The principle of action of antifungal agents, from a practical perspective, is that when microorganisms no longer grow or reproduce after using chemical antifungal agents, we say they have died, which means that these chemical antifungal agents have bactericidal effects. However, some chemicals can also make microorganisms appear dead, no longer growing or reproducing. However, when the chemicals on the bacterial cells are washed away by water or acid, microorganisms will grow and reproduce again. We call the action of chemicals in this situation antibacterial. Of course, the bactericidal and bacteriostatic effects are relative and often depend on the concentration of the drug. When the concentration of the drug is high, it shows a killing effect on microorganisms, while when the concentration is low, it shows an inhibitory effect on microorganisms
After being treated with chemical preservatives, many characteristics of microorganisms will change, such as growth, reproduction, morphology, spore formation, spore germination, spore expansion, cell mitosis, cell permeability, respiration, spore color, and other physiological, biochemical reactions and metabolic activities, which will ultimately manifest as inhibition of microbial growth and reproduction, or even killing microorganisms.
So, how do mold inhibitors have inhibitory or killing effects on microorganisms? Firstly, the antifungal agent comes into contact with the outer membrane of the cell and is adsorbed, then enters the cytoplasm through the cell membrane. Due to their different functions, various antifungal agents act on various parts of microbial cells, inhibiting their growth and reproduction, and even causing their death.
The action sites of antifungal agents can be roughly divided into various metabolic mechanisms essential for maintaining microbial cell life, such as cell wall synthesis, cell membrane function, protein synthesis, nucleic acid synthesis, energy metabolism, etc., or acting on various enzyme systems related to these metabolic mechanisms.
Generally speaking, the action sites of halogens, alkylating agents, phenols, quaternary ammonium salts, and biguanide fungicides are to damage cell membranes and react with cellular components such as nucleic acids and proteins. However, various conditions such as the chemical structure of mold inhibitors, the microstructure of microbial cells, and the working environment have a significant impact on the mechanism of action of mold inhibitors.
Preservatives used in food preservation, such as benzoic acid, sorbic acid, propionic acid, etc., often inhibit enzymes related to acetic acid metabolism, glycolysis, tricarboxylic acid cycle, oxidative acidification, etc., thereby suppressing microbial metabolism; It also breaks the cell membrane, inhibits matrix absorption and transport, and causes protein denaturation.