Integrating independent microbial studies to build predictive models of anaerobic digestion inhibition by ammonia and phenol

Abstract

Anaerobic digestion (AD) is a microbial process that can efficiently degrade organic waste into renewable energies such as methane-rich biogas. However, the underpinning microbial mechanisms are highly vulnerable to a wide range of inhibitory compounds, leading to process failure and economic losses. High-throughput sequencing technologies enable the identification of microbial indicators of digesters inhibition and can provide new insights into the key phylotypes at stake during AD process. But yet, current studies have used different inocula, substrates, geographical sites and types of reactors, resulting in indicators that are not robust or reproducible across independent studies. In addition, such studies focus on the identification of a single microbial indicator that is not reflective of the complexity of AD.Our study proposes the first analysis of its kind that seeks for a robust signature of microbial indicators of phenol and ammonia inhibitions, whilst leveraging on 4 independent in-house and external AD microbial studies. We applied a recent multivariate integrative method on two-in-house studies to identify such signature, then predicted the inhibitory status of samples from two datasets with more than 90% accuracy. Our study demonstrates how we can efficiently analyze existing studies to extract robust microbial community patterns, predict AD inhibition, and deepen our understanding of AD towards better AD microbial management.

Microbiological Surveillance of Biogas Plants: Targeting Acetogenic Community

“…During the VFA accumulation phase in C1-DD1, a decrease in RA of phylum Candidatus Clocimonetes was also observed. Disappearance of this phylum is suggested to be an indicator of disturbance (Calusinska et al, 2018;Klang et al, 2019;Poirier et al, 2020;Singh et al, 2021a), which is further supported by the results in this study. In the present analysis, it was observed that not all species belonging to this phylum were present in all types of reactors.…”

Profiling acetogenic community dynamics in anaerobic digesters - comparative analyses using next-generation sequencing and T-RFLP

“…S9C, S9D). Since phylum Cloacimonadota has been proposed as an indicator taxon pertaining to reactor disturbances (Calusinska et al 2018; Klang et al 2019; Poirier et al 2020), its correct profiling is very important. Fluctuations (near-disappearance) in RA of the phylum Cloacimonadota and class Cloacimonadia were observed in the control reactor profile of 16S-community (Supp.…”

“…Candidatus Cloacimonetes was found to be highly reduced during the disturbance phase. It has previously been reported to be present in high abundance in high-ammonia systems and is suggested to have a specialist function (syntrophic propionate-oxidation) (Müller et al 2016; Poirier et al 2020) and to be a potential acetogenic candidate (Pelletier et al 2008; Juste-Poinapen et al 2015; Lucas et al 2015; Nobu et al 2015; Ahlert et al 2016; Stolze et al 2018, 2016; Calusinska et al 2018; Nazina et al 2018; Braz et al 2019; Klang et al 2019). In line with the results in the present study, a decrease abundance in the phylum Cloacimonetes in association with process disturbance has been seen previously (Klang et al 2019).…”

Triangulation of microbial fingerprinting in anaerobic digestion reveals consistent fingerprinting profiles

“…Subsequently, we have to define safe operation borders for these panels by extensive experiments and modelling, before providing them to AD operators. For example, biogas production and process stability can be monitored based on the abundance of methanogens and their enzymes (Heyer et al, 2013;Munk et al, 2012), and a multivariate integrative method, based on a microbial signature of AD inhibition by ammonia and phenol could be used to predict ammonia inhibition (Poirier et al, 2020). On-demand, the complexity of these panels could be extended.…”