| As one of the green additives for alternative antibiotics,studies on yeast cell wall go on deeper and deeper in recent years.The main components of the yeast cell wall as glucan,mannan and protein.There are a great amount of researches reported that the yeast cell wall has function of anti-tumor,anti-viral,anti-oxidant,stimulate and enhance immune function,and adsorption of pathogenic bacteria and mycotoxin.Because of its wide range of biological activities,it is widely adopted on industries such as food,farming,medicine,cosmetics and so on.In order to better guide the application of yeast cell wall in practical production,this article aims at evaluating the stability of the yeast cell wall from two aspects,one is the its influence on different bacteria`s antibacterial stability,and the other is it`s intervention effect on mycotoxin DON cytotoxicity.This study takes escherichia coli and staphylococcus aureus as tested bacterias,and explores the physical stability and antibacterial stability of yeast cell wall under different pH,temperature,concentration of metal ions.Taking IPEC-J2 as cell strain,using the MTS method to evaluate yeast cell wall`s intervention effect on DON induced enterocyte`s vigour.Using the method of Immunofluorescence to evaluating yeast cell wall`s intervention effect on DON induced intestinal epithelial cells closely protein?ZO-1,Claudin,Occludin?.The main results are as following:1.To evaluate the physical stability of yeast cell wall in different pH,temperature and concentration of metal ions according to the particle size and electric potential changes.The results show that the yeast cell wall remain physical stable in different temperature.The yeast cell wall tends to gather and become precipitate in alkaline condition,especially when the pH is 10 to 11.In other pH conditions,the yeast cell wall remain stable.Under the impact of different metal ions,the yeast cell wall solution remain stable,with the exception of the Zn2+concentration over0.1mol/L,which can cause the yeast cell wall`s gathering.2.The results of antibacterial stability indicate that,the yeast cell wall`s inhibitory effect on staphylococcus aureus is better than that on escherichia coli O157:H7,the minimum bacteriostasis concentration are 2.08 x 10-2 g/mL and 1.04 x 10-2g/mL.Under acid condition,especially when the pH is 4 to 6,the yeast cell wall have good bacteriostatic performance on staphylococcus aureus and escherichia coli O157:H7.when it is disposed by heat between 4?121?,the yeast cell wall still keep antibiosis activity.Different metal ions can greatly influence on the yeast cell wall`s antibiosis activity,Zn2+and Mn2+can improve the yeast cell wallit`s antibiosis performance,and the affect of Zn2+is the stongest,where as the Ca2+can reduce it`s antibiosis performance.3.Measuring the vigour of enterocyte with MTS method indicates that,the low concentration yeast cell wall solution can promote cell`s growth,which is a dose-response relationship;and the high concentration yeast cell wall solution can restrain cell`s growth.4.The results of yeast cell wall`s intervention on DON cytotoxicity indicates that,the yeast cell wall can reduce the DON induced enterocyte toxicity,and it also can help repairing the DON damaged cells.DON can reduce the fluorescent expression of protein ZO-1,Claudin and Occludin,and medium concentration yeast cell wall solution can largely improve the Claudin protein`s fluorescent expression.5.The results of absorption experiment show that,yeast cell wall MP60 have a weak absorption effect for DON,where as the yeast cell wall PW220 and?-glucan G70 have strong adsorption effect for DON,with the adsorption rate up to 28.8%and31.8%. |
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