title: Real-time monitoring and automatic density control of large-scale microalgal cultures using near infrared (NIR) optical density sensors.
abstract: Signals from near infrared (NIR) light transmittance sensors were used for both real-time monitoring of algal biomass density in growing mass cultures (200l tubular biofences), and also as feedback in a system that controlled the density of the culture by automatic injection of fresh growth medium. When operated in a semi-continuous production mode between predefined density values, diurnal growth patterns were recorded on-line that provided information on the dynamics of the microalgal cultures with respect to environmental conditions. The bioreactor system was also programmed to operate in constant biomass density mode, thereby maintaining the culture at the optimal population density (OPD), and sustaining high biomass production levels. The system has potential for operating a dynamic density set point for microalgal cultures where the optimal population density varies as a function of ambient growing conditions.
authors.affiliation: Norwegian University of Life Sciences (UMB), Department of Plant and Environmental Sciences, P.B. 5003, 1432 As, Norway. joanna.sandnes@umb.no
authors.forename: J M
authors.initials: JM
authors.lastname: Sandnes
authors.forename: T
authors.initials: T
authors.lastname: Ringstad
authors.forename: D
authors.initials: D
authors.lastname: Wenner
authors.forename: P H
authors.initials: PH
authors.lastname: Heyerdahl
authors.forename: T
authors.initials: T
authors.lastname: Källqvist
authors.forename: H R
authors.initials: HR
authors.lastname: Gislerød
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D018929:Cell Culture Techniques; D056890:Eukaryota / Q000254:growth & development*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors