Microbial community dynamics reflect reactor stability during the anaerobic digestion of a very high strength and sulfate-rich vinasse
Janet Jiménez (University of Sancti Spíritus)
Ernesto L. Barrera (University of Sancti Spíritus)
Jo De Vrieze (Universiteit Gent)
Nico Boon (Universiteit Gent)
Steven DeMeester (Universiteit Gent)
H Spanjers (TU Delft - Sanitary Engineering)
Osvaldo Romero (University of Sancti Spíritus)
Jo Dewulf (Universiteit Gent)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
BACKGROUND: Microbial community dynamics during the anaerobic digestion of vinasse has been little studied. However, having knowledge about it is essential for early detection of reactor operational difficulties to apply preventive actions. This research studies the microbial community dynamics in the anaerobic digestion of vinasse, linking to experimental observations about product yields and organic matter degradation. RESULTS: Methane and sulfide yields decreased with increasing SO4 2-/COD ratio, while the fraction of organic matter degraded by sulfate reducing bacteria increased from 4.5 ± 0.3% to 27.1 ± 0.6%. The archaeal community showed that acetoclastic Methanosaetaceae were little affected by the increase of the SO4 2-/COD ratio, in contrast to the Methanomicrobiales and Methanobacteriales population, which decreased during the experiment. The total bacterial diversity was influenced mainly by substrate composition, showing that the increase of the SO4 2-/COD ratio above 0.10 shifted the bacterial community to a lower richness. CONCLUSION: These results provide knowledge on the dynamics of the microbial communities, which can be useful to control the anaerobic digestion of sulfate-rich vinasses, showing that reactor stability equates to the higher ratios between total methanogens and total bacteria gene copy numbers, whereas operational difficulties can be associated to lower bacterial richness and higher community organization.