Moss is a very frugal
photoautotrophic organism that has been kept in vitro for research purposes since the beginning of the 20th century.[1]
The first moss
bioreactors for the
model organismPhyscomitrella patens were developed in the 1990s to comply with the safety standards regarding the handling of genetically modified organisms and to gain sufficient
biomass for experimental purposes.[2]
Functional principle
The moss bioreactor is used to cultivate moss in a suspension culture in agitated, and aerated liquid medium. The culture is kept under lighting with temperature and
pH value held constant. The
culture medium—often a
minimal medium—contains all
nutrients and
minerals needed for growth of the moss.[3]
To ensure a maximum growth rate, the moss is kept at the
protonema stage by continuous mechanical disruption, e.g. by using rotating blades.[4] Once the density of the culture has reached a certain threshold, the lack of nutrients and the increasing concentration of
phytohormones in the medium triggers the differentiation of the protonema to the adult
gametophyte. At this point the culture has to be diluted with fresh medium if it is intended for further use.
According to the intended yield, this basic principle can be adapted to various types and sizes of bioreactors. The cultivation chamber can, for example, consist of a column, a tube, or exchangeable plastic bags.[5]
^Hohe, A.;
Reski, R. (2005). "From axenic spore germination to molecular farming: one century of bryophyte in vitro culture". Plant Cell Reports. 23 (8): 513–521.
doi:
10.1007/s00299-004-0894-8.
PMID15558285.
^Hohe, A.; Reski, R. (June 2005). "Control of growth and differentiation of bioreactor cultures of Physcomitrella by environmental parameters". Plant Cell, Tissue and Organ Culture. 81 (3): 307–311.
doi:
10.1007/s11240-004-6656-z.
^Decker, E. L.; Reski, R. (April 2004). "The moss bioreactor". Current Opinion in Plant Biology. 7 (2): 166–170.
doi:
10.1016/j.pbi.2004.01.002.
^Homepage of greenovation GmbH, showing various types of moss bioreactors:
[1]Archived November 9, 2011, at the
Wayback Machine
^Decker, Eva L.; Reski, Ralf (2008). "Current achievements in the production of complex biopharmaceuticals with moss bioreactors". Bioprocess and Biosystems Engineering. 31 (1): 3–9.
doi:
10.1007/s00449-007-0151-y.
PMID17701058.