The transient nature of humic substances: changes in their molecular composition during stimulated microbial composting and Agaricus bisporus growth

Abstract The substrate production process for the edible mushroom Agaricus bisporus offers a controlled model environment to investigate organic matter transformation. Despite the central role of humic substances (HS) in organic matter dynamics, detailed insights into their compositional changes during decomposition are limited. We investigated the formation and transformation of dissolved and solid phase HS during microbial composting and subsequent mycelial growth of A. bisporus . Total carbon