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

Abstract

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 Rosetta tM (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.Surfactants are amphipathic compounds that have a hydrophobic moiety that is directed towards the surface and a hydrophilic portion that is directed towards the solution 1 . These amphiphilic molecules can reduce surface tension at air/water and oil/water interfaces 2,3 . Surfactants produced by organisms are called biosurfactants, which are extracellular products or components within the cell membranes of prokaryotes and eukaryotes 1,4,5 . Biosurfactants are classified into four major categories: glycolipids, fatty acids, lipopeptides, and polymeric types. These categories are represented by amphipathic polysaccharides, lipopolysaccharides, lipoproteins, fatty acids, or complex mixtures of these biopolymers. In general, the synthesis of biosurfactants involves elaborate genetic systems, including operons, non-ribosomal peptide synthetases, and/or multiprotein assembly complexes 6-9 .The synthesis of biosurfactants occurs in the presence of different substrates as a carbon source. To reduce production costs, cheaper substrates have been used. The most commonly used substrates for biosurfactant production are agro-industrial products such as molasses, marc, or vegetable oils 6-8 . Rhamnolipids and surfactin are among the best studied biosurfactants. Rhamnolipids are glycolipids first discovered in Pseudomonas aeruginosa, which are formed by the bonding between a rhamnose moiety and a 3-(3-hydroxyalkanoyloxy)alkanoic acid (HAA) fatty acid tail. The essen...

Biosurfactants: Production and application prospects in the food industry

“…Depending on the type of system, the hydrophilic portion of the biosurfactant may be turned towards the external or internal region of the system, such that a protected region is formed for the micelles. 36 A greater number of micelles leads to a lower surface tension and is directly influenced by the increase in the concentration of the biosurfactant. The minimum concentration of biosurfactant necessary for the maximum reduction in surface and interfacial tension is denominated the Critical Micelle Concentration (CMC) ( Figure 2).…”

Planococcus Species – An Imminent Resource to Explore Biosurfactant and Bioactive Metabolites for Industrial Applications

“…Due to financial constraints and the inability to grow in common media, ∼0.01 to 0.1% marine microbes are culturable (Baharum et al, 2010;Antunes et al, 2019). Currently, with the advancement of metagenomics, the approaches have been used to identify new genes involved in the secretion of BS (Araújo et al, 2020). In this review, readers are served with an interesting but brief information on overall diversity of BS produced by marine microbes with a particular emphasis on Planococcus sp.…”

Microbial Culture in Minimal Medium With Oil Favors Enrichment of Biosurfactant Producing Genes

“…The evaluation of interfacial tension was performed according to Araújo et al (2020) in a tensiometer, model DVT50 (Krüss, Hamburg, DEU) using the Rising Drop method, as recommended by the manufacturer. The assay was performed between two phases, the interfacial force between the liquid containing surfactant (bulk phase), and the oil droplet formed in dispense phase is evaluated.…”

“…Biodegradation percentage was calculated based on the following equation: 02. B p = [(C i −C f )/C i ] × 100, where B p , C i , and C f are the biodegradation percentages at the end of the incubation time, the amount of contaminant at the start of incubation, and the amount of contaminant at the end of incubation, respectively (Araújo et al, 2020).…”

“…Most biosurfactants are synthesized by non-ribosomal pathways, however, the mechanisms that control their synthesis and production are poorly understood, which demands investigation (Nurfarahin et al, 2018). The recent discovery of a ribosomal protein with surfactant properties, named MBSP1, emphasizes the advantage of furthering the knowledge about biosurfactant biosynthesis (Araújo et al, 2020). Although various studies have described microbial consortia capable of bioremediation petrochemical waste through biosurfactant production, there are many questions about the role and production of biosurfactants for bioremediation (Ławniczak et al, 2013;Patowary et al, 2016;Lee et al, 2018).…”