Stydy On The Antibacterial Effect Of Bio-liquid And Chitosan On Penicillium Expansum

In order to explore the antibacterial effect of bio-liquid and its application in agricultural products,bio-liquid as experimental material,chitosan as auxiliary material,Penicillium expansum was separated from diseased apple pear,chemical composition of bio-liquid was detected by GC-MS,the antibacterial effect and the antibacterial mechanism of bio-liquid and chitosan on Penicillium expansum were studied.The results showed that,23 components were identified from bio-liquid,the total content of acids,amines and ketones is 89.56%,which are the main components of bio-liquid.The relative content of acid was the highest,accounting for 58.89%of all the samples,the relative content of acetic acid was 40.34%,the relative content of amines was 17.84%,the relative content of ketones was 12.83%,there are also a small amount of alcohols,esters,phenols,aldehydes and other substances.The antibacterial effect of bio-liquid and chitosan on Penicillium expansum was determined by growth rate method,EC50 of bio-liquid against Penicillium expansum was diluted 69.18 times,the minimum inhibitory concentration was diluted 33 times,the minimum fungicidal concentration was diluted 30 times.EC50 of chitosan against Penicillium expansum was 1.4 g/L,the minimum inhibitory concentration was 5 g/L,chitosan has no fungicidal effect on Penicillium expansum.Biomass pyrolysis liquid and chitosan EC50 solution mixed in different proportions has synergistic effect,and the proportion of 1:1 was an ideal compound bacteriostatic agent determined by the method of CO toxicity factor.The treatment of bio-liquid and chitosan could increase the conductivity of the culture medium and cause the leakage of protein and nucleic acid.And can also inhibit the synthesis of protein and total sugar of Penicillium expansum silk,and interfere with the normal growth and reproduction.The higher the bio-liquid concentration,the greater the inhibition,bio-liquid and chitosan composite with 1:1 had significantly synergistic effect.The treatment of bio-liquid and chitosan could increase ?-1,3 glucanase activity,protease activity and chitinase activity,the metabolism of the protein of Penicillium expansum was accelerated,and cause the cell wall hydrolysis of Penicillium expansum so that inhibit its growth and development.The in vivo antibacterial experiment showed that,the incidence of apple pear after infection was inhibitd and the disease index of Penicillium was alleviated after the treatment of bio-liquid and chitosan.The treatment effect of bio-liquid and chitosan was higher than that of biomass pyrolysis liquid only.The bio-liquid and chitosan treatment had a better inhibitory effect on the early stage of the disease,and the treatment effect was better than the protective effect.