To carry out the extraction, purification and biological characterization, and assess the
antibacterial activity of bacteriocin from Lactobacillus acidophilus
Chloroform extraction method was used for bacterioc
in extraction while characterization of
bacteriocin was carried out by flat-dug well agar diffusion assay. The antibacterial mechanisms of
bacteriocin were examined by scanning electron microscopy and atomic emission spectroscopy. The
molecular weight of l
actobacillin XH1 was measured using Tricine-SDS-PAGE electrophoresis.
The bacteriocin (lactobacillin XH1) inhibited Escherichia coli
, Staphylococcus aureus
. It showed a wide range of antimicrobial activity at pH 1.0-5.0 while at 37
120 °C, it
was sensitive to trypsin, pepsin and papain, but insensitive to proteinase K and neutral protease. The
intracellular UV-absorbing substances, namely, lactate dehydrogenase macromolecules, K+
and ATP of
, decreased rapidly. The molecular weight of
lactobacillin XH1 was approximately 16 kDa.
Lactobacillin XH1 is a broad-spectrum antimicrobial substance that is thermostable. Its
antibacterial mechanism on Escherichia coli
is similar to that of bacteriocins on Gram-positive bacteria.
The agent is a hydrophobic protein with more acidic groups.