differently. This is due to the characteristic antimicrobial mechanisms and the differ- e Road ceSinphysiologyofthe. micro-organisms. Simple categorization ofmicro-organisms maybe very help as to select specific antimicrobial agents, which maybe categorized by oxygen requirement (aerobes or anaerobes), cell-wall composition (gram-positive and gram-negative), growth-stage (spores. or vegetative cells), optimal growth tem- perature (thermophilic, mesophilicorpsychrotrophic), oracidosmosis resistance. Besides the microbial characteristics, the antimicrobial characteristics of the agent are also important in understanding the efficacy as well as the limits of the activity. For exam- ple. , some antimicrobial agents inhibit essential metabolic (or reproductive genetic) pathways of micro-organisms, while others alter cell membrane wall structure-Two major-functions ofmicrobial inhibition are microbiocidal and microbiostatic effects. Microbiocidal Itis expected that antimicrobial packaging systems would kill target spoilage and. pathogenic bacteria, since the system could eliminate any micro-organisms from the food / packagingsystem.Though itis practically very hard to remove allmicro-organisms, microbiocidal antimicrobial system may kill the target micro-organisms when the antimicrobial concentration goes above the mic. for awhile. . Mth other treatment to