Microbial metagenomics for identification of microviridin encoding-genes from Brazilian cyanobacteria

• Grant number: 15/02785-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2015
• Effective date (End): December 31, 2016
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Douglas Gatte Picchi
• Grantee: Luiza Cortes
• Home Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Cyanobacteria have recently been rediscovered as proficient producers of bioactive secondary metabolites, in special, polyketides, alkaloids and peptides. Noteworthy are the peptides produced by megasyntethases (microcystins, nodularin, aeruginosina) or ribosomally (microviridins, cyanobactins, lantipeptides). Microviridins belong to a new class of depsipeptides horbouring a unique cage-like tricyclic structure. Due to their inhibitory activity against proteases, microviridins have high potential in drug design, notably for the treatment of protease-related-diseases, e.g., pulmonary emphysema, cystic fibrosis or infection. Up to now, 13 microviridins derivatives have been discovered. However, metagenomics studies revealed an unexpected cryptic genetic diversity of microviridins in field samples. In the last decades, metagenomics has rapidly developed into an efficient culture-independent approach, allowing to access any gene sequence or function of a given environmental sample. Metagenomics offers powerfull and modern tools to characterise genes, gene clusters and the production metabolites from complex samples, such as cyanobacterial blooms. These metacomunity harbours a huge genetic diversity, mostly cryptic, for the production of bioactive secondary metabolites. Metagenomic mining studies of a number of environmental cyanobacterial samples have revealed a surprising gene variability for the synthesis of microviridins, expanding the natural library of these tricyclic peptides. This research project is part of the post-doctoral research plan "Expanding the natural library microviridins through metagenomic data mining techniques of cyanobacteria in Brazilian biomes" (Process FAPESP nr.: 2013 / 50755-8) aimed at prospecting cryptic microviridins in isolated strains and cyanobacterial blooms from Brazilian biomes.