Studies On The Bactericidal Action And Application Of Pyrola Calliantha Extracts

The bactericidal action and application of Pyrola calliantha extracts and the antibacterial mechanism of Pyrolin were studied in this text Firstly proceeded to its antimicrobial characteristic, and on the basis of this experiment, studied the antibacterial mechanism of Pyrolin, Finally applied it to fresh preservation of strawberry. The main results were as follows:(1) The extraction of antimicrobial compound from Pyrola calliantha and the antimicrobial property including temperature and pH influence to the extraction was investigated. The result showed that the extraction had obvious antimicrobial actions especially to Staphylococcus aureus and Escherichia coli. It is not very effective to Pseudomonas aeruginosa, Monilinia fructicola, Cryphonectria parasitica. As for the common spoiage mould including penicillium and Rhizopus, it is also very effective. The minimal inhibition concentration(MIC) was as follows: Staphylococcus aureus 5%, Escherichia coli 10%, Pseudomonas aeruginosa 20%, Penicillium 10%, Rhizopus 10%And it was proved that the more the concentration of the extraction, the more the antimicrobial activity it has. It was also proved that the extraction hasn't very ordinary temperature stability and it can be effective from pH＜7.Besides, the addition of sugar or salt can improve the antimicrobial activity. The antimicrobial of extraction by different solvent is quite different. 70% and 60% ethanol gave the best results followed by 95% ethanol＞anhydrous ethanol＞acetonein＞ethyl acetate＞trichloromethane＞distilled water. In the same action time, the higher the concentration of the extraction, the higher of the inhibition rate is. With the same concentration of extraction, the longer the action time will bring higher inhibition rate.(2) Pyrolin is the primary bactericidal substance of Pyrola calliantha. It has strong antimicrobial actions especially to Staphylococcus aureus and Pseudomonas aeruginosa. The minimal inhibition concentration(MIC) was as follows: Staphylococcus aureus 0.015%, Pseudomonas aeruginosa 0.02%.The temperature stability of Pyrolin was not very good, especially at high temperature, the antimicrobial action will depressed, and Pyrolin can be effective from pH=6.0 or 6.5. From the experimentation of antibacterial mechanism, we can draw a conclusion that Pyrolin keep Staphylococcus aureus and Pseudomonas aeruginosa utilizing nutrition such as sugar and protein, and seriously restrain the activity of SDH and MDH. Meanwhile we also could find that Pyrolin destroy badly cellularity in the photo. So we educe that Pyrolin could take nether measures to rest badly rain antibacterial activity:①destroy badly cellularity and change cell osmosis;②restrain the activity of enzyme, and disturb metabolism;③may alter the molecule of protein and nucleic acid.(3) From the fresh preservation experimentation of strawberry, we can conclude that Pyrola calliantha extracts has obvious antimicrobial actions. It prevents the decay of fruit, and restrains the growth of microorganism, so it achieves the fresh preservation. At the same time, the treatment could keep the content of soluble solid substance, firmness, Vc, titratable acid and cut down the weight loss, further the shelf life of strawberry.From what we have stated above, we can draw a conclusion that extraction of Pyrola calliantha is a new kind of natural medicament with very good antimicrobial. Given further research, it is very promising to be used as natural food preservative in food industry. Thus it will be very profitable to the Pyrola calliantha industry.