Dynamic variation of the microbial community structure during the long‐time mono‐fermentation of maize and sugar beet silage

Abstract

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 (TRFLP) in combination with a cloning-sequencing approach was applied.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 Bacteroidetes 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 Methanosaeta are highly sensitive against sudden stress situations such as a strong decrease in the ammonium nitrogen (NH4+-N) concentration or a drop of the pH value. In both cases, a functional compensation by members of the genera Methanoculleus and/or Methanosarcina 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.

Description of Proteiniphilum saccharofermentans sp. nov., Petrimonas mucosa sp. nov. and Fermentimonas caenicola gen. nov., sp. nov., isolated from mesophilic laboratory-scale biogas reactors, and emended description of the genus Proteiniphilum

“…The family Porphyromonadaceae within the Bacteroidetes includes many (mostly uncultured) bacteria from different biogas reactors and other methanogenic environments showing close affiliation to Proteiniphilum acetatigenes and Petrimonas sulfuriphila (Kampmann et al, 2012(Kampmann et al, , 2014Klang et al, 2015;Krause et al, 2008;Li et al, 2009;Liu et al, 2009;Theuerl et al, 2015;Zakrzewski et al, 2012). Several of these bacteria formed clusters with three strains that we isolated from laboratory-scale biogas reactors.…”

Stochasticity in microbiology: managing unpredictability to reach the Sustainable Development Goals

“…Benchmarking of microbial community dynamics is essential to distinguish between a system with acceptable background dynamics, as observed in anaerobic digestion (Klang et al , 2015) and activated sludge (Mielczarek et al , 2012; Mielczarek et al , 2013; Ju and Zhang, 2015) systems, and uncontrollable domination of stochasticity over deterministic effects. Conventional microbial community dynamics at steady state ranges between 20 and 30% change in microbial community composition in a 14‐day window in anaerobic digestion (Pycke et al , 2011; De Vrieze et al , 2016) and activated sludge (Wang et al , 2010) systems.…”

Effect of a Profound Feedstock Change on the Structure and Performance of Biogas Microbiomes

“…The samples were analyzed using the capillary sequencer GenomeLab™ GeXP Genetic Analysis System (AB SCIEX Germany GmbH, Darmstadt, Germany) according to Rademacher et al [25]. The phylogenetic assignment of the recorded terminal restriction fragments (TRFs) was conducted with the sequence library produced in Klang et al [13,14]. Additionally, we used an in-house database, currently containing about 3000 16S rRNA gene sequences from various projects carried out at the Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB) during the last ten years [19].…”

“…The development of the microbial community depends on the available substrates. Different feedstocks with different chemical compositions and bioavailability lead to different microbial communities [11,[13][14][15][16][17][18][19]. Therefore, knowledge of the microbial reaction to different feedstock compositions is highly important in order to avoid process disturbances, and changes in the feedstock composition have to be performed with caution.…”