Lignocellulosic biomass is a promising renewable resource for the production of biofuels and biochemicals. Energycane is considered a lignocellulosic biomass characterized by its high fiber content and cold tolerance. It can be planted on marginal land and does not need to compete with the food supply. Wet storage in combination with sodium hydroxide (NaOH) or white-rot fungi was applied to energycane bagasse to preserve the lignocellulosic polymeric sugars (cellulose and hemicellulose) during short-term storage (60 days) and to make them accessible for conversion into biofuels and biochemicals.
Alkaline-assisted wet storage was successful in preserving the biomass by minimizing microbial degradation, increasing lignin degradation, preventing cellulose degradation, and enhancing sugar digestibility. Four sodium hydroxide loadings (0, 5, 7.5, and 10 g NaOH/kg dry matter) at two moisture contents (45% and 75%) were applied to energycane bagasse. Higher loadings of sodium hydroxide and lower moisture content resulted in less cellulose degradation and greater lignin degradation. Higher moisture content (75%) resulted in higher sugar digestibility. Sodium hydroxide loading of 10% wt. at a moisture content of 45% was the optimal condition that preserved the most glucan (40%), degraded the most lignin (67%) and hemicellulose (48%), and resulted in 69% cellulose digestibility and 43% hemicellulose digestibility during the 60 days storage of energycane bagasse.
Fungal-assisted wet storage using white-rot fungus, Ceriporiopsis subvermispora, was also successful in preserving the biomass by inhibiting microbial growth, increasing lignin degradation, preventing cellulose degradation, and enhancing sugar digestibility. At 75% moisture, fungal-assisted storage of energycane bagasse resulted in 44% lignin degradation and 2% cellulose loss as compared to 14% and 31% from untreated samples, respectively. The majority of lignin degradation occurred after 10 days, and no significant difference (p > 0.05) was observed in fungal treated samples after 50 days. Cellulose digestibility (67%) and hemicellulose digestibility (34%) of white-rot fungus treated samples were higher than untreated samples (38% and 20%, respectively).
This study indicated that sodium hydroxide and white-rot fungal assisted wet storage were efficient in preserving glucan, removing lignin and increasing sugar digestibility of energycane bagasse.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04042016-153937 |
| Date | 15 April 2016 |
| Creators | Cao, Jing |
| Contributors | Aita, Giovanna, Losso, Jack N., Xu, Zhimin |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04042016-153937/ |
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