Is high cell density good?
High cell- density culture (HCDC) techniques for culturing E. coil have been developed to improve productivity, and also to provide advantages such as reduced culture volume, enhanced downstream processing, reduced wastewater, lower production costs and reduced investment in equipment.
How do you get high cell density?
Increase in cell density can be achieved in shaken cultures by the choice and optimization of cultivation medium. In short-term shaken cultures, different combinations of yeast extract and peptones are favored due to easy preparation and availability of essential growth factors and vitamins.
What is high cell density cultivation?
High cell density cultivation (HCDC) is a powerful technique for production of recombinant proteins, the annual market growth of which is expected to increase at a rate of 10-15% per annum (Werner, 2004). Once the expression system is developed, fermentation is carried out to increase the protein product titer.
What will help to achieve high density of E. coli cells?
The standard procedure for growing E. coli cells to high cell densities is the fed-batch technique, where the carbon substrate, e.g. glucose, controls the growth as a limiting factor. To minimize the volume change in the bioreactor, high concentrated glucose solutions are often used.
What is high cell density?
High-cell-density cultivation (HCDC) is required to improve microbial biomass and product formation substantially. An overview of HCDC is given for microorganisms including bacteria, archae and eukarya (yeasts). Problems encountered by HCDC and their possible solutions are discussed.
Why is cell density important?
Seeding the right cell density is necessary for optimum cell growth. Seeding a lower cell density will result in lack of cell to cell interaction and communication. As a result the cells will show slow growth and eventually die.
What is cell density?
Cell density refers to the number of cells per unit volume. Often cell density is denoted as viable cell density which is the number of living cells per unit volume.
What are bioreactors used for?
Bioreactor systems are a vital component in the process of 3D tissue engineering and the formation of tissue constructs. Bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. Based on the bioreactor technology, various tissue systems can be incubated in vitro.
What sugars does E coli ferment?
Under anaerobic conditions and in the absence of alternative electron acceptors Escherichia coli converts sugars to a mixture of products by fermentation. The major soluble products are acetate, ethanol, acetate and formate with smaller amounts of succinate.
What does cell density mean?
How are cells cultured?
Cell culture refers to the removal of cells from an animal or plant and their subsequent growth in a favorable artificial environment. At this stage, the cells have to be subcultured (i.e., passaged) by transferring them to a new vessel with fresh growth medium to provide more room for continued growth.
Which is the most cost effective high cell density fermentation?
High cell density fermentation by fed-batch strategies is one of the most cost-effective means of achieving high yields for the production of large scale recombinant proteins in the bio-industry.
How are cell mass and productivity maximized in high cell density cultures?
In fed-batch cultures, cell mass and productivity are maximized by adjusting culture conditions, including temperature and pH, the composition of the feed media, and the substrate feed rate. As one of the most critical factors to the success of high cell density culture, various nutrient feeding strategies have been developed.
How are nutrient feeding rates determined in fermentor?
Cell concentration – the nutrient feeding rate determined from the cell concentration is measured by a laser turbidimeter. Substrate concentration control – nutrient feeding is directly controlled by the concentration of the principal carbon source (e.g. an on-line glucose analyzer in the fermentor).
What is the purpose of the industrial fermentation process?
Industrial fermentation is the intentional use of fermentation by microorganisms such as bacteria and fungi to make products useful to humans. Fermented products have applications as food as well as in general industry.