Respiratory depression driven by membrane damage as a mechanism for linalool to inhibit Pseudomonas lundensis and its preservation potential for beef

Abstract

Aims: This study aimed to investigate the mechanism of linalool against Pseudomonas lundensis and its application on beef.

Methods and results: Field emission scanning electron microscopy found that linalool exerted antibacterial activity with a minimum inhibitory concentration (MIC) of 1.5 ml l-1 by disrupting cell structure. Loss of cell membrane integrity was monitored due to leakage of nucleic acids and K+. In addition, respiratory depression appeared in Ps. lundensis based on inhibition of enzyme activities including hexokinase (HK), glucose 6-phosphate dehydrogenase (G6PDH), phosphofructokinase (PFK), pyruvate kinase (PK), pyruvate dehydrogenase (PDH), citrate synthase (CS), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH). Subsequently, energy limitation also occurred according to the decrease in ATP content and ATPase activity. Molecular docking confirmed that linalool can combine with enzymes in cell wall (ddlB) and energy synthesis (AtpD) pathways to exert antibacterial effect. Of note, linalool has advantages for beef preservation by delaying quality changes including pH, total volatile basic nitrogen (TVB-N) and total viable count (TVC).

Conclusions: Linalool has significant inhibitory effect on Ps. lundensis, and respiratory depression driven by membrane damage is the main inhibitory mechanism.

Keywords: Pseudomonas lundensis; ATP; beef; enzyme activity; linalool; molecular docking.