scalability (As their products do not need expensive additives and ecologically
damaging pre- as well as post-treatment processes) and no endotoxin production in
photoautotrophic organisms make them commercially appropriate hosts for SynBio
approaches (Roell and Zurbriggen 2020). Standardized methods have been
recognized to improve the design of molecular farming products and furthermore,
plant cell suspension cultures can be screened to opt the most prolific cells to be used
for high-yielding monoclonal cell lines (Kirchhoff et al. 2012). The moss
Physcomitrella patens, a model organism in SynBio, is an excellent green metabolic
cell factory for the characterisations of novel biosynthetic pathways and sustainable
production of highly valuable compounds such as terpenoids (Pan et al. 2015),
biopharmaceuticals (Reski et al. 2015) and cosmetic products (Henes et al. 2018).
Mosses have delivered the efficiency in the delivery of taxadiene synthase from
Taxus brevifolia (Anterola et al. 2009), an enzyme required for the synthesis of a
precursor of an anticancer drug—paclitaxel (Baird et al. 2010) and to produce the
antimalarial drug artemisinin (Ikram and Simonsen 2017). P. patens have also been
engineered for the delivery of sesquiterpenoids like sanatlol, patchoulol synthase
alpha/beta-santalene synthase, a diterpenoid Sclareol (sclareol) in fragrance industry
(Zhan et al. 2014; Pan et al. 2015). Rerouting the synthetic pathway of patchoulol
from the cytosol to plastids enhanced the metabolic flux and consequently increased
the production yield (Zhan et al. 2014). Another aspect is the difficulty to retrieve
fragrance compounds because of the volatility and hydrophobicity. In this regard,
Peramuna et al. (2018) showed that the introduction of patchoulol synthase on the
lipid droplet membrane of P. Patens enhances the storage ability of the cell, thus
recovering its assortment. Recently, insight into an efficient growth of bryophytes in
bioreactors is being looked into so as to enable its application in the manufacture of
valuable bio-products like pharmaceuticals (Tschofen et al. 2016). Several human
proteins are being produced in moss P. patens as potential biopharmaceuticals like
tumour-directed monoclonal antibodies with enhanced antibody-dependent cytotoxicity, vascular endothelial growth factor and many more. The plant made
pharmaceuticals (PMPs) are not only analogous to those produced in mammalian
systems, but are of superior quality, thus called as Biobetters. Clinical trials are being
carried out to assess the feasibility of the moss system as chassis for next-generation
biobetter pharmaceuticals (Reski et al. 2015). However, for broad-spectrum profit,
mosses should be engineered for tolerance against strong light and drought. Secondly, the establishment of the first synthetic plant cell, for which P. patens would be
perfect, with a minimal genome would probably direct towards simpler engineering
(Reski et al. 2018).
Woodard et al. (2003) characterized the expression of bovine trypsin in maize
seeds by inserting inactive trypsinogen under the regulation of the embryo-preferred
globulin-I promoter and the optimized barley α-amylase signal sequence. Inactive
trypsinogen gets activated by autocatalytic processing and/or endopeptidases in the
seeds. Kim et al. (2014) also produced recombinant bovine trypsin in rice cell
suspension cultures under the regulation of sucrose starvation–inducible rice
α-amylase 3D promoter. Plant-based tough, elastic, fibrous animal proteins can be
utilized to produce pathogen-free sustainable biopolymers, thus substituting
460
P. Singla
damaging pre- as well as post-treatment processes) and no endotoxin production in
photoautotrophic organisms make them commercially appropriate hosts for SynBio
approaches (Roell and Zurbriggen 2020). Standardized methods have been
recognized to improve the design of molecular farming products and furthermore,
plant cell suspension cultures can be screened to opt the most prolific cells to be used
for high-yielding monoclonal cell lines (Kirchhoff et al. 2012). The moss
Physcomitrella patens, a model organism in SynBio, is an excellent green metabolic
cell factory for the characterisations of novel biosynthetic pathways and sustainable
production of highly valuable compounds such as terpenoids (Pan et al. 2015),
biopharmaceuticals (Reski et al. 2015) and cosmetic products (Henes et al. 2018).
Mosses have delivered the efficiency in the delivery of taxadiene synthase from
Taxus brevifolia (Anterola et al. 2009), an enzyme required for the synthesis of a
precursor of an anticancer drug—paclitaxel (Baird et al. 2010) and to produce the
antimalarial drug artemisinin (Ikram and Simonsen 2017). P. patens have also been
engineered for the delivery of sesquiterpenoids like sanatlol, patchoulol synthase
alpha/beta-santalene synthase, a diterpenoid Sclareol (sclareol) in fragrance industry
(Zhan et al. 2014; Pan et al. 2015). Rerouting the synthetic pathway of patchoulol
from the cytosol to plastids enhanced the metabolic flux and consequently increased
the production yield (Zhan et al. 2014). Another aspect is the difficulty to retrieve
fragrance compounds because of the volatility and hydrophobicity. In this regard,
Peramuna et al. (2018) showed that the introduction of patchoulol synthase on the
lipid droplet membrane of P. Patens enhances the storage ability of the cell, thus
recovering its assortment. Recently, insight into an efficient growth of bryophytes in
bioreactors is being looked into so as to enable its application in the manufacture of
valuable bio-products like pharmaceuticals (Tschofen et al. 2016). Several human
proteins are being produced in moss P. patens as potential biopharmaceuticals like
tumour-directed monoclonal antibodies with enhanced antibody-dependent cytotoxicity, vascular endothelial growth factor and many more. The plant made
pharmaceuticals (PMPs) are not only analogous to those produced in mammalian
systems, but are of superior quality, thus called as Biobetters. Clinical trials are being
carried out to assess the feasibility of the moss system as chassis for next-generation
biobetter pharmaceuticals (Reski et al. 2015). However, for broad-spectrum profit,
mosses should be engineered for tolerance against strong light and drought. Secondly, the establishment of the first synthetic plant cell, for which P. patens would be
perfect, with a minimal genome would probably direct towards simpler engineering
(Reski et al. 2018).
Woodard et al. (2003) characterized the expression of bovine trypsin in maize
seeds by inserting inactive trypsinogen under the regulation of the embryo-preferred
globulin-I promoter and the optimized barley α-amylase signal sequence. Inactive
trypsinogen gets activated by autocatalytic processing and/or endopeptidases in the
seeds. Kim et al. (2014) also produced recombinant bovine trypsin in rice cell
suspension cultures under the regulation of sucrose starvation–inducible rice
α-amylase 3D promoter. Plant-based tough, elastic, fibrous animal proteins can be
utilized to produce pathogen-free sustainable biopolymers, thus substituting
460
P. Singla