title: Modeling of exo-inulinase biosynthesis by Kluyveromyces marxianus in fed-batch mode: correlating production kinetics and metabolic heat fluxes.
abstract: A metabolic heat-based model was used for estimating the growth of Kluyveromyces marxianus, and the modified Luedeking-Piret kinetic model was used for describing the inulinase production kinetics. For the first time, a relationship was developed to relate inulinase production kinetics directly to metabolic heat generated, which corroborated well with the experimental data (with R2values of above 0.9). It also demonstrated the predominantly growth-associated nature of the inulinase production with Luedeking-Piret parameters α and β, having values of 0.75 and 0.033, respectively, in the exponential feeding experiment. MATLAB was used for simulating the inulinase production kinetics which demonstrated the model's utility in performing real-time prediction of inulinase concentration with metabolic heat data as input. To validate the model predictions, a biocalorimetric (Bio RC1e) experiment for inulinase production by K. marxianus was performed. The inulinase concentration (IU/mL) values acquired from the model in were validated with the experimental values and the metabolic heat data. This modeling approach enabled the optimization, monitoring, and control of inulinase production process using the real-time biocalorimetric (Bio RC1e) data. Gas chromatography and mass spectrometry analysis were carried out to study the overflow metabolism taking place in K. marxianus inulinase production.
authors.affiliation: Thermochemical Lab, Chemical Engineering Department, Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai, 600020, India.
authors.forename: Leelaram
authors.initials: L
authors.lastname: Santharam
authors.affiliation: Department of Chemical Engineering, Birla Institute of Technology & Science (BITS), Pilani, Rajasthan, 333031, India.
authors.forename: Ashwath Balaje
authors.initials: AB
authors.lastname: Samuthirapandi
authors.affiliation: Thermochemical Lab, Chemical Engineering Department, Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai, 600020, India.
authors.forename: Sivanesh Nanjan
authors.initials: SN
authors.lastname: Easwaran
authors.affiliation: Thermochemical Lab, Chemical Engineering Department, Central Leather Research Institute (CSIR-CLRI), Adyar, Chennai, 600020, India. msuri1@vsnl.com.
authors.forename: Surianarayanan
authors.identifier: http://orcid.org/0000-0001-7046-7042
authors.initials: S
authors.lastname: Mahadevan
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D002151:Calorimetry / Q000379:methods; D002245:Carbon Dioxide / Q000378:metabolism; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D007716:Kluyveromyces / Q000254:growth & development / Q000378:metabolism*; D008962:Models, Theoretical; D010100:Oxygen / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D006026:Glycoside Hydrolases; C023086:inulinase; D010100:Oxygen
keywords: Biocalorimetry; Bioprocess control; Inulinase; Kluyveromyces marxianus; Luedeking-Piret model; Modeling