Antibacterial activity of phenyllactic acid against Listeria monocytogenes and Escherichia coli by dual mechanisms.
Phenyllactic acid (PLA), a phenolic acid phytochemical, is considered to be a promising candidate for use as a chemical preservative due to its broad antimicrobial activity. The antibacterial target of PLA has rarely been reported, thus investigations were performed to elucidate the antibacterial mechanism of PLA against Listeria monocytogenes and Escherichia coli. Flow cytometry analysis stained with propidium iodide (PI) demonstrated that PLA could damage the membrane integrity of L. monocytogenes, while it could not disrupt that of E. coli. The uptake of 1-N-phenylnaphthylamine (NPN) indicated that PLA interrupted the outer membrane permeability of E. coli. Scanning electron microscopy (SEM) observation visualized the damage caused by PLA as morphological changes in L. monocytogenes and E. coli. Fluorescence assays demonstrated that PLA could interact with bacterial genomic DNA in the manner of intercalation. This finding suggested dual antibacterial targets of PLA, namely membrane and genomic DNA.
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Yawei
Y
Ning
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Aihong
A
Yan
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Kun
K
Yang
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Zhixin
Z
Wang
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, China. Electronic address: foodsciencelab@163.com.
Xingfeng
X
Li
School of Food and Chemical Engineering, Beijing Technology and Business University, Beijing 100048, China. Electronic address: jiayingmin@btbu.edu.cn.
Yingmin
Y
Jia
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004926:Escherichia coli / Q000737:chemistry*; D005516:Food Microbiology / Q000379:methods*; D062385:Hydroxybenzoates / Q000737:chemistry*; D008089:Listeria monocytogenes / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D062385:Hydroxybenzoates; C017616:phenolic acid
1-N-phenylnaphthylamine (PubChem CID: 7013); 3,3′-Dipropylthiadicarbocyanine iodide (PubChem CID: 5706741); Antibacterial activity; DNA; Ethidium bromide (PubChem CID: 14710); Membrane integrity; Phenyllactic acid; Phenyllactic acid (PubChem CID: 3848); Propidium iodide (PubChem CID: 104981); o-Nitrophenyl-β-d-galactopyranoside (PubChem CID: 96647)