AUTHOR=Bajpai Vivek K. , Han Jeong-Ho , Rather Irfan A. , Park Chanseo , Lim Jeongheui , Paek Woon Kee , Lee Jong Sung , Yoon Jung-In , Park Yong-Ha 

TITLE=Characterization and Antibacterial Potential of Lactic Acid Bacterium Pediococcus pentosaceus 4I1 Isolated from Freshwater Fish Zacco koreanus

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.02037

DOI=10.3389/fmicb.2016.02037

ISSN=1664-302X

ABSTRACT=<p>This study was undertaken to characterize a lactic acid bacterium 4I1, isolated from the freshwater fish, <italic>Zacco koreanus</italic>. Morphological, biochemical, and molecular characterization of 4I1 revealed it to be <italic>Pediococcus pentosaceus</italic> 4I1. The cell free supernatant (CFS) of <italic>P. pentosaceus</italic> 4I1 exhibited significant (<italic>p</italic> &lt; 0.05) antibacterial effects (inhibition zone diameters: 16.5–20.4 mm) against tested foodborne pathogenic bacteria with MIC and MBC values of 250–500 and 500–1,000 μg/mL, respectively. Further, antibacterial action of CFS of <italic>P. pentosaceus</italic> 4I1 against two selected bacteria <italic>Staphylococcus aureus</italic> KCTC-1621 and <italic>Escherichia coli</italic> O157:H7 was determined in subsequent assays. The CFS of <italic>P. pentosaceus</italic> 4I1 revealed its antibacterial action against <italic>S. aureus</italic> KCTC-1621 and <italic>E. coli</italic> O157:H7 on membrane integrity as confirmed by a reduction in cell viability, increased potassium ion release (900 and 800 mmol/L), reduced absorption at 260-nm (3.99 and 3.77 OD), and increased relative electrical conductivity (9.9 and 9.7%), respectively. Gas chromatography–mass spectrometry (GC–MS) analysis of the CFS of <italic>P. pentosaceus</italic> 4I1 resulted in the identification of seven major compounds, which included amino acids, fatty acids and organic acids. Scanning electron microscopic-based morphological analysis further confirmed the antibacterial effect of CFS of <italic>P. pentosaceus</italic> 4I1 against <italic>S. aureus</italic> KCTC-1621 and <italic>E. coli</italic> O157:H7. In addition, the CFS of <italic>P. Pentosaceus</italic> 4I1 displayed potent inhibitory effects on biofilms formation by <italic>S. aureus</italic> KCTC-1621 and <italic>E. coli</italic> O157:H7. The study indicates the CFS of <italic>P. pentosaceus</italic> 4I1 offers an alternative means of controlling foodborne pathogens.</p>