Winner – 2nd Prize
Team LixiLab – Daniela Barón, María Valentina Forero, María Alejandra Parra, Valentina Pérez, Lina Sánchez, Laura Velasco
Univerisad de Los Andes ,Colombia
In 2015, the FAO reported soil contamination as one of the main threats affecting the world’s land services. The source of this type of pollution can be linked to chemical products used in agriculture, manufacturing, and even military operations. These substances, which include heavy metals such as chromium, lead, nickel, copper, cadmium, and arsenic, end up being released into the environment.
This project started in Mochuelo Alto, a rural community in the outskirts of Bogotá, located next to the city’s landfill. This population relies on agriculture for its livelihood and is directly affected by leachate’s heavy metals coming from waste decomposition, causing contamination in water sources, and altering the soil’s biodiversity.
These metals reduce organic matter and inhibit growth and nutrition assimilation in crops, generating low productivity and crop quality reduction. On the other hand, they affect the health of the consumers, as heavy metals are related to cancer and adverse effects on the nervous, respiratory, reproductive, and cardiovascular systems.
LixiLab is a bioremediation technology using the dead bacterium Lysinibacillus sphaericus CBAM5 for extracting heavy metals in farmed soils. This non-pathogenic bacterium is resistant to heavy metals and can adsorb them even after completing its life cycle, because it has an extracellular self-assembly protein. This layer is found negatively charged on the cell membrane; therefore, bacteria can adsorb positively charged metals. Also, since it is dead, the uncertainty of bacterial reproduction in crops disappears.
LixiLab is a grassroot, feasible solution joining science and design to develop hands-on practical strategies along with farmers’ knowledge and tools. The technology applies the dead bacteria in a dehydrated hydrogel matrix, made of a chitosan and alginate blend, that works in water and soil. Those biopolymers are non-toxic, biocompatible, biodegradable and are obtained in large quantities all over the world at a low cost.
The first biotech application is LixiSoil, a biofilter which is introduced into the soil to reduce contaminants on surface rooted plants like vegetables and tubers measuring up to 60 cm or 2 feet. A fence can be created using several filters placed individually, covering the length of the land that the farmers need. The filter comes with a package of dehydrated spheres that can be changed, refilled or removed once the conductivity sensor indicates the maximum level of heavy metals in the spheres.
Ultimately, the farmers will return the packaging with the bacteria-filled metals for collection at indicated locations. At the end of the spheres’ life cycle, metals are extracted from the bacteria in a lab.
LixiAqua, the second biotech application, is implemented in water sources used for irrigation, storage tanks, and ponds. It should be placed in the medium up to one day to do its filtering process.
LixiLab’s mission is to make toxic-free crops possible, reducing the risk of diseases and increasing the well-being of farming communities and consumers. Finally, LixiLab seeks to ensure access to improved nutrition and promote sustainable agriculture by creating more fertile lands, reducing crop losses and soil degradation to guarantee the ecosystem’s biodiversity.