Lignocellulosic biomass is both low cost and abundant, and unlike energy crops, can escape associated ethical dilemmas such as arable land use and food security issues. However, their usage as raw material in a biorefinery implies an inherent upstream pretreatment step to access compounds of interest derived from lignocellulosic biomass. Importantly, the efficiency of this step is determinant for the downstream processes, and while many pretreatment methods have been explored, extrusion is both a very flexible and promising technology. Extrusion is well-known in both the polymer and pharmaceutical industries and has been used since the 18th century. However, as a pretreatment method for lignocellulosic biomass, extrusion is relatively new. The first use for this purpose dates back to the 1990s. Extrusion enjoys a high degree of flexibility due to the many available parameters, but an understanding of extrusion requires a knowledge of these parameters and the different relationships between them. In this paper, we present a concise overview of lignocellulosic biomass extrusion by reviewing key extrusion parameters and their associated extruder design components and operating conditions.

Co-contamination of polycyclic aromatic hydrocarbons (PAHs) with heavy metals (HMs) in aquatic environments is a global threat; however, little is understood about PAH biodegradation in these sites. In this study, PAHs’ biodegradation in the presence of HMs in water by a metal-tolerant consortium composed of Bacillus subtilis and fungus Acremonium sp. was investigated. The consortium demonstrated higher tolerance to the tested HMs (Fe²⁺, Al³⁺, Ni²⁺, Cu²⁺, Mn²⁺ and Zn²⁺) than the individual consortium components, and the tolerance to individual metals decreased with increasing metal concentrations. In the absence of HMs in aquatic systems, the consortium efficiently degraded naphthalene, fluorine, phenanthrene, anthracene and fluoranthene individually (50 mmol/L) over 10 days. However, while Ni²⁺ supplementation (5 mmol/L) suppressed phenanthrene and anthracene removal (p ≤ 0.01), enhanced fluoranthene degradation relative to the control was observed. Cu²⁺, Zn²⁺, Fe²⁺ and Al³⁺ supplementation demonstrated significant inhibition against individual phenanthrene, anthracene and fluoranthene removal, and Cu²⁺ showed a more significant effect on the degradation of these PAH compounds compared to other metals. Conversely, Mn²⁺ significantly enhanced the removal of fluorene, phenanthrene and fluoranthene, but inhibited anthracene degradation. HM contamination in aquatic systems did not show any effect on naphthalene bioremediation, possible due to its rapid degradation over a short time. Thus, metals affect PAH aquatic biodegradation by consortia, depending on metal species and PAH compound, underlining the complex nature of co-contaminated systems containing HMs and PAHs. To our knowledge, this is the first study to examine the influence of HMs on PAHs’ bioremediation by such PAH-degrading consortia in water.

Little is known about the chemical structure of purified extracellular polysaccharides from Phellinus sp., a fungal species with known medicinal properties. A combination of IR spectroscopy, methylation analysis and NMR were performed for the structural analysis of a purified extracellular polysaccharide derived from Phellinus sp. culture, denoted as SHP-1, along with an evaluation of the anti-aging effect in vivo of the polysaccharide supplementation. The structure of SHP-1 was established, with a backbone composed of →2,4)-α-D-glucopyranose-(1→ and →2)-β-D-mannopyranose-(1→ and two terminal glucopyranose branches. Biochemical analysis from mammalian animal experiments demonstrated that SHP-1 possesses the ability to enhance antioxidant enzyme activities, such as catalase (CAT) and superoxide dismutase (SOD) activities, Trolox equivalent antioxidant capacity (TEAC) in serum of D-galactose-aged mice, while reducing lipofuscin levels, another indicator of cell aging, indicating a potential association with anti-aging activities in a dose dependent manner. This compound had a favourable influence on immune organ indices, and a marked amelioration ability of histopathological hepatic lesions such as necrosis, karyolysis and reduced inflammation and apoptosis in mouse hepatocytes. These results suggest that SHP-1 has strong antioxidant activities and a significant protective effect against oxidative stress or hepatotoxicity induced by D-galactose in mice and it could be developed as a food ingredient or a pharmaceutical to prevent many age-associated diseases such as major depressive disorder and hepatotoxicity. To our knowledge, this is the first report on the antioxidant effects of a novel purified exopolysaccharide derived from Phellinus sp.