Bi9540 Biotechnology and practical use
of algae and fungi
Lecture 12 – Fungal and algal platforms for
recombinant expression
Advantages of fungal platforms
 As eukaryotes, yeasts and filamentous fungi have many of
the advantages of higher-eukaryotic cells, such as posttranslational
modifications.
 Yeast cell growth is faster, easier and less expensive than
other eukaryotic cells, and generally gives higher
expression levels.
 Three main species of yeast are used for the production of
recombinant proteins – Saccharomyces cerevisiae, Pichia
pastoris and Schizosaccharomyces pombe.
Methods of DNA transfer
 Chemical transformation of intact cells and spheroplasts
 Electroporation
 Micromanipulation
 Biolistic method
 Glass beads method
 Magnetic beads method
 Liposome transformation
 Agrobacterium-based method
Spheroplast transformation
Lithium acetate transformation
Electroporation
Strategies for heterologous expression in yeast
Therapeutic proteins
Biopharmaceuticals production
HPV vaccine
 Virus-like particles
 Cervarix , Silgard, Gardasil, …
 Available in CZE since 2006
Saccharomyces cerevisiae
Figure: Galactose inducible gene expression in yeast. The
expression of genes from multicopy vectors under the control of the
GAL1 promoter (PGAL1) can be increased substantially if the gene
encoding the transcriptional activator of GAL1, GAL4, is also placed under
the control of PGAL1. In this case, induction by galactose will produce
more Gal4p and consequently more of the target protein.
Pichia pastoris
Hansenula polymorpha
Yarrowia lipolytica
Kluyveromyces lactis
Schizosascharomyces pombe
Arxula adeninivorans
 Relatively new expression system
 Genome sequence published in 2014
 Dimorphic fungus
 Budding yeast form up to 42 °C
 Mycelial form at higher temperatures
 Can grow on variety of substrates including n-alkanes,
purines and starch
Other yeast expression platforms
 Endomyces (Dipodascus) magnusii
 Candida boidinii
 Pichia methanolica
 Pichia stipitis
 Schwanniomyces occidentalis
 Debaryomyces hansenii
Filamentous fungi
Microalgae
 Promising platforms for heterologous protein expression
 Several systems are currently in use
 Biggest obstacles are in transformation and cell biomass
productivity
 Nuclear and chloroplast expression is available
 Limited number of species is being used, most of them
belong to Chlamydomonas