Improving anaerobic digestion with support media: Mitigation of ammonia inhibition and effect on microbial communities

[Display omitted] •10g/L of zeolite or of activated carbon mitigated inhibition caused by 19g/L of TAN.•Zeolite preserved Methanosarcina and reduced CH4 production lag phase (λCH4) by 47%.•Activated carbon enhanced Methanoculleus emergence and reduced λCH4 by 22%.•Under non-inhibiting conditions, support media did not influence AD microbiota. This study aimed at providing a better understanding of the influence of support media (10g/L of zeolites, 10g/L of activated carbons, and 1g/L of chitosan) on key phylotypes steering anaerobic digestion (AD) performance in presence of 19g/L of Total Ammonia Nitrogen (TAN) within batch digesters. Support media did not influence TAN concentration. However, both zeolites and activated carbon 1 reduced methanization lag phase by 47% and 25%, respectively. By contrast, activated carbon 2 and chitosan led to an increase of methanization lag phase by 51% and 32%, respectively. 16S rRNA gene sequencing revealed that zeolites preserved Methanosarcina and enhanced Methanobacterium. In presence of activated carbon 1, Methanoculleus, became predominant earlier than without support while chitosan and activated carbon 2 limited its implantation. This study highlighted potentialities to use supports to enhance AD stability under extreme TAN concentration and evidenced their specific influence on the microbiota composition.