fairfolio
Saved Projects

Harnessing Tardigrade Genes to Enhance Bacterial Biosensors for Heavy Metal Pollutant Detection

CSEF · 2026 Microbiology (Senior Division)

Maggie Hao

Overview

Heavy metal water pollution is a growing concern in Southern California due to industrial discharge and urban stormwater runoff. Live bacterial biosensors provide a low-cost platform for monitoring heavy metal contaminants such as Pb(II), but their field deployment is limited by poor robustness under environmental stresses. My goal is to improve the stress resilience and functional reliability of a Pb(II)-responsive bacterial biosensor through heterologous expression of tardigrade stress-resistance genes. Five tardigrade genes encoding CAHS, MAHS, SAHS1, TRID1, and rvLEAM were cloned under an IPTG-inducible LacO promoter using Gibson Assembly. Two plasmid architectures were developed: a GFP-tagged design to evaluate expression and growth impacts, and an untagged design for incorporation into a PzraP-GFP lead biosensor strain. N-terminal targeting sequences were removed from MAHS and SAHS1 to enhance proper bacterial expression. Biosensor performance was quantitatively tested under oxidative stress, high salinity, and post-desiccation recovery, with empty-plasmid controls across at least 3 repeats. CAHS, MAHSΔN, TRID1, and rvLEAM were successfully expressed, while SAHS1ΔN failed to express and impaired growth. Expression of CAHS, MAHSΔN, and rvLEAM improved biosensor signal integrity under oxidative stress and enabled faster recovery following six days of desiccation. TRID1 did not confer measurable protection, and no constructs mitigated salinity-induced loss of Pb(II) concentration discrimination. Overall, this work provides the first systematic evaluation of tardigrade stress-resistance genes in engineered bacteria for heavy metal biosensing. The resulting stress-resistant Pb(II) biosensors support more reliable detection in complex environments and advance the feasibility of dried storage and field-deployable microbial monitoring systems.

Competition history

  • CSEF 2026 Microbiology (Senior Division) · Entry S-16-11

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

Source: California Science & Engineering Fair public projects

Save projects to your library

Sign in with Google to keep track of projects you find interesting, organized into folders. An account also raises your daily allowance for “Has this been done?”, and lets you create a key for the MCP server with a much higher limit than anonymous use. Browsing stays public.

Continue with Google