Main Objectives

The objective was to select and adapt mixed microbial cultures (MMCs), able to ferment crude glycerol generated from 2nd generation biodiesel from animal fat, and produce building-blocks and green chemicals, with a special focus on butyric acid; and 2) to establish stable continuous reactor operations with the selected MMCs.

 Main Outcomes

 Different selection and adaptation strategies were tested to obtain MMCs able to convert crude glycerol into preferably butyrate. Different inoculum sources requested different approaches, but showed to be able to acclimatize to the diluted (fat-derived) crude glycerol, without the need of any costly pretreatment (purification) of the feed.

Maximum butyrate production yield was obtained with enriched activated sludge BA_EF, which reached around 0.4 g/g (with 10 g/L substrate).

The inoculum that led to the best butyrate production during steady state in CSTR was obtained through enrichment of anaerobic sludge, grown in MM medium, and was used for subsequent statistical optimization. In general and for all continuous experiments performed with different inocula and media, an HRT of 12h, pH 5.5 and a substrate concentration of 10 g/L (T= 37 °C) allowed to reach a steady state.


  • Review of technical glycerol potential from biodiesel production and availability for improved cascading in Europe

    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: […]


  • 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     […]


  • GRAIL e-NEWSLETTER #5 – February 2017

    February 22, 2017

    PROJECT SUMMARY GRAIL : GLYCEROL BIOREFINERY APPROACH FOR THE PRODUCTION OF HIGH QUALITY PRODUCTS OF INDUSTRIAL VALUE GRAIL is a 48-months collaborative project funded by the European Commission, under the FP7 Programme for Knowledge Based Bio-Economy. The topic of GRAIL project is “Preventing and valorizing bio-waste in biorefineries optimal and cost-effective industrial biocatalysts”. What’s inside […]


  • 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 […]