Microbial Responses to Different Operating Practices for Biogas Production Systems

Abstract

Biogas production requires a number of different microbial groups that work in a synchronized and closely interacting manner. For bioreactors constructed to maximize waste treatment and energy production, it is crucial to manage this process in a way that secures the growth and activity of these microorganisms, as otherwise there is a great risk of process failure. However, the microbiome has a remarkable ability to adapt to various conditions related to substrate composition and operating conditions, thus showing high functional redundancy and robustness. In order to optimize and steer the process, it is important to have an understanding of the anaerobic microbiome, how it responds to various conditions, and its upper limits. This chapter reviews current knowledge regarding microbial responses to different operational management strategies. Microbial responses under various conditions and how the process can be operated to maintain the activity of key species are addressed. Parameters discussed include for example substrate composition, pretreatment, ammonia level, temperature and organic load.

Impact of process temperature and organic loading rate on cellulolytic / hydrolytic biofilm microbiomes during biomethanation of ryegrass silage revealed by genome-centered metagenomics and metatranscriptomics

“…Apart from fermentative bacteria, the order Thermoanaerobacteriales, including several known syntrophic acetate-oxidizing bacteria e.g., Caldanaerobacter and Alkaliphilius, was shown to increase [32]. The methanogenic archaeal community mainly consisted of members of the genera Methanosarcina [33][34][35]. The Methanobacteria, Methanomicrobiales, and/or Methanomassiliicoccaceae members were also observed in certain AD-processes featuring a high organic load, depending on other prevailing conditions [36].…”

Acetate and Lactate Production During Two-Stage Anaerobic Digestion of Food Waste Driven by Lactobacillus and Aeriscardovia

“…Moreover, Bacteroides was enriched in M1 and Defluviitoga was enriched in M2. Both these genera are known to degrade both smaller and more complex carbohydrates (Maus et al, 2015;Westerholm and Schnürer, 2019). Defluviitoga has previously been observed in both one-stage and two-stage processes, but its occurrence in the present study was somewhat unexpected as, to our knowledge, this genus has so far only been observed in thermophilic conditions (Giuliano et al, 2014;Fontana et al, 2018).…”

Identification and cultivation of hydrogenotrophic methanogens from palm oil mill effluent for high methane production

“…[30][31][32]60 The uncultured proteiniborus detected in this study might be related to P. ethanoligenes and P. indolifex, which had been found in the thermophilic biogas reactor. 33,61 However, the involvement of uncultured clostridium in biogas production has not been reported. The relative proportion of uncultured bacterium accounted for more than 33.35% of bacterial species ( Figure 4).…”