Cyanosense
Why Our Waterways Matter
The waterways in Austin, TX are central to our city's identity. From kayaking on Lady Bird Lake (also known as “Town Lake”) to relaxing along Barton Creek, or taking your dogs out for a swim, these spaces bring people together and provide habitats for local wildlife. In recent years, however, harmful algal blooms have disrupted these environments. These blooms are typically caused by cyanobacteria (or blue-green algae) and can release several types of toxins—microcystins, anatoxins, or saxitoxins, for example—that pose serious risks to the health of humans, pets, and wildlife. 1
In 2023, Austin's lakes, including Lady Bird Lake and Lake Austin, were ranked among the top 10 worst places globally for toxic algae blooms.2 With an estimated 5 million annual visitors to Lady Bird Lake alone, this issue directly threatens public health, recreation, and the city's way of life.3
MC-LR Toxicity and Impact on Our Waterways
Some cyanobacterial blooms release microcystins, a type of potent liver toxin that can accumulate in the water and persist even after the algae has disappeared. Because they are difficult to detect without thorough testing, they present a serious threat. Since 2019, multiple dogs in Austin have died after swimming in waterways contaminated with toxic blue-green algae, further highlighting the serious risk these blooms pose.4
While several cyanotoxins exist, our team chose to focus on microcystin-LR (MC-LR), the most environmentally prevalent and well-known variant.5 We selected MC-LR because it is one of the most commonly studied and concerning cyanotoxins in freshwater systems, including reports of its presence in Austin-area harmful algal blooms.4
The Solution: CyanoSense
To address this problem, our project, CyanoSense, applies synthetic biology to create a biosensor for detecting and degrading microcystins. By engineering Acinetobacter baylyi (ADP1), we aim to provide a system that is cost-effective and does not require specialized lab equipment. CyanoSense combines two key functions: detection, by signaling when microcystins are present, and degradation, by enzymatically breaking down toxins to reduce harm. Utilizing the novel chassis organism Acinetobacteri baylyi (ADP1) to house our DNA sensor allows for the use of modular parts and systems, such as promoters and the use of other homology flanks for unique target regions. Together, these features make CyanoSense a potential tool to protect Austin's waterways, wildlife, and public health, while also laying the groundwork for future iGEM teams to build their own biosensors and innovative solutions.
How Our Sensor Works
CyanoSense is built using ADP1 as our chassis because it can naturally take up DNA, which allows our sensor to be integrated directly into the chromosome via homologous recombination. The sensor is designed to detect target DNA sequences that are characteristic of microcystin-producing cyanobacteria, such as Microcystis aeruginosa. When the target sequence is detected, homologous recombination corrects a frameshift mutation, allowing for downstream expression of a chloramphenicol antibiotic resistance gene. Additionally, we are designing the detector so that, upon DNA recognition, it can turn on genes encoding enzymes capable of breaking down microcystins into less harmful byproducts.
Through the use of synthetic biology, CyanoSense aims to reduce environmental and public health risks of microcystins in waterways, thereby protecting ecosystems, animals, and humans.
References
- Buchele, Mose. “Rite of Spring: Dog-Killing Algae Is Back in Austin Waterways.” KUT Radio, Austin's NPR Station, KUT, 23 Apr. 2025, https://www.kut.org/energy-environment/2025-04-23/blue-gree-algae-cyanobacteria-toxins-lady-bird-lake-austin-tx.
- (2023, December 27). Top 10 Worst Algal Blooms of 2023. Blue Green Water Technologies. https://bluegreenwatertech.com/post/top-10-worst-algal-blooms-of-2023
- Bent, E. (2023, March 3). Data: Lady Bird Lake Capacity Study finds capacity exceeded on some days; Austinites concerned with crowding. Community Impact. https://communityimpact.com/austin/northwest-austin/city-county/2023/03/03/data-lady-bird-lake-capacity-study-finds-capacity-exceeded-on-some-days-austinites-concerned-with-crowding/
- The City of Austin (n.d.). Algae in Austin's Waterways. Austintexas.gov. https://www.austintexas.gov/page/algae-austins-waterways
- Common Toxins Produced by Cyanobacteria, Dinoflagellates, and Diatoms | US EPA. (2024, February 16). US EPA. https://www.epa.gov/habs/common-toxins-produced-cyanobacteria-dinoflagellates-and-diatoms#common1