Use Of Bacterial Sensors In Environment Pollutant Detection

Recently, the researchers have created various engineered bacterial strains that could be used as sensors to identify the environmental contaminants, like heavy metals. These sensors if used in the natural environment can actually help researchers trace pollutant levels that alter each passing day over diverse geographic areas. The engineers from MIT have recently made a safer, tough hydrogel shell enclosed bacterial sensor to prevent the bacteria from escaping into the air and spreading mutant genes to other organisms. Even though there are many whole-cell biosensors it is difficult to use them as there are chances of creating genetically engineered organisms by altering the genetic material with wild-type microbes.

The researchers added E. coli in the hydrogel spheres for helping detect contaminants without affecting the organisms. The hydrogel shells tend to shield the sensors from the environment damage. The idea of engineering bacteria to activate the genetic circuit they generally do not use can actually help enable them to identify the various molecules. The circuits have been designed such that target detection can help develop green fluorescent protein or bioluminescence. Usually, in the other circuits the event stored as a memory in the DNA of the cells. The antibiotic resistance genes form a part of these genetic circuits in the bacteria.

The gene exchanging property in the bacteria makes them harmful. To prevent any kind of gene exchange the researchers have used the chemical containment strategy in which the bacterial sensors require artificial molecule to not get wild. In the large number of bacteria, there are chances that a few of them mutate to survive without the need for a molecule. The physical containment options in which encapsulating bacteria in a device can help prevent them from escaping. The use of glass and plastic show diffusion barriers which prevent bacteria from interacting with the molecules designed to detect them. The bacterial sensors are encapsulated in the tough hydrogels with pores that help entry of essential nutrients. These sensors were designed to detect heavy metals such as cadmium. The researchers hope adding two containment options in the sensors and also encourage its use for medical applications such as detecting digestive tract bleeding.