Development of a Whole-Cell System Based on Genetically Modified Protoplasts to Detect Nickel Ions in Food Matrices

Heavy metals are dangerous contaminants constituting a threat to human health because they persist in soils and are easily transferred into the food chain, causing damages to human health. Among heavy metals, nickel appears to be one of the most dangerous responsible for different disorders. Public health protection requires nickel detection in environment and food chains; a simple, rapid and sensitive method to detect nickel contamination is represented by biosensors. In this paper we report the setup of a whole-cell based system, in which protoplasts, obtained from Nicotiana tabacum leaves, were used as transducers to detect the presence of heavy metal ions and, in particular, nickel ions. Protoplasts were genetically modified with a plasmid containing the GFP reporter gene under the promoter region of a sunflower small HSP gene control. By this device the presence of heavy metal ions was detected. Thus, the possibility to use this whole-cell system as a novel tool to detect the presence of nickel ions in food matrices was assessed.