Bioresour. Bioprod., Volume 1, Issue 2 (December 2025) – 4 articles

Wood is a primary bioproduct widely utilized as timber in construction and carpentry. Characterization of its properties, particularly moisture response, is essential for industrial performance. The Fiber Saturation Point (FSP) influences the dimensional stability and efficiency of industrial processes such as drying. This study determines the maximum dimensional variation and the FSP of Eucalyptus nitens solid wood from plantations in Northwestern Spain, studying 354 specimens of 20 × 20 × 50 mm. Mean and median values were calculated considering and omitting outliers. Additionally, a graphical FSP value was obtained by applying the statistical theory of the center of gravity, defined as the intersection of lines derived from the two-dimensional data distribution. For maximum dimensional variation, the analysis yielded mean values of 5.2% [±1.53] and 11.2% [±2.84] and medians of 4.8% and 10.4%, in radial and tangential directions, respectively. The mean FSP was 29.9% [±7.95], the median 28.9%, and the graphical estimate 30.8%. Establishing the FSP defines the critical moisture threshold at which significant changes in physical and mechanical properties, as well as dimensional alterations, occur in this bioresource, particularly for its use as a bioproduct in carpentry and construction or for industrial wood drying. Full article

Fatty acid desaturase 12 (FAD12) is a key enzyme in fatty acid biosynthesis, responsible for converting oleic acid to linoleic acid through desaturase activity. Euglena gracilis (Euglena) is an emerging platform for the industrial production of various metabolites, including lipids. However, a comprehensive understanding of Euglena’s fatty acid biosynthesis pathways remains incomplete, posing a significant barrier to the commercialization of Euglena bioproducts. To address this gap, we employed a bioinformatics approach to identify a Euglena gracilis FAD12 (Eg FAD12). We analyzed the evolutionary relationship of Eg FAD12 with its homologs from other organisms and revealed that the three canonical histidine box motifs are conserved among FAD12s. To characterize EgFAD12, we cloned it into the pEAQ-hyperstrans vector and overexpressed it in Nicotiana benthamiana to take advantage of its endogenous fatty acid pool, which could act as a substrate. The heterologous expression of FAD12 in N. benthamiana led to an increased linoleic acid content, demonstrating the suspected desaturase activity. To further confirm the function of Eg FAD12, we performed CRISPR-Cas9-mediated knockout of Eg FAD12 in Euglena, which resulted in a drastic reduction in linoleic acid (C18:2) without compromising biomass yield or lipid content. This work advances our understanding of fatty acid biosynthesis in Euglena and will aid in its adoption as a platform for producing customized lipids. Full article

Methane is a potent greenhouse gas that requires its emissions to be mitigated. A significant source for methane emissions is in the form of the biogas that is produced from anaerobic digestion in wastewater reclamation and landfill facilities. Biogas has a high valorization potential in the form of its bioconversion into ectoines, an active ingredient in skin care products, by halotolerant alkaliphilic methanotrophs. Cultures of Methylotuvimicrobium alcaliphilum 20Z were grown in bench scale stirred-tank reactors to determine factors to improve methane uptake and removal. Tangential flow filtration was also implemented for a bio-milking method to recover ectoine from culture media. Methane uptake and reactor productivity increased, with a temperature of 28 °C compared with 21 °C. Decreasing the methane gas bubble diameter by decreasing the sparger pore size from 1 mm to 0.5 µm significantly improved methane removal and reactor productivity by increasing mass transfer. Premixing methane and air before sparging into the reactor saw a higher removal of methane, while sparging methane and air separately created an increase in reactor productivity. Maximum methane removal efficiency was observed to be 70.56% ± 0.54 which translated to a CH₄-EC of 93.82 ± 3.36 g CH₄ m⁻³ h⁻¹. Maximum ectoine yields was observed to be 0.579 mg ectoine L⁻¹ h⁻¹. Full article

Spontaneous combustion of charcoal is still not fully understood, generating uncertainties among producers, regulatory agencies, and the scientific community. This study evaluated the influence of final pyrolysis temperature (350, 450, 550, and 650 °C) on the properties of Eucalyptus spp. charcoal and its relation to ignition behavior. Gravimetric yield, proximate composition, calorific value, and ignition temperature were determined. Charcoal yield decreased by 31% between 350 °C and 650 °C. Fixed carbon content increased from ~65% to ~93%, accompanied by a reduction in volatile matter (~35% to ~6%) and a corresponding rise in calorific value. Step-heating experiments, conducted in a furnace with infrared camera monitoring, showed that ignition temperature increased from ~273 °C in charcoal produced at 350 °C to ~424 °C in charcoal produced at 650 °C. Strong correlations indicated that higher fixed carbon and lower volatile matter contents are directly associated with higher ignition temperatures. These results demonstrate that increasing the final pyrolysis temperature improves both the thermal stability and the energy quality of charcoal, although at the expense of gravimetric yield. Since the methodology was based on forced heating rather than spontaneous combustion under near-ambient conditions, complementary tests are required to evaluate spontaneous combustion propensity. Overall, the findings provide practical insights to balance yield, quality, and safety while reinforcing the importance of standardized assessment protocols to ensure safer storage and transport of charcoal. Full article