The purpose of the experiment was to observe the changes occurring in the different phosphorus (P) pools in sludge‐amended soils during incubation using 31P nuclear magnetic resonance spectroscopy (31P NMR) to qualitatively and quantitatively register P transformations. An acid and an alkaline soil were each incubated with sludges that underwent different digestion processes. The 31P NMR spectra of those soils after 1, 28, 70, and 140 d of incubation showed that P diesters completely hydrolyzed after 28 d of incubation in both soils, irrespective of the type of sludge incorporated. After 140 d of incubation, P monoesters were still detected in the acid soil while they had completely hydrolyzed in the alkaline soil. Pyrophosphates were detected after 70 d of incubation in the alkaline soil and 140 d of incubation in the acid soil. The study suggested that acidity has an adverse effect on the microbial degradation of P monoesters and pyrophosphates in sludge‐amended soils.

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Infection by Schistosoma mansoni resulted in morphological and biochemical changes to the foot of its intermediate host, Biomphalaria glabrata. Migration through, and emergence of cercariae from, the foot was observed and evidenced by lesions on the ciliated foot surface. This was accompanied by a significant decrease in the velocity of movement by infected individuals. In vivo 31P NMR spectral analyses demonstrated that the foot of infected snails had a lower phosphoarginine (PA)/adenosine 5' triphosphate (ATP) ratio than that of uninfected controls. Moreover, kinetic experiments, employing saturation transfer, demonstrated the pseudo-first-order rate constant for the arginine kinase-catalysed exchange reaction in the forward direction, that is, PA-->ATP was decreased by infection. The reverse reaction was not observed by the NMR methods used. PA was depleted upon exposure to hypoxic conditions suggesting its traditional role in preserving ATP level. Partly oxidized metabolic end-products were not observed in snails maintained under aerobic conditions, but succinate, propionate, acetate and lactate rapidly accumulated under hypoxic conditions.

The basis of the nuclear magnetic resonance (NMR) phenomenon is described in a classical framework with emphasis on magnetic nuclei of 1/2 spin, including 1H, 13C, and 31P. Biological applications of NMR spectroscopy and magnetic resonance imaging (MRI) are outlined briefly. NMR spectroscopic studies on parasitic protozoa, cestodes, nematodes, trematodes, and hymenopterous insect parasites are reviewed. NMR and MRI investigations on the pathophysiology of the host are also discussed, and the potential future of NMR applications in parasitology outlined.