D3.16 – OPERATING PARAMETERS FOR OPTIMAL BUTYRIC ACID PRODUCTIVITY AND YIELD

Main Objectives

The objective was to study the distribution of metabolic products during MMC fermentation in continuous mode and statistical optimization of key process parameters for enhanced productivity and yield of butyric acid and 1,3 propanediol.

Main Outcomes

The enrichment and adaptation of MMCs proved to be a winning strategy to efficiently convert complex substrates, such as crude glycerol derived from animal fat (with no pretreatment). The adaptation allowed the bacteria to grow in CSTR on high feed concentration, performing a high glycerol consumption rate. 1.3 PDO turned out to be the dominant metabolite during steady state, followed by butyrate. The statistical optimization (Inscribed Central Composite Design) allowed to maximize productivity of PDO and butyric acid, with a 5-fold increase compared to steady state results in standard fermentation conditions prior to optimization. The results showed a model with a complex interaction between the key factors (pH, HRT and glycerol concentration), which implied a very careful choice of operating parameters. The model further showed the need for a fine tuning of HRT in combination with the other parameters, in order to maximize productivities and avoid cells wash out. To avoid this problem, preliminary tests and kinetic characterization of the consortium turned out to be fundamental to choose the proper experimental range.

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    May 2, 2017

    The article entitled: “Review of technical glycerol potential from biodiesel production and availability for improved cascading in Europe” has been published and is available online. Authors: André Brosowski (DBFZ), Stephanie Hauschild (DBFZ), Karin Naumann (DBFZ), Jens Hösel (DBFZ), Daniela Thrän (Helmholtz Centre for environmental research), Type of publication: Article – Research Paper Date: April 2017 Publication: […]

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  • 42M Progress Meeting – April 26 to 28, 2017 – Leipzig (Germany)

    April 11, 2017

    All the project partners will be hosted by DBFZ in Leipzig (Germany) from April 26 to 28, 2017. This is a good opportuny to discuss about the project advancement after the last Consortium Meeting which took place from October 12 to 14, 2016 in Hurtigruten, Bergen – Trondheim, Norway. Agenda available here: GRAIL_42M_Agenda     […]

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  • GRAIL e-NEWSLETTER #5 – February 2017

    February 22, 2017

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  • D2-2 – Operating parameters for batch experiments

    January 5, 2017

    Main Objectives To provide information about operational parameters at batch configurations such as, the effect of inoculum, addition of nutrients, pH control and substrate concentration to improve hydrogen and ethanol production  Main Outcomes According to the results, the selected inoculum was sludge from an aerobic wastewater treatment plant and an aerobic pretreatment. Also, it was […]

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