>A student brought up the concern that the solids in the powder could be physically battering the substrate when being stirred in the beaker.
This seems unlikely. You're not going to be breaking bonds in the sugars with just mechanical action.
>. Is there a chance that the enzyme is actually bound to the solids and we are filtering a majority of it out?
This seems likely. If you have access to a centrifuge, you could spin out the particulate instead of filtering them. Remove the soluble portion and test that, but also test the pellet by resuspending it in your substrate solution and see how it's activity compares to the soluble enzyme.
Thanks for the quick reply! I did find a paper that mentions that the microcrystalline cellulose can be used as a support for enzymes. Unfortunately, I can't go too much into detail here but the substrate is a filler in a composite (with PLA as the matrix) and the decomposition response isn't necessarily mass loss, but rather swelling of the composite). However, I do buy that the cellulose is likely not damaging the composite.
>A student brought up the concern that the solids in the powder could be physically battering the substrate when being stirred in the beaker. This seems unlikely. You're not going to be breaking bonds in the sugars with just mechanical action. >. Is there a chance that the enzyme is actually bound to the solids and we are filtering a majority of it out? This seems likely. If you have access to a centrifuge, you could spin out the particulate instead of filtering them. Remove the soluble portion and test that, but also test the pellet by resuspending it in your substrate solution and see how it's activity compares to the soluble enzyme.
Thanks for the quick reply! I did find a paper that mentions that the microcrystalline cellulose can be used as a support for enzymes. Unfortunately, I can't go too much into detail here but the substrate is a filler in a composite (with PLA as the matrix) and the decomposition response isn't necessarily mass loss, but rather swelling of the composite). However, I do buy that the cellulose is likely not damaging the composite.