Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2014

Synthetic biology based microbial biosensors for the detection of heavy metals (#97)

Lara T Bereza-Malcolm 1 2 , Gülay Mann 3 , Ashley E Franks 1 2
  1. Department of Microbiology , La Trobe University , Melbourne , Vic, Australia
  2. Defence Science Institute, Melbourne, Vic, Australia
  3. Defence Science and Technology Organisation, Melbourne, Vic, Australia

Rapid detection and quantification of environmental contaminates is necessary for the successful identification of polluted ecosystems. Heavy metals are compounds that significantly impact the environment and are identified as detrimental to human health due to accumulation and toxicity. Current technology for the detection of metals in suspected contaminated sites is often cost prohibitive and time consuming, especially in less developed nations. Microbes offer the potential to act as biosensors to detect a range of anolytes including heavy metals, on-site, without the need for expensive equipment. Synthetic biology has recently provided novel methods for the rapid design of de novo modular biosensing pathways that can be utilised across a range of microbes. Sensing pathways are composed of functional genes that form constructs. Constructs can be programmed to respond to specific anolytes and provide quantifiable outputs modulated through a series of signal cascades.  The construction of previous successful biosensors (i.e. arsenic and mercury detectors) have been limited to aerobic, laboratory microbes. To gain the full potential of biosensor technology, this study reports soil-associated microorganisms as novel chassis for synthetic biology. Initial biosensing constructs were optimized in E. coli utilizing standardized Biobricks™ (functional gene sequences in standardized vectors) to provide an assembly pipeline for the detection of various heavy metal anolytes. These initial experiments allowed the selection of defined, designed parts for multiplexing signal outputs in novel biosensors. To further enhance the utility of the heavy metal biosensors, contaminated sites were screened for heavy metal tolerant microbes and are being explored as novel chassis for the biosensing constructs. Movement and optimization of the synthetic pathways in alternate microbial chassis will provide more robust biosensors with increased specificity and sensitivity to heavy metal ions. This project aims to develop novel biosensing modules for use across soil associated microorganisms and further develop synthetic biology capacities in Australia.