Biodiesel production in the U.S. from vegetable oils has increased substantially during the past decade. However, its further increase is limited by the low amounts of oil produced per hectare from temperate oilseed crops. Recently novel transgenic sugarcane has been developed to accumulate both sugars and lipids in stems, making it a promising dual-purpose feedstock to produce both ethanol and biodiesel.
Results from analysis and processing of transgenic lipid producing sugarcane (lipid-cane) and the non-transformed sugarcane were published April in Biocatalysis and Agricultural Biotechnology journal. The total lipid concentrations were 0.66, 0.93 and 1.34 g per 100 g dry stem for the non-transformed sugarcane and lipid-cane line, respectively. Lipid composition analysis showed that about 31–33% of the total lipids were triacylglycerols, main feedstock for biodiesel production, for the lipid-cane samples, while this value was only 5% for the non-transformed sugarcane. By processing the sugarcane stems with a juicer, about 90% of the sugars and 60% of the lipids were extracted with juice. The extracted sugars in juice were fermented to ethanol and the lipids were later recovered from the fermented juice using organic solvents. The recovered lipids from the fermented juice were 0.3, 0.5 and 0.8 g/100 g dry stem for the non-transformed sugarcane and lipid-cane lines, respectively.
This study showed that the transgenic lipid-cane could be a potential dual-purpose feedstock for both ethanol and biodiesel production, but it also needs some future improvements to be commercialized, such as increasing lipid concentrations in stems and improving lipid extraction efficiency. Тhe novel lipid-cane have a potential to make a large-scale replacement of fossil derived fuel without unrealistic demands on land area.
Source: Haibo Huang et al, Evaluation of the quantity and composition of sugars and lipid in the juice and bagasse of lipid producing sugarcane, Biocatalysis and Agricultural Biotechnology (2017). DOI: 10.1016/j.bcab.2017.03.003
