Protistology 1 (3) 87–91 (2000)
Activities of enzymes of carbohydrate and energy metabolism of the intracellular stages of the microsporidian, Nosema grylli
Viacheslav V. Dolgikh
Laboratory of Microbiological Control, All-Russian Institute for Plant Protection, St. Petersburg, Russia
Summary
The activities of nine enzymes were investigated in intracellular stages of the microsporidian Nosema grylli
from the fat body of the crickets Gryllus bimaculatus purified by centrifugation in Percoll density gradient. Phosphoglucomutase
(EC 5.4.2.2), hexokinase (EC 2.7.1.1) and fructose 6-phosphate kinase (EC 2.7.1.11) were not detectable in stages. Glucose 6-phosphate
dehydrogenase (EC 1.1.1.49), phosphoglucose isomerase (EC 5.3.1.9), 3-phosophoglycerate kinase (EC 2.7.2.3), pyruvate kinase
(EC 2.7.1.40), glycerol 3-phosphate dehydrogenase (EC 1.1.1.8) and ATP-ase were detected with activities of
7 ± 1, 23 ± 2, 7 ±1, 2 ±0.3, 17 ± 3 and 17 ± 4 nmol/min x mg protein respectively. A comparison of these values with
activities of enzymes of spores shows that the rate of carbohydrate catabolism in microsporidian meronts and early sporonts is lower than
in spores. The observed results may be explained by the host-derived ATP dependence of microsporidian intracellular stages.
Key words: carbohydrate catabolism, enzymes, intracellular stages, microsporidia
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