title: Syringe test screening of microbial gas production activity: Cases denitrification and biogas formation.
abstract: Mass produced plastic syringes may be applied as vessels for cheap, simple and large scale batch culture testing. As illustrated for the cases of denitrification and of biogas formation, metabolic activity was monitored by direct reading of the piston movement due to the gas volume formed. Pressure buildup due to friction was shown to be moderate. A piston pull and slide back routine can be applied before recording gas volume to minimize experimental errors due to friction. Inoculum handling and activity may be conveniently standardized as illustrated by applying biofilm carriers. A robust set of positive as well as negative controls ("blanks") should be included to ensure quality of the actual testing. The denitrification test showed saturation response at increasing amounts of inoculum in the form of adapted moving bed biofilm reactor (MBBR) carriers, with well correlated nitrate consumption vs. gas volume formed. As shown, the denitrification test efficiently screened different inocula at standardized substrates. Also, different substrates were successfully screened and compared at standardized inocula. The biogas potential test showed efficient screening of different substrates with effects of relative amounts of carbohydrate, protein, fat. A second case with CO2capture reclaimer waste as substrate demonstrated successful use of co-feeding to support waste treatment and how temperature effects on kinetics and stoichiometry can be observed. In total, syringe test screening of microbial gas production seems highly efficient at a low cost when properly applied.
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, NO 7491 Trondheim, Norway. Electronic address: ostgaard@ntnu.no.
authors.forename: Kjetill
authors.initials: K
authors.lastname: Østgaard
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, NO 7491 Trondheim, Norway.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Kowarz
authors.affiliation: Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Kjølnes Ring 56, NO 3918 Porsgrunn, Norway.
authors.forename: Wang
authors.initials: W
authors.lastname: Shuai
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, NO 7491 Trondheim, Norway.
authors.forename: Ingrid A
authors.initials: IA
authors.lastname: Henry
authors.affiliation: Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Kjølnes Ring 56, NO 3918 Porsgrunn, Norway.
authors.forename: Michal
authors.initials: M
authors.lastname: Sposob
authors.affiliation: Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Kjølnes Ring 56, NO 3918 Porsgrunn, Norway.
authors.forename: Hildegunn Hegna
authors.initials: HH
authors.lastname: Haugen
authors.affiliation: Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Kjølnes Ring 56, NO 3918 Porsgrunn, Norway.
authors.forename: Rune
authors.initials: R
authors.lastname: Bakke
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D002241:Carbohydrates / Q000032:analysis; D003470:Culture Media / Q000737:chemistry; D058440:Denitrification; D005223:Fats / Q000032:analysis; D009566:Nitrates / Q000378:metabolism; D011506:Proteins / Q000032:analysis; D013594:Syringes
chemical_list: D056804:Biofuels; D002241:Carbohydrates; D003470:Culture Media; D005223:Fats; D009566:Nitrates; D011506:Proteins
keywords: Biodegradation; Biogas formation; Denitrification; Screening test; Syringe test