Phytase activity in Cryptococcus laurentii ABO 510
Date
2007
Authors
Van Staden J.
Den Haan R.
Van Zyl W.H.
Botha A.
Viljoen-Bloom M.
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Abstract
Ten Cryptococcus strains were screened for phytase activity, of which the Cryptococcus laurentii ABO 510 strain showed the highest level of activity. The cell wall-associated enzyme displayed temperature and pH optima of 62°C and 5.0, respectively. The enzyme was thermostable at 70°C, with a loss of 40% of its original activity after 3 h. The enzyme was active on a broad range of substrates, including ATP, d-glucose 6-phosphate, d-fructose 1,6-diphosphate and p-nitrophenyl phosphate (p-NPP), but its preferred substrate was phytic acid (Km of 21 μM). The enzyme activity was completely inhibited by 0.5 mM inorganic phosphate or 5 mM phytic acid, and moderately inhibited in the presence of Hg2+, Zn2+, Cd2+ and Ca 2+. These characteristics suggest that the Cry. laurentii ABO 510 phytase may be considered for application as an animal feed additive to assist in the hydrolysis of phytate complexes to improve the bioavailability of phosphorus in plant feedstuff. © 2007 Federation of European Microbiological Societies.
Description
Keywords
4 nitrophenyl phosphate, adenosine triphosphate, cadmium, calcium, food additive, fructose, fungal enzyme, glucose 6 phosphate dehydrogenase, mercury, phosphate, phosphorus derivative, phytase, phytate, phytic acid, zinc ion, animal food, article, bioavailability, cell wall, Cryptococcus laurentii, enzyme activity, enzyme substrate, fungal strain, hydrolysis, nonhuman, pH, screening, temperature, thermostability, 6-Phytase, Animal Feed, Cell Wall, Cryptococcus, Enzyme Stability, Hydrogen-Ion Concentration, Metals, Heavy, Phosphates, Phytic Acid, Substrate Specificity, Animalia, Cryptococcus laurentii
Citation
FEMS Yeast Research
7
3
7
3