Qualitative analysis of biosurfactants from Bacillus species exhibiting antifungal activity

Abstract

Bacillus spp. produce a broad spectrum of lipopeptide biosurfactants, among which surfactin, iturin and fengycin are widely studied families. The goals of this study were to characterize the biosurfactant activity of Bacillus spp. and to investigate their motility and biofilm formation capabilities. In addition, we extracted lipopeptides from these bacteria to assess their antifungal activities and analyzed these products by mass spectrometry (MS). B. amyloliquefaciens FZB42, Bacillus sp. NH 217 and B. subtilis NH-100 exhibited excellent biosurfactant and surface spreading activities, whereas B. atrophaeus 176s and Paenibacillus polymyxa C1225 showed moderate activity, and B. subtilis 168 showed no activity. Strains FZB42, NH-100, NH-217, 176s and CC125 exhibited excellent biofilm formation capabilities. Lipopeptide extracts displayed good antifungal activity against various phytopathogens and their associated diseases, such as Fusarium moniliforme (rice bakanae disease), Fusarium oxysporum (root rot), Fusarium solani (root rot) and Trichoderma atroviride (ear rot and root rot). Lipopeptide extracts of these strains also showed hemolytic activity, demonstrating their strong potential to produce surfactants. LCMS-ESI analyses identified the presence of surfactin, iturin and fengycin in the extracts of Bacillus strains. Thus, the strains assayed in this study show potential as biocontrol agents against various Fusarium and Trichoderma species.

In Vitro and Ex Vivo Antibiofilm Activity of a Lipopeptide Biosurfactant Produced by the Entomopathogenic Beauveria bassiana Strain against Microsporum canis

“…The determination of antifungal activity revealed that BBLP has potent activity against M. canis mycelia growth, consistent with the previous reports of the lipopeptide biosurfactants potency as antifungal agents [60][61][62][63][64]. In addition, the MIC result (1.95 µg/mL) showed for BBLP was better than the results reported for the aqueous extract of 22 medicinal plants used as a remedy for the skin dermatophyte infections (MIC ranged from 3 to 35 µg/mL) [65].…”

“…Until now, the antifungal activity against M. canis strains has been determined against their mycelial growth, which is unwarranted due to the ability of M. canis to form biofilm; this biofilm offers them protection against antibiotics and the host immune system and led to indolent infections [60]. In the current study, BBLP displayed significant antibiofilm activity against M. canis pre-formed biofilm.…”

“…The chemical nature of the biosurfactant produced by B. bassiana (BBLP) is a mixture of lipid and protein (with approximately a 1:4 ratio) [39,[59][60][61]. Impressively, the BBLP exhibited excellent surface active abilities which made it one of the rare fungal based-surfactants that can be effective in reducing surface tension, with respect to bacterial based-surfactants [14,23,62].…”

Microbial biosurfactants: current trends and applications in agricultural and biomedical industries

“…Sarwar et al . (,b) in their investigations of microbial biosurfactants from Bacillus species found that LP extracts displayed antifungal activity against Fusarium moniliforme, Fusarium oxysporum, Fusarium solani and Tricoderma atroviride . Additionally, the LP extracts showed haemolytic activity and potential as biocontrol agents against various Fusarium and Trichoderma species.…”

Biosurfactants: Eco-Friendly and Innovative Biocides against Biocorrosion

“…Bacillus species are worth the treatment because they produce a great diversity of secondary metabolites with high biological activity (bioactive compounds). Specifically, they are known to possess antagonistic activities against many fungal pathogens [69]. Some strains of Bacillus subtilis and B. amyloliquefaciens are known to produce antifungal peptides that belong to antifungal peptides, such as bacilysin and rhizocticin; antifungal lipopeptides (LPPs) such as surfactins, iturins, and fengycins; and antimicrobial polypeptides such as subtilin [69,70].…”