Functional characterization of Gram-negative bacteria from different genera as multiplex cadmium biosensors.
Widespread presence of cadmium in soil and water systems is a consequence of industrial and agricultural processes. Subsequent accumulation of cadmium in food and drinking water can result in accidental consumption of dangerous concentrations. As such, cadmium environmental contamination poses a significant threat to human health. Development of microbial biosensors, as a novel alternative method for in situ cadmium detection, may reduce human exposure by complementing traditional analytical methods. In this study, a multiplex cadmium biosensing construct was assembled by cloning a single-output cadmium biosensor element, cadRgfp, and a constitutively expressed mrfp1 onto a broad-host range vector. Incorporation of the duplex fluorescent output [green and red fluorescence proteins] allowed measurement of biosensor functionality and viability. The biosensor construct was tested in several Gram-negative bacteria including Pseudomonas, Shewanella and Enterobacter. The multiplex cadmium biosensors were responsive to cadmium concentrations ranging from 0.01 to 10µgml-1, as well as several other heavy metals, including arsenic, mercury and lead at similar concentrations. The biosensors were also responsive within 20-40min following exposure to 3µgml-1cadmium. This study highlights the importance of testing biosensor constructs, developed using synthetic biology principles, in different bacterial genera.
Applied and Environmental Microbiology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Plenty Road, Melbourne, Victoria 3086, Australia. Electronic address: ltbereza-malcolm@students.latrobe.edu.au.
Lara
L
Bereza-Malcolm
Applied and Environmental Microbiology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Plenty Road, Melbourne, Victoria 3086, Australia. Electronic address: sa.aracic@gmail.com.
Sanja
S
Aracic
Applied and Environmental Microbiology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Plenty Road, Melbourne, Victoria 3086, Australia. Electronic address: ruban_andrew@hotmail.com.
Ruban
R
Kannan
Land Division, Defence Science and Technology Group, Melbourne, Victoria 3207, Australia. Electronic address: gulaymann@gmail.com.
Gülay
G
Mann
Applied and Environmental Microbiology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Plenty Road, Melbourne, Victoria 3086, Australia. Electronic address: A.Franks@latrobe.edu.au.
Ashley E
AE
Franks
D001151:Arsenic / Q000302:isolation & purification / Q000633:toxicity; D015374:Biosensing Techniques / Q000379:methods*; D002104:Cadmium / Q000302:isolation & purification* / Q000633:toxicity; D004784:Environmental Monitoring; D006090:Gram-Negative Bacteria / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D007854:Lead / Q000302:isolation & purification / Q000633:toxicity; D008164:Luminescent Proteins / Q000737:chemistry; D008628:Mercury / Q000302:isolation & purification / Q000633:toxicity; D000097573:Red Fluorescent Protein
D001151:Arsenic; D002104:Cadmium; D007854:Lead; D008164:Luminescent Proteins; D008628:Mercury; D000097573:Red Fluorescent Protein
Cadmium; Environmental monitoring; Heavy metals; Microbial biosensors; Multiplex; Synthetic biology