title: Debottlenecking product inhibition in 1,3-propanediol fermentation by In-Situ Product Recovery.
abstract: The present work describes the application of liquid-liquid extraction as an In-Situ product recovery (ISPR) technique to overcome the problem of product inhibition in 1,3-PD fermentation. As a part of initial screening experiments, six solvents were subjected to phase separation and biocompatibility tests to find the best extractant for in-situ removal of 1,3-PD from the bioreactor. These included tributylphosphate, ethyl acetate, butyl acetate, oleyl alcohol, oleic acid and hexanol. Of these, ethyl acetate was found to be the most suitable solvent for 1,3-PD extraction. Use of the selected extractant in continuous integrated fermentation-extraction was established by batch and fed-batch extractive fermentations which demonstrated a significantly improved 1,3-PD production of 35g/L and 74.5g/L, respectively. A steady state 1,3-PD concentration of 58g/L was obtained in continuous extractive system. Continuous cultivation with in-situ cell retention and in-situ 1,3-PD removal demonstrated a 5-fold enhancement in 1,3-PD productivity over non-extractive batch.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Guneet
authors.initials: G
authors.lastname: Kaur
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Electronic address: ashokks@dbeb.iitd.ac.in.
authors.forename: A K
authors.initials: AK
authors.lastname: Srivastava
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Subhash
authors.initials: S
authors.lastname: Chand
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D003013:Clostridium / Q000187:drug effects / Q000378:metabolism; D005233:Fatty Alcohols / Q000737:chemistry; D005285:Fermentation; D059625:Liquid-Liquid Extraction / Q000379:methods*; D011409:Propylene Glycols / Q000302:isolation & purification* / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology
chemical_list: D005233:Fatty Alcohols; D011409:Propylene Glycols; D012997:Solvents; C010268:oleyl alcohol; C041787:1,3-propanediol
keywords: 1,3-Propanediol; Clostridium diolis; In-Situ Product Recovery (ISPR); Liquid–liquid extraction; Product inhibition