Study On Antimicrobial Effect Of Rosemary Extract

The present study was to take Rosemary as the research material. The research had investigated the antimicrobial activity of extracts from Rosemary. And the antimicrobial constituent of extracts from Rosemary were preliminary studied in this paper.First, The bacteriostatic activity of petroleum ether extract, ethyl acetate extract, butanol extract, water extract isolated from80%ethanol extract of Rosemary and80%ethanol extract of Rosemary were studied by oxford plate and micro-dilution. The constituents were tested with E. coli, Bacillus subtilis, Bacillus cereus, Salmonella, Staphylococcus aureus, Proteus vulgaris Hauser and Micrococcus Iuteus. The results showed that80%alcohol extract, petroleum ether extract and ethyl acetate extract had good bacteriostatic activity,while Petroleum ether extract had the best bacteriostatic activity, the MIC was0.500mg/mL for Bacillus cereus and2.00mg/mL for Staphylococcus aureus and4.00mg/mL for E. coli, Salmonella, Proteus vulgaris Hauser and Micrococcus Iuteus.Butanol extract and water extract only had obvious bacteriostatic activity on Proteus vulgaris Hauser. The bacteriostatic activity of80%alcohol extract, petroleum ether extract and ethyl acetate extract would not be affected in a lower temperature than80℃.Second, The antimicrobial activity of80%alcohol extract, petroleum ether extract and ethyl acetate extract were studied by micro-dilution. The constituents were tested with Aspergillus niger, Alternaria, Botrytis cinerea, Fusarittm, Pythium Pringsheim, Trichoderma viride and Penicillium sp. The results showed that80%alcohol extract, petroleum ether extract and ethyl acetate extract had good antimicrobial activity on Alternaria, Botrytis cinerea, Fusarittm and Pythium Pringsheim, meanwhile the three kinds of extracts didn’t have obvious antimicrobial activity on Aspergillus niger. Trichoderma viride and Penicillium sp. Petroleum ether extract had the best antimicrobial activity, the MIC was0.125mg/mL for Alternaria and1.OOmg/mL for Fusarittm.Third, The effect of80%ethanol extract. petroleum ether extract and ethyl acetate extract added individually, on the sensory changes, the total count of bacteria colonies, pH and the value of MDA of refrigeration (4℃)pork and fish stored for15days was investigated. The results showed that the pork or fish added petroleum ether extract could maintain better characterisitics than other groups, and the petroleum ether extract have preservative effect on pork and fish.Finally, the research had studied the antimicrobial constituent of extracts from Rosemary. The bacteriostatic activity of80%carnosic acid were studied by oxford plate and micro-dilution. The results showed that80%carnosic acid have the same bacteriostatic activity as petroleum ether extract. Carnosic acid was not the only antimicrobial constituent of extracts from Rosemary.