Production and characterization of a low-molecular-weight bacteriocin from Bacillus licheniformis MKU3.

AIMS

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 degrees 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.