Beschreibung:
<jats:title>Summary</jats:title><jats:p>This study investigated the development of the microbial community during a long‐term (337 days) anaerobic digestion of maize and sugar beet silage, two feedstocks that significantly differ in their chemical composition. For the characterization of the microbial dynamics, the community profiling method terminal restriction fragment length polymorphism (<jats:styled-content style="fixed-case">TRFLP</jats:styled-content>) in combination with a cloning‐sequencing approach was applied.</jats:p><jats:p>Our results revealed a specific adaptation of the microbial community to the supplied feedstocks. Based on the high amount of complex compounds, the anaerobic conversion rate of maize silage was slightly lower compared with the sugar beet silage. It was demonstrated that members from the phylum <jats:styled-content style="fixed-case"><jats:italic>B</jats:italic></jats:styled-content><jats:italic>acteroidetes</jats:italic> are mainly involved in the degradation of low molecular weight substances such as sugar, ethanol and acetate, the main compounds of the sugar beet silage. It was further shown that species of the genus <jats:styled-content style="fixed-case"><jats:italic>M</jats:italic></jats:styled-content><jats:italic>ethanosaeta</jats:italic> are highly sensitive against sudden stress situations such as a strong decrease in the ammonium nitrogen (<jats:styled-content style="fixed-case">NH</jats:styled-content><jats:sub>4</jats:sub><jats:sup>+</jats:sup>‐<jats:styled-content style="fixed-case">N</jats:styled-content>) concentration or a drop of the <jats:styled-content style="fixed-case">pH</jats:styled-content> value. In both cases, a functional compensation by members of the genera <jats:styled-content style="fixed-case"><jats:italic>M</jats:italic></jats:styled-content><jats:italic>ethanoculleus</jats:italic> and/or <jats:styled-content style="fixed-case"><jats:italic>M</jats:italic></jats:styled-content><jats:italic>ethanosarcina</jats:italic> was detected. However, the overall biomass conversion of both feedstocks proceeded efficiently as a steady state between acid production and consumption was recorded, which further resulted in an equal biogas yield.</jats:p>