Construction of an ultrasensitive arsenic biosensor through synthetic biology approaches

• Grant number: 16/11093-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2016
• End date: July 31, 2017
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Rafael Silva Rocha
• Grantee: Gabriel Lencioni Lovate
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 12/22921-8 - Synthetic biology approaches for deciphering the logic of signal integration in complex bacterial promoters, AP.JP

Abstract

One of the biggest water contamination problems of our days is the releasing of arsenic from natural or human action in potable water sources. Being arsenic a relatively common element in the earth's crust, a lot of microorganisms developed resistance systems to this element. Among these systems, the best studied is the arsRDABC operon of R773 plasmid from Escherichia coli. The development of a discipline dedicated to the engineering of circuits in life forms, the Synthetic Biology, facilitated the development of detection devices based on living beings, the so called biosensors. This way, a lot of arsenite (As3+) biosensors were constructed using the Pars promoter and the arsR gene, which encodes a repressor protein that binds to the Pars promoter inhibiting the transcription of the resistance genes when As3+ is absent in the media. The construction of these biosensors has even generated field applications, although the existent systems possess low sensitivity to doses of arsenic. Therefore, the present project aims to construct an ultrasensitive arsenic biosensor in the molds of the model bacteria E. coli. To generate an ultrasensitive biosensor this work proposes the combination of 3 different optimizations described on the literature, which would enhance the sensibility of the biosensor, they are: (I) uncoupling the arsR transcription from the reporter, (II) use of a weak promoter to control the arsR transcription and the (III) use of two ArsR Binding Sites coupled to the Pars. Besides that, will be implemented to the circuit a more sensitive variation of arsR and a cascade expression system amplifying the resultant signal.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARTINS-SANTANA, LEONARDO; NORA, LUISA C.; SANCHES-MEDEIROS, ANANDA; LOVATE, GABRIEL L.; CASSIANO, MURILO H. A.; SILVA-ROCHA, RAFAEL. Systems and Synthetic Biology Approaches to Engineer Fungi for Fine Chemical Production. FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY, v. 6, OCT 3 2018. (15/22386-3, 17/17924-1, 16/11093-8, 17/04217-5, 16/03763-3, 12/22921-8)