Abstract: Inhibitory activities of four plant essential oils against eleven animal pathogenic bacteria and environmental mould were determined using broth dilution method and gaseous fumigation.The results showed that The MICs of oils fromLitsea mollis,Citrus reticulata,Erigeron acer and Ageratum conyzoides to thetested animal pathogenic bacteria were 0.062 5～0.5,0.125～1,2～4 and 0.062 5～0.125 mL/L,respectively.The inhibitory activities ofoils from L.mollis,C.reticulata and E.acer were high,and that of A.conyzoides oil was relatively low.At a dose of 16 μL per utensil,the four plant essential oils had inhibition against environmental mould,and the inhibitory activities of oils from L.mollis and C.reticulata were higher than that of anothertwo oils.The oils of L.mollis and C.reticulata also had inhibitory effect onmould growth of bread at 27 °C and RH 80%.By studying the formulation of mouthwash of plant essential oil,the optimum proportion of all components in the mouthwash was confirmed,and the mouthwash of L.mollis essential oil prepared.Theremoving rate of mouth bacteria by the new mouthwash reached 39.96%,which was similar to the removing rate by commercial mouthwash and met the demand of industrial product.The principal compounds of four plant essential oils were also identified using GC/MS technique.

Key words: plant essential oils, animal pathogenic bacteria, inhibitory activity, antisepsis, mouthwash