Doderlin: Isolation and Characterization of a Broad-Spectrum Antimicrobial Peptide from Lactobacillus acidophilus

Abstract

Lactobacillus acidophilus are Gram-positive bacteria distributed in diverse environments, and as being a component of the normal microbiota of gastrointestinal and urogenital tract, being relevant to humans. Classified as lactic acid bacteria, due to the pro-duction of lactic acid, Lactobacillus can also produce antimicrobial peptides (AMPs), which is a compound synthesized by all forms of life aiming for protecting themselves from threats and to increase their competitivity to survive in a specific environment. AMPs are molecules capable of inhibiting the growth of microorganisms and, due to the indiscriminate use of conventional antibiotics and the emergence of multi-resistant bacteria, they have become an alternative, not only for treating multi-resistant infections, but also for probiotic product confection and food conservation. Considering the rampant rise of resistance, the present study aimed to isolate and characterize antimicrobial peptides from Lactobacillus acidophilus extracts. Samples were obtained from Lactobacillus acid extract supernatant which was pre-fractionated on disposable cartridges, followed by a high-performance liquid chromatography (HPLC). The collected fractions were evaluated in a liquid growth inhibition assay where eight fractions antimicrobial activity were obtained. One of them was selected for further characterization by mass spectrometry (MS), due to its antimicrobial activity against Candida albicans and conclusive results in mass spectrometry analysis. This molecule was identified as a peptide having a molecular mass of 1788.01 Da, peptide sequence NEPTHLLKAFSKAGFQ, and named Doderlin. Interestingly, antimicrobial molecules isolated from L. acidophilus have already been described previously, but few reports in the literature describe an AMP effective against C. albicans as reported here. The results obtained suggest that this newly discovered molecule have a biological property with potential to be applied in pharmaceutical and food companies in the fight against contamination and/or for treating infections caused by microorganisms. IMPORTANCEDoderlin, this newly discovered molecule have a biological property with potential to be applied in pharmaceutical and food companies in the fight against contamination and/or for treating infections caused by microorganisms.