Studies On The Isolation, Immunomodulation And Tumor-inhibition Of Whole Peptidoglycan From Bifidobacterium Longum

Bifidobacterium is an important inhabitant in intestinal tracts of people and animals.It has beneficial effects of intestinal health.Whole peptidoglycan(WPG) is the main component of Bifidobacterium which can inhibit the growth of tumours,resist to infection and enhance immunity.it is also a regulator that has no toxin and side effects.WPG is the main component of cell wall and it was isolated from whole cells without being subjected to physically destructive methods,completely retained a physically intact skeleton structure of whole cells.it would seem reasonable to suggest that WPG has a bag-shaped structure formed by polysaccharide and peptidoglycan. At present,the study on WPG was focused on the physiological functions and mechanism ,however,there are few reports of isolation method oversea and at home.We choose Bifidobacterium longum as our subject which is often used in microecology.By research time after time,we get a new way to isolate WPG.Compared with the old method, it has many virtues such as easier technics,lower cost and shorter cycles.In addition, It`s the first time to study Bifidobacterium longum at this kind of research in our country.It has been proved by lysozyme and UV-visible absorption spectra that the material isolated by this method were peptidoglycan.Chemical analysis indicates that WPG was composed of 69.78%protein,10.60%amino sugar and10.60% neutralsugars.and molar ratio of amino acids (alanine:glutamic acid:Lysine:threonine:serime) is 3.5:1:0.7:0.3:0.3;The ultrastructural examination by transmission electeonmicroscopic demonstrated that WPG retained whole-cell shape completely. We get the conclusion by experiment in vivo that our WPG can improve immunity of body.It can inhibit the growth of man gastric cancer cells and galactophore cancer cells markedly while it can not inhibit the growth of man liver cancer cell.