Nowadays antibiotics have become indispensable drugs for treatment of bacterial infections. Owing to this popularity, it comes as no surprise that most city waste water is contaminated with antibiotics. This is caused by several factors including antibiotic presence in human waste due to insufficient metabolism, as well as unnecessary usage of these drugs (Malay, 2015). It is approximated that developing countries spend up to 35% of their budget to antibiotics (Isturiz, 2000; Saltoğlu, 2005). Moreover, it is especially in these countries where antibiotics are used incorrectly and unnecessarily (Hart, 1998). In some countries it is actually legal to sell un-prescribed antibiotics in drug stores and even in supermarkets (Saltoğlu, 2005).

Considering that antibiotics cannot be purified by conventional aerobic sludge systems, they are detected in the water even after exposure to wastewater treatment, and as a result received to the surrounding environment. High antibiotic concentrations cause toxicity in organisms, damage the ecosystem and as an outcome dispersal of antibiotic resistance is observed. Antibiotics primarily mix with city waste water by getting carried via hospital water waste, resulting to significant damage of human population and microorganisms around the contamination site. Arguably, most detrimental damage caused by such contamination is emergence of super bugs in the ecosystem. Small but constant dose of antibiotics is perfect for such selection. Emergence of super bugs is a global problem and one day may cause most simple infections to become deadly. Taking into account what is aforementioned it is evident that before recycling use, waste water should be free of antibiotics. That is why detecting and degrading antibiotics in waste water is in upmost importance (Topal, 2013).

In medicine beta-lactam antibiotics are found to be the most commonly used ones. The oldest and most utilized one is penicillin (Topal, 2013; Yaşar, 2013). Seemingly, aiming for penicillin bioremediation is the most logical and efficient way to come with a solution to this problem.

Figure 1. Molecular structures of some antibiotics characterized by the presence of the beta-lactam ring

Description of the project

Our project aims to firstly express a penicillin binding peptide on biofilms in order to capture the penicillin on the bacteria cell’s surface, secondly to express proteins that can trap iron ions so that bacteria gains magnetic properties and finally filter bacteria with captured penicillin by means of a magnetic field. This would present a cheap and easy way to filter penicillin from waste water. Bacteria strain that is going to be used in our project (Escherichia coli) has no side effect on the environment. In addition to that, the proteins possessing magnetic properties are not going to be released in the water after being synthesized in the bacteria. Thus the resulting filtered water will be free of magnetic compounds.

Figure 2.An illustrative representation of the idea behind the project’s aim

Furthermore, we aim to extend the scope of our project by capturing other types of antibiotics as well as other contaminants such as pesticides, insecticides and heavy metals from waste water. Our purpose is to develop this system such that it can be used in water refining facilities cost-effectively, with speed and ease.

Team:Bilkent-UNAMBG

Bilkent-UNAMBG