Observations on sulfur transformations and methanogenic pathways in tannic acid-sodium fluoride inhibited and acidified livestock waste

Anaerobic digestion of livestock waste results in emissions of reduced sulfur compounds and methane, which affect nature and the climate. These gas emissions from livestock waste are efficiently mitigated by using a tannic acid-sodium fluoride combination inhibitor (TA-NaF), and to some extent by acidification. In this paper, TA-NaF or acidification treatment was performed on swine and cattle manure to study the treatment influence on methanogenic pathways and sulfur transformation pathways in various laboratory batch experiments. Samples for microbial community analysis were taken at experiment start and after 30 days from various batch reactors. Sulfate reducing bacteria community structure was assessed by PCR amplifying the V3-V4 variable regions of the 16S rRNA gene.