Topic
Bioreactor
About: Bioreactor is a research topic. Over the lifetime, 9980 publications have been published within this topic receiving 192690 citations. The topic is also known as: bioreactors.
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TL;DR: Rocking-motion-type bioreactors may provide an interesting alternative to standard cultivation in bioreacts for cultivation of bacteria and recombinant protein production and internal substrate delivery systems such as EnBase® Flo provide an opportunity for adopting simple to use fed-batch-type strategies to shaken cultures.
Abstract: Single-use rocking-motion-type bag bioreactors provide advantages compared to standard stirred tank bioreactors by decreased contamination risks, reduction of cleaning and sterilization time, lower investment costs, and simple and cheaper validation. Currently, they are widely used for cell cultures although their use for small and medium scale production of recombinant proteins with microbial hosts might be very attractive. However, the utilization of rocking- or wave-induced motion-type bioreactors for fast growing aerobic microbes is limited because of their lower oxygen mass transfer rate. A conventional approach to reduce the oxygen demand of a culture is the fed-batch technology. New developments, such as the BIOSTAT® CultiBag RM system pave the way for applying advanced fed-batch control strategies also in rocking-motion-type bioreactors. Alternatively, internal substrate delivery systems such as EnBase® Flo provide an opportunity for adopting simple to use fed-batch-type strategies to shaken cultures. Here, we investigate the possibilities which both strategies offer in view of high cell density cultivation of E. coli and recombinant protein production. Cultivation of E. coli in the BIOSTAT® CultiBag RM system in a conventional batch mode without control yielded an optical density (OD600) of 3 to 4 which is comparable to shake flasks. The culture runs into oxygen limitation. In a glucose limited fed-batch culture with an exponential feed and oxygen pulsing, the culture grew fully aerobically to an OD600 of 60 (20 g L-1 cell dry weight). By the use of an internal controlled glucose delivery system, EnBase® Flo, OD600 of 30 (10 g L-1 cell dry weight) is obtained without the demand of computer controlled external nutrient supply. EnBase® Flo also worked well in the CultiBag RM system with a recombinant E. coli RB791 strain expressing a heterologous alcohol dehydrogenase (ADH) to very high levels, indicating that the enzyme based feed supply strategy functions well for recombinant protein production also in a rocking-motion-type bioreactor. Rocking-motion-type bioreactors may provide an interesting alternative to standard cultivation in bioreactors for cultivation of bacteria and recombinant protein production. The BIOSTAT® Cultibag RM system with the single-use sensors and advanced control system paves the way for the fed-batch technology also to rocking-motion-type bioreactors. It is possible to reach cell densities which are far above shake flasks and typical for stirred tank reactors with the improved oxygen transfer rate. For more simple applications the EnBase® Flo method offers an easy and robust solution for rocking-motion-systems which do not have such advanced control possibilities.
123 citations
TL;DR: Instead of dissolved sulfide (HS−), S seemed to be the most important electron donor for HA‐SOB under S0 producing conditions, and abiotic oxidation of S x2− was the main cause of undesirable formation of S2O 32− .
Abstract: A biotechnological process is described to remove hydrogen sulfide (H2S) from high-pressure natural gas and sour gases produced in the petrochemical industry. The process operates at halo-alkaline conditions and combines an aerobic sulfide-oxidizing reactor with an anaerobic sulfate (SO) and thiosulfate (S2O) reducing reactor. The feasibility of biological H2S oxidation at pH around 10 and total sodium concentration of 2 mol L-1 was studied in gas-lift bioreactors, using halo-alkaliphilic sulfur-oxidizing bacteria (HA-SOB). Reactor operation at different oxygen to sulfide (O2:H2S) supply ratios resulted in a stable low redox potential that was directly related with the polysulfide (S) and total sulfide concentration in the bioreactor. Selectivity for SO formation decreased with increasing S and total sulfide concentrations. At total sulfide concentrations above 0.25 mmol L-1, selectivity for SO formation approached zero and the end products of H2S oxidation were elemental sulfur (S0) and S2O. Maximum selectivity for S0 formation (83.3±0.7%) during stable reactor operation was obtained at a molar O2:H2S supply ratio of 0.65. Under these conditions, intermediary S plays a major role in the process. Instead of dissolved sulfide (HS-), S seemed to be the most important electron donor for HA-SOB under S0 producing conditions. In addition, abiotic oxidation of S was the main cause of undesirable formation of S2O. The observed biomass growth yield under SO producing conditions was 0.86 g N mol-1 H2S. When selectivity for SO formation was below 5%, almost no biomass growth was observed
123 citations
TL;DR: In this paper, a hollow fibre membrane bioreactor with bubbleless membrane aeration was tested over 5 months for its ability to treat synthetic sewage and achieved 86% COD removal.
122 citations
TL;DR: PAD was shown to be favourably comparable to MAD for brewery wastewater treatment and biogas generation, underlining the robustness of the latter, which appeared underloaded.
121 citations
TL;DR: In this paper, the feasibility of integrating acidogenic and methanogenic processes for simultaneous production of biohydrogen (H2) and methane (CH4) was studied in two separate biofilm reactors from wastewater treatment.
121 citations