Clay minerals are ubiquitous on epigeosphere, especially in soils and sediments where microbes thrive.The clay-microbe interactions are common in these geological media and greatly contribute to accelerating the mineral transformation process, e.g.the illitization of nontronite (a Fe-rich smectite) catalyzed by microbes under anoxic atmosphere in 2 weeks.However, few has considered montmorillonite, a Fe-poor smectite more typical in natural environments than nontronite.This study therefore focuses on the interaction between montmorillonite and bacteria under conditions relevant to those in natural soils and sediments.