Enhancing production and characterization of a low-molecular-weight bacteriocin from Bacillus licheniformis MKU3.Methods and Results
The culture supernatant of B. licheniformis MKU3 exhibited bacteriocin-like activity against Gram-positive and-negative bacteria and different fungi and yeast. SDS–PAGE analysis of the extracellular proteins of B. licheniformis MKU3 revealed a bacteriocin-like protein with a molecular mass of 1·5 kDa. This bacteriocin activity was found to be stable under a pH range of 3·0–10·0 and at temperatures up to 100°C for 60 min, but inactivated by proteinase K, trypsin or pronase E. An experimental fractional factorial design for optimization of production medium resulted in a maximum activity of bacteriocin (11 000 AU ml−1) by B. licheniformis MKU3.Conclusions
A low-molecular-weight bacteriocin-like protein from B. licheniformis MKU3 exhibited a wide spectrum of antimicrobial activity against several Gram -positive bacteria, several fungi and yeast. A 3·6-fold increase in the production of bacteriocin was achieved using the culture medium optimized through a fractional factorial design.Significance and Impact of the Study
A bacteriocin with wide spectrum of activity against Gram-positive bacterial pathogens, filamentous fungi and yeast suggested its potential clinical use. Statistical method facilitated optimization of cultural medium for the improved production of bacteriocin.