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Simultaneous production of 1,3-propanediol and n-butanol by clostridium pasteurianum: in situ gas stripping and cellular metabolism
Publikationstyp
Journal Article
Date Issued
2016-08-17
Sprache
English
Author(s)
Institut
TORE-URI
Journal
Volume
16
Issue
7
Start Page
664
End Page
674
Citation
Engineering in Life Sciences 7 (16): 664-674 (2016-10-01)
Publisher DOI
Scopus ID
Publisher
Wiley-VCH
Clostridium pasteurianum is a promising producer of the bulk chemicals 1,3-propanediol and n-butanol (BuOH), with significantly different product patterns and physiology from other typical Clostridia. Nevertheless, its growth and product formation are ultimately limited by the accumulation of inhibiting products, especially by BuOH. In this study, we implemented in situ gas stripping for BuOH removal and compared the stripping performance of external nitrogen (N2) and fermentation effluent gas (FG) from the process itself. Gas stripping was studied in fermentations of glycerol and a mixture of glycerol and glucose. In general, N2 exhibits favourable physical properties to strip out BuOH from an aqueous phase. However, in situ removal of butanol in C. pasteurianum culture with N2 stripping strongly perturbs the culture conditions such as the redox potential and thus the physiology of the microorganism, leading to enhanced formation of organic acids, especially in cosubstrate fermentation, whereas the use of FG does not show such perturbations. In an effort to explore the use of FG for gas stripping the effects of FG circulation rate and stirring speed of the bioreactor on BuOH stripping efficiency and the fermentation performance were studied in more detail. Mass transfer coefficient (kSa) of BuOH in the bioreactor was also characterized at different gas circulation rates and stirring speeds. In a fermentation of glycerol with FG stripping at a relatively high gas flow rate (7 vvm) as high as 39.2 g/L BuOH (total) and 53.7 g/L 1,3-PDO can be simultaneously produced. The results are discussed in view of further process optimization and scale up.
Subjects
1,3-Propanediol
Butanol
Clostridium pasteurianum
Gas stripping
In situ product recovery
DDC Class
570: Biowissenschaften, Biologie
600: Technik
More Funding Information
Supported by the European Union Sev-enth Framework Program (FP7/2007-2013) under grant agree-ment no. 241718 “EuroBioRef”.