title: Model based optimization of high cell density cultivation of nitrogen-fixing cyanobacteria.
abstract: In the present study, fed-batch cultivation of Cyanothece sp. ATCC 51142, a known hydrogen producer, was optimized for maximizing biomass production. Decline in growth of this organism in dense cultures was attributed to increased substrate consumption for maintenance and respiration, and photolimitation due to self shading. A model incorporating these aspects was developed, and by using control vector parameterization (CVP), substrate feeding recipe was optimized to achieve 12-fold higher biomass concentration. The optimization results were verified experimentally on shake flask and bioreactor. The latter resulted in greater exponential growth rate possibly by overcoming photolimitation by simulating flashing light effect. Such a strategy can be readily applied for mixotrophic cultivation of cyanobacterial cultures in the first stage followed by photoautotrophic growth at the production stage.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
authors.forename: Swathi
authors.initials: S
authors.lastname: Alagesan
authors.forename: Sandeep B
authors.initials: SB
authors.lastname: Gaudana
authors.forename: S
authors.initials: S
authors.lastname: Krishnakumar
authors.forename: Pramod P
authors.initials: PP
authors.lastname: Wangikar
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D000458:Cyanobacteria / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D005990:Glycerol / Q000494:pharmacology; D008027:Light; D008954:Models, Biological; D009566:Nitrates / Q000032:analysis; D009586:Nitrogen Fixation / Q000187:drug effects / Q000528:radiation effects; D014131:Trace Elements / Q000032:analysis
chemical_list: D009566:Nitrates; D014131:Trace Elements; D005990:Glycerol
keywords: Cyanothece; Fed-batch; Feeding strategy; Mixotrophic; Photolimitation