Project

Studies on the Use of Bacterial Cell as Glucose Biosensor

As the importance of blood glucose control for both diabetic and non diabetic patients continues to increase, there is a need for advanced glucose sensing technologies. The low accuracy and sensor drift become major problems with in vivo environments especially for enzyme based electrochemical glucose sensors. This study dealt with the use of E.coli as an effective biorecognition element in a whole cell based biosensor. A lac operon based sensor has been decided to develop. The reaction was set up in test tubes adding x-gal(5-bromo 4-chloro indolyl-β-galactopyranoside), IPTG (isopropyl β-D-thiogalactopyranoside), glucose of different concentration and microorganism, inorder to study the effect of different concentration of glucose in inducing beta galactosidase synthesis by the E.coli cell. In the beginning colorimetric assay and Biophotometric readings were taken, but the cells settled down faster, so toluene was introduced to disrupt the cell and to release the blue colored indigo product. DMSO(dimethyl sulphoxide) was introduced to solubilise the precipitate. A relative decrease in absorbance observed with increase in concentration of glucose.