UG Summer Placement 2026 - University of Bristol

The extracellular enzymes secreted by soil microorganisms play a crucial role in the decomposition of organic matter in topsoil (around 0-15 cm deep) and thus in the carbon, nitrogen, phosphorous and sulphur cycles. The presence and activity of these enzymes is an important indicator of the fertility of the soil and can inform the efficacy of remedial actions, assess the effects of overuse of chemical fertilisers and on general soil health. Their response to external changes like temperature, moisture, soil pH and substrate availability makes them also a good source of information to predict the resilience of the soil to land use and climate change perturbations, such as flooding and drought, amongst others.

We will be focusing on β-glucosidase (takes part in the degradation of cellulose by breaking down cellobiose and other oligosaccharides into glucose), arylsulfatase (breaks organic sulphur into bioavailable sulphate), N-acetyl-β-glucosaminidase (breaks down chitin and peptidoglycans in soil releasing both usable C and N) and phosphomonoesterease (breaks down organic phosphorous into bioavailable phosphate).

The enzymatic activity of each of them will be measured by incubating soil samples with a suitable substrate for the enzyme and quantifying the p-nitrophenol released.