title: Metabolic analysis of the removal of formic acid by unacclimated activated sludge.
abstract: This paper investigates the removal of formic acid by unacclimated biomass from a municipal activated sludge wastewater treatment plant. The biomass was initially able to remove formic acid, but its removal rate and Oxygen Uptake Rate (OUR) decreased with time, until formic acid removal stopped before the formic acid had been exhausted. Formaldehyde was removed in a similar way, whereas the same biomass was simultaneously able to grow and store PHAs when acetic acid was used as substrate. Batch tests with glycine and (13)C NMR analysis were performed, showing that unacclimated biomass was not able to synthesize all the metabolic intermediates from formic acid alone. At least glycine needed to be externally supplemented, in order to activate the serine synthesis pathway. A small amount of formic acid removal in the absence of growth was also possible through formaldehyde formation and its further conversion to formalin (1,2-formaldehyde dimer), whereas no PHAs were formed.
authors.affiliation: Department of Chemistry, University of Rome La Sapienza, p.le A. Moro 5, 00185 Rome, Italy. carolina.cruzviggi@uniroma1.it
authors.forename: Carolina Cruz
authors.initials: CC
authors.lastname: Viggi
authors.forename: Davide
authors.initials: D
authors.lastname: Dionisi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Miccheli
authors.forename: Mariacristina
authors.initials: M
authors.lastname: Valerio
authors.forename: Mauro
authors.initials: M
authors.lastname: Majone
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D005557:Formaldehyde / Q000032:analysis / Q000378:metabolism; D005561:Formates / Q000032:analysis / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid
chemical_list: D005561:Formates; D012722:Sewage; C030544:formic acid; D005557:Formaldehyde; D019342:Acetic Acid