Dissolving Chitin by Novel Deep Eutectic Solvents for Effectively Enzymatic Hydrolysis.

Chitin is the most productive nitrogen-containing polysaccharide in nature with immense potential for transforming into a range of chemicals. However, its dense crystal structure poses a challenge for depolymerization, limiting its applications. To overcome these challenges, a novel series of deep eutectic solvents (DESs) based on benzyltrimethylammonium chloride (TMBAC) as the hydrogen bond acceptor was developed. These TMBAC-based DESs, in combination with lactic acid, oxalic acid, and malic acid as the hydrogen bond donor demonstrated efficient chitin dissolution, achieving a solubility of up to 12% and an 88% recovery rate of regenerated chitin. The regenerated chitin was characterized using XRD, FT-IR, SEM, and 13C CP-MAS NMR, which indicated the preservation of chitin's chemical structure, a significant decrease in crystallinity, and a reduction in the molecular weight. Furthermore, the enzymatic hydrolysis efficiency of chitin was nearly doubled after treatment with TMBAC-based DESs, surpassing the effectiveness of untreated chitin. This approach holds promise for facilitating subsequent transformation and utilization of chitin.

[Effects of simulated nitrogen deposition on growth and phosphorus efficiency of Pinus massoniana under low phosphorus stress].

Atmospheric nitrogen (N) deposition dramatically raised in recent decades, resulting in increases of soil N availability and N/P ratio, which would impact plant growth and P efficiency under low P stress. Taking breeding population of Pinus massoniana as test materials, a pot experiment was conducted to simulate two P conditions, i. e., homogeneous low P availability vs. heterogeneous low P among soil layers, in combination with two N deposition levels on growth traits and P absorption and utilization efficiency of P. massoniana. Under the homogeneous low phosphorus condition, growth traits and P efficiency of P. massoniana were not significantly improved by simulated nitrogen deposition, but significant nitrogen x family interaction effect was detected, with the biomass of family 40x44 and 71x20 being increased, 36x29 and 73x23 being decreased. Under the heterogeneous low P condition, significant N effects on the seedling height, biomass and P absorption efficiency were observed, due to promoted root length and root distribution ratio of topsoil. In addition, the effects of simulated N deposition on growth and P efficiency of P. massoniana were relevant to the N/P ratio. Under the homogeneous low P condition, the N/P ratio of P. massoniana plant was 13.8, plants exhibited a low sensitivity to simulated N deposition, root secreted APase activity was increased but the plant growth was not promoted. In comparison, the plant N/P ratio was 9.7 under the heterogeneous low P condition, and the plant growth and P efficiency were significantly promoted, while no obvious change occurred in root secreted APase activity.