Analysis Package P19 : Deluxe Lignocellulose Package

The biofuel production potentials for encroacher and invasive bush biomass species found in Southern Africa were assessed using different valorization routes. Theoretical models were employed to calculate the biofuel yields. The gasification-catalytic route produced highest ethanol yields (450–488 L/t) while the lowest values were from enzymatic/acid hydrolysis-to-fermentation route. Blue gum gave the highest ethanol yields. Biodiesel and naphtha yields produced through Fischer-Tropsch synthesis were highest for blue gum (196 L/t) and lowest for Acacia raficiens (176 L/t). The highest biogas and biomethane potential of 458 L/kg.VS and 229 L/kg.VS respectively were obtained from black wattle while the respective lower values (270 L/kg.VS and 132 L/kg.VS) were recorded for blue gum. Senegalia mellifera gave the highest torrefied biofuel energy and mass yields at 0.92 and 0.97 respectively while black wattle had the lowest mass and energy yields at 0.75 and 0.83 respectively. From an energy yield basis, the acid hydrolysis-fermentation route yielded an average of 3.69 GJ/t of biomass while the highest yields came from the gasification-catalytic conversion route which was 9.7 GJ/t. The average energy yield variations across biomass species ranged 5.11–6.19 GJ/t which is around 30 % of the raw biomass' calorific value. These early results provide insights towards the best pairing of appropriate biomass species and energy conversion route. Further evaluations of these biomass-valorization technology pairing to unpack process efficiencies, cost and kinetics are required using real process experiments instead of using theoretical models. These additional tests should include sustainability assessment to guide future commercialization decisions.

Understanding the transcriptional regulation of biomass accumulation and sucrose storage is critical for enhancing sugarcane productivity. In this study, we quantified transcription factor protein (TFP) abundance across sugarcane internodes at different developmental stages and growth rates, correlating these profiles with key biochemical traits including lignin, glucan, hemicellulose, and sucrose content. Among 7333 proteins identified, 205 were classified as transcription factors spanning 22 families. Trait-centric correlation networks revealed 107 TFP-trait associations via Pearson correlation; refinement using the Partial Correlation with Information Theory (PCIT) algorithm identified 46 high-confidence regulatory links. Key transcription factors, such as ScMYB113, ScMADS15, and ScbZIP85, displayed trait-specific roles in coordinating sucrose storage and cell wall biosynthesis. Network topology uncovered distinct regulatory modules associated with biomass production, structural polysaccharide deposition, and intermediary metabolism. Notably, sucrose and lignin accumulation primarily occurred after internode elongation ceased, implicating shifts in transcriptional regulation during maturation. This study delivers the first protein-level regulatory map linking TF abundance to metabolic traits in sugarcane and provides a robust framework for identifying candidate regulators to optimize biomass quality and yield for bioenergy applications.

Sugarcane is a globally important C4 crop traditionally bred for sucrose yield. However, its potential as a bioenergy crop depends on understanding lignocellulosic quality across developmental stages and environments. This study investigates the variability in fibre composition and theoretical digestibility among 17 sugarcane genotypes grown at two contrasting locations in northern Queensland. Plants were sampled at maximum vegetative growth and at peak sucrose accumulation. Fibre traits, including glucan, xylan, and lignin content, were quantified, and digestibility was estimated using cell wall composition ratios. The results revealed that digestibility declined with plant age, primarily due to increased lignin and xylan deposition. However, several genotypes maintained relatively high digestibility even at later stages. The study also identified substantial genotype-environment interactions influencing biomass quality. These findings suggest that harvesting sugarcane earlier in the cropping cycle, particularly when sucrose is not the main product, could improve fibre digestibility and biomass yield per unit time. This supports the use of sugarcane in circular bioeconomy systems and highlights opportunities for developing dual-purpose cropping strategies that align with sustainability goals.

The relationship between metabolic changes occurring in the developing internodes of sugarcane and the final yield and sugar characteristics is poorly understood due to the lack of integration between phenotypic and metabolic data. To address this issue, a study was conducted where sugarcane metabolism was modeled based on the measurement of cellular components in the top internodes, at two stages of crop development. The study also looked at the effects of Trinexapac-ethyl (Moddus) on growth inhibition. The metabolome was measured using GC-analysis, while LC-MS/MS was used to measure proteome changes in the developing internodes. These data were then integrated with the metabolic rates. Regardless of the growth rate, internode elongation was restricted to the top five internodes. In contrast, sucrose and lignin accumulation was sensitive to the growth rate. Crossover plots showed that sucrose accumulation only occurred once the cell wall synthesis had slowed down. These data suggest that sucrose accumulation controlled a reduction in sucrose breakdown for metabolic activity and a reduction in demand for carbon for cell wall polysaccharide synthesis. This study also found that nucleotide sugar metabolism appears to be a key regulator in regulating carbon flow during internode development.