Inhibition of pyrophosphatase activity in soils by trace elements

Journal Article · Thu Jan 31 23:00:00 EST 1985 · Soil Sci.; (United States)

OSTI ID:5380877

Stott, D E; Dick, W A; Tabatabai, M A

Pyrophosphatase catalyzes the hydrolysis of pyrophosphatase to orthophosphate. Information on the control of pyrophosphatase activity in soil is desired. Thus the authors conducted this study to evaluate the effect of 21 trace elements on the activity of this enzyme in soils. Results showed that 19 of these elements inhibited pyrophosphatase activity and that the relative effectiveness of the trace elements in inhibiting this enzyme depended on the soil. When the trace elements were compared by using 25 ..mu..mol/g soil, the average inhibition in three soils showed that Hg(II), As(V), Mo(VI), and W(VI) were the most effective inhibitors (average inhibition > 50%). Moderately effective inhibitors were: Cd(II), Cu(II), Fe(II), B(III), and V(IV) (average inhibition between 30 and 50%). Other trace elements that inhibited pyrophosphatase activity in soils were: As(I), Cu(I), Mn(II), Ni(II), Pb(II), Sn(II), Zn(II), Al(III), As(III), Cr(III), Fe(III), Se(IV), and Ti(IV). Pyrophosphatase activity was not inhibited by Ba(II) or Co(II). The inhibitory effect of trace elements added per gram soil was decreased fivefold (from 25 to 5 ..mu..mol/g soil). The inhibition by the divalent cations Hg, Cd, Cu, Fe, and Sn showed noncompetitive kinetics, but BO/sub 3//sup 2 -/, MoO/sub 4//sup 2 -/, WO/sub 4//sup 2 -/, AsO/sub 4//sup 2 -/, and VO/sup 2 +/ exhibited competitive kinetics. Among the trace elements studied, MoO/sub 4//sup 2 -/ and WO/sub 4//sup 2 -/ are the most effective inhibitors of pyrophosphatase activity in soils.

• Research Organization: Iowa State Univ., Ames
• OSTI ID: 5380877
• Journal Information: Soil Sci.; (United States), Journal Name: Soil Sci.; (United States) Vol. 139:2; ISSN SOSCA
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
BORON COMPOUNDS
CADMIUM COMPOUNDS
CHROMIUM COMPOUNDS
COPPER COMPOUNDS
DATA
DOSE-RESPONSE RELATIONSHIPS
ENZYME ACTIVITY
ENZYMES
ESTERASES
EXPERIMENTAL DATA
HYDROLASES
INFORMATION
INHIBITION
IRON COMPOUNDS
LEAD COMPOUNDS
MANGANESE COMPOUNDS
MERCURY COMPOUNDS
MOLYBDENUM COMPOUNDS
NICKEL COMPOUNDS
NUMERICAL DATA
PHOSPHATASES
REFRACTORY METAL COMPOUNDS
SELENIUM COMPOUNDS
SOILS
TIN COMPOUNDS
TITANIUM COMPOUNDS
TOXICITY
TRACE AMOUNTS
TRANSITION ELEMENT COMPOUNDS
VALENCE
VANADIUM COMPOUNDS
ZINC COMPOUNDS