title: Methanogenic community changes, and emissions of methane and other gases, during storage of acidified and untreated pig slurry.
abstract: OBJECTIVE
  Acidification with concentrated H(2)SO(4) is a novel strategy to reduce NH(3) emissions from livestock slurry. It was recently found that also CH(4) emissions from acidified slurry are reduced. This study investigated the microbiological basis and temporal stability of these effects.
  
  
  RESULTS
  Pig slurry from two farms, acidified by different techniques or untreated, was stored for 83 days in a pilot-scale facility. Methanogens were characterized before and after storage by T-RFLP and qPCR targeting mcrA. Emissions of NH(3) and CH(4) during storage were quantified. Acidified slurry pH was nearly constant at values of 5·5 and 6·5. Ammonia losses were reduced by 84 and 49%, respectively, while CH(4) emission with both acidification techniques was reduced by >90%. T-RFLP fingerprints showed little effect of acidification or storage time. A major T-RF of 105 bp could represent methanogens related to Thermoplasmata (Tp). No treatment effects on gene copy numbers were seen with universal methanogen primers, whereas effects were found with Tp-specific primers.
  
  
  CONCLUSIONS
  Methane emissions were reduced >90% during storage. Thermoplasmata-related methanogens could be involved in CH(4) emissions from pig slurry.
  
  
  CONCLUSIONS
  The effect of acidification on CH(4) emissions during storage of pig slurry was quantified for the first time. Acidification with sulphuric acid holds promise as a novel greenhouse gas mitigation strategy for confined livestock production.
authors.affiliation: Department of Agroecology, Aarhus University, Tjele, Denmark.
authors.forename: S O
authors.initials: SO
authors.lastname: Petersen
authors.forename: O
authors.initials: O
authors.lastname: Højberg
authors.forename: M
authors.initials: M
authors.lastname: Poulsen
authors.forename: C
authors.initials: C
authors.lastname: Schwab
authors.forename: J
authors.initials: J
authors.lastname: Eriksen
mesh_terms: D000393:Air Pollutants / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000641:Ammonia / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D019605:Euryarchaeota / Q000235:genetics* / Q000378:metabolism; D018628:Gene Dosage; D019766:Genes, Archaeal; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008462:Meat-Packing Industry; D008697:Methane / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D013464:Sulfuric Acids / Q000737:chemistry*; D013552:Swine; D014866:Waste Products
chemical_list: D000393:Air Pollutants; D013464:Sulfuric Acids; D014866:Waste Products; D000641:Ammonia; C033158:sulfuric acid; D008697:Methane
keywords: T-RFLP; Thermoplasmata; ammonia; methane; qPCR; slurry acidification