Team:NYU-AD/Description
Exterminator Coli
The NYUAD iGEM team have created a self-sustaining mosquito trap. The trap attracts mosquitoes by having E.coli secreting indole and lactic acid, both of which are highly attractive to a broad range of mosquitoes, particularly, the Aedes Aegpyti, mosquito - the vector for Dengue and Yellow fever. Indole is produced from tryptophan by E.coli with the genes tnaA and tnaB. Similarly, lactic acid is produced from fructose by E. coli with the gene lldD. The trap was built predominantly by using a large Coca Cola bottle. It was cut into half horizontally and with the top half inverted and placed above the bottom, it forms an air-tight funnel-like structure with an opening where the lid would have been through which the mosquito can enter. The genetically modified E-coli was placed on a petri dish at the base of the bottle and the electric mesh was held in place at the neck of the bottle so that once the mosquito attempts to leave the bottle, it is stunned and falls back into the petri dish containing the bacterial colony. Upon contact with the medium, the hard exoskeleton of the mosquitoes is digested by chitinase (chitinase is produced by the gene ChiA in E.coli). With the hard outer exoskeletons removed, the E. coli uses the mosquitoes as a carbon source to sustain growth.
Despite action taken by many countries during the past decade to reduce mosquito-borne illnesses and the numerous advancements in the medical field in the global context, thousands of people die from diseases such as Malaria, Dengue, Yellow fever and Chikungunya. Such diseases are still very much a cause for concern particularly in many countries in South Asia and Africa. Most people are unable to afford expensive medical treatment against such diseases so their next best alternative would be a cheap, effective, easy-to-use mechanism that would trap these mosquitos. This was the main focus of our project. The entire concept of the Coca Cola bottle is sustainable and is an ideal solution as it is easy to make and does not require resources that are difficult to obtain. Our team itself has a great deal of diversity. With 4 engineers, 2 biologists, a computer scientist and a mathematician, this project presented everyone with a key role to play. While the biologists spent most of their summer preparing the genetically modified E-coli, the engineers thought of the most feasible and appropriate way to design the trap and turned it into a functioning prototype. Of course, a collaborative team input on all aspects of the project was often required but having specific set tasks was what made this project ideal for a team like ours.
Reaching a decision to proceed with this as our final project was by no means a straightforward task. It involved many weeks of extensive research, first on background information related to our idea followed by more specific scholarly research related directly to the project itself. Different biological and physiological characteristics of mosquitos, particularly those of the Aedes Aegpyti mosquito that would influence our project were looked into in great deal. These characteristics involved (but were not limited to) responsiveness and sensitivity of the receptors on the mosquito to attractants such as indole. Information was also sought on how other types of mosquitos respond to substances such as indole and lactic acid and whether noticeable trends were present in the data that was available. Other important areas of research were different methods of genetically engineering E-coli to increase the production of substances such as tryptophan and lactic acid by the overexpression of certain important genes. Some emphasis was also placed on bacterial-specific details such as how certain substances are transported across the E-coli membranes.
All references and evidence of research described above is documented as shown below:
Bohbot, Jonathan D., et al. "Conservation of indole responsive odorant receptors in mosquitoes reveals an ancient olfactory trait." Chemical senses36.2 (2011): 149-160.
Mulok, T. E. T. Z., et al. "Engineering of E. coli for increased production of Llactic acid." African Journal of Biotechnology 8.18 (2009).
Shen, Tong, et al. "Improved production of tryptophan in genetically engineered Escherichia coli with TktA and PpsA overexpression." BioMed Research International 2012 (2012).
Li, Gang, and Kevin D. Young. "Indole production by the tryptophanase TnaA in Escherichia coli is determined by the amount of exogenous tryptophan."Microbiology 159.Pt 2 (2013): 402-410.
Pinero-Fernandez, S., et al. "Indole transport across Escherichia coli membranes." Journal of bacteriology 193.8 (2011): 1793-1798.
Steib, Birgit M., Martin Geier, and Jürgen Boeckh. "The effect of lactic acid on odour-related host preference of yellow fever mosquitoes." Chemical Senses26.5 (2001): 523-528.