Scale culture

Although from theoretical considerations biomass yields from methane could be as high as 1.4, in laboratory-scale cultures values of about 1.0 were obtained, and in larger scale systems values were around 0.3-0.6. Methane fermentation also incurs high aeration and cooling costs. 

In parallel with these studies, developments were underway to find the most economical method of large-scale culture and down-stream processing. The biochemistry of methanol and ammonia utilisation by MethylopHlus methylotrophus was also studied to pinpoint possibilities for manipulation. 

Overall, therefore, the routine manufacture of a biopharmaceutical product is initiated by large-scale culture of its producing cell line (upstream processing). Subsequent to this, the product is recovered, purified and formulated into final product format. These latter operations are collectively termed downstream processing and are described in Chapter 6. 

Bushell ME, Dunstan GL, Wilson GC, Effect of small scale culture vessel type on hyphal fragment size and erythromycin production in Saccharopolyspora ery-threae, Biotechnol Lett 19 849—852, 1997. 

The present paper reports on the development of a culture collection of potentially toxic dinoflagellates from the Virgin Islands, large-scale culture and screening for toxicity in nine species, and a more detailed consideration of the toxic properties of G. toxicus and P. concavum. 

Large-scale culture and harvest of dinoflagellates. Large-scale cultures were initiated by first inoculating 2 liters of our... 

Table II. Production of Cells and Crude Extracts of Nine Species of Dinoflagellates in Large-Scale Culture. Ages of Cultures Ranged From 20 to 36 Days.

Crude and three diethyl ether extracted, acetone treated, fractions were isolated from large-scale cultures of Gambierdiscus toxicus. Crude extracts at. 04 mg/ml inhibited the histamine contraction response in smooth muscle of the guinea pig ileum. Three semi-purified fractions at 5 ng/ml, effectively inhibited the guinea pig ileum preparation. Two of these fractions followed Michaelis-Menten kinetics for a competitive inhibition. The third fraction inhibited in a non-reversible manner. This study has established the presence of three lipid extracted toxins in toxicus, outlined a method for their assay in small quantities, and identified at least two of the effects of these toxic extracts in animals. 

The development of large-scale cultures involved transferring cells from stock cultures to a series of two liter Fernbach flasks containing enriched seawater medium. After the early stationary phase of growth had been reached (approximately 15-20 days) each of these cultures were used to innoculate 18 liters of the same medium in 20 liter carboys. Large-scale cultures were grown under continuous light (4300 lux cool white fluorescent) at 27.0° C. 

Extraction and Purification of Toxins. Two large-scale cultures were examined (1) 350F and (2) 350G. Culture F consisted of 53... 

Extraction and Purification of Toxin. Products of two batches of large-scale cultures were extracted (A) 350F and (B) 350G. 

Large-Scale Cultures. Results of growth in large-scale culture are presented In Table III. Cultures of toxlcus attained their... 

For large-scale cultures, use 2-litre flasks (with baffles). Induce by adding 1/3 volume prewarmed LB at 65 C to the culture. 

Historically, HCDC was first established for yeasts to produce single-ceU protein, ethanol, and biomass. Later, dense cultures of other mesophiles producing various types of products were developed, e.g.,by Suzuki et al. [96]. The combination of recombinant DNA technology and large-scale culture processes has enabled human proteins to be produced in a number of hosts, in particular in Escherichia coli [97-100]. Approaches to optimize the production of recombinant proteins are the subject of recent reviews from Winter et al. [101]. 

To develop a process for production of the biocatalyst, small scale cultures (5mL to 5L) are used. Initially, tubes or shake flasks are commonly apphed, especially when a large number of values for a given variable such as media composition, temperatnre and pH are evaluated. As development progresses and quantitative data are required, more controlled conditions than those provided by Erlemneyer flasks are necessary. Commoidy,... 

Contaminant (mg/kg) Scale Culture (inoculum and size) Temp- perature (°C) Half-life (days) Treatment time (days) Residual concentration (mg/kg) Other remarks Reference... 

Several bioreactor designs have been demonstrated for large-scale culture of hairy roots (6,7). Bioreactors used for hairy root culture are more complex owing to continuous growth of hairy root and must compensate for the heterogeneous, cohesive, structured, and entangled nature of fibrous roots (4). Hairy root cultures may be feasible for large-scale applications, but many problems with the hairy root culture system are still unsolved (6-9). 

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