title: Calorespirometric feeding control enhances bioproduction from toxic feedstocks-Demonstration for biopolymer production out of methanol.
abstract: The sustainable production of fuels and industrial bulk chemicals by microorganisms in biotechnological processes is promising but still facing various challenges. In particular, toxic substrates require an efficient process control strategy. Methanol, as an example, has the potential to become a major future feedstock due to its availability from fossil and renewable resources. However, besides being toxic, methanol is highly volatile. To optimize its dosage during microbial cultivations, an innovative, predictive process control strategy based on calorespirometry, i.e., simultaneous measurements of heat and CO2 emission rates, was developed. This rarely used technique allows an online-estimation of growth parameters such as the specific growth rate and substrate consumption rate as well as a detection of shifts in microbial metabolism thus enabling an adapted feeding for different phases of growth. The calorespirometric control strategy is demonstrated exemplarily for growth of the methylotrophic bacterium Methylobacterium extorquens on methanol and compared to alternative control strategies. Applying the new approach, the methanol concentration could be maintained far below a critical limit, while increased growth rates of M. extorquens and higher final contents of the biopolymer polyhydroxybutyrate were obtained. Biotechnol. Bioeng. 2016;113: 2113-2121. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Maria-Teresa
authors.initials: MT
authors.lastname: Rohde
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Paufler
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Hauke
authors.initials: H
authors.lastname: Harms
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany. thomas.maskow@ufz.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Maskow
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D002153:Calorimetry, Indirect / Q000379:methods*; D049109:Cell Proliferation / Q000502:physiology; D003198:Computer Simulation; D025461:Feedback, Physiological / Q000502:physiology; D006885:Hydroxybutyrates / Q000302:isolation & purification / Q000378:metabolism*; D000432:Methanol / Q000378:metabolism*; D020601:Methylobacterium extorquens / Q000502:physiology*; D008954:Models, Biological
chemical_list: D001427:Bacterial Toxins; D006885:Hydroxybutyrates; D000432:Methanol
keywords: Methylobacterium extorquens; biocalorimetry; methylotrophy; process control; respirometry