Growth, proteolytic activity and adhesion to sheep epithelial cells of four species of bifidobacteria
A. S. ZAHRAN, Dairy Science Dept., Minia Univ., College of Agriculture, Minia, 61111, Egypt
Bifidobacteria are the predominant bacteria in the stools of breast-fed infants.They were reported as an example of beneficial bacteria.These bacteria contribute to digestion,immunity promotion,production of vitamins and inhibition of pathogens.The benfits of consuming milk products containing bifidobacteria are well documented and have been reported by many researchers.Bifidobacterium longum,B. bifidum,B. adolescentis and B.angulatum were evaluated for their growth,acid production,alpha-and beta-galactosidase activities in MRS supplemented with 5%(w/w) lactose(MRSL).Viability and proteolytic activity in pasteurized cow milk were also studied.Adhesion of the four species to freshly collected sheep intestinal cells was also investigated.The results showed that B.longum had the the highest growth rate and acid production in MRSL compared to the other species.On the other hand,B.adolescentis was the least active bacterium.B.bifidum had the highest alpha-galactosidase activity,whereas,B.longum possessed the highest beta-galactosidase activity.The growth of all species was enhanced due to the presence of cysteine -HCl (reducing agnet)in MRSL.B.angulatum and B.longum grew well in pasteurized cow milk,they also showed the highest proteolytic activity.The attachment of bifidobacteria to columnar epithelial cells of sheep was species dependant.B.longum and B.bifidum bound much better than the other two species.This study suggests that B.longum and B.bifidum could be used for the manufacture of dairy products containing probiotics.
Session 30D, Nutrition