Hunting for a Needle in a Haystack: the Search for Indications of DDT-Consuming Microbes at Dump-Sites off the Coast of Los Angeles

In the approximately twenty years that dichlorodiphenyltrichloroethane (commonly known as DDT) was used as an agricultural pesticide, barrels of DDT waste were dumped in various locations off the coast of Los Angeles. The purpose of this study is to take the first step in establishing if microbial communities on the sea floor are breaking down this toxic waste as an energy resource. Before we can start understanding how the microbial communities are using DDT waste and establish if they can be used as natural bioremediation of this toxin, we must prove that the microbes are actually present in the system. Cores were taken from areas surrounding dump-sites and an uncontaminated site for comparison and analysis. Genetic material will be extracted from the cores, cleaned, and processed using PCR and cloning to isolate the highly conserved 16S RNA subunit. Comparison to a national database of 16S RNA sequences will give us the diversity and abundances of known and unknown microbes, as well as an idea of how the unknown microbes are related to those that have already been cultured. We hope that the results of this preliminary study will validate more intensive searches for DDT-consuming microbes at this site, by finding a dramatically different community structure or genes that indicate the presence of microbes that may have the functional potential to break down DDT. The results from this study will be used to direct further research into understanding the microbial community and its potential applications towards natural bioremediation of DDT waste.