title: Influence of alternating oxic/anoxic conditions on growth of denitrifying bacteria.
abstract: Denitrifying bacteria that are switched from oxic to anoxic conditions can experience diauxic lag, which is the time required for re-synthesis of nitrate reductase and other denitrifying enzymes. Pseudomonas denitrificans were exposed to alternating oxic/anoxic phases in a continuous flow reactor with either 4-h or 8-h anoxic phase lengths, in comparison to a measured diauxic lag of 9.5h following steady-state oxic conditions. The P. denitrificans were unable to sustain anoxic growth at either of the anoxic phase lengths tested. Diauxic lag observed after several cycles of alternating oxic/anoxic phases was significantly longer than the diauxic lag measured after steady-state oxic conditions. This may be attributed to increase of cell maintenance energy requirements due to substrate accumulation during anoxic phases and concomitant high specific growth rates during oxic phases.
authors.affiliation: Jones Edmunds, Gainesville, FL 32606, USA. dulee@jonesedmunds.com
authors.forename: Dong-Uk
authors.initials: DU
authors.lastname: Lee
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Woo
authors.forename: Spyros
authors.initials: S
authors.lastname: Svoronos
authors.forename: Ben
authors.initials: B
authors.lastname: Koopman
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D003198:Computer Simulation; D004734:Energy Metabolism; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000032:analysis; D011549:Pseudomonas / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism; D013997:Time Factors
chemical_list: D009566:Nitrates; D009573:Nitrites