FACTORS AFFECTING GLUCOSIDASE AND GALACTOSIDASE ACTIVITIES IN SOILS

This study was carried out to assess the effects of soil treatments, the addition of 12 inorganic salts and of 20 trace elements on α- and β-glucosidase and α- and β-galactosidase activities in soils. Results showed that air-drying of field-moist soils resulted in marked increases in the activity of these enzymes and that steam sterilization of soils completely destroyed the activities. In general, the inorganic salts were stronger inhibitors of α-glucosidase and α-galactosidase activities (range 0 to 70%) than the activities of their β counterparts (range 0 to 44%). The effect of trace elements on the activities of these enzymes varied considerably among the elements, enzymes and soils. The percentage inhibition of α-glucosidase activity in Webster soil ranged from 4% with Mo(VI) to 66% with Ag(I) and in Luton soil ranged from 9% with V(IV) to 66% with Cd(II). In general, the inhibition values of β-glucosidase activity by trace elements were much lower than those obtained for α-glucosidase activity. The inhibition values of α-galactosidase activity in Webster soil ranged from 10% with Hg(II) to 13% with Sn(II). The inhibition values for this enzyme in Luton soil ranged from 12% with Hg(II) to 73% with Mo(VI). Studies on the distribution of the activities of these enzymes showed that they are concentrated in surface soils and decrease with depth. The activities of these enzymes were significantly correlated with organic C in soil profiles and surface soils and were, in most cases, significantly but negatively correlated with pH. © 1990.