Abstract

The aim of this work was to examine the feasibility of ethanol bioproduction from hydrolysate of macroalgea. Firstly, experiments were carried out with a synthetic medium adjusted on algal hydrolysate composition with four yeast strains: Saccharomyces cerevisiae, Pichia stipitis, Candida guilliermondii and Kluyveromyces marxianus. Nitrogen source, inoculum size and salt contents were examined.
Secondly, the study focused on the fermentation of hydrolysate from the green macroalgae Ulva rigida, confirming the possibility of converting algal hydrolysate into bioethanol, without nitrogen enrichment and sterilization. It was observed that pH regulation and aeration were not essential for the ethanol production. In these conditions, the experiment gave a concentration of 12 g L-1 and the conversion rate of glucose into bioethanol reached 82%. For the lab-scale assays, the media volume varied between 250 to 1 500 mL.
Finally, the scale up process was examined on a pilot scale (77 L) using S. cerevisiae growing on a hydrolysate of Chaetomorpha sp. This experiment gave a concentration of 5.6 g L-1 (lower than the results obtained during previous tests because of the limited hydrolysis yield), but with an efficiency of 97%.

Biography

Dr. Hayet DJELAL is Associate Professor at UniLasalle-Ecole des Métiers de l’Environnement, France. Her main research activities are related to Bioprocess Engineering, particularly chemical and bioprocesses development, development of elimination of micropollutants and biotreatment of industrial wastewater. She also works on aerobic and anaerobic fermentation technologies.
She supervised 7 PhD thesis concluded and 3 others are in progress, as well as more than 10 Master students. She has published 55 articles in scientific international journals with peer reviewing and she is associate editor of one scientific journal. She participated and coordinated several scientific projects with external financial support and she is implicated in national and international collaborations as Mexico, Algeria, Tunisia, Lebanon …

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