Study On The Primary Antimicrobial Ingredients Of Linberry (Vaccinium Vitis-idaea L.)

Organic acids,vitamins,carbohydrates,trace elements anthocyan and sugars are extremely abundant in Linberry,which contained the biological active component of anthocyanins,proanthocyanidins,flavanols,flavonols and its glucoside and so on.Linberry had the function of antioxidation,anti-inflammatory,anticancer and many other physiological activities.Currently,Linberry was mainly used in fruit wine,beverage and tea.The studies about antimicrobial activity of L are relatively scarce.In order to investigate the bioactive activity of the fruit,this paper focused on the extract from Linberry fruit and its antimicrobial properties and the inhibition of different microorganisms,as well as the antimicrobial mechanism.This study can provide experimental references for further development and utilization of Linberry.First of all,to water and ethanol from Linberry,the results show that the main componets of Linberry are amino acid,protein,organic acids,carbohudrates,phenols,flavonols and its glucoside,coumarins,tannins,anthraquinone and its glucoside and so on by system preblimlnary experiments.The antimicrobial properties of extracting solution from Linberry against the test bacteria were screened by antibacterial filter paper and doubling dilution method measured minimum inhibitory concentration(MIC).Results:the diameter of inhibition zone by the water extract of Linberry were Escherichia coli 17.3mm,Bacillus subtilis 11.6mm,Aspergillus niger 5.4mm and Penicillium 6.0mm;the MIC of the water extract of Linberry were 31.25mg/mL,62.5mg/mL,250mg/mL and 125mg/mL,respectively.And the diameter of inhibition zone by the ethanol extract of Linberry were Escherichia coli 27mm,Bacillus subtilis20.6mm,Aspergillus niger 5.9mm and Penicillium 6.3mm;the MIC of the water extract of Linberry were 31.25mg/mL,15.625mg/mL,125mg/mL and 62.5mg/mL.Obviously,inhibitory effect of ethanol extract was better than the water extract from Linberry.Using ultrasonic power,extraction time,solvent concentration and extraction time as factors,extraction yield of total flavonoids as indicator to optimize the extraction conditions of the total flavonoids from blueberry by orthogonal experiment,the antibacterial activity of flavonoids was investigated systematically.Results:the optimal extraction conditions of total flavonoids of Linberry were as follows:ultrasonic power 450W,ultrasonic time 25min,ethanol concentration 50%,solid-liquid ratio 1:15,under above conditions,total flavonoids extraction rate was 29.87mg/g.When the concentration(pH=2.8)of total flavonoids from Linberry was 39.83ng/mL,it had obvious antibacterial effect on Escherichia coli.Bacillus subtilis,Aspergillus niger and Penicillium with the inhibition zone diameter of 21.67mm,21.17mm.5.81mm and 6.10mm respectively.The MIC was 5mg/mL,5mg/mL,20 mg/mL,and 20 mg/mL respectively.The low pH of the total flavonoids contributed to some extend to the antibacterial activity of the flavonoids,after neutralization,the antibacterial activity decreased significantly,the MIC were Escherichia coli 400mg/mL and Bacillus subtilis 600mg/mL,however,there was no obvious inhibitory effect on Aspergillus niger and Penicillium.The optimal extraction conditions of organic acids from Linberry,optimized by response surface,were as follows:ultrasonic power 150W,temperature 70?,ethanol concentration 10%,solid-liquid ratio 1:25,ultrasonic time 40min.When the concentration(pH=2.8)of organic acids from Linberry was 1.275g/mL,it had obvious antibacterial effect on Escherichia coli,Bacillus subtilis,Aspergillus niger and Penicillium with the MIC of 7.969mg/mL,15.938mg/mL,63.75mg/mL and 31.875mg/mL respectively.Ultrastructural observation and biochemical tests revealed that the organic acid from Lingonberries could inhibit the test bacteria growth.After affected by the organic acid,permeability of cell membrane and wall were increased,and cell components were released,the ability of reducing the utilization of reducing sugar was decreased,the soluble protein was dissolved,and the surface of the cells was wrinkled and some of them were swollen and broken.