiella planticola 106 and single-celled extremophiles 107 could thrive in environments deadly for model organisms like E. coli. Electron conducting strains like cable bacteria Candidatus, 108,109 which are highly conductive (∼10 10 electrons/s) over centimeter length scales, could be engineered to synthesize remarkable biogenic products, like microbial fuel cells.…”

Synthetic biology as driver for the biologization of materials sciences

“…This material is applied for the targeted delivery of chemotherapeutic drugs [ 76 ] A genetically engineered diatom produces a silica matrix that incorporates proteins of interest. The proteins' stability and functionality in the silica matrix is assessed [ 77 ] Calcium carbonate production and crystal formation is achieved by urease-expressing engineered E. coli cells [ 78 ] Silaffin and Major ampullate Spidroin 1 (MaSp1) protein from spider silk Protein-silica composites able to form structures with different morphologies were obtained by combining silica precursors with a spider silk protein fused to a silaffin peptide [ 79 ] Silicatein Synthetic sponge spicules are obtained by means of recombinant silicatein mixed with inorganic compounds [ 80 ] Thiosulfate reductase & arsenal reductase Redox pathways from two strains of bacteria are transferred into a heterologous host to synthesize arsenic sulfide nanomaterials [ 81 ] …”

Bacteria in Heavy Metal Remediation and Nanoparticle Biosynthesis

“…ANA-3 and Salmonella enterica serovar Typhimurium into E. coli bacterium (as a heterologous host), thus making the expression of arsenate and thiosulfate reductase genes responsible for arsenic sulfide nanomaterial synthesis. Additionally, cellular components nucleated the generation of these nanomaterials . In the case of Shewanella oneidensis MR-1, subcellular located selenium-containing NPs with fine-tuned compositions were produced by changing the extracellular electron transfer (EET) chain.…”

“…Additionally, cellular components nucleated the generation of these nanomaterials. 89 In the case of Shewanella oneidensis MR-1, subcellular located selenium-containing NPs with fine-tuned compositions were produced by changing the extracellular electron transfer (EET) chain. Further, the synthetic abilities of the cells has been exploited for the assembly of cadmium selenide NPs in the cytoplasm with remarkable purity and uniformity in sizes, typically with higher rate of production and endowed with related fluorescent intensities.…”