Heterologous expression of bovine lactoferrin C-lobe in Bacillus subtilis and comparison of its antibacterial activity with N-lobe

The natural concentration of bovine lactoferrin C-lobe is low and its separation by proteolytic enzyme digestion difficult. Here, we expressed the codon-optimized fragment on plasmid pMA0911 with Pveg promoter in Bacillus subtilis 168 at 20 °C. yield was 7.5 mg/L, 90.6% purity achieved using ammonium sulfate precipitation, Ni–NTA molecular exclusion. 10 mg/mL completely inhibited cell growth Escherichia coli JM109 (DE3) Pseudomonas aeruginosa CGMCC 1.6740, 48.4% Staphylococcus aureus 1.282, result similar to that 200 ng/mL N-lobe. minimum inhibitory concentrations were 4, 8 16 mg/mL, while those N-lobe 128, 256 512 μg/mL for E. coli, P. S. aureus, respectively. This first report expression comparative resistance recombinant N- C-lobes a food-safe strain B. subtilis. Our findings offer potential study structure–function relationship recombinantly produced same host.