Identification of Different Lipopeptides Isoforms Produced by Bacillus mojavensis BI2 and Evaluation of Their Surface Activities for Potential Environmental Application

摘要

Six clusters of Lipopeptides Isoforms belonging to Cyclic and Linear Surfactin and Fengycin A and B Families were identified from a newly identified strain identified as B. mojavensis BI2. Purification by anionic exchange chromatography and Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) and identification by High Performance Liquid Chromatography-Mass Spectroscopy (HPLC-MS) analyses were applied to characterize lipopeptides biosurfactants derived from B. mojavensis BI2. The m/z values of Cyclic and Linear homologues of Surfactin ranged from 980 and 1096 Da. The m/z values of cyclic homologues of Fengycin A and Fengycin B ranged from 1449 and 1505 Da. The m/z values of linear homologues of Fengycin A and Fengycin B ranged from 1467 and 1523 Da. Functional properties of the BI2 lipopeptides revealed a powerful surface activity with the capacity to decrease the surface tension of water to about 27.4 mN/m and a Critical Micelle Concentration (CMC) value of 200 mg/L along with great efficiency when compared to chemical surfactants (Triton X100; CTAB and SDS). Additionally, similarly to chemical surfactants, they exhibited similar foaming and oil dispersing activities. Interestingly, lipopeptides isoforms are characterized by non-phytotoxicity with potential fertilizing effect. All these functional properties offer potential application of these lipopeptides in bioremediation of contaminated water.