Crab shell amendments enhance the abundance and diversity of key microbial groups in sulfate-reducing columns treating acid mine drainage.

Substrate amendments composed of crab shell (CS) waste materials have been shown to significantly improve the longevity and performance of acid mine drainage (AMD) treatment systems containing spent mushroom compost (SMC), yet the development of key microbial populations within these systems has not been investigated. To better understand the effects of CS on microbial dynamics in these systems, clone libraries and real-time quantitative PCR (qPCR) were performed on materials from a laboratory-scale AMD treatment system containing SMC and 0 to 100% CS substrate after receiving a continuous flow of AMD for 148 days (428 pore volumes). The proportion of CS in the substrate positively correlated with the diversity of sulfate-reducing bacteria (SRB) and archaeal clones, but negatively correlated with fungal diversity.