Antimycoplasma properties and application in cell culture of surfactin, a lipopeptide antibiotic from Bacillus subtilis

Abstract

Surfactin, a cyclic lipopeptide antibiotic and biosurfactant produced by Bacillus subtilis, is well-known for its interactions with artificial and biomembrane systems (e.g., bacterial protoplasts or enveloped viruses). To assess the applicability of this antiviral and antibacterial drug, we determined the cytotoxicity of surfactin with a 50% cytotoxic concentration of 30 to 64 M for a variety of human and animal cell lines in vitro. Concomitantly, we observed an improvement in proliferation rates and changes in the morphology of mycoplasmacontaminated mammalian cells after treatment with this drug. A single treatment over one passage led to complete removal of viable Mycoplasma hyorhinis cells from various adherent cell lines, and Mycoplasma orale was removed from nonadherent human T-lymphoid cell lines by double treatment. This effect was monitored by a DNA fluorescence test, an enzyme-linked immunosorbent assay, and two different PCR methods. Disintegration of the mycoplasma membranes as observed by electron microscopy indicated the mode of action of surfactin. Disintegration is obviously due to a physicochemical interaction of the membrane-active surfactant with the outer part of the lipid membrane bilayer, which causes permeability changes and at higher concentrations leads finally to disintegration of the mycoplasma membrane system by a detergent effect. The low cytotoxicity of surfactin for mammalian cells permits specific inactivation of mycoplasmas without significant deleterious effects on cell metabolism and the proliferation rate in cell culture. These results were used to develop a fast and simple method for complete and permanent inactivation of mycoplasmas in mammalian monolayer and suspension cell cultures.

Toxic lactonic lipopeptide from food poisoning isolates of Bacillus licheniformis

“…Surfactin is a surfactant structurally related to lichenysin A. It has l-glutamic acid instead of l-glutamine and l-leucine instead of l-isoleucine [23]. We showed that lichenysin A and surfactin both damage the cell membrane and activate the acrosome reaction of boar spermatozoa.…”

Natural functions of lipopeptides fromBacillusandPseudomonas: more than surfactants and antibiotics

“…The antiviral activity of LPs was already reported in 1951 by Groupé and colleagues (reviewed in Nybroe & Sørensen, 2004) for viscosin against enveloped viruses. In addition, surfactin was shown to inactivate various enveloped viruses by acting directly on the lipid envelope, leading to disintegration of the virus particles (Vollenbroich et al, 1997b;Huang et al, 2006). Disintegration of membranes was also shown to be the primary activity of surfactin against several human and animal pathogenic mycoplasmas (Vollenbroich et al, 1997a).…”

Conservation of genes and processes controlled by the quorum response in bacteria: characterization of genes controlled by the quorum‐sensing transcription factor ComA in Bacillus subtilis

“…Expression of several operons involved in production of at least four extracellular antimicrobial products is regulated by ComA (Table 1). The antibiotics (TasA, surfactin, sublancin and sporulation killing factor) produced by the products of the tasA, srfA, sunA and skfA (previously ybcO) operons have a variety of activities, including killing other B. subtilis cells (Gonzalez-Pastor et al, 2003), and other bacterial species (Vollenbroich et al, 1997;Kleerebezem et al, 1999;Stover and Driks, 1999;Kearns and Losick, 2003). Additionally, the ComA-regulated yfmH gene product is similar to an antimicrobial cationic peptide (Zuber, 2001).…”