Mitigating phosphate interference in bacterial endospore detection by Tb dipicolinate photoluminescence

Effect of sporulation medium on wet-heat resistance and structure of Alicyclobacillus acidoterrestris DSM 3922-type strain spores and modeling of the inactivation kinetics in apple juice

“…DPA is usually present in 1:1 molar ratio with Ca first minute of germination, spore activation by a lethal heat treatment or wet-heat induced spore inactivation (Kort et al, 2005). For DPA analysis, spectrophotometry (Janssen et al, 1958), ultraviolet spectroscopy (Scott and Ellar, 1978), Fourier transform infrared spectroscopy (Goodacre et al, 2000), liquid chromatography (Paulus, 1981), luminescence (Fell et al, 2001), electron monochromator mass polarography spectroscopy (Beverly et al, 2000), fluorescence (Hindle and Hall, 1999), and pyrolysis-gas chromatography/ion mobility electrophoresis spectroscopy (Goodacre et al, 2000) have been used.…”

Interaction of dipicolinic acid with water-soluble and immobilized porphyrins

“…Recent threats of contamination in the United States and the continuing danger to military personnel and civilians alike indicate the need for a detector of biological agents that operates in real time and that can function in a variety of environments. Several methods for detection of bacterial spores have been developed including PCR [2,3], immunofiltration assay [4,5], polymorphism analysis [6], direct detection of DNA sequences [7], liquid chromatography [8], FT-IR [9] and those which indicate bacterial spore presence by detection of DPA [10][11][12][13][14][15][16][17][18][19][20].…”

“…One method currently employed for detection of DPA is to measure the increase in terbium fluorescence when it binds DPA [15,17,18,20]. In this method, solutions of DPA or bacterial spores are mixed with terbium solutions followed by separation of insoluble materials.…”

“…Emission and excitation spectra are recorded from 450 to 640 and 270 to 280 nm, respectively. The Tb fluorescence intensity increases without a wavelength shift in the emission spectrum [14,15,17,18,20]. However, phosphate-containing compounds quench the fluorescence of the Tb-DPA complex [18]; this problem can be solved by adding AlCl 3 to the solution prior to separation of insoluble particles [20] to remove phosphate from solution.…”

Pre‐column liquid chromatographic determination of dipicolinic acid from bacterial endospores

“…Hydrolysis and evaporation of samples followed the procedure described previously for extraction of DPA from B. subtilis endospores with the exception that the dried sample was dissolved in 4 mL 1 M NaAc (pH 5.6), and 80 µL 2 mM AlCl 3 was added before 0.2 µm filtration. AlCl 3 was added to precipitate phosphate, which otherwise could bind terbium (Fell et al 2001). The concentration of DPA in the dissolved hydrolyzate was calculated from 4-5 point standard addition curves encompassing the concentrations in the samples.…”