Editing Bioreactor (section)

{{Short description|System that supports a biologically active environment}}
{{More citations needed|date=October 2010}}A '''bioreactor''' is any manufactured device or system that supports a biologically active environment.<ref>{{GoldBookRef|title=bioreactor|file=B00662}}</ref> In one case, a bioreactor is a vessel in which a [[chemical reaction|chemical process]] is carried out which involves [[organism]]s or [[biochemistry|biochemically]] active [[chemical substance|substance]]s derived from such organisms. This process can either be [[Aerobic organism|aerobic]] or [[Anaerobic organism|anaerobic]]. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of [[stainless steel]].{{citation needed|date=October 2019}}

It may also refer to a device or system designed to grow [[Cell (biology)|cells]] or [[Biological tissue|tissues]] in the context of [[cell culture]].<ref>{{cite web |url=http://www.eolss.net/Sample-Chapters/C17/E6-58-04-15.pdf|title=Bioreactoes and Cultivation Systems for Cell and Tissue Culture|website=eolss.net|access-date=12 August 2023}}</ref> These devices are being developed for use in [[tissue engineering]] or [[biochemical engineering|biochemical]]/[[bioprocess engineering|bioprocess]] engineering.{{citation needed|date=October 2019}}[[File:Bioreactor principle.svg|thumb|210px|General structure of a continuous stirred-tank type bioreactor]]

On the basis of mode of operation, a bioreactor may be classified as [[batch reactor|batch]], [[fed-batch|fed batch]] or [[continuous reactor|continuous]] (e.g. a [[continuous stirred-tank reactor model]]). An example of a continuous bioreactor is the [[chemostat]].{{citation needed|date=October 2019}}

Organisms or biochemically active substances growing in bioreactors may be submerged in liquid medium or may be anchored to the surface of a solid medium. Submerged cultures may be suspended or immobilized. Suspension bioreactors may support a wider variety of organisms, since special attachment surfaces are not needed, and can operate at a much larger scale than immobilized cultures. However, in a continuously operated process the organisms will be removed from the reactor with the effluent. Immobilization is a general term describing a wide variety of methods for cell or particle attachment or entrapment.<ref>{{cite journal |last1=López |first1=Asunción |last2=Lázaro |first2=Nuria |last3=Marqués |first3=Ana M. |title=The interphase technique: a simple method of cell immobilization in gel-beads |journal=Journal of Microbiological Methods |date=September 1997 |volume=30 |issue=3 |pages=231–234 |doi=10.1016/S0167-7012(97)00071-7 }}</ref> It can be applied to basically all types of
biocatalysis including enzymes, cellular organelles, animal and plant cells and organs.<ref>{{Cite journal |last1=Kowalczyk |first1=Tomasz |last2=Sitarek |first2=Przemysław |last3=Toma |first3=Monika |last4=Rijo |first4=Patricia |last5=Domínguez‐Martín |first5=Eva |last6=Falcó |first6=Irene |last7=Sánchez |first7=Gloria |last8=Śliwiński |first8=Tomasz |date=August 2021 |title=Enhanced Accumulation of Betulinic Acid in Transgenic Hairy Roots of Senna obtusifolia Growing in the Sprinkle Bioreactor and Evaluation of Their Biological Properties in Various Biological Models |url=https://onlinelibrary.wiley.com/doi/10.1002/cbdv.202100455 |journal=Chemistry & Biodiversity |language=en |volume=18 |issue=8 |pages=e2100455 |doi=10.1002/cbdv.202100455 |pmid=34185351 |hdl=10261/247635 |s2cid=235672736 |issn=1612-1872|hdl-access=free }}</ref><ref>{{cite journal |last1=Peinado |first1=Rafael A. |last2=Moreno |first2=Juan J. |last3=Villalba |first3=Jose M. |last4=González-Reyes |first4=Jose A. |last5=Ortega |first5=Jose M. |last6=Mauricio |first6=Juan C. |title=Yeast biocapsules: A new immobilization method and their applications |journal=Enzyme and Microbial Technology |date=December 2006 |volume=40 |issue=1 |pages=79–84 |doi=10.1016/j.enzmictec.2005.10.040 }}</ref> Immobilization is useful for continuously operated processes, since the organisms will not be removed with the reactor effluent, but is limited in scale because the microbes are only present on the surfaces of the vessel.

Large scale immobilized cell bioreactors are: 
*moving media, also known as [[moving bed biofilm reactor]] (MBBR)
*[[packed bed]]
*[[fibrous bed]]
*[[Membrane bioreactor|membrane]]