Oulu, Finland
Oulu, Finland

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The present invention provides a method for improving the preparation and use of growth media by the uses of specific pellet formulations, which especially are tablets of different sizes, which contain the growth medium or parts thereof and are sterilized with the standard methods of pharmaceutical technology. Specifically these pellet formulations are applied to control a cell culture in a way that the adaptation phase is shorter or that the growth is controlled by a release of certain components at a certain time and in a certain concentration during the process, and nutrients (e.g., nitrogen) can be packed into the cultivation vessel in amounts sufficient for high cell densities without the risk of intoxication of the organism.


Ukkonen K.,BioSilta | Ukkonen K.,University of Oulu | Vasala A.,BioSilta | Ojamo H.,University of Oulu | Neubauer P.,TU Berlin
Microbial Cell Factories | Year: 2011

This report describes the combined use of an enzyme-based glucose release system (EnBase ®) and high-aeration shake flask (Ultra Yield Flask™). The benefit of this combination is demonstrated by over 100-fold improvement in the active yield of recombinant alcohol dehydrogenase expressed in E. coli. Compared to Terrific Broth and ZYM-5052 autoinduction medium, the EnBase system improved yield mainly through increased productivity per cell. Four-fold increase in oxygen transfer by the Ultra Yield Flask contributed to higher cell density with EnBase but not with the other tested media, and consequently the product yield per ml of EnBase culture was further improved. © 2011 Ukkonen et al; licensee BioMed Central Ltd.


Ukkonen K.,University of Oulu | Ukkonen K.,BioSilta | Veijola J.,University of Oulu | Vasala A.,BioSilta | Neubauer P.,TU Berlin
Microbial Cell Factories | Year: 2013

Background: Fab antibody fragments in E. coli are usually directed to the oxidizing periplasmic space for correct folding. From periplasm Fab fragments may further leak into extracellular medium. Information on the cultivation parameters affecting this leakage is scarce, and the unpredictable nature of Fab leakage is problematic regarding consistent product recovery. To elucidate the effects of cultivation conditions, we investigated Fab expression and accumulation into either periplasm or medium in E. coli K-12 and E. coli BL21 when grown in different types of media and under different aeration conditions.Results: Small-scale Fab expression demonstrated significant differences in yield and ratio of periplasmic to extracellular Fab between different culture media and host strains. Expression in a medium with fed-batch-like glucose feeding provided highest total and extracellular yields in both strains. Unexpectedly, cultivation in baffled shake flasks at 150 rpm shaking speed resulted in higher yield and accumulation of Fabs into culture medium as compared to cultivation at 250 rpm. In the fed-batch medium, extracellular fraction in E. coli K-12 increased from 2-17% of total Fab at 250 rpm up to 75% at 150 rpm. This was partly due to increased lysis, but also leakage from intact cells increased at the lower shaking speed. Total Fab yield in E. coli BL21 in glycerol-based autoinduction medium was 5 to 9-fold higher at the lower shaking speed, and the extracellular fraction increased from ≤ 10% to 20-90%. The effect of aeration on Fab localization was reproduced in multiwell plate by variation of culture volume.Conclusions: Yield and leakage of Fab fragments are dependent on expression strain, culture medium, aeration rate, and the combination of these parameters. Maximum productivity in fed-batch-like conditions and in autoinduction medium is achieved under sufficiently oxygen-limited conditions, and lower aeration also promotes increased Fab accumulation into extracellular medium. These findings have practical implications for screening applications and small-scale Fab production, and highlight the importance of maintaining consistent aeration conditions during scale-up to avoid changes in product yield and localization. On the other hand, the dependency of Fab leakage on cultivation conditions provides a practical way to manipulate Fab localization. © 2013 Ukkonen et al.; licensee BioMed Central Ltd.


The present invention relates to the enrichment and detection of microorganisms which contaminate food products, especially beverages and soft-drinks. It is particularly suitable for the detection of beer-spoiling bacteria. The present invention provides a novel system which a) improves the recovery of spoilage microbes b) provides faster detection and earlier emergence of colonies on plates, and c) provides larger colony sizes which makes detection easier.


Patent
BioSilta | Date: 2010-03-04

The present invention is generally in the field of continuous and high-cell-density cultivation in laboratory- or large-scale liquid shaken cultures. More particularly it relates to a method of enzyme-based fed-batch (EnBase) for liquid microbial prokaryotic or eukaryotic cell cultivation having the possibility to manipulate the growth rate of the cultured organisms by a controlled enzymatic release of the growth-limiting substrate-monomer from substrate-polymers or substrate-oligomers.


Trademark
BioSilta | Date: 2012-01-10

Chemical preparations for scientific purposes, other than for medical or veterinary use. Nutritive substances for microorganisms. Flasks for laboratory use.


The present invention relates to a method for increasing the expression of a recombinant protein and plasmid yield in an eukaryotic or prokaryotic high cell density culture. The increase of the expression is achieved by the use of perfluorochemicals as ingredients of an enzyme-based fed-batch cultivation system by enhancing the cell growth rate and the final cell density.


The present invention relates to the enrichment and detection of microorganisms which contaminate food products, especially beverages and soft-drinks. It is particularly suitable for the detection of beer-spoiling bacteria. The present invention provides a novel system which a) improves the recovery of spoilage microbes b) provides faster detection and earlier emergence of colonies on plates, and c) provides larger colony sizes which makes detection easier.


Patent
BioSilta | Date: 2010-09-08

The present invention is generally in the field of continuous and high-cell-density cultivation in laboratory- or large-scale liquid shaken cultures. More particularly it relates to a method of enzyme-based fed-batch (EnBase) for liquid microbial prokaryotic or eukaryotic cell cultivation having the possibility to manipulate the growth rate of the cultured organisms by a controlled enzymatic release of the growth-limiting substrate-monomer from substrate-polymers or substrate-oligomers.


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