title: Model development and experimental validation of capnophilic lactic fermentation and hydrogen synthesis by Thermotoga neapolitana.
abstract: The aim of the present study was to develop a kinetic model for a recently proposed unique and novel metabolic process called capnophilic (CO2-requiring) lactic fermentation (CLF) pathway in Thermotoga neapolitana. The model was based on Monod kinetics and the mathematical expressions were developed to enable the simulation of biomass growth, substrate consumption and product formation. The calibrated kinetic parameters such as maximum specific uptake rate (k), semi-saturation constant (kS), biomass yield coefficient (Y) and endogenous decay rate (kd) were 1.30 h(-1), 1.42 g/L, 0.1195 and 0.0205 h(-1), respectively. A high correlation (>0.98) was obtained between the experimental data and model predictions for both model validation and cross validation processes. An increase of the lactate production in the range of 40-80% was obtained through CLF pathway compared to the classic dark fermentation model. The proposed kinetic model is the first mechanistically based model for the CLF pathway. This model provides useful information to improve the knowledge about how acetate and CO2 are recycled back by Thermotoga neapolitana to produce lactate without compromising the overall hydrogen yield.
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio, 43, 03043, Cassino, FR, Italy; Institute of Biomolecular Chemistry, Italian National Council of Research, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli, Italy; Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio, 21, 80125, Naples, Italy. Electronic address: nirakar.pradhan@gmail.com.
authors.forename: Nirakar
authors.initials: N
authors.lastname: Pradhan
authors.affiliation: Institute of Biomolecular Chemistry, Italian National Council of Research, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli, Italy. Electronic address: ldipasquale@icb.cnr.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Dipasquale
authors.affiliation: Institute of Biomolecular Chemistry, Italian National Council of Research, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli, Italy. Electronic address: gdippolito@icb.cnr.it.
authors.forename: Giuliana
authors.initials: G
authors.lastname: d'Ippolito
authors.affiliation: Institute of Biomolecular Chemistry, Italian National Council of Research, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli, Italy. Electronic address: afontana@icb.cnr.it.
authors.forename: Angelo
authors.initials: A
authors.lastname: Fontana
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio, 21, 80125, Naples, Italy. Electronic address: anpanico@unina.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Panico
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio, 21, 80125, Naples, Italy. Electronic address: francesco.pirozzi@unina.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Pirozzi
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611-AX, Delft, The Netherlands. Electronic address: p.lens@unesco-ihe.org.
authors.forename: Piet N L
authors.initials: PNL
authors.lastname: Lens
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio, 43, 03043, Cassino, FR, Italy. Electronic address: giovanni.esposito@unicas.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
mesh_terms: D018533:Biomass; D019149:Bioreactors; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D046949:Thermotoga neapolitana
chemical_list: D019344:Lactic Acid; D006859:Hydrogen
keywords: Calibration; Capnophilic lactic fermentation; Hydrogen; Kinetic model; Sensitivity analysis; Validation