Enzyme activity in soils at subzero temperatures

Spatial Heterogeneity of Substrates: Effects on Hydrolysis, Immobilization and Nitrification of Urea-N

“…Measurable urea hydrolysis at -5oC is consistent with data reported by Bremner and Zantua (1975) who reported activity of urease down to -20"C in five soils. Such hydrolysis at low temperatures yields NHI which could be oxidized.…”

Modelling in situ activities of enzymes as a tool to explain seasonal variation of soil respiration from agro-ecosystems

“…Our results indicate that the Weibull function fitted the data well since this assumed a certain threshold of enzyme activity,~50 nmol g À1 dry soil h À1 and~12 mg GE g À1 dry soil 24 h À1 for b-glucosidase and xylanase, respectively, below which detection of the respired CO 2 may not be possible. Since EE retain their catalytic ability under cold conditions (Bremner and Zantua, 1975;Blankinship et al, 2014) and enzymatic products are being formed, further processing of these products to CO 2 production may decline, resulting in a lag phase such as that observed in our study for respired CO 2 at lower in situ enzyme potential (Fig. 5).…”

Seasonal Changes in Carbon Content, and Dehydrogenase, Phosphatase, and Urease Activities in Mixed Prairie and Fescue Grassland Ah Horizons

“…Bremner and Zantua (1975) have shown that significant enzymatic activity occurs in soils at -10 and -20? C. This was attributed to enzyme-substrate interaction in unfrozen water at the surfaces of soil particles, because, as soil freezes, an unfrozen film of water is formed between the growing ice lens and the soil particles (Miller et al 1960).…”