Paracin 1.7, a bacteriocin produced by Lactobacillus paracasei HD1.7 isolated from Chinese cabbage sauerkraut, a traditional Chinese fermented vegetable food.
OBJECTIVE
To purify and characterize bacteriocin produced by L. paracasei HD1.7.


METHODS
Paracin 1.7 was purified by chromatography and its molecular weight was measured by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Antibacterial activity was measured by using the agar-well diffusion method.


RESULTS
The bacterial strain for the fermentation was identified as Lactobacillus subsp. paracasei. Paracin 1.7 had the activity of inhibiting the growth of other bacteria. Maximum production of Paracin 1.7 was in the stationary phase. Paracin 1.7 can be well purified with Cation exchange chromatography, Sephedex (G50, G25, G10) gel chromatography and high performance liquid chromatography (HPLC) on C18 column and its determined molecular weight was about 11 kDa by Tricine-SDS-PAGE. Paracin 1.7 shows a broad spectrum of activities against various strains in the genera of Proteus, Bacillus, Enterobacter, Staphylococcus, Escherichia, Lactobacillus, Microccus, Pseudomonas, Salmonella and Saccharomyces, some of which belong to food borne pathogenic bacteria. Although Paracin 1.7 displayed stability toward heat and acidic pH, it was sensitive to several proteolytic enzymes. The inhibitory activities remain well after stored at 4 degrees C for 4 months; the inhibitory activity declined only 4.19%.


CONCLUSIONS
Paracin 1.7 can be a potential food preservative on the basis of its antibacterial characters.
Ge
Jingping
J
Key Laboratory of Microbiology, College of Life Science, Heilongjiang University, Harbin 150080, China. gejingping512@yahoo.com.cn
Ping
Wenxiang
W
Song
Gang
G
Du
Chunmei
C
Ling
Hongzhi
H
Sun
Xin
X
Gao
Ying
Y
D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001430:Bacteriocins / Q000302:isolation & purification / Q000494:pharmacology*; D001937:Brassica / Q000382:microbiology*; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D007778:Lactobacillus / Q000737:chemistry*; D014675:Vegetables / Q000382:microbiology
D000900:Anti-Bacterial Agents; D001430:Bacteriocins