Reagentless identification of human bifidobacteria by intrinsic fluorescence.
A new identification method for bifidobacteria species from the human gastrointestinal tract was developed based on the measurement and statistical analysis of the intrinsic fluorescence of aromatic amino acids (AAA) and nucleic acids (NA), following their excitation at 250 nm. The model was constructed by recording the fluorescence spectra of 53 Bifidobacterium strains of 10 different species, including the corresponding type strains, and validated by analyzing the spectra data from nine further problem strains. Principal components analysis (PCA) and factorial discriminant analysis (FDA) of the results showed the technique to distinguish between the isolates at the species level; the Bifidobacterium pseudolongum subspecies (globosum and pseudolongum) could also be distinguished. The proposed method provides a powerful, inexpensive and convenient means of rapidly identifying intestinal bifidobacteria, which could be of help for large probiotic surveys.
Ammor
Mohammed Salim
MS
Instituto de Productos Lácteos de Asturias (CSIC), Carretera de Infiesto s/n, 33300 Villaviciosa, Asturias, Spain. ammor@ipla.csic.es
Delgado
Susana
S
Alvarez-Martín
Pablo
P
Margolles
Abelardo
A
Mayo
Baltasar
B
D024322:Amino Acids, Aromatic / Q000032:analysis; D039941:Bifidobacteriales Infections / Q000175:diagnosis; D001644:Bifidobacterium / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D008962:Models, Theoretical; D009696:Nucleic Acids / Q000032:analysis; D025341:Principal Component Analysis; D013050:Spectrometry, Fluorescence / Q000379:methods*
D024322:Amino Acids, Aromatic; D009696:Nucleic Acids