MBSP1: uma nova proteína surfactante derivada de biblioteca metagenômica

Abstract

Microorganisms represent the largest biomass on the planet, but due to the limitations of cultivation techniques, most of this genetic patrimony has been inaccessible. With the advent of metagenomic methodologies, these limitations have been overcome, allowing the exploitation of the genetic pool of noncultivable microorganisms. These methodologies allow us to obtain new genes and develop biotechnological products. In this work, a metagenomic approach was used to select genes involved in hydrocarbon degradation and emulsification. Environmental DNA was extracted from soil collected in a saline river of Rio Grande do Norte and a metagenomic library was constructed. A clone identified as 3C6 was positive in functional screening for biosurfactant protein and revealed an open reading frame (ORF) of 897 bp with high identity to sequences encoding a hypothetical protein from species of Halobacteriaceae family. This ORF was subcloned into expression vector and its heterologous expression was performed on Escherichia coli, being further purified exhibiting biosurfactant activity with high stability. This new protein with biosurfactant activity was obtained from a metagenomic approach, and called metagenomic biosurfactant protein 1, MBSP1. Here we describe the cloning of an environmental gene encoding a protein with interesting tensoactive properties that can be produced in a host cell such as E. coli without substrate dependence. MBSP1 is the first protein with these characteristics described in the Archaea or Bacteria domains.