Investigating the production of coenzyme F430 variants in methanogenic archaea

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

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Iron corrosion by methanogenic archaea characterized by stable isotope effects and crust mineralogy

Environmental Microbiology ◽

10.1111/1462-2920.15658 ◽

2021 ◽

Author(s):

Marc Tamisier ◽

Matthias Schmidt ◽

Carsten Vogt ◽

Steffen Kümmel ◽

Hryhoriy Stryhanyuk ◽

...

Keyword(s):

Stable Isotope ◽

Isotope Effects ◽

Methanogenic Archaea ◽

Iron Corrosion

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Oral Iron Supplementation—Gastrointestinal Side Effects and the Impact on the Gut Microbiota

Microbiology Research ◽

10.3390/microbiolres12020033 ◽

2021 ◽

Vol 12 (2) ◽

pp. 491-502

Author(s):

Sarah R. Bloor ◽

Rudolph Schutte ◽

Anthony R. Hobson

Keyword(s):

Side Effects ◽

Gut Microbiota ◽

Iron Supplementation ◽

Methanogenic Archaea ◽

Intravenous Iron ◽

Oral Iron ◽

Intestinal Lumen ◽

Gastrointestinal Side Effects ◽

Potential Link ◽

The Impact

Iron deficiency anaemia (IDA) is a worldwide healthcare problem affecting approximately 25% of the global population. The most common IDA treatment is oral iron supplementation, which has been associated with gastrointestinal (GI) side effects such as constipation and bloating. These can result in treatment non-adherence and the persistence of IDA. Intravenous iron does not cause GI side effects, which may be due to the lack of exposure to the intestinal lumen. Luminal iron can cause changes to the gut microbiota, aiding the promotion of pathogenic species and decreasing beneficial protective species. Iron is vital for methanogenic archaea, which rely on iron for growth and metabolism. Increased intestinal methane has been associated with slowing of intestinal transit, constipation, and bloating. Here we explore the literature to understand a potential link between iron and methanogenesis as a novel way to understand the mechanism of oral iron supplementation induced GI side effects.

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