Study On Bacteriostatic Mechanism And Establishment Of Mathematical Model By Saponins From Momordica Charantia L

The saponins is one of the mainly active ingredients from Momordica charantia L.The inhibition effect of saponins from Momordica charantia L on microorganisms,it is a good natural antimicrobials.In this thesis,our research focuses on MIC and bacteriostatic stability(temperature,PH,salt ions concentration) of three common bacteria (coliform bacteria, Staphylococcus aureus and C.sporogenes) in low-temperature enema products. Secondly, Staphylococcus aureus were selected as the indicator bacteria, some mechanism of saponins from Momordica charantia L inhibition of Staphylococcus was investigated. Thirdly, the growth curves of certain bacteria were fitted by modified Gompertz, then, establishment and validation of bacteria inhibition model from Saponins in low-temperature enema products by forecast microbiology. The contents and results of each chapter are as follows: 1. The reults of bacteriostatic experiment of saponins from Momordica charantia L. indicated that it is obvious to certain bacteria suppression effect and their minimum inhibitory concentration (MIC) below 30mg/mL, MIC to Escherichia coli was 10 mg/ml; best bacteriostasis pH was 5.0~7.0.The antibacterial activity of saponins were stable under heating and concentration of NaCl, at 121℃, for 10min processing still maintained the good antimicrobial effect.2.From the growth curves, bacterial biofilm, protein aspect and respiratory of bacteria, some mechanism of Staphylococcus aureus inhibition was investigated in this chapter. The observation under the growth curve of Staphylococcus aureus was indicated that logarithmic phase of Staph.aureus sensitive to the saponins, while close to a stable period its bacteriostatic action is weak. Saponins from Momordica charantia L were added to the bacterial biofilm of Staphylococcus aureus, the bacterial colonies were calculated to evaluate the bacteriostatic effect at different times(1 h,2 h,3 h),the inhibitory effect was the strongest at 3 h. Electrophoretic patterns of cell protein of staphylococcus aureu were detected by SDS-PAGE. As a result, protein composition and content appeared apparent shift in the SDS-PAGE map. Further investigation indicated that Saponins from Momordica charantia L mainly inhibit TCA route of bacteria.3.The investigation of establishment and validation of bacteria inhibition model from Saponins in low-temperature enema products indicated that the growth curves of coliform bacteria, Staphylococcus aureus and C.sporogenes were fitted by modified Gompertz function which was used to estimate two growth parameters(growth rate;lag-time). Furthermore, Ratkowsky function of root-square was applied for the fitting bacteria inhibition from Saponins in low-temperature enema products. The highest enduring concentrations of Saponins were lower than 200,180 and 170mg/kg, respectively. The result of evaluation of mathematical parameters indicated that root-mean-squares error (RMSE),bias factor (Bf) and accuracy factor (Af) were within acceptable range and bacteria inhibition model was value for application in low-temperature enema products.