A novel chimaeric flocculation protein enhances flocculation in Saccharomyces cerevisiae
Journal article, 2018

Yeast flocculation is the reversible formation of multicellular complexes mediated by lectin-like cell wall proteins binding to neighbouring cells. Strong flocculation can improve the inhibitor tolerance and fermentation performance of yeast cells in second generation bioethanol production. The strength of flocculation increases with the size of the flocculation protein and is strain dependent. However, the large number of internal repeats in the sequence of FLO1 from Saccharomyces cerevisiae S288c makes it difficult to recombinantly express the gene to its full length. In the search for novel flocculation genes resulting in strong flocculation, we discovered a DNA sequence, FLONF, that gives NewFlo phenotype flocculation in S. cerevisiae CEN.PK 113-7D. The nucleotide sequence of the internal repeats of FLONF differed from those of FLO1. We hypothesized that a chimaeric flocculation gene made up of a FLO1 variant derived from S. cerevisiae S288c and additional repeats from FLONF from S. cerevisiae CCUG 53310 would be more stable and easier to amplify by PCR. The constructed gene, FLOw, had 22 internal repeats compared to 18 in FLO1. Expression of FLOw in otherwise non-flocculating strains led to strong flocculation. Despite the length of the gene, the cassette containing FLOw could be easily amplified and transformed into yeast strains of different genetic background, leading to strong flocculation in all cases tested. The developed gene can be used as a self-immobilization technique or to obtain rapidly sedimenting cells for application in e.g. sequential batches without need for centrifugation.

Protein engineering

Saccharomyces cerevisiae

Chimaeric

Cell-cell adhesion

Bioethanol

Author

Johan Westman

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Chr. Hansen

Jonas Nyman

University of Southampton

Richard M.A. Manara

University of Southampton

Valeria Mapelli

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Sacco

Carl Johan Franzén

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Metabolic Engineering Communications

2214-0301 (eISSN)

Vol. 6 49-55

Subject Categories

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

Genetics

Other Industrial Biotechnology

DOI

10.1016/j.meteno.2018.04.001

More information

Latest update

5/3/2018 1