SummaryA precursor of miR156 (MsmiR156d) was cloned and overexpressed in alfalfa (Medicago sativa L.) as a means to enhance alfalfa biomass yield. Of the five predicted SPL genes encoded by the alfalfa genome, three (SPL6, SPL12 and SPL13) contain miR156 cleavage sites and their expression was down-regulated in transgenic alfalfa plants overexpressing miR156. These transgenic plants had reduced internode length and stem thickness, enhanced shoot branching, increased trichome density, a delay in flowering time and elevated biomass production. Minor effects on sugar, starch, lignin and cellulose contents were also observed. Moreover, transgenic alfalfa plants had increased root length, while nodulation was maintained. The multitude of traits affected by miR156 may be due to the network of genes regulated by the three target SPLs. Our results show that the miR156/SPL system has strong potential as a tool to substantially improve quality and yield traits in alfalfa.

A novel route has been developed that yields levulinic acid (4-oxopentanoic acid, LA) and 5-hydroxymethylfurfural (5-HMF) from chitosan. Hydrolysis of chitosan was performed in the presence of a range of Lewis acids with SnCl 4 ·5H 2 O providing the best results. All reactions were performed in sealed vessels under microwave irradiation at 200°C for 30 min. Typical pressures achieved were 17 to 19 bar. 23.9 wt% LA was produced from 100 mg chitosan using 0.24 mmol SnCl 4 ·5H 2 O and 4 mL water. Under more dilute conditions, 10.0 wt% 5-HMF was obtained using 0.12 mmol SnCl 4 ·5H 2 O and 15 mL water. We propose that under more concentrated reaction conditions the 5-HMF formed reacts further to produce LA. When chitin is treated similarly, no 5-HMF is produced but up to 12.7 wt% LA can be obtained. For comparison, 32.0 wt% LA was produced from 100 mg glucosamine hydrochloride using 0.26 mmol SnCl 4 ·5H 2 O and 20 mL water. This corresponds to a yield of 59.4%. The SnCl 4 forms SnO 2 and HCl in solution and under similar conditions using SnO 2 and HCl, chitosan formed 27.4 wt% LA.

Research into renewable chemicals, fuels and materials sourced from the oceans at Memorial University and elsewhere is employing green chemical technologies for the transformation of algae and food industry waste streams into useful products. A very small proportion of biomass utilization research is currently focused on these feedstocks and efforts focused in this area could reduce land space competition between food and chemical/fuel production. This perspective highlights some of the achievements and potential opportunities surrounding the use of algae and waste from shellfish and finfish processing. In particular, investigations in this field have used alternative solvents (water, supercritical carbon dioxide and methanol or ionic liquids) extensively. Supercritical Fluid Extraction (SFE) has been used to extract lipids and pigments from algae, and oils from fish-processing plant waste streams. Water can be used to isolate potentially high value biologically-active oligosaccharides from some seaweeds. Biotechnological approaches are showing promise in the separation of biopolymers from shellfish waste streams. Production of new nitrogen-containing bioplatform chemicals (e.g. 3-acetamido-5-acetylfuran) from aminocarbohydrates (chitin, chitosan and N-acetylglucosamine) is being pursued.

An efficient process for converting N-acetyglucosamine (NAG) into 3-acetamido- This solution-phase process produces approximately 30 times more 3A5AF than via a previously reported pyrolysis route.

An effective method for transforming an amino-sugar into an N-substituted furan in an ionic liquid is reported. B(OH) 3 significantly improves the yield (60%, 3 min MW heating).