Chromobacterium violaceum for rapid measurement of biochemical oxygen demand

Abstract

Biochemical Oxygen demand (BOD) is an important parameter indicating the total biodegradable organic pollutants in waters. Fast BOD determination could be achieved using BOD biosensor. However, most of the developed BOD biosensors are dependent on dissolved oxygen concentrations. Low solubility of oxygen in water decreases the reliability of oxygen-dependent BOD biosensor. However, replacement of oxygen with a mediator solution solves this problem. In the present study, an effective ferricyanide-mediated approach was modified from ferricyanide-mediated BOD assay and used for BOD determination in a water system. Several different types of microorganisms were isolated from different organic-rich environmental sources and their ability to use ferricyanide during organic (standard glucose-glutamic acid solution) degradation were effectively assessed using ferricyanide-mediated BOD assay. Around 90% of the GGA was degraded by Chromobacterium violaceum after 1 hour of incubation period. Therefore, C. violaceum has been found to be a potential microorganism to be used as a biosensing element in the BOD biosensor. This assay is not only effective in selecting the suitable microorganisms for ferricyanide-mediated BOD detection; it also could be applied to select the suitable microorganisms for other mediated microbial biosensor and bioremediation by changing the substrate and conditions