Microbial Biosensor for Marine Environments

A biosensor is an analytical device which integrates a biological recognition element with a physical transducer to generate a measurable signal proportional to the concentration of the analyses. A microbial biosensor consists of a transducer in conjunction with immobilized viable or non-viable microbial cells. Non-viable cells obtained after Permeable or whole cells containing periplasmic enzymes have mostly been used as an economical substitute for enzymes. Based on the sensing technique, recent reported microbial biosensors can be classified into two major groups: electrochemical microbial biosensors and optical microbial biosensors. Microbial biosensors based on light emission from luminescent bacteria are being applied as a sensitive, rapid and non-invasive assay in several biological systems. Bioluminescent bacteria are found in nature, their habitat ranging from marine (Vibrio fischeri) to terrestrial (Photorhabdus luminescens) environments. Bioluminescent whole cell biosensors have also been developed using genetically engineered microorganisms (GEM) for the monitoring of organic, pesticide and heavy metal contamination. The major application of microbial biosensors is in the environmental field. Currently, different microorganisms have been genetically engineered to respond to particular stresses or toxicity and are described in the literatures as biosensors for environmental stressesthough for them to be biosensors in these of this publication these organisms would have to be coupled to a suitable transducer. Based on the respiration of cells, Pseudomonas sp. entrapped polycarbonate membrane modified oxygen electrode was also applied to detect PNP which serves as the sole carbon and nitrogen source for the bacteria. By application of these biosensor in the marine environment the pollution in these ecosystems can be better manage.