This manuscript presents a rigorous analysis of two contrasting formulations to simulating soil organic matter decomposition, based on Michaelis Menten and reverse Michaelis Menten kinetics. No consensus exists in the literature for which approach, if either, is most appropriate to represent the complexity of substrate-enzyme dynamics involved with transformation of plant biomass to litter to soil organic matter by soil microbes. However, the authors have justified the scope of their analysis based on several important, recently published empirical and theoretical papers, along with a few key older references. The main result demonstrates that the choice of mathematical formulation underlying the model can influence whether or not carbon is stored in soils in a scenario of a warming climate, with altered substrate inputs. The discussion paper and the expert reviews have made a useful contribution to the literature on soil carbon cycle modelling, and the revised manuscript should be publishable following a few technical corrections.
My main recommendation is to briefly introduce the importance of the concept of oscillatory behaviour in response to a model perturbation in diagnosing the nonlinear dynamics of the models. This should also help inform readers that the manuscript builds on the more detailed analysis in Wang et al., 2014 (Biogeosciences, 11, 1817–1831). Currently this concept is first introduced in the beginning of the results section, but adding one or two sentences toward the end of the introduction section would set up this objective better.

Detailed comments (line numbers based on bgd-12-C8258-2015-supplement.pdf)
Title: Consider changing to “Responses of two nonlinear microbial models to warming *and* increased carbon input”
L 169: typo in citation (should be Weintraub). Also please double-check for other citation typos (Kuzyakov, Kuzyakova, etc).
L 193-195: please change to “decomposition is assumed to depend non-linearly on.... and to depend linearly on...”
L 283: differences
L 393: please double-check citations
L 483: varies nonlinearly
L 587: taxa (not taxam)
L 608: shorter

Thank you for your careful attention to the details and for improving the manuscript in response to the referees' insightful comments throughout the review process. The manuscript is now ready for publication.