title: Software sensors for fermentation processes.
abstract: Four software sensors based on standard on-line data from fermentation processes and simple mathematical models were used to monitor a number of state variables in Escherichia coli fed-batch processes: the biomass concentration, the specific growth rate, the oxygen transfer capacity of the bioreactor, and the new R(O/S) sensor which is the ratio between oxygen and energy substrate consumption. The R(O/S) variable grows continuously in a fed-batch culture with constant glucose feed, which reflects the increasing maintenance demand at declining specific growth rate. The R(O/S) sensor also responded to rapid pH shift-downs reflecting the increasing demand for maintenance energy. It is suggested that this sensor may be used to monitor the extent of physiological stress that demands energy for survival.
authors.affiliation: School of Biotechnology, Royal Institute of Technology, Roslagstullsbacken 21, 10691, Stockholm, Sweden. helenes@kth.se
authors.forename: Heléne
authors.initials: H
authors.lastname: Sundström
authors.forename: Sven-Olof
authors.initials: SO
authors.lastname: Enfors
mesh_terms: D000465:Algorithms; D019149:Bioreactors / Q000382:microbiology*; D049109:Cell Proliferation; D003198:Computer Simulation; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005285:Fermentation; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D012984:Software
chemical_list: D029968:Escherichia coli Proteins; D010100:Oxygen