BIOSENSING PERFORMANCE OF THREE DIFFERENT WHOLE CELL BIOSENSOR BASED ON LEAD-RESPONSIVE TRANSCRIPTION FACTORS

GÁNDOLA, YAMILA; ALVAREZ, MACARENA; GASULLA, JAVIER; NADRA, ALEJANDRO D

Mendoza

Congreso; LVIII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2022

SAIB Argentine Society for Biochemistry and Molecular Biology Research

This study utilizes synthetic biologyprinciples to develop plasmid-based whole-cell bacterial biosensorsfor detection of lead. Lead is one of ten chemicals that the WorldHealth Organization (WHO) has identified as a major public healthconcern (it is recommended to be lower than 10 µg/L (ppb) indrinking water). The lead biosensors evaluated are based on thenatural metal detoxification mechanism of theCupriavidus metallidurans(previously Ralstoniametallidurans) CH34 strain. Thegenetic element of the lead biosensor constructs consists of i) pbrR1or ii) pbrR2 of C. metalliduransand of iii) pbrR of K. pneumoniaecombined with pbrT of C.metallidurans genes sequences.All pbrR genes encode the lead-specific binding proteins (regulatoryproteins), that specifically bind to their respective divergentpromoter regions. Depending on the presence or absence of lead, theyregulate the expression of a reporter gene (GFP/BGalactosidase). ThepbrT gene encodes the Pb(II)-uptake protein. Results obtained with i)and ii) biosensors presented good sensitivity at low levels butshowed high variability between assays and high basal expression ofthe reporter protein. The resultsobtained with iii) showedthat our biosensor can detect lead in drinking water at levels as lowas 10 ppb and could be used in a low-cost, portable and easy to usedevice to test home’s water. p { line-height: 115%; text-align: left; orphans: 2; widows: 2; margin-bottom: 0.25cm; direction: ltr; background: transparent }