[Objectives]To investigate the antimicrobial activity and mechanism for saponin from Sapindus mukorossi against Escherichia coli.[Methods]E.coli was used as the test bacteria,and the antimicrobial effect of Sapindus s...[Objectives]To investigate the antimicrobial activity and mechanism for saponin from Sapindus mukorossi against Escherichia coli.[Methods]E.coli was used as the test bacteria,and the antimicrobial effect of Sapindus saponin was studied by the minimum inhibitory concentration method.The antimicrobial mechanism of Sapindus saponin was studied in terms of growth curves,membrane potential,activity of cells,cell surface morphology and cell internal structure.[Results]The results indicate that Sapindus saponin can inhibit the growth of E.coli,the minimum inhibitory concentration is 5 mg/mL and has a significant inhibitory effect on the growth of E.coli.After treated with Sapindus saponin,the membrane potential of E.coli increased by 16.7,17.3 and 19.1 times after exposition to 0.5,1,2 MIC Sapindus saponin respectively.PI staining results show that cell viability decreased and permeability of cell membranes increased.The results of SEM and TEM further corroborate the membrane damage,the cell was damaged after exposition to Sapindus saponin.[Conclusions]The antimicrobial mechanism of Sapindus saponin were to changed membrane potential of cell,and damage the cell membrane structures.展开更多
A90°elbow equipped with guide vanes was developed with the intent of reducing elbow erosion.Numerical models were formed to predict the maximum erosion rate of elbow and Face-1,and the response surface methodolog...A90°elbow equipped with guide vanes was developed with the intent of reducing elbow erosion.Numerical models were formed to predict the maximum erosion rate of elbow and Face-1,and the response surface methodology was used to study the relationship between the erosion rate and structural parameters of guide vane.A second-order response surface model was established to determine the relationship between R and variables,and a reduced cubic(RC)polynomial model was obtained to reveal the relation-ship between R2 and the three factors.The numerical results show that the low-speed region is expended and the maximum discrete particle matter(DPM)concentration is reduced after installing the guide vane.This internal component provides a shelter for the elbow from the direct impact of high-speed solids.展开更多
文摘[Objectives]To investigate the antimicrobial activity and mechanism for saponin from Sapindus mukorossi against Escherichia coli.[Methods]E.coli was used as the test bacteria,and the antimicrobial effect of Sapindus saponin was studied by the minimum inhibitory concentration method.The antimicrobial mechanism of Sapindus saponin was studied in terms of growth curves,membrane potential,activity of cells,cell surface morphology and cell internal structure.[Results]The results indicate that Sapindus saponin can inhibit the growth of E.coli,the minimum inhibitory concentration is 5 mg/mL and has a significant inhibitory effect on the growth of E.coli.After treated with Sapindus saponin,the membrane potential of E.coli increased by 16.7,17.3 and 19.1 times after exposition to 0.5,1,2 MIC Sapindus saponin respectively.PI staining results show that cell viability decreased and permeability of cell membranes increased.The results of SEM and TEM further corroborate the membrane damage,the cell was damaged after exposition to Sapindus saponin.[Conclusions]The antimicrobial mechanism of Sapindus saponin were to changed membrane potential of cell,and damage the cell membrane structures.
基金The authors gratefully acknowledge the financial supports by the National Youth Foundation of China(51806248)Natural Science Foundation of Shandong Province(ZR2018BB068)and Innovation Project for Postgraduate of UPC(20CX02215A).
文摘A90°elbow equipped with guide vanes was developed with the intent of reducing elbow erosion.Numerical models were formed to predict the maximum erosion rate of elbow and Face-1,and the response surface methodology was used to study the relationship between the erosion rate and structural parameters of guide vane.A second-order response surface model was established to determine the relationship between R and variables,and a reduced cubic(RC)polynomial model was obtained to reveal the relation-ship between R2 and the three factors.The numerical results show that the low-speed region is expended and the maximum discrete particle matter(DPM)concentration is reduced after installing the guide vane.This internal component provides a shelter for the elbow from the direct impact of high-speed solids.
