Skip to main content
Research article - Peer-reviewed, 2020

Effect of Cobalt, Nickel, and Selenium/Tungsten Deficiency on Mesophilic Anaerobic Digestion of Chemically Defined Soluble Organic Compounds

Safaric, Luka; Yekta, Sepehr Shakeri; Svensson, Bo H.; Schnurer, Anna; Bastviken, David; Bjorn, Annika

Abstract

Trace elements (TEs) are vital for anaerobic digestion (AD), due to their role as cofactors in many key enzymes. The aim of this study was to evaluate the effects of specific TE deficiencies on mixed microbial communities during AD of soluble polymer-free substrates, thus focusing on AD after hydrolysis. Three mesophilic (37 degrees C) continuous stirred-tank biogas reactors were depleted either of Co, Ni, or a combination of Se and W, respectively, by discontinuing their supplementation. Ni and Se/W depletion led to changes in methane kinetics, linked to progressive volatile fatty acid (VFA) accumulation, eventually resulting in process failure. No significant changes occurred in the Co-depleted reactor, indicating that the amount of Co present in the substrate in absence of supplementation was sufficient to maintain process stability. Archaeal communities remained fairly stable independent of TE concentrations, while bacterial communities gradually changed with VFA accumulation in Ni- and Se-/W-depleted reactors. Despite this, the communities remained relatively similar between these two reactors, suggesting that the major shifts in composition likely occurred due to the accumulating VFAs. Overall, the results indicate that Ni and Se/W depletion primarily lead to slower metabolic activities of methanogenic archaea and their syntrophic partners, which then has a ripple effect throughout the microbial community due to a gradual accumulation of intermediate fermentation products.

Keywords

artificial substrate; biogas; trace elements; micronutrients; volatile fatty acids; kinetics

Published in

Microorganisms
2020, volume: 8, number: 4, article number: 598
Publisher: MDPI

Authors' information

Safaric, Luka
Linkoping Univ
Yekta, Sepehr Shakeri
Linkoping Univ
Svensson, Bo H.
Linkoping Univ
Swedish University of Agricultural Sciences, Department of Molecular Sciences
Linköping University
Bastviken, David
Linkoping Univ
Bjorn, Annika
Linkoping Univ

Associated SLU-program

Food Waste

UKÄ Subject classification

Microbiology

Publication Identifiers

DOI: https://doi.org/10.3390/microorganisms8040598

URI (permanent link to this page)

https://res.slu.se/id/publ/106424