title: Engineered catalytic biofilms for continuous large scale production of n-octanol and (S)-styrene oxide.
abstract: This study evaluates the technical feasibility of biofilm-based biotransformations at an industrial scale by theoretically designing a process employing membrane fiber modules as being used in the chemical industry and compares the respective process parameters to classical stirred-tank studies. To our knowledge, catalytic biofilm processes for fine chemicals production have so far not been reported on a technical scale. As model reactions, we applied the previously studied asymmetric styrene epoxidation employing Pseudomonas sp. strain VLB120ΔC biofilms and the here-described selective alkane hydroxylation. Using the non-heme iron containing alkane hydroxylase system (AlkBGT) from P. putida Gpo1 in the recombinant P. putida PpS81 pBT10 biofilm, we were able to continuously produce 1-octanol from octane with a maximal productivity of 1.3 g L ⁻¹(aq) day⁻¹ in a single tube micro reactor. For a possible industrial application, a cylindrical membrane fiber module packed with 84,000 polypropylene fibers is proposed. Based on the here presented calculations, 59 membrane fiber modules (of 0.9 m diameter and 2 m length) would be feasible to realize a production process of 1,000 tons/year for styrene oxide. Moreover, the product yield on carbon can at least be doubled and over 400-fold less biomass waste would be generated compared to classical stirred-tank reactor processes. For the octanol process, instead, further intensification in biological activity and/or surface membrane enlargement is required to reach production scale. By taking into consideration challenges such as biomass growth control and maintaining a constant biological activity, this study shows that a biofilm process at an industrial scale for the production of fine chemicals is a sustainable alternative in terms of product yield and biomass waste production.
authors.affiliation: Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, Technische Universität Dortmund, Emil-Figge-Str. 66, Dortmund 44221, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Gross
authors.forename: Katja
authors.initials: K
authors.lastname: Buehler
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmid
mesh_terms: D020003:1-Octanol / Q000032:analysis / Q000378:metabolism*; D057005:Bioengineering; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D018914:Cells, Immobilized; D042926:Cytochrome P-450 CYP4A / Q000235:genetics / Q000378:metabolism; D004852:Epoxy Compounds / Q000032:analysis / Q000378:metabolism*; D005240:Feasibility Studies; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012107:Research Design
chemical_list: D004852:Epoxy Compounds; C013690:styrene oxide; D042926:Cytochrome P-450 CYP4A; D020003:1-Octanol