neutropenia and aplastic anemia) in transgenic sugarcane plants. Accumulation of
GM-CSF protein ranged from undetectable to 0.02 of total soluble protein. Human
bone marrow cells (TF-1), which require GM-CSF for cell division, proliferated
when growth media was supplemented with transgenic sugarcane extracts. Comparison to purified commercially produced GM-CSF indicated that sugarcaneproduced protein had essentially identical activity levels. In a 14-month field trial,
accumulation levels remained stable.
Arvinth et al. (2010) transformed sugarcane cultivars Co 86032 and CoJ 64
with the cry1Ab gene driven by maize ubiquitin promoter through particle bombardment and Agrobacterium-mediated transformation systems. Gene pyramiding
was also attempted by retransforming sugarcane plants carrying the bovine
pancreatic trypsin inhibitor (aprotinin, which reduces bleeding during complex
surgeries) gene, with cry1Ab. Aprotinin-expressing sugarcane pyramided with
cry1Ab showed reduction in damage by the shoot borer Chiloinfuscatellus.
Henrique-Silva and Soares-Costa (2012) generated transgenic sugarcane
expressing a His-tagged cystatin (a human protein used as biomarker for the
identification and prevention of various diseases) under the control of the maize
ubiquitin promoter. A transformed sugarcane plant presented high levels of protein
expression and was selected for the purification of this protein through affinity
chromatography in nickel columns. Therefore, it was demonstrated that sugarcane
can be a viable expression system for recombinant protein production and that the
His-tag purification strategy used to isolate the purified protein was effective.
Recently, Barros et al. (2013) generated transgenic sugarcane expressing
recombinant bovine lysozyme (BvLz, used to control gram-negative pathogenic
bacteria) in order to evaluate the feasibility of extraction and fractionation of
recombinant proteins expressed in sugarcane stalks. Partial removal of native
proteins was achieved using a 100 kDa membrane, but 20–30 % of the extracted
BvLz was lost. Concentration of clarified extracts using a 3 kDa membrane
resulted in twofold purification and 65 % recovery of BvLz. Loading of concentrated sugarcane extract on hydrophobic interaction chromatography (HIC)
resulted in 50 % BvLz purity and 69 % recovery of BvLz.
5.5 Sugarcane Biofactory for High-Value Carbohydrates
and Alternative Sugars
Other research groups have focused on developing sugarcane as a platform for the
production of higher value isomers of sucrose such as isomaltulose and trehalose.
Isomaltulose is a natural isomer of sucrose. It is widely approved as a food with
properties including slower digestion, a lower glycaemic index, and low cariogenicity, which can benefit consumers. Furthermore, isomaltulose displays
reducing properties that make it attractive as industrial precursor for the manufacturing of biosurfactants and biopolymers (Lichtenthaler and Peters 2004;
136
F. C. Gómez-Merino et al.
GM-CSF protein ranged from undetectable to 0.02 of total soluble protein. Human
bone marrow cells (TF-1), which require GM-CSF for cell division, proliferated
when growth media was supplemented with transgenic sugarcane extracts. Comparison to purified commercially produced GM-CSF indicated that sugarcaneproduced protein had essentially identical activity levels. In a 14-month field trial,
accumulation levels remained stable.
Arvinth et al. (2010) transformed sugarcane cultivars Co 86032 and CoJ 64
with the cry1Ab gene driven by maize ubiquitin promoter through particle bombardment and Agrobacterium-mediated transformation systems. Gene pyramiding
was also attempted by retransforming sugarcane plants carrying the bovine
pancreatic trypsin inhibitor (aprotinin, which reduces bleeding during complex
surgeries) gene, with cry1Ab. Aprotinin-expressing sugarcane pyramided with
cry1Ab showed reduction in damage by the shoot borer Chiloinfuscatellus.
Henrique-Silva and Soares-Costa (2012) generated transgenic sugarcane
expressing a His-tagged cystatin (a human protein used as biomarker for the
identification and prevention of various diseases) under the control of the maize
ubiquitin promoter. A transformed sugarcane plant presented high levels of protein
expression and was selected for the purification of this protein through affinity
chromatography in nickel columns. Therefore, it was demonstrated that sugarcane
can be a viable expression system for recombinant protein production and that the
His-tag purification strategy used to isolate the purified protein was effective.
Recently, Barros et al. (2013) generated transgenic sugarcane expressing
recombinant bovine lysozyme (BvLz, used to control gram-negative pathogenic
bacteria) in order to evaluate the feasibility of extraction and fractionation of
recombinant proteins expressed in sugarcane stalks. Partial removal of native
proteins was achieved using a 100 kDa membrane, but 20–30 % of the extracted
BvLz was lost. Concentration of clarified extracts using a 3 kDa membrane
resulted in twofold purification and 65 % recovery of BvLz. Loading of concentrated sugarcane extract on hydrophobic interaction chromatography (HIC)
resulted in 50 % BvLz purity and 69 % recovery of BvLz.
5.5 Sugarcane Biofactory for High-Value Carbohydrates
and Alternative Sugars
Other research groups have focused on developing sugarcane as a platform for the
production of higher value isomers of sucrose such as isomaltulose and trehalose.
Isomaltulose is a natural isomer of sucrose. It is widely approved as a food with
properties including slower digestion, a lower glycaemic index, and low cariogenicity, which can benefit consumers. Furthermore, isomaltulose displays
reducing properties that make it attractive as industrial precursor for the manufacturing of biosurfactants and biopolymers (Lichtenthaler and Peters 2004;
136
F. C. Gómez-Merino et al.