Effect of Heavy Metal Contamination on Soil Enzymes Activities

Abstract

Several enzymes catalyze much of the processes that exist in the soil. Enzymes in polluted soils are usually less active due to their exposure to heavy metals. The main goal of this study was to see how bioavailable types of Cd affected the behavior of catalase, urease, and dehydrogenases, as well as to compare the findings from naturally and artificially polluted samples. An experiment was conducted on two types of farmland (garden) soil: natural soil and soil that had been chemically polluted with Cd. The total content of heavy metal graded these soils as very highly polluted with Cd. The experiment was repeated four times to test the effects of increasing concentration and days (time). Extracellular enzymes from farmland performed enzymatic activity tests that lasted 6 to 29 days after soil sampling. After 0, 5, 10, 20, 30, and 45 days of incubation, soil samples were taken for testing respectively. However, even though no nutrient was added, dehydrogenase and urease activity increased as Cd concentration increased from 0 to 5 mg/L as the days passed. This is a result of enzymes engaging in respiratory and other living activities because of the low cadmium concentration and respiratory soil properties. However, there were significant variations in enzyme activity between naturally polluted and artificially contaminated soils. Dehydrogenases, Urease, and Catalase all showed a common pattern of enzyme sensitivity, which could be ordered as Dehydrogenase > Urease > Catalase. Dehydrogenase enzyme activity has been discovered to be more Cd resistant.

Altered activities of extracellular soil enzymes by the interacting global environmental changes

“…Their effects vary depending on their shape, which affects the way they physically interact with the soil particles (Lehmann et al, 2020), and on their chemical composition (Pathan et al, 2020). The effects of microplastics can also be indirect, for are persistent organic pollutants (Begum et al, 2021), pharmaceutical and cosmetic products (Yu et al, 2020), heavy metals (Yeboah et al, 2021), pesticides, and herbicides (Riah et al, 2014), which reduce their production, activity, and diversity.…”

“…Some studies show negative impacts of nanoplastics on functional diversity of soil microbes and enzymes (e.g., Awet et al, 2018; Yu et al, 2020) but having this issue recently arisen, further investigation is needed. Other contaminants connected to global change impacting soil enzymes are persistent organic pollutants (Begum et al, 2021), pharmaceutical and cosmetic products (Yu et al, 2020), heavy metals (Yeboah et al, 2021), pesticides, and herbicides (Riah et al, 2014), which reduce their production, activity, and diversity.…”

Effects of Clay Minerals on Enzyme Activity as a Potential Biosensor of Soil Pollution in Alice Township

“…They reported a decrease in enzymatic activity, which is associated with a high concentration of metals in the soil. Additionally, the evaluated enzymes in the soil responded differently to increased levels of heavy metals [26].…”

A Thermostable Lipase Isolated from Brevibacillus thermoruber Strain 7 Degrades Ɛ-Polycaprolactone

“…The enzyme from strain 7 demonstrated a high sensitivity to Fe 3+ , detergents, and inhibitors. Inhibition of the enzyme activity by transition and heavy metal ions was suggested to be a result of the formation of a complex with the reactive groups of the enzymes, denaturing the enzyme protein [ 36 , 37 ]. The inhibitory effect of detergents such as SDS, Tween 20 and DTT was suggested to be a result of the decreased surface tension of aqueous systems and possible modification of the enzyme distribution between the lipid surface and the aqueous phase [ 36 , 38 ].…”