Planta Med 2012; 78 - PI60
DOI: 10.1055/s-0032-1320747

Antiparasitic screening of metagenomic libraries from two Brazilian hotspots: Cerrado and Atlantic Rainforest

RC Pessotti 1, I Silva-Jardim 2, DO Guimarães 3, SA Uyemura 1, SF Brady 4, OH Thiemann 2, MT Pupo 1
  • 1School of Pharmaceutical Sciences of Ribeirão Preto – University of Sao Paulo (USP). Ribeirão Preto, SP, Brazil
  • 2Physics Institute of São Carlos – USP. São Carlos, SP, Brazil
  • 3Federal University of Rio de Janeiro. Macaé, RJ, Brazil
  • 4Laboratory of Genetically Encoded Small Molecules – The Rockefeller University. New York, NY, USA

* Both authors contributed equally to this work.

The soil metagenome from the Brazilian hotspots “cerrado” and Atlantic rainforest were explored to search for bioactive natural products using an anti-Leishmania assay. Two libraries were constructed and tested: one from cerrado soil (500.000 clones), and other from Atlantic rainforest soil (250.000 clones), both in Escherichia coli strain EC300. Screenings against Leishmania major promastigotes (strain MHOM/IL/81/Friedlin) were carried out: libraries were cultivated in plates, followed by L. major overlay. No leishmanicidal activity was observed for the Atlantic rainforest library. For the “cerrado” library 84 L. major growth inhibition halos were observed and six of them were confirmed upon retesting. These six clones were cultivated for chemical profiling by HPLC-DAD and HPLC-MS and are being submitted to DNA sequencing. Therefore, this work shows that the metagenomic approach is a useful tool for searching antiparasitic molecules. The libraries construction, biological results and chemical profiling of positive clones will be presented.