61C-22 |
Partial characterization of propionicin HJ227, a newly identified bacteriocin of Propionibacterium freudenreichii KCCM 31227 |
H. D. PAIK1, H. J. Park1, and Y. J. Chung2. (1) Division of Life Sciences, Kyungnam University, 449 Wolyoung-Dong, Masan, 631-701, South Korea, (2) Department of Microbiology, JeonJu University, Jeonju, South Korea Bacteriocins are proteins produced by heterogeneous group of bacteria that have a bactericidal effect on closely related organisms. Because bacteriocins are natural products of many microorganisms associated with foods, there is currently much interest in their use as natural food preservatives. The Propionibacterium strain has the industrial importance on the production of antimicrobial substances, such as organic acids and bacteriocin(s). Our objective was to partially characterize propionicin HJ227, a bacteriocin produced by P. freudenreichii KCCM 31227. Bacteriocin activity was measured by well-diffusion method and Micrococcus flavus ATCC 15313 was used as indicator strain for bacteriocin activity. Propionicin HJ227 produced by P. freudenreichii KCCM 31227 was partially purified by 75% ammonium sulfate precipitation followed by subsequent dialysis. This partially purified bacteriocin showed antibacterial spectrum of activity against most of propionibacteria and bacilli, Staphylococcus aureus KCCM 32359, Lactococcus lactis KCCM 32406, M. flavus KCCM 10240 and some pathogenic organismsms. The antibacterial activity on sensitive cells was disappeared completely by ес-chymotrypsin, which indicates its proteinaceous nature. The inhibitory activities of propionicin HJ227 were detected during treatments up to 100C for 30 min. Propionicin HJ227 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. The bacteriocin exhibited a bactericidal mode of action against M. flavus KCCM 10240. The apparent molecular mass of propionicin HJ227 was estimated to be about 6-6.5 kDa by direct detection of bactericidal activity after SDS-PAGE. In conclusion, when compared to the properties of Propionibacterium bacteriocins, propionicin HJ227 seems to differ from the bacteriocins so far identified.
Session 61C, Food Microbiology: General I
|