tudied the antimicrobial mechanism of LAE and nisin combination. They
found that LAE caused the morphology change of bacteria cells, such as distorted and
dimpled E. coli O157: H7 cells based on scanning electron microscopy. Formation of
irregular cross-wall and abnormal septation was also observed in the cytoplasmic
membrane of L. monocytogenes using TEM, which was similar to observation of
Rodriguez et al. (2004). Cell lysis was not observed either. The authors hypothesized that
LAE affected the outer membrane of Gram-negative bacteria E. coli O157:H7 through
the electrostatic interaction between the positively charged arginine and negatively
charged outer membrane. Overall, these studies show that LAE mainly act towards the
cell envelop of bacteria to cause the instability of cell membrane without causing cell
lysis to inhibit bacteria growth (Gil Bakal, 2005). Other mechanisms are to be further
investigated.