Download Department of Bioprocess Technology

KTH School of Biotechnology
Department of Bioprocess Technology
Head of Department: Prof. Sven-Olof Enfors
August 2006
Royal Institute of Technology
AlbaNova University Center
SE-106 91 Stockholm
Sweden
www.biotech.kth.se
At the Department of Bioprocess technology the research is focused on
studies of the physiology of microorganisms and animal cells under process
conditions, with the goal to understand and improve protein production
processes. E. coli, Pichia pastoris, and mammalian and insect cells are the
main hosts for the production.
E. coli strain development. A toolbox of vectors for high-throughput
cloning, cultivation, protein targeting and purification is developed. The outer
membrane structure and function is studied under different environmental
conditions with the aim to derive mechanisms of controlled localization of
heterologous proteins in cytoplasm, periplasm, or the medium. Furthermore,
the possibilities of glycosylating proteins in E. coli are explored.
Integrated Pichia process technology. The objective for the P. pastoris
work is to develop an integrated process technology including strain design
and evaluation, fermentation and product recovery and purification. Through
proper cell viability control the cell proteolysis is minimized and the product
secreted to a relatively pure medium from which the product is recovered
with an expanded-bed-adsorption column connected to the bioreactor outlet
flow or by CFF.
Animal cell technology. Serum or protein-free media are developed for
mammalian and insect cells. The aim is to understand how proliferation is
regulated in a medium with no added mitogenic factors. This knowledge is
then used to improve production processes. Another focus is metabolic
engineering of the central metabolism.
Process analytical technology. Software sensors are developed based on
standard logg-data. A new sensor RO/S is evaluated as a potential sensor for
physiological stress in E. coli processes. The temperature-limited fed-batch
(TLFB) system was developed and patented for elimination of the excessive
release of endotoxin in high-cell-density E. coli processes. This technique is
further developed to exploit other advantages in E. coli and Pichia
processes.
Senior researchers
Prof. Sven-Olof Enfors ([email protected])
Process Analytical Technology, DNA-chips, Pichia technology
2 PhD students
Prof. Lena Häggström ([email protected])
Animal Cell Technology
1 PhD student
Prof. Gen Larsson ([email protected])
E. coli strain development
2 PhD students
Assoc. prof. Andres Veide ([email protected])
DSP and pilot plant manager
Dr. Mehmedalija Jahic ([email protected])
Pichia technology
Dr. Magdalena Gabig-Ciminska ([email protected])
Electric DNA chips
1 PhD student
Electric DNA chips are developed both for bioprocess control and
for rapid analysis of pathogenic microorganisms. The latter is part of
the EU-project eBIOSENSE (www.eBIOSENSE.org), which is coordinated by us. An alternative electric DNA chips technology is
developed in co-operation with KTH-ICT in Kista, where silicon arrays
for simple lable-free DNA recognition is developed as well as silicon
nanowire and carbon nanotube based field-effect transistors for DNA
recognition.
The pilot plant at the department is used for contract research and
production and for teaching in bioprocess technology The equipment
includes 5 well instrumented and automatised bioreactors ( lab scale
- 500L), a scale-down reactor for studies of physiological responses
to concentration gradients of large bioreactors, and a highly
automatised multi-bioreactor set (6x 200-1000 mL) for highthroughput strain and process evaluation. Pilot-scale equipment for
DSP (centrifugal separator, CFF, and high-pressure homogenisation)
is also available (www.biotech.kth.se/bioprocess/pilot_plant).
Key references:
Boström et al., (2005) Process design for recombinant protein
production based on the promoter PmalK. Appl. Microbiol. Biotechnol.,
66, 200-208; Jahic M. et al. (2006) Process technology for production
and recovery of heterologous proteins with Pichia pastoris.
Biotechnol. Progress, (in press); Spens E. et al. (2005) Defined
Protein-Free NS0 Myeloma Cell Cultures: Stimulation of proliferation
by conditioned medium factors. Biotechnol. Prog. 21(1), 87-95;
Eriksson U et al. (2005) Metalloproteinase activity is the sole factor
responsible for the growth-promoting effect of conditioned medium in
Trichoplusia ni insect cells. J. Biotech. 119, 76-86; Svensson M. et al.
(2004) Control of endotoxin release in Escherichia coli fed-batch
cultures. Bioproc. Biosyst. Eng. 27, 91-98; Gabig-Ciminska M., et al.
(2005) Gene based identification of bacterial colonies with an electric
chip. Analyt. Biochem. 345, 270-276; Kepka C et al. (2005) Twostep recovery process for tryptophan-tagged cutinase: Interfacing
aqueous two-phase extraction and hydrophobic interaction
chromatography. J. Chrom. A, 1075, 33-41.
Funding: VR, FORMAS, SSF, EU, Industry