EVALUATION OF BACTERIOCIN PURIFIED FROM POTENT LYSINIBACILLUSSPHAERICUS MK788143 ISOLATED FROM INFANT FAECAL

Abstract

Numerous bacteriocins purified from Lactobacilli have been studied as anticancerous, biocontroling, preservatives, and
immunostimulatory. But, antimicrobial potential of Lysinibacillus is not much reported. In this study, a focus was made to
isolate and explore therapeutic potential of Lysinibacillus from infant fecal. A total 5 isolates were selected for their
antagonistic nature against human pathogen. Amid them, one Bacillus sp. was phenotypically, and molecularly using 16S
rRNA gene based identified as Lysinibacillus sphaericus which given with accession numbers MK788143 in NCBI. The
strain MK788143 has revealed the 99.89% identity with the Lysinibacillus sphaericus, 99.77% with Lysinibacillus fusiformis
and 99.55% Lysinibacillus parviboronicapiens. The isolate showed broad-spectrum antibacterial activity against gram
positive (10-14 mm) and gram-negative (9-10 mm) bacteria. Active bacteriocin was extracted at 40% ammonium sulfate
precipitation afterward dialysis and further purification was done by gel filtration chromatography. The molecular weight
of bacteriocin was obtained nearly 14 kDa by SDS-PAGE. According to physico-biochemical properties, the purified
bacteriocin belongs to class I bacteriocin. The bacteriocin was enormously heat stable in the range of 15 to 100˚C
temperature for 1 hr and stable within the pH range 2-9. In addition, bactericidal activity of purified protein was
decreased when treated with proteolytic enzymes i.e. trypsin, proteinase K and pepsin, these results confirmed the
peptide nature of isolated bacteriocin. As a reflection of results, the broad-spectrumantagonistic potential and physical
stability of bacteriocinmight be applied as an alternative therapeutic as well as food preservative agent to control
pathogenic bacterial abundance.