:: Volume 26, Issue 2 (6-2018) ::
sjimu 2018, 26(2): 198-209 Back to browse issues page
Investigation of Proteolytic Ctivity of Lactococcus lactis in Reducing Cow´s Milk Caseins Allergenicity
Reihaneh Kordesedehi1 , Asghar Taherikafrani 2, Mohammad Rabbanikhorasgani3
1- Dept of Biotechnology, Faculty of Advanced Sciences and Technologies, Isfahan University , Isfahan, Iran
2- Dept of Biotechnology, Faculty of Advanced Sciences and Technologies, Isfahan University , Isfahan, Iran , a.taheri@ast.ui.ac.ir
3- Dept of Biology, Faculty of Science, Isfahan University , Isfahan, Iran
Abstract:   (2446 Views)

 Introduction: Bovine milk is the first and most common cause of food allergy in early childhood with a prevalence rate of about 2-7/5%. The milk coagulum consists of four proteins αS1, αS2, β and к-caseins. Cowchr('39')s milk caseins play a basic role in persistence of cow’s milk allergy (CMA) in children. Proteolytic system of lactic acid bacteria (LAB) has the ability to hydrolyze antigenic epitopes of milk proteins and, as a result, can reduce allergy to caseins.The aim of this study was to isolate the best lactic acid bacteria strain from cow’s milk samples in order to reduce bovine milk caseins allergenicity. 
 
Materials & Methods: In the present study, after isolation of 30 cocci LAB from 20 Iranian cow’s milk samples, the effect of proteolytic activity of these bacteria on milk caseins was investigated by SDS-PAGE and RP-HPLC techniques. Subsequently, among the 15 strains with protease activity, the binding ability of native and hydrolyzed αS1-casein to IgE sera from cow’s milk allergic patients was determined by competitive ELISA test.
 
Findings: After accomplishing biochemical tests including gram staining and catalase test, molecular identification of the strains was done by 16s rRNA fragment sequencing. The obtained results suggested that Lactococcus lactis was able to hydrolyze casein fractions in both skim milk and sodium caseinate and could reduce allergenicity of bovine milk αS1-casein.
 
Discussion & Conclusions: Our conclusion demonstrated that the isolated Lactococcus lactis strain from cow’s milk samples can be used as a main or adjunct starter culture in dairy products to reduce immunor-eactivity of cow’s milk caseins.  

Keywords: food hypersensitivity, casein, lactic acid bacteria, competitive ELISA
Full-Text [PDF 1141 kb]   (954 Downloads)    
Type of Study: Research |
Received: 2017/01/12 | Accepted: 2017/04/5 | Published: 2018/06/15



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Volume 26, Issue 2 (6-2018) Back to browse issues page