Additives Incorporated in Cellulose Acetate Membranes to Improve Its Performance as a Barrier in Periodontal Treatment

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young's modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

Lignin-Assisted Water Electrolysis for Energy-Saving Hydrogen Production With Ti/PbO2 as the Anode

Replacing the oxygen evolution reaction (OER), which is of high energy consumption and slow kinetics, with the more thermodynamically favorable reaction at the anode can reduce the electricity consumption for hydrogen production. Here we developed a lignin-assisted water electrolysis (LAWE) process by using Ti/PbO2 with high OER overpotential as the anode aimed at decreasing the energy consumption for hydrogen production. The influence of key operating parameters such as temperature and lignin concentration on hydrogen production was analyzed. Compared with alkaline water electrolysis (AWE), the anode potential can be decreased from 0.773 to 0.303 (V vs. Hg/HgO) at 10 mA/cm2 in LAWE, and the corresponding cell voltage can be reduced by 546 mV. With increasing the temperature and lignin concentration, current density and H2 production rate were efficiently promoted. Furthermore, the anode deactivation was investigated by analyzing the linear sweep voltammetry (LSV) and cyclic voltammetry (CV) tests. Results showed that the anode deactivation was affected by the temperature.

Ultrasonic or Microwave Cascade Treatment of Medicinal Plant Waste

In this study, we present a strategy for valorizing lignocellulosic wastes (licorice root and willow bark) that result from industrial extraction of active principles using water as green solvent and aqueous NaOH solution. The wastes were submitted to severe ultrasound (US) and microwave (MW) treatments. The aim of these treatments was to extract the remaining active principles (using water as a solvent) or to prepare them for cellulose enzymatic hydrolysis to hexoses (performed in an NaOH aqueous solution). The content of glycyrrhizic acid and salicin derivatives in licorice root and willow bark wastes, respectively, were determined. The best results for licorice root were achieved by applying the US treatment for 5 min at 25 °C (26.6 mg glycyrrhizic acid/gDM); while, for willow bark, the best results were achieved by applying the MW treatment for 30 min at 120 °C (19.48 mg salicin/gDM). A degradation study of the targeted compounds was also performed and showed good stability of glycyrrhizic acid and salicin derivatives under US and MW treatments. The soluble lignin concentration prior to enzymatic hydrolysis, as well as the saccharide concentration of the hydrolyzed solution, were determined. As compared with the MW treatment, the US treatment resulted in saccharides concentrations that were 5% and 160% higher for licorice root and willow bark, respectively.

Screening and Comparison of Lignin Degradation Microbial Consortia from Wooden Antiques

Lignin, which is a component of wood, is difficult to degrade in nature. However, serious decay caused by microbial consortia can happen to wooden antiques during the preservation process. This study successfully screened four microbial consortia with lignin degradation capabilities (J-1, J-6, J-8 and J-15) from decayed wooden antiques. Their compositions were identified by genomic sequencing, while the degradation products were analyzed by GC-MS. The lignin degradation efficiency of J-6 reached 54% after 48 h with an initial lignin concentration of 0.5 g/L at pH 4 and rotation speed of 200 rpm. The fungal consortium of J-6 contained Saccharomycetales (98.92%) and Ascomycota (0.56%), which accounted for 31% of the total biomass. The main bacteria in J-6 were Shinella sp. (47.38%), Cupriavidus sp. (29.84%), and Bosea sp. (7.96%). The strongest degradation performance of J-6 corresponded to its composition, where Saccharomycetales likely adapted to the system and improved lignin degradation enzymes activities, and the abundant bacterial consortium accelerated lignin decomposition. Our work demonstrated the potential utilization of microbial consortia via the synergy of microbial consortia, which may overcome the shortcomings of traditional lignin biodegradation when using a single strain, and the potential use of J-6 for lignin degradation/removal applications.

Decomposition and temperature sensitivity of fine root and leaf litter of 43 mediterranean species

Aims Data on the decomposition of fine roots are scarce for the Mediterranean basin. This work aims to compare chemical traits, decomposition rate, and temperature sensitivity (Q10) for root and leaf litter of 43 Mediterranean species. Methods We carried out a two-years litterbag decomposition experiment using 43 fine roots litter and leaf litter types incubated in laboratory conditions at three different temperatures, i.e. 4 °C, 14 °C, and 24 °C. Litter was characterized for carbon (C), nitrogen (N), lignin and cellulose concentration, C/N, and lignin/N ratios. Results Fine root litter had lower N content but higher lignin concentration, lignin/N, and C/N ratios compared to leaf litter. The decay rate of fine root litter was slower than leaf litter. For both tissues, the decay rate was negatively associated with lignin concentration, lignin/N, and C/N ratios but positively with N concentration. Q10 was higher for fine root than leaf litter, with a positive correlation with lignin while negative with N concentration. Conclusions Our findings demonstrate a higher Q10 accompanied by a slower decomposition rate of fine root litter compared to leaf litter in Mediterranean ecosystems. These results must be considered in modeling organic C at the ecosystem scale.

Decomposition and Temperature Sensitivity of Fine Root and Leaf Litter of 43 Mediterranean Species

Aims: Data on the decomposition of fine roots are scarce for the Mediterranean basin. This work aims to compare chemical traits, decomposition rate, and temperature sensitivity (Q10) for root and leaf litter of 43 Mediterranean species. Methods: We carried out a two-years litterbag decomposition experiment using 43 fine roots litter and leaf litter types incubated in laboratory conditions at three different temperatures, i.e. 4°C, 14°C, and 24°C. Litter was characterized for carbon (C), nitrogen (N), lignin and cellulose concentration, C/N, and lignin/N ratios. Results: Fine root litter had lower N content but higher lignin concentration, lignin/N, and C/N ratios compared to leaf litter. The decay rate of fine root litter was slower than leaf litter. For both tissues, the decay rate was negatively associated with lignin concentration, lignin/N, and C/N ratios but positively with N concentration. Q10 was higher for fine root than leaf litter, with a positive correlation with lignin while negative with N concentration. Conclusions: Our findings demonstrate a higher Q10 accompanied by a slower decomposition rate of fine root litter compared to leaf litter in Mediterranean ecosystems. These results must be considered in modeling organic C at the ecosystem scale.

Multiseriate cortical sclerenchyma enhance root penetration in compacted soils

Mechanical impedance limits soil exploration and resource capture by plant roots. We examine the role of root anatomy in regulating plant adaptation to mechanical impedance and identify a root anatomical phene in maize (Zea mays) and wheat (Triticum aestivum) associated with penetration of hard soil: Multiseriate cortical sclerenchyma (MCS). We characterize this trait and evaluate the utility of MCS for root penetration in compacted soils. Roots with MCS had a greater cell wall-to-lumen ratio and a distinct UV emission spectrum in outer cortical cells. Genome-wide association mapping revealed that MCS is heritable and genetically controlled. We identified a candidate gene associated with MCS. Across all root classes and nodal positions, maize genotypes with MCS had 13% greater root lignin concentration compared to genotypes without MCS. Genotypes without MCS formed MCS upon exogenous ethylene exposure. Genotypes with MCS had greater lignin concentration and bending strength at the root tip. In controlled environments, MCS in maize and wheat was associated improved root tensile strength and increased penetration ability in compacted soils. Maize genotypes with MCS had root systems with 22% greater depth and 49% greater shoot biomass in compacted soils in the field compared to lines without MCS. Of the lines we assessed, MCS was present in 30 to 50% of modern maize, wheat, and barley cultivars but was absent in teosinte and wild and landrace accessions of wheat and barley. MCS merits investigation as a trait for improving plant performance in maize, wheat, and other grasses under edaphic stress.

Bio-Pulping of Bagasse As The Material For Paper Making Using Different Species of White Rot Fungi and Incubation Time

The Biopulping is defined as the biological process of lignin degradation by utilizing microorganisms that produce some enzymes. A microorganism which widely known in the degradation of lignin and cellulose is a group of white-rot fungi. The aims for this research to know the most effective white rot fungi species of G.lucidum, P.tuber-regium, and T.versicolor in the degradation of lignin and cellulose with different incubation time on bagasse substrate. The effectivity of biopulping indicated by the highest degradation of lignin concentration and the lowest degradation of cellulose concentration. This study used an experimental design with Completely Randomized design with a two factorial pattern. The independent variable of this study is white rot fungi species and incubation time while the dependent variable is the concentration of lignin and cellulose. The main parameter was the concentration of lignin and cellulose, supporting parameters were pH, weight loss of substrate and mycelial growth. The result showed the degradation of lignin and cellulose in all treatment. The best degradation of lignin and cellulose showed by species T.versicolor and P.tuber-regium within 30 days of incubation

Derived high reducing sugar and lignin colloid particles from corn stover

Lignocellulosic biomass is considered as the largest potential candidate to develop alternative energy, such as biofuel, biomaterial. However, the efficient conversion of cellulose and practical utilization of lignin are great challenges for sustainable biorefinery. In this study, high reducing sugar yield and different size of lignin colloid particles (LCPs) were obtained via tetrahydrofuran–water (THF–H2O) pretreatment of corn stover (CS). THF–H2O as a co-solvent, could efficiently dissolve lignin and retain cellulose. After the pretreatment, 640.87 mg/g of reducing sugar was produced, that was 6.66-fold higher than that of the untreated CS. Meanwhile, the pretreatment liquor could form spherical LCPs with different sizes ranged from 202 to 732 nm through self-assembly. We studied the optimal pretreatment condition to simultaneously realize the high reducing sugar yield (588.4 mg/g) and excellent LCPs preparation with average size of 243 nm was under TH22 (THF–H2O pretreatment at 120 °C for 2 h). To further explore the formation of LCPs with different sizes. We studied the lignin structure changes of various conditions, concluded the size of LCPs was related to the lignin concentration and syringyl/guaiacyl (S/G) ratio. As the increase of the lignin concentration and S/G, the sizes of LCPs were increased. G-type lignin was easier to dissolve in the mild pretreatment supernatant, contributing to form smaller LCPs with a good dispersibility. In the severe condition, both of S and G-type lignin were dissolved due to the lignin depolymerization, formed the larger sphere particles. This work provides a novel perspective for the technical design of lignocellulosic biomass conversion.