Abstract

BIO-HUG aims to ensure the competitiveness of European starch industry by engineering new integrated bioprocesses. Steam pre-treatment and enzymatic hydrolysis of starch derived hemicellulose containing by-products will be optimised with respect to sugar yield and fermentability. Novel enzyme cocktails tailor-made for this purpose will be developed. New recombinant strains of Saccharomyces cerevisiae fermenting hemicellulose hydrolysates will be generated with metabolic engineering and directed evolutionary approaches. When integrated into existing industrial processes the new hydrolysis and fermentation technologies will increase the ethanol yield from starch processing by-products.

Objectives

The primary objective of BIO-HUG is to upgrade hemicellulose-containing by-products from the starch industry by engineering new integrated bioprocesses. Special emphasis will be given to the development of:

• Cost-effective hydrolysis processes - mechanical, thermal and enzymatic - generating fermentable sugar mixtures from starch processing hemicellulose containing by-products.
• Novel polyploid industrial yeasts strains capable of efficiently fermenting hemicellulose based sugar mixtures.
• Strategies for the integration of the new hydrolysis and fermentation technologies.

Description of the work

BIO-HUG combines European expert research groups in both companies and universities in the fields of :

(i) pre-treatment and hydrolysis of hemicellulose
(ii) yeast genomics
(iii) high through-put screening
(iv) directed evolution
(v) bio-informatics, and
(vi) biochemical engineering.

Two major European companies and one SME assure the technology implementation and exploitation of results generated in the project along the following lines.

• Generation of a fermentable hydrolysate from starch processing hemicellulose by-products aims at developing a combined physical-chemical and enzymatic hydrolysis process which allows both efficient hemicellulose hydrolysis, yeast growth and fermentation. For the enzymatic hydrolysis novel enzyme mixtures will be developed.
• Generation of industrial recombinant strains of S. cerevisiae fermenting hemicellulose hydrolysates involves "bottom-up" genetic engineering strategies.
• Directed evolution of hemicellulose hydrolysate utilising strains of S. cerevisiae involves "top-down" breeding strategies including:
  (i) adaption,
  (ii) mutation,
  (iii) selection and,
  (iv) isolation.
• Cutting edge experimental techniques generated in the Yeast Genome Project and the Functional Analysis Project permit identification of genes with deregulating functions in relation to fermentation of hemicellulose hydrolysates. The results will guide new targeted metabolic engineering approaches.
• Pre-treatment and hydrolysis protocols will be implemented in a starch processing industry. The newly developed enzyme cocktails will be produced in a large scale. The newly developed industrial strains of S. cerevisiae will ferment starch derived hemicellulose hydrolysates in pilot scale.

Deliverables

The project is expected to generate:

• New process technology for the bioconversion of hemicellulose containing starch processing by-products.
• Enzyme cocktails for hydrolysis of hemicellulose containing starch processing by-products.
• Polyploid industrial glucose derepressed strains of S. cerevisiae fermenting hemicellulose hydrolysates.

Contacts

Coordinator

• Bärbel HAHN-HÄGERDAL / Lund University Lund Institute of Technology / SWEDEN

Participant

• James E BAILEY / ETH Zürich Institute of Biotechnology / SWITZERLAND
• Juana Maria GANCEDO / Instituto de Investigaciones Biomédicas CSIC SPAIN
• New University of Lisbon Faculty of Sciences and Technology / PORTUGAL
• Claus FELBY / Novo Nordisk A/S DENMARK
• Emmanuel MAILLY / ORSAN-AMYLUM France Fermentation R&D / FRANCE
• Joerg HAUF / Scientific Research and Development GmbH GERMANY
• Lisbeth OLSSON / Technical University of Denmark Department of Biotechnology / DENMARK
• Universitaet Duesseldorf Institut fuer Mikrobiologie / GERMANY