Spectrochemical Analysis of Vegetative Cells and Spores of Bacteria

Abstract

Six mesophilic aerobic spp. (2 unidentified) and 4 unidentified thermophilic (flat sour types) were analyzed spectrochemically, each in the vegetative and spore forms. Quantitative data were obtained for K, Ca, P, Mg, Fe, Al, Cu, Mn, and B. The organisms were cultivated on the surface of beef infusion agar slopes, washed in Pyrex-distilled water, and dried on Lucite at 45[degree] C in vacuo. 5 mg. samples were analyzed by means of a large Littrow spectrograph. Standards were prepared by dilution of stock solns. containing known amts. of the elements under investigation. Density or % transmission measurements of the spectral lines of these standards permitted the construction of working curves, which were used for the detn. of conc. of elements in the test samples. In the vegetative cells, the conc. of K was usually between 0.7 and 2.9% of the dry wt.; in the spores, 0.5% or lower. In the mesophilic vegetative cells the Ca limits were 0.1-0.4% ; in the thermophilic vegetative cells. 0.7-1.8%. In the spore samples the Ca range was 1-2.7%. P varied from about 1 to 6% and was usually higher in the vegetative than in spore samples. Mg concs. varied from 0.2 to 1.4%. Fe, Al and Cu ranged from about 20 to 600 ppm. Cu was higher in the spores than in the vegetative cells. The Mn limits were 10-120 ppm.; B, 1-20 ppm. There was no direct correlation between elemental inorganic composition of spores and their degree of resistance to heat.