Continuous bioreactor system

More specifically, the invention involves the use of Thiobacillus denitrificans under anaerobic conditions to oxidize sulfur compounds such as hydrogen sulfide to sulfate. The process may be carried out in various ways such as in a batch or a continuous bioreactor system using a suspended or an immobilized biocatalyst. The method is particularly applicable to treating natural gas containing hydrogen sulfide and producing a biomass byproduct. 

While the batch process is the dominant one in current use, researchers and companies have attempted to create continuous bioreactor systems. Lopez et al. immobilized Candida rugosa in polymethacrylamide hydrazide beads and polyurethane foam 3 with the intent to achieve the continuous production of lipase enzymes. Despite flow problems with the polyurethane foam, it showed high lipolytic activity. Biomass buildup was problematic. Feijoo et al. immobilized Phanerochaete chry-sosporium on polyurethane foam in packed bed bioreactors under near-plug flow conditions. Continuous lignin peroxidase production was accomplished, the rate of which was studied as a function of recycle ratio. 

Takeshita, K. et al.. Mass production of D-psicose from D-fructose by a continuous bioreactor system using immobilized D-tagatose 3-epimerase, J. Biosci. Bioeng., 90, 453, 2000. 

Kopsahelis N., Papachronopoulos A., Bosnea L., Bekatorou A., Tzia C. and Kanellaki M. Alcohol production from sterilized and non-sterilized molasses by Saccharomyces cerevisiae immobilized on brewer s spent grains in two types of continuous bioreactor systems. Biomass and Bioenergy 46 (2012) 809-809. 

In Japan Chlorella spp has been produced for food in continuous aseptic systems in conventional bioreactors. The organisms are grown in the dark as heterotrophs using sucrose (in the form of molasses) or glucose as carbon and energy source. Production has been 2,000-3,000 tonnes per year at a selling price of (US)10-22 kg 1 (1990 prices). This product is sold as a high-value health food. 

Yang F, Yu J (1996) Development of a bioreactor system using an immobilized white rot fungus. Part II. Continuous decolorization tests. Bioprocess Eng 16 9-11... 

High expression levels of proteins are potentially attained. In many instances, the level of expression exceeds 1 g protein/litre milk. In one case, initial expression levels of 60 g l-1 were observed, which stabilized at 35 g L1 as lactation continued (the expression of the arantitrypsin gene, under the influence of the ovine P-lactoglobulin promoter, in a transgenic sheep). Even at expression levels of 1 g L1, one transgenic goat would produce a similar quantity of product in 1 day as would be likely recoverable from a 50-1001 bioreactor system. 

INHIBCONT - Continuous Bioreactor with Inhibitory Substrate System... 

Tata, M., Bower, R, Bromberg, S. et al.. Immobilized yeast bioreactor systems for continuous beer fermentation. Biotech. Prog., 15 (1999) 105-113. 

Risk analysis has been proven to retain the flexibility necessary to make it a useful model system for addressing the countless issues that are found to be associated with plant-derived pharmaceuticals (Wolt and Peterson, 2000). Over the past few years, a great deal of information and experience has steadily accumulated with respect to risk analysis of pharmaceuticals that are currently produced in bacterial and aifimal cell bioreactor systems. Risk analysis has also been performed on transgenic crops used for food production as well as for other applications. As a result, elements from each of these disciplines can be incorporated into the design of optimal production and testing policies and practices. Risk analysis has been employed to cover a series of important issues regarding the large-scale manufacture of plant-made biopharmaceuticals, and will continue to present serious issues for researchers in the academic, corporate, and public health arenas to address (Miele, 1997 Ciliberti and Molinelli, 2005). 

Nemati investigated the inhibiting effect of ferrous iron on the rate of oxidation in a bioreactor packed with a polyurethane foam. Fynn and Whitmore investigated the ability of methanogen species to colonize reticulated polyurethane foam in a continuous culture system. Electron micrographs confirmed that two methanogen species colonized the matrix. The methane output was superior to a liquid culture control. 

Degradation constant k = 3.2-M/h for anaerobic batch experiment in serum bottles k = 2.4 -M/h for dechlorination in anaerobic batch or continuous bioreactor k = 2.4 -M/h in the sequential anaerobic-aerobic continuous reactor system (Armenante et al. 1999)... 

The OHLM systems, integrating reaction, separation, and concentration functions in one equipment (bioreactor), find a great interest of researchers in the last few years. A bioreactor combines the use of specific biocatalyst for the desired chemical reactions, and repeatedly or continuously application of it under very specific conditions. Such techniques were termed as hybrid membrane reactors. In biotechnology and pharmacology, these applications are termed as hybrid membrane bioreactors or simply bioreactors (see Table 13.11). Experimental setup of the bioreactor system is shown schematically in Figure 13.17. 

For SCP production continuous rather than batch cultures are preferred because continuous culture systems give higher outputs for a bioreactor of given size ... 

In the pharmaceutical industry, the reactors are closed to maintain aseptic conditions, and agitation and aeration are provided as needed. The classic example is the Monod chemostat, often found in laboratories. A representative chemostat, fermentation vessel, or bioreactor, is shown in Fig. 2 with an air sparger, agitator, and feed or exit streams. The continuous flow system is usually replaced by a batch process for production in the pharmaceutical and biotechnology industries. The general relationships for a constant volume system are developed in terms of cell concentration (A), often the component of interest, and substrate concentration (5), such as a sugar or oxygen. 

Craveiro AC, Lima MB. Bioreactor system with chitosan semipermeable membranes and continuous extraction process, 2000 Brazil Patent Priority CAN 134 177457 AN 2001 164817. 

Figure 29. Continuous culture system. (A) Small glass vessel (Wilson, et at., 1976). (B) Pilot plant for continuous cultures with 20 kl bioreactor (Azechi, et al., 1983).

A special type of membrane bioreactor is called a porous pot reactor (PER) [19,37,90,91]. A 0.48-cm-thick filter grade porous polyethylene membrane is used in all applications to separate biomass from effluent. The same format is used to enrich bacterial cultures in continuous suspension systems, both under aerobic and anaerobic conditions [43,54]. 

The results of the column tests clearly show that the inoculated consortium has potential for enhancing MTBE-biodegradation in continuous flow systems such as bioreactors. Within a week after the inoculation, MTBE-degradation was observed, and a single inoculation event led to a MTBE-degradation over more than 9 months. 

Degradation of organopollutants by fungal cultures has been carried out successfully at bench and pilot scale, preferentially in batch or semi-continuous operations (Alleman et al. 1995 Fujita et al. 2002 Mielgo et al. 2002). Continuous treatment systems are desirable alternatives to increase process efficiency. A modified conventional configuration (fixed-bed bioreactor) coupled with a pulsation system has... 

Morimoto, K. et al.. Large scale production of D-allose from D-psicose using continuous bioreactor and separation system. Enzyme Microb. TechnoL, 38, 855, 2006. 

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