Synthesis of 2, 5 Dimethyl Furan from Renewable Lignocellulosic Biomass

Renewable biomass resources could reduce the dependency on the fossil fuels by conversion of its lignocellulose into bio-fuels and other valuable chemicals. Depolymerisation of lignocellulose, hydrolysis of cellulose to monomer glucose and its subsequent dehydration results 5-hydroxymethyl furfural (HMF). HMF is an important platform chemical for fuels and various other applications. The hydrogenation of HMF results 2, 5-dimethylfuran (DMF), which may be a biofuel with 40 per cent greater energy density than that of ethanol. The homogeneous catalytic method is preferred for lignocellulosic biomass conversion to cellulose, its hydrolysis and further dehydration to HMF. The Cu-Ru/C and related catalysts are preferred for hydrogenation of HMD to 2, 5-dimethylfuran. This review is an attempt to summarise the current research and developments in the field of lignocellulose derived HMF and further conversion to DMF as a potential biofuel.

Effect of Aerobic Hydrolysis on Anaerobic Fermentation Characteristics of Various Parts of Corn Stover and the Scum Layer

To solve the difficulty of lignocellulose hydrolysis and the formation of crusted scum in anaerobic fermentation, various parts of corn stover, i.e., pith, rind and leaf, were subjected to a two-phase processing including aerobic hydrolysis (AH) and anaerobic fermentation. The results showed that AH significantly broke down the lignin structure of the various components of corn stover and increased the rate of lignin degradation. After 16 h of AH, the lignin degradation rates of the pith, rind and leaf were 4.20%, 3.91% and 4.90%, respectively, and the acetic acid produced accounted for more than 60% of the total amount of volatile fatty acids (VFAs) and ethanol. After hydrolyzing the pith and rind for 12 h and the leaf for 8 h, the maximum methane yields of fresh mass volatile solid (VS) were 323 ml g-1, 251 ml g-1 and 264 ml g-1, respectively, which were increased by 35.02%, 30.05% and 8%, respectively, while the fermentation cycle of T90 (90% of the total gas production) was shortened by 4-5 days. After hydrolyzing the rind and leaf for 12 h and the pith for 16 h, the thicknesses of the scum layer were only 7.1%, 13.6% and 18%, respectively, of that of the untreated group, indicating that AH coupled with anaerobic fermentation can effectively degrade lignin, reduce the thickness of the scum layer and increase the methane yield.

RNA extraction from decaying wood for (meta)transcriptomic analyses

Wood decomposition is a key step of the terrestrial carbon cycle and is of economic importance. It is essentially a microbiological process performed by fungi and to an unknown extent by bacteria. To gain access to the genes expressed by the diverse microbial communities participating in wood decay, we developed an RNA extraction protocol from this recalcitrant material rich in polysaccharides and phenolic compounds. This protocol was implemented on 22 wood samples representing as many tree species from 11 plant families in the Angiosperms and Gymnosperms. RNA was successfully extracted from all samples and converted into cDNAs from which were amplified both fungal and bacterial protein coding genes, including genes encoding hydrolytic enzymes participating in lignocellulose hydrolysis. This protocol applicable to a wide range of decomposing wood types represents a first step towards a metatranscriptomic analysis of wood degradation under natural conditions.