[Protein profile strain specificity of Bifidobacterium genus members]

Analysis of differences in protein spectra of various bifidobacteria strains of intestine microsymbiocenosis using identification results from MALDI-TOF mass-spectrometer.

Results of mass-spectrometry ("Bruker Daltonics", Germany) for 57 intestine isolates' of Bifidobacterium spp. are provided. 500,laser impulses were used for obtaining every mass-spectrum; parameters of mass-spectrometer were optimized for the 1000-18000 m/z (mass to charge) range.

Comparative analysis of mass-spectrometry biomarkers for Bifidobacterium genus members has detected variations in the quantity of peaks (4 to 56) among both various species and within bifidobacteria species, that reflects uniqueness of the protein profile of separate strains. Along with biomarkers, specific for most cultures, significant differences of the examined peaks were detected; including among microorganisms, that belong to the same species. As such, for B. bifidum species strains--only in 67 ± 7.5% of cultures the presence of common peaks in'the 9282-9901 m/z was detected, whereas protein spectra in other ranges differed by both quantity and molecular mass.

Differences in protein profile of Bifidobacterium genus microorganisms reflect uniqueness of protein spectra (proteome) of every separate strain; determining their functional activity, features of interaction, with associative microsymbionts and host organism in human associative symbiosis.