Exploiting the biological activities of a lipopeptide extract produced by Bacillus subtilis UFPEDA 438 in light of the SARS-CoV-2 pandemic

Abstract

Lipopeptides are biosurfactants, substances with a high surfactant potential where each family corresponds to a group of isoforms that differs in the peptide's composition and the length of the lipid chain. Among them, iturin and surfactin, lipopeptides with high surfactant and antibiotic potential, stand out. As a lipopeptide, they are a set of isoforms, biosynthesized or engineered, where the relationship between their structures and properties helps choose and direct the product to the final application. Those applications can range from the surface cleaning and disinfection industry to crude oil recovery, in addition to being the subject of studies in medical and pharmacological processes. In the context of COVID-19, the present study aims to produce an extract of lipopeptides rich in surfactin and iturin's isoforms through the cultivation of Bacillus subtilis UFPEDA 438, using sugarcane molasses as a substrate, as well as to evaluate their biological activity in vitro, including their antiviral potential through in silico analysis, against the 4 main target proteins of SARS-CoV 2. The results showed maximum productivity of 148.55 ± 4.67 mg/L of surfactin with satisfactory levels of emulsification activities, a reduction in the surface tension of water by up to 55.24%, and strong antioxidant activities. Regarding the in silico evaluation, the greatest interaction of the studied biosurfactants was with the Spyke protein, which is crucial for the binding of the virus with the host human cell. The achieved results point to the extract produced as a promising constituent in the elaboration of products with high antioxidant and surfactant potential; and, in addition, moves future trials of his antiviral activity against SARS-CoV-2.