Fluorescence spectroscopy shows porphyrins produced by cultured oral bacteria differ depending on composition of growth media.

This study examined and compared the fluorescence spectra produced by selected cultured oral bacteria when grown on agars containing different nutrients with spectra for protoporphyrin IX, Zn-protoporphyrin IX, haematoporphyrin and haematin. Actinomyces israelii (DSM, Deutsche Sammlung von Mikroorganismen, 43320), Actinomyces naeslundii (DSM 43013), Fusobacterium nucleatum (DSM 20482), Lactobacillus casei (DSM 20011), Prevotella intermedia (DSM 20706), Streptococcus mutans (DSM 20523), Streptococcus oralis (DSM 20627), Streptococcus salivarius (DSM 20560) and Streptococcus sobrinus (DSM 20742) were rehydrated and grown anaerobically on caso, caso blood (containing 5% sheep blood) and caso chlorophyll (containing 5% spinach extract) agar for 3 days at 37 °C, in the dark. Colonies were harvested, transferred to ethanol, and centrifuged. Fluorescence emission spectra were recorded from the supernatant at 405nm excitation (Fluorolog 3-22. Jobin Yvon-Spex ISA, Edison, NJ, USA). All streptococci, L. casei and F. nucleatum produced red fluorescence when grown on caso and caso chlorophyll agar, but not on caso blood agar. A. naeslundii and P. intermedia emitted intense red fluorescence when grown on caso or caso blood agar but not on caso chlorophyll agar. Fluorescence emission spectra of A. naeslundii and P. intermedia grown on caso blood agar corr elated exactly with both fluorescence peaks for protoporphyrin-IX at 632 and 701nm. Most peaks observed could be correlated with at lea...
Source: Caries Research - Category: Dentistry Source Type: research