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2 years ago in Enzymology , Soil Science By Shilpa

How can phenoloxidase and peroxidase be measured in alkaline soils?

Standard protocols using L-DOPA and buffers at pH 5-6 are optimized for forest soils. Our arid-land soils have pH >8, and we suspect enzyme activities are being underestimated due to suboptimal assay conditions. Do we need different substrates, buffer systems, or extraction methods to get a true reading of the potential oxidative capacity in these systems?

 

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By Sourabh Answered 1 year ago

This is a common issue in arid and semi-arid systems I've worked in. The key is to match the assay pH to the in situ soil pH to measure the enzyme's actual potential activity in its native environment. I recommend these steps: First, use a buffer like Tris-HCl or CHES that effectively maintains pH 8-8.5 throughout the assay. Second, consider alternative substrates; ABTS is often more reliable than DOPA at high pH. Finally, run a parallel set of assays at the standard acidic pH as a reference this comparative data can be very informative about how pH shapes the microbial community's functional capacity.

 

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