Identification and natural functions of cyclic lipopeptides from Bacillus amyloliquefaciens An6

Abstract

Lipopeptides constitute a structurally diverse group of metabolites produced by various bacterial and fungal genera. In the past decades, research on lipopeptides has been fueled by their surfactant activities. However, natural functions of lipopeptides compounds have received considerably less attention. The aim of this study was to isolate and identify the lipopeptides from Bacillus amyloliquefaciens An6, and further evaluate their biological activities. An6 lipopeptides were detected by PCR using degenerated primers and MALDI‐TOF‐MS. An6 strain was found to produce surfactin, fengycin, and bacillomycin. Following their purification, the in vitro antioxidant activity of An6 lipopeptides was studied through different assays. The scavenging effect on 1,1‐diphenyl‐2‐picrylhydrazyl radicals at a dosage of 0.75 mg/mL was 81%. Its reducing power was concentration‐dependant and reached a maximum of 1.07 at 2.5 mg/mL. Moreover, they showed a strong inhibition of β‐carotene bleaching. An6 lipopeptides mixture was also found to display significant antimicrobial activity against several Gram‐positive, Gram‐negative bacteria, and fungal strains. An6 lipopeptides were insensitive to proteolytic enzymes, stable between pH 4.0 and 12.0, and resistant to high temperature. Our results provided enough evidence proving that An6 lipopeptides could be used as functional‐food components.

Isolation and Characterization of Fengycins Produced by Bacillus amyloliquefaciens JFL21 and Its Broad-Spectrum Antimicrobial Potential Against Multidrug-Resistant Foodborne Pathogens

“…Due to their specific amphiphilic structure, CLPs primarily destroy target organisms by directly disrupting the integrity of the plasma membrane or cell wall in a detergent-like manner, and thus display a lower propensity to develop resistance than do conventional antibiotics (Banat et al, 2010;Mandal et al, 2013;Singh and Abraham, 2014;Patel et al, 2015;Ndlovu et al, 2017). Besides, CLPs are biodegradable, biocompatible, eco-friendly, relatively non-toxic, and resistant to extreme conditions of temperatures, pH, and salinity (Pradhan et al, 2013;Ben Ayed et al, 2017). Because of these attractive characteristics, naturally produced antimicrobial CLPs have received increasing attention as promising new antibiotic candidates for food, pharmaceutical, and biomedical applications.…”

Antioxidant properties of Enterobacter cloacae C3 lipopeptides in vitro and in model food emulsion

“…The inhibition ability of C3 lipopeptides was 59.2% at 0.3 mg/ml. However, lipopeptides of Bacillus amyloliquefaciens An6 showed an inhibition value of 53% and 17.15% at 5 and 1 mg/ml, respectively (Ben Ayed et al, ).…”

“…In summary, the in vitro antioxidant capacities of C3 lipopeptides evaluated using different biochemical methods were found to be interesting. Many Gram‐positive bacteria including different species of the genus Bacillus are reported to produce antioxidant lipopeptides like B. methylotrophicus DCS1 (Jemil et al, ), B. mojavenis A21 (Ben Ayed et al, ), B. amyloliquefaciens An6 (Ben Ayed et al, ), B. subtilis (Tabbene et al, ; Zouari et al, ). This is the first report on antioxidant lipopeptides produced by Enterobacter strain.…”

“…To overcome these drawbacks, many natural molecules were studied for their antioxidant activities like protein hydrolysates from animal, plant, and aquatic products (Hmidet et al, ; Nasri et al, ). Among these biomolecules, biosurfactants were described for their antioxidant properties (Ben Ayed et al, ; Ben Ayed, Hmidet, Béchet, Jacques, & Nasri, ; Jemil, Ben Ayed, Manresa, Nasri, & Hmidet, ) and emulsions stabilization (Bai & McClements, ; Pekdemir, Çopur, & Urum, ).…”

Isolation, Identification and Characterization of Two Kinds of Deep-Sea Bacterial Lipopeptides Against Foodborne Pathogens

“…Many studies have shown that lipopeptides produced by Bacillus have effective antibacterial activity against resistant bacterial strains (Gudina et al, 2016;Zhao et al, 2018). Due to their specific amphiphilic structure, the antibacterial mechanisms of lipopeptides are different from conventional antibiotics, mainly by destroying the integrity of microbial cell membrane or cell wall, forming holes in the membrane, allowing the leakage of cell contents and killing cells, so as to show lower drug resistance (Banat et al, 2010;Yount and Yeaman, 2013;Patel et al, 2015;Ben Ayed et al, 2017). In addition, lipopeptides have the excellent characteristics of low toxicity, biodegradability, environmental friendliness and tolerance to extreme environmental conditions (Cameotra and Makkar, 2004), which confer lipopeptides the promising potential utilization value in food health, biological prevention and medical treatment.…”