Antifungal properties of durancins isolated from Enterococcus durans A5-11 and of its synthetic fragments

Abstract

Significance and Impact of the Study: Antifungal properties of durancins isolated from Enterococcus durans A5-11 and of their chemically synthesized fragments were determined. Treatment of D. hansenii LMSA2.11.003 strain with 2 mmol l À1 of the synthetic peptides led to the loss of the membrane integrity and to several changes in the ultra-structure of the yeast cells. This work contributes to improve understanding of molecular causes of antimicrobial activities of bacteriocins and their fragments. It may be proposed that the studied peptides affect all the yeast cellular and intramembranes including cytoplasmatic reticulum and nuclear and vacuolar membranes. AbstractThe aim of this work was to study the antifungal properties of durancins isolated from Enterococcus durans A5-11 and of their chemically synthesized fragments. Enterococcus durans A5-11 is a lactic acid bacteria strain isolated from traditional Mongolian airag cheese. This strain inhibits the growth of several fungi including Fusarium culmorum, Penicillium roqueforti and Debaryomyces hansenii. It produces two bacteriocins: durancin A5-11a and durancin A5-11b, which have similar antimicrobial properties. The whole durancins A5-11a and A5-11b, as well as their N-and C-terminal fragments were synthesized, and their antifungal properties were studied. C-terminal fragments of both durancins showed stronger antifungal activities than other tested peptides. Treatment of D. hansenii LMSA2.11.003 strain with 2 mmol l À1 of the synthetic peptides led to the loss of the membrane integrity and to several changes in the ultrastructure of the yeast cells. Chemically synthesized durancins and their synthetic fragments showed different antimicrobial properties from each other. N-terminal peptides show activities against both bacterial and fungal strains tested. C-terminal peptides have specific activities against tested fungal strain and do not show antibacterial activity. However, the C-terminal fragment enhances the activity of the N-terminal fragment in the whole bacteriocins against bacteria.

Diversity and functional characteristics of lactic acid bacteria from traditional kefir grains

“…durans KF65 was observed although previously it was reported that Ent. durans A5–11 was effective for the inhibition of fungal growth (Belguesmia et al ) showing that strain‐specific properties could play roles for antifungal functions. Another important observation was the fact that kefir isolates were less effective against A. niger compared to the other fungi tested in this study which was also observed for other Lactobacilli previously (Hassan and Bullerman ; Demirbaş et al ).…”

Enterocin AS-48 as Evidence for the Use of Bacteriocins as New Leishmanicidal Agents

“…In this trend, the number of reports concerning bacteriocins as antiprotozoal agents (20)(21)(22)(23) is surprisingly lower than that of reports aiming at other eukaryotic targets such as fungi (24)(25)(26) or even tumoral cells (27)(28)(29).…”

Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae)

“…As a class, AMPs are a conserved defense mechanism across most eukaryotic species (7). Indeed, organisms as genetically diverse as snails and humans both generate AMPs to limit growth of pathogenic microorganisms, including fungi (8)(9)(10)(11). Several mechanisms of action have been proposed for these molecules, and current findings suggest that many of them have more than one antimicrobial target at the cellular level (12,13).…”