Culture conditions

Fig. 3. Overview of puriftcation sequence for the nonrecombinant tissue plasminogen activator (t-PA) which also contains urokinase plasminogen activator (u-PA). Serum-free culture conditional media is from normal human ceU line. The temperature for aU. steps, except for size-exclusion chromatography...

Adsorption of t-PA to process equipment surfaces consisting of either stainless steel or glass was minimized by adding the detergent polyoxyethylene sorbitan monooleate (Tween 80) to the semm-free culture conditioned media at 0.01% (vol/vol). The equipment was also rinsed, before use, with phosphate buffered saline (PBS) containing 0.01% Tween 80. Hydrophilic, plastic equipment was used whenever possible. AH buffers were sterile filtered. Sterile filtration of Hquids and gases is usually carried out using 0.2 or 0.45 p.m filters. 

Approximately half of the terminal D-mannosyl residues have pymvate present as 4,6-0-(l-carboxyethyhdene) substituents. The pymvate content has been shown to vary with culture conditions (337,338) and strains of A. campestris (339). The internal D-mannosyl residue is acetylated at the 0-6 position. 

Microorganisms Primary mutation Genetic markers or culture conditions which Yield, mg/mL References... 

Microorganisms requite several minerals such as ferrous and potassium ions which play important roles in glutamic acid fermentation. Other important culture conditions include regulating aeration stirring. The biosynthesis of L-glutamic acid is performed under regulated aerobic conditions. 

There are many approaches that may be used here. One approach is to screen related new strains, organisms to see if a higher yielding strain may be obtained. Alternatively, the culture "culture conditions used to cultivate the antibiotic-producing strain may be modified with the conditions objective of increasing antibiotic production. This may include manipulation of physical... 

Consideration of pencillin production serves to illustrate the success of these strategies. Penicillin was produced at a concentration of about 1 ppm by the first penicillin producers that were isolated. By manipulation of culture conditions together with genetic manipulation, yields in excess of 10 g l 1 (excess of 10,000 ppm) are routinely achieved. This development has also been paralleled by the diversification of the... 

Bermudes, D., Gerlach, V. L., and Nealson, K. H. (1990). Effects of culture conditions on mycelial growth and luminescence in Panellus stypticus. Mycologia 82 295-305. 

Producing the kilograms of tPA necessary to satisfy the world s therapeutic needs requires the special skills possessed by modern biochemical engineers. Sophisticated engineering of the fermentation vessels, culturing conditions, and media compositions is required to culture thousands of liters of mammalian cells. In addition, new extremes of purity must be achieved in order to assure the safety of proteins derived from mammalian cells. The cost of the starting materials and the capacity constraints of the present-day equipment require that yields from each fermentation batch be as high as possible. 

In culture, the human colon carcinoma cell hne Caco-2 spontaneously differentiates at confluency into polarized cells with enterocyte-like characteristics. The principle of this approach consists of following the passage of the compound of interest from the apical or lumen-like sides to the basolateral or lymph-hke sides of Caco-2 cells, thus following the absorption of the compound per se. One obhgate step for fat-soluble nutrients such as carotenoids to cross the intestinal barrier is their incorporation into CMs assembled in the enterocytes. Under normal cell culture conditions, Caco-2 cells are unable to form CMs. When supplemented with taurocholate and oleic acid, Caco-2 cells were reported to assemble and secrete CMs. ... 

The main concern regarding the utilization of Monascus pigments relates to the production of the citrinin mycotoxin in Monascus cultures. Several methods for controlling the mycotoxin production were proposed, including selection of non-toxinogenic strains, control of citrinin biosynthesis, and modifications of culture conditions. Despite their wide and traditional food applications in Asian countries, Monascus pigments have not been approved for use in the United States or European Union. 

Porphyridium species are the sources of fluorescent pink color. The main Porphyridium phycobiliproteins are B-phycoerythrin and b-phycoerythrin. Maximum absorbance of a 1% solution of B-phycoerythrin in a 1-cm cuvette is at 545 inn, and the fluorescence emission peak is at 575 inn molecular weight is 240 kda. Batch culture of Porphyridium species outdoors yields approximately 2(X) mg of colorant per liter of culture after 3 days the phycoerythrin level in the colorant is about 15%. A higher concentration of phycoerythrin, up to 30%, can be achieved under optimal algal culture conditions. 

Sarada, R., Usha, T, and Ravishankar, G.A., Influence of stress on astaxanthin production in Haematococcus pluvialis grown under different culture conditions. Process Biochem., 37, 623, 2002. 

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