The pH optimum of soil exoenzymes adapt to long term changes in soil pH

Publication date: Available online 16 September 2019Source: Soil Biology and BiochemistryAuthor(s): Jérémy Puissant, Briony Jones, Tim Goodall, Dana Mang, Aimeric Blaud, Hyun Soon Gweon, Ashish Malik, Davey L. Jones, Ian M. Clark, Penny R. Hirsch, Robert GriffithsAbstractSoil exoenzymes released by microorganisms break down organic matter and are crucial in regulating C, N and P cycling. Soil pH is known to influence enzyme activity, and is also a strong driver of microbial community composition; but little is known about how alterations in soil pH affect enzymatic activity and how this is mediated by microbial communities. To assess long term enzymatic adaptation to soil pH, we conducted enzyme assays at buffered pH levels on two historically managed soils maintained at either pH 5 or 7 from the Rothamsted Park Grass Long-term experiment. The pH optima for a range of exoenzymes involved in C, N, P cycling, differed between the two soils, the direction of the shift being toward the source soil pH, indicating the production of pH adapted isoenzymes by the soil microbial community. Soil bacterial and fungal communities determined by amplicon sequencing were clearly distinct between pH 5 and soil pH 7 soils, possibly explaining differences in enzymatic responses. Furthermore, β-glucosidase gene sequences extracted from metagenomes revealed an increased abundance of Acidobacterial producers in the pH 5 soils, and Actinobacteria in pH 7 soils. Our findings demonstrate that the ...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research