Antimicrobial Activity ofCladonia verticillarisLichen Preparations on Bacteria and Fungi of Medical Importance

Abstract

Cladonia verticillaris lichen lectin (ClaveLL) was purified using a previously established protocol and then evaluated for its potential antimicrobial activity. Initially, the autochthonous lichen was submitted to extraction with sodium phosphate buffer pH 7.0, followed by filtration and centrifugation to obtain crude extract. A salt fractionation was performed with 30% ammonium sulfate. After centrifugation, the protein fraction was loaded onto molecular exclusion chromatography using Sephadex G-100 matrix to purify active lectin. ClaveLL showed antibacterial activity against Gram-positive (Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) assayed strains, with greater inhibitory effect on growth of E. coli (MIC of 7.18 g mL −1 ). The lowest minimum bactericidal concentration (MBC, 57.4 g mL −1 ) was detected against E. faecalis. The antifungal assay performed with Trichophyton mentagrophytes, Microsporum gypseum, Trichophyton rubrum, Trichosporon cutaneum, and Trichosporon asahi evaluated crude extract, fraction, and ClaveLL preparations. ClaveLL was the most active against T. rubrum with an inhibition percentage of 35% compared to negative control (phosphate buffer). Extract and fraction showed better activity on growth inhibition of T. mentagrophytes (35%). The results indicate the potential of ClaveLL and other C. verticillaris preparations as antimicrobial agents useful for applications focusing on human health.

Genomic insights into the mitochondria of 11 eastern North American species ofCladonia

“…This morphological variation is mirrored in the chemical diversity within the genus, which spans a wide variety of secondary metabolites (Rundel 1969;Ahti 1998;Nash et al 2002), many among which have been inferred to have pharmacological importance (Lauterwein et al 1995;Zhang et al 2012;Kosani c et al 2014;Ramos et al 2014). The visually striking thalli of Cladonia frequently comprise the dominant groundcover in diverse habitats including deserts, temperate forest glades, and boreal forests.…”

Legume Lectins: Proteins with Diverse Applications

“…Microbial resistance is a genetic phenomenon resulting in a reduction in effectiveness of drug therapy; it may be caused by mutations during the reproductive process of the microorganisms or by imported genes acquired through transduction, conjugation, and transformation mechanisms [78]. Therefore, there is a growing interest in developing new strategies for inhibiting the growth or survival of microorganisms based on the screening of new sources of natural compounds as alternatives to commercially available drugs [74,79]. …”

Lichen Secondary Metabolites

“…Cladonia verticillaris lichen lectin was evaluated by Ramos et al (2014) for its antimicrobial potential, and it showed activity against Gram-positive (Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) assayed strains, with greater inhibitory effect on the growth of E. coli (MIC of 7.18 μg/ml). The lowest minimum bactericidal concentration (MBC, 57.4 μg/ml) was detected against E. faecalis.…”