Agitation cultures

Strsiins were grown at 30°C as non agitated cultures. Measurements were made on 300 nl of the culture supernatants as described by Milner et Avigad... 

For surface aeration of static cultures, in a closed system, a void volume 10 times larger than the culture medium volume is necessary for adequate oxygen supply. In agitated cultures with surface aeration, oxygen transfer is dependent on agitation rate and impeller geometry. 

There may be several mechanisms for these metabolic effects. Unsaturated fatty acids have been shown to directly activate specific enzymes and to induce DNA synthesis and cytokine release from lymphocytes (Karsten et al., 1994). The induction of specific protein synthesis may produce the reduction in glutamine metabolism. The increase in the robustness of the fatty acid-grown hybridomas in agitated cultures could be explained by a high incorporation of the available fatty acids into the cellular phospholipids fraction, which is a major structural component of the outer membrane of the cell (Butler et al., 1999). 

Cell-protecting additives, such as Pluronic F-68, are commonly included as a media component to reduce cell damage in gas-sparged, agitated cultures. Despite the value of Pluronic F-68 in protecting cells, there is a potential problem in that Pluronic may have some cytosolic effects it may reduce the yield of the producer cell line in culture and there is a possibility of complexation or co-purification with a cell product. The replacement of Pluronic with fatty acids, as well as being positive for the half-lives and production of cultured cell lines, provides an alternative method to protect producer cells in agitated cultures (Butler et al., 1999). 

Butler M, Huzel N, Barnabe N, Gray T, Bajno L (1999), Linoleic acid improves the robustness of cells in agitated cultures, Cytotechnology 30 27-36. 

Kouda, T., et al. (1997). Effects of oxygen and carbon dioxide pressmes on bacterial cellulose production by acetobacter in aerated and agitated culture. J. Fermentation Bioengineering, 84, 2, 124-127. 

If protection is found, check how good the protective effect is by comparing with parallel static or low-agitation cultures. 

ID Reid, EE Chao, SS Dawson. Lignin degradation by Phanerochaete chrysosporium in agitated cultures. Can JMicrobiol 31 88-90, 1985. 

Hawari J et al., Biotransformation of 2,4,6-trinitrotoluene with Phanaerochaete chrysosporium in agitated cultures at pH 4.5, Appl. Environ. Microbiol., 65, 2977, 1999. 

BC suspension obtained from an agitation culture system was mixed with PVA powder to fabricate PVA-BC composite by considering PVA as a matrix and BC as a reinforcement material. The composite was proposed for cardiovascular soft tissue replacement application [78], The composite could be adjusted its mechanical properties to get close to those of specific tissue [aorta and heart valve] by changing the composition of the composite and the processing parameters. 

Czaja, W, Romanovicz, D., and Brown, Jr. R M. (2004). Structural investigations of microbial cellulose produced in stationary and agitated culture. Cellulose. 11,403-411. 

Yan, Z., Chen, S., Wang, H., Wang, B., and Jiang, J. (2008). Biosynthesis of bacterial cellulose/multi-walled carbon nanotubes in agitated culture, Carhnhvd. Polvm.. 74,659-665. 

Jung, J.Y., Park, J.K., Chang, H.N. Bacterial cellulose production by Gluconoacetobacter hansenii in an agitated culture without living non-cellulose producing cells. Enzyme Microb. Technol. 37(3), 347-354 (2005)... 

Watanabe, K., Tabuchi, M., Morinaga, Y., Yoshinaga, F. Structural features and properties of bacterial cellulose produced in agitated-culture. Cellulose 5(3), 187-200 (1998)... 

Czaja W, Romanovicz D, Brown RM (2004) Structural investigations of microbial cellulose produced in stationary and agitated culture. Cellulose 11 403-411 Czaja WK, David JY, Kawecki M et al (2007a) The future prospects of microbial cellulose in biomedical applications. Biomacromolecules 8 1-12 Czaja W, Krystynowicz A, Kawecki M et al (2007) Biomedical applications of microbial cellulose in bum wound recovery. In Brown Jr. RM, Saxena IM (eds) Cellulose Molecular and Structural Biology Selected Articles on the Synthesis, Stracture, and Applications of Cellulose. Springer, Dordrecht, The Netherlands... 

Yoshinaga, F., Tonouchi, N., Watanabe, K., 1997. Research progress in production of bacterial cellulose by aeration and agitation culture and its application as a new industrial material. Bioscience, Biotechnology, and Biochemistry 61, 219—224. 

Kouda, T., Naritomi, T., Yano, H., Yoshinaga, F., 1998. Inhibitory effect of carbon dioxide on bacterial cellulose production by Acetobacter in agitated culture. Journal of Fermentation and Bioengineering 85, 318—321. 

Figure 2.6 Photograph of spherical BC particles produced in agitated culture under different rotational speeds (a) 125 rpm (particle diameter of 8mm), (b) 150 rpm (particle size 2.5 mm), (c) 175 rpm (particle size 1 mm), (d) 200 rpm (particle size < 1 mm) (reproduced with permission from [47]) and Reproduced in a biofilm reactor. Reproduced with permission from [46],...

Agitated culture is considered as the most suitable cultivation technique for the commercial production of BC once, in comparison with static culture, requires less space and work force and higher production rates may be possibly achieved [45,48]. 

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