Authors: Ayrat M Ziganshin Thomas Schmidt Frank Scholwin Olga N Il’inskaya Hauke Harms Sabine Kleinsteuber
Publish Date: 2010/11/09
Volume: 89, Issue: 6, Pages: 2039-2052
Abstract
Cereal distillers grains a byproduct from bioethanol industry proved to be a suitable feedstock for biogas production in laboratory scale anaerobic digesters Five continuously stirred tank reactors were run under constant conditions and monitored for biogas production and composition along with other process parameters Iron additives for sulfide precipitation significantly improved the process stability and efficiency whereas aerobic pretreatment of the grains had no effect The microbial communities in the reactors were investigated for their phylogenetic composition by terminal restriction fragment length polymorphism analysis and sequencing of 16S rRNA genes The bacterial subcommunities were highly diverse and their composition did not show any correlation with reactor performance The dominant phylotypes were affiliated to the Bacteroidetes The archaeal subcommunities were less diverse and correlated with the reactor performance The wellperforming reactors operated at lower organic loading rates and amended with iron chloride were dominated by aceticlastic methanogens of the genus Methanosaeta The wellperforming reactor operated at a high organic loading rate and supplemented with iron hydroxide was dominated by Methanosarcina ssp The reactor without iron additives was characterized by propionate and acetate accumulation and high hydrogen sulfide content and was dominated by hydrogenotrophic methanogens of the genus MethanoculleusThis work was partially supported by a grant “Alğarış” from the Republic of Tatarstan Russia and a program “Development of Scientific Potential of High School” project № 8159 Russia to Ayrat Ziganshin We gratefully acknowledge Ute Lohse for technical assistance and the helpful comments and suggestions of Jan Postel
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