Whole-cell bacterial biosensors for rapid and effective monitoring of heavy metals and inorganic pollutants in wastewater

Abstract

The increasing number of potentially harmful pollutants in the wastewater effluent discharge necessitates the need for the development of fast and cost effective analytical techniques for extensive monitoring programmes to assess the effectiveness of the treatment process. This study compared the use of bacterial biosensors to the conventional Daphnia magna assay, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) tests as well as chemical analysis, for monitoring the toxicity of wastewater. The bacterial biosensors constructed in this study, using S. sonnei and E. coli, were found to be sensitive to the toxicity of the wastewater effluents. A linear increase in bioluminescence with increasing concentration of heavy metals and inorganic pollutants in water was observed, with a correlation coefficient (r(2)) as high as 0.995 and 0.997, respectively. No notable correlation between biosensor toxicity and BOD and COD test results was observed. These bacterial biosensors could provide appropriate alternatives for a rapid, sensitive and cost effective detection of wastewater quality. However, the differences in sensitivity obtained for the different systems suggest that the use of a battery of toxicity assays may be required to provide a real ecotoxicological assessment of wastewater samples.

Biosensors and Bioremediation as Biotechnological Tools for Environmental Monitoring and Protection

“…Air toxicity is monitored using fiber-optic biosensor developed by; Eltzov et al, Bioluminescence was suppressed when the biosensor was exposed to toxic compounds present in air Chloroform could be detected by this method with a LOD of 6.6 ppb. The same group developed a flowthrough fiber-optic sensing system by immobilizing two other bacterial strains for the online monitoring of toxic pollutants in water (Eltzov et al, 2009, Amaro et al, 2011, Arain et al, 2006, Eltzov et al, 2011, Olaniran et al, 2011. The sensor could detect pollutants in flowing tap water and surface water within 24 h, but a loss of functionality of the bacteria was observed after longer periods.…”

Biosensors for on-line water quality monitoring – a review

“…Whole cells are excellent sensors for contaminant detection. Many biosensors incorporating whole microbes as the sensing element have been designed for the fast and impressive detection of inorganic pollutants and heavy metals (Amaro, Turkewitz, Mart ın-Gonz alez, & Guti errez, 2011;Olaniran, Hiralal, & Pillay, 2011). A reagentless platform in which biocompatible agarose is used as an entrapment agent, with cell sensors and growth media mounted within the gel matrix, has also been developed (Lin, Zhang, & Yeh, 2019).…”

Developing Biosensors in Developing Countries: South Africa as a Case Study

“…Examination of the biosensor transducer types in Table 2 [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ] reveals an overwhelming amount of research originating from South Africa has been focused on electrochemical (amperometric, impedimetric, potentiometric and voltammetric) configurations of biosensors, with only a few publications found investigating colourimetric/photometric bases for signal generation. This is, itself, due to the many commonly reported beneficial properties of electroanalysis over other transducers—e.g., low fabrication-cost, consistency of fabrication, high degree of alloweable automation, ability to derive multiple signals from a single analytical device (signal multiplexing), lower anal...…”