CABLES: Cultivating And Bioengineering Living Electronic Sediments
Abstract
[Approved for Public Release]Electronic components that bridge the biotic-abiotic interface have implications in both measuring andcontrolling biological systems. Current bioelectronic materials derived from microbes (e.g., nanowires or conductive biofilms from Geobacter sulfurreducens or Shewanella oneidensis) are limited to electron transport at micrometer scales. Recently, cable bacteria were discovered to perform long-distance electron transfer through conductive periplasmic fibers that connect thousands of cells into multicellular filaments that span centimeter-scale redox gradients found in sediment environments. Cable bacteria are the only known biological systems that support electron transport (ET) over macroscopic scales and perform ET at rates that are previously unprecedented in biology. The charge carrying biomolecules in cable bacteria represent novel bioelectronic materials with potential uses in biosensing and bio-machine interface applications but require fundamentalresearch to enable these future applications. Thus far, it has not been possible to isolate and grow cable bacteria in pure culture, requiring enrichment of cable bacteria from environmental samples. The reliance on environmental samples has limited fundamental research into the identity of the charge carrying molecules within these filamentous bacteria. The research problem that this project is addressing is to develop a method for cultivating cable bacteria in chemically defined conditions and utilize in situ genetic engineering tools to establish sequence-function relationships in cable bacteria microbiomes. The objectives of this project are to: (i) fabricate ecosystems to cultivate and enrich cable bacteria and their associated microbiome by designing artificial sediments with tunable physiochemical properties, (ii) evaluate in situ genetic engineering potential of cable bacteria and the microbial communities associated with cable bacteria by using synthetic biology tools for microbiome engineering including components for broad-host and selective delivery of genetic payloads, and (iii) characterize and tune the physiological properties of cable bacteria by using (a) solid-state and electrochemical approaches to characterize electrical properties; (b) electron microscopy, spectroscopy, and mass spectrometry to characterize ultrastructure; and (c) using environmental and genetic control factors to tune these properties. The anticipated outcomes of the proposed research are: (i)the production of a reproducible method for cultivating cable bacteria that is not reliant on environmental samples, (ii) maps of organisms within sediment microbial communities that are genetically accessible (i.e., uptake exogenous DNA and express the encoded genetic circuits), (iii) selective delivery of DNA payloads to specific members of the microbial community, and (iv) electrical characterization and identification of proteins associated with the conductive fibers of cable bacteria.This research project will impactthe DoD#s capabilities by: (i) revealing fundamental properties of conductive polymers in cable bacteria which represent next-generation biomaterials for constructing macroscale bioelectronic devices and human-machine interfaces, (ii) providing a generalizable framework for mapping genetic accessibility and deploying genetic circuits to microbial communities residing in sediment ecosystems for future in situ synthetic biology applications including deployment of genetic circuits for chemical hazard detection and remediation, and (iii) enabling future applied studies of cable bacteria for controlling ecosystem services including elemental cycling and mineralization as well as macroscale bioelectronic sensing within sediment samples.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N000142412708
Entities
People
- Joshua T Atkinson
Organizations
- Office of Naval Research
- Trustees of Princeton University
- United States Navy