Solid-state (substrate) fermentation (SSF) has been defined as the fermentation process occurring in the absence or near-absence of free water. SSF processes generally employ a natural raw material as carbon and energy source. Just this past January, it has been shown that grape and sugar beet pomaces have provided a mechanism for the direct production of bioethanol. In this study, researchers report a laboratory scale SSF to obtain alcohol from grape and sugar beet pomace by means of Saccharomyces cerevisiae yeasts. Furthermore, SSF showed ethanol maximum concentrations after two days and ethanol yield on sugars consumed was more than 82%, suggesting that this yield is in fact sufficient to use SSF to obtain fuel alcohol. Perhaps more promising, however, is a recent article articulating poplar trees as a new source of bioethanol. Researchers from the University of Maryland are currently in the progress of developing means to turn poplar trees into high-yield crops for biofuels including ethanol. The hybrid trees would be grown on plantations and harvested without affecting existing woodlands; the notion that this hybrid would not affect existing woodlands is key to its carbon footprint. Poplar is a perennial plant capable of pulling nitrogen from its leaves, storing it through the winter, and redistributing it in the spring. While a crop like corn must be replanted each year, a poplar tree is capable of regrowing itself from its roots after being cut, and may go through several cycles of growth and harvest throughout its life before a new tree needs to replace it. Since growing trees doesn’t eat into farmland, and trees do not require a lot of maintenance during their growth cycle. A dedicated energy crop like poplar would significantly contribute to the development of a sustainable and renewable energy system. Being one of first groups to work on nitrogen cycling and metabolism in poplar, the Researchers expect to produce a large amount of unprecedented information about the way nitrogen moves around and is stored in a tree.
New-Age Bioethanol Production via Poplar Trees