Screening of Bacillus mojavensis biofilms and biosurfactants using laser ablation electrospray ionization mass spectroscopy.

Aims: Biofilms are composed of micro-organisms within a matrix of chemically complex polymer compounds and from these structures many unknown competitive factors are suggested that many considered are important consequences for biological control. This research was undertaken to study further the endophyte, Bacillus mojavensis and its relationships to biofilm and two classes of lipopeptides considered relevant for biocontrol of plant pathogens.

Methods And Results: Laser ablation electrospray ionization mass spectrometry and conventional MS/MS were used to study in situ biofilm production and the production of lipopeptides fengycin and surfactin in different strains of B. mojavensis in plate and test tube culture on two media. All strains were capable of producing biofilm in vitro along with the accumulation of surfactin and fengycin although no concentration-dependent relationship between lipopeptide accumulation and biofilm was observed.

Conclusion: All strains studied produce biofilms in culture with the accumulated surfactin and fengycin, demonstrating that endophytic bacteria also produced biofilms.

Significance And Impact Of The Study: This study demonstrates that this endophytic species produced biofilms along with two biocontrol compounds of which one, surfactin, considered by others as a quorum sensor, highlighting its ecological role as a signalling mechanism in planta.