Fig. 2. BbAMP1 expression and antimicrobial activity assays.

A Heterologous expression of the GST-fused form of mature BbAMP1 (mBbAMP1-GST). The targeted protein bands are arrowed. B Western blot analysis of the fused protein with an anti-GST antibody. C Tricine-gel analysis of the purified mBbAMP1 (arrowed). D MIC analysis of mBbAMP1 against different bacteria. Ampicillin (Amp) was used as a positive control. E Targeting of bacterial cells by BbAMP1. The GFP-fused protein was concentrated and incubated with the cells of L. plantarum for 1 h. GFP treatment was included as a control. The treated cells were washed twice with sterile water prior to being imaged. Bar, 1 μm. F Lysis of L. plantarum cells by BbAMP1. The cells of L. plantarum were treated with BbAMP1-GFP and GFP proteins (100 μg mL⁻¹) for different times as indicated and then fixed on the poly-lysine coated slides for SEM observations. Bar, 1 μm.