MBSP1: a biosurfactant protein derived from a metagenomic library with activity in oil degradation.

Microorganisms represent the most abundant biomass on the planet; however, because of several cultivation technique limitations, most of this genetic patrimony has been inaccessible. Due to the advent of metagenomic methodologies, such limitations have been overcome. Prevailing over these limitations enabled the genetic pool of non-cultivable microorganisms to be exploited for improvements in the development of biotechnological products. By utilising a metagenomic approach, we identified a new gene related to biosurfactant production and hydrocarbon degradation. Environmental DNA was extracted from soil samples collected on the banks of the Jundiaí River (Natal, Brazil), and a metagenomic library was constructed. Functional screening identified the clone 3C6, which was positive for the biosurfactant protein and revealed an open reading frame (ORF) with high similarity to sequences encoding a hypothetical protein from species of the family Halobacteriaceae. This protein was purified and exhibited biosurfactant activity. Due to these properties, this protein was named metagenomic biosurfactant protein 1 (MBSP1). In addition, E. coli RosettaTM (DE3) strain cells transformed with the MBSP1 clone showed an increase in aliphatic hydrocarbon degradation. In this study, we described a single gene encoding a protein with marked tensoactive properties that can be produced in a host cell, such as Escherichia coli, without substrate dependence. Furthermore, MBSP1 has been demonstrated as the first protein with these characteristics described in the Archaea or Bacteria domains.

A characterization of a MutM/Fpg ortholog in sugarcane--A monocot plant.

Plant genomic projects, such as Arabidopsis thaliana, rice, and maize, have provided excellent tools for comparative genome analysis on Base Excision DNA Repair (BER). A data-mining study associated with the SUCEST Genome project identified two EST clusters that shared homology to the bacteria MutM/Fpg protein. Comparative analyses presented here show a duplication of the MutM/Fpg gene in sugarcane, wheat and rice. The complementation assays show that both cDNAs from sugarcane are able to complement the Fpg and MutY-glycosylase deficiency in a double mutant Escherichia coli strain (CC104mutMmutY), reducing the spontaneous mutation frequency by 10-fold. The expression analyses by semi-quantitative RT-PCR show that these two mRNAs have different expression levels.