Nutrient controlled release performance of bio-based coated fertilizer enhanced by synergistic effects of liquefied starch and siloxane.

The porous structure and hydrophilicity of coating shells affect the nutrient controlled-release performance of castor oil-based (CO) coated fertilizers. In order to solve these problems, in this study, the castor oil-based polyurethane (PCU) coating material was modified with liquefied starch polyol (LS) and siloxane, and a new coating material with cross-linked network structure and hydrophobic surface was synthesized, and used it to prepare the coated controlled-release urea (SSPCU). The results demonstrated that the cross-linked network formed by LS and CO improved the density and reduced the pores on the surface of the coating shells. The siloxane was grafted on the surface of coating shells to improve its hydrophobicity and thus delayed water entry. The nitrogen release experiment indicated that the synergistic effects of LS and siloxane improved the nitrogen controlled-release performance of bio-based coated fertilizers. Nutrient released longevity of SSPCU with 7 % coating percentage reached >63 days. Moreover, the nutrient release mechanism of coated fertilizer was further revealed by the analysis of the release kinetics analysis. Therefore, the results of this study provide a new idea and technical support for development of efficient and environment-friendly bio-based coated controlled-release fertilizers.

Preparation and characterization of functionalized chitosan/polyvinyl alcohol composite films incorporated with cinnamon essential oil as an active packaging material.

In this study, amphiphilic chitosan (NPCS-CA) was synthesized by grafting quaternary phosphonium salt and cholic acid onto the chain of chitosan, aiming to develop an active edible film based on NPCS-CA and polyvinyl alcohol (PVA) incorporated with cinnamon essential oil (CEO) by the casting method. The chemical structure of the chitosan derivative was characterized by FT-IR, 1H NMR and XRD. Through the characterization of FT-IR, TGA, mechanical and barrier properties of the composite films, the optimal proportion of NPCS-CA/PVA was determined as 5/5. And, the tensile strength and elongation at break of the NPCS-CA/PVA (5/5) film with 0.4 % CEO were 20.32 MPa and 65.73 %, respectively. The results revealed that the NPCS-CA/PVA-CEO composite films exhibited an excellent ultraviolet barrier property at 200-300 nm and significantly reduced oxygen permeability, carbon dioxide permeability and water vapor permeability. Furthermore, the antibacterial property of film-forming solutions against E. coli, S. aureus, and C. lagenarium was distinctly improved with the increase of NPCS-CA/PVA proportion. And, the multifunctional films effectively extended the shelf-life of mangoes at 25 °C based on the characterization of surface changes and quality indexes. The NPCS-CA/PVA-CEO films could be developed as biocomposite food packaging material.

Preparation and characterization of chitosan derivatives modified with quaternary ammonium salt and quaternary phosphate salt and its effect on tropical fruit preservation.

In this paper, HACC modified with (5-Carboxypentyl) (triphenyl) phosphonium bromide (HA-CS-NP) was synthesized. Then, a multifunctional food packaging composite film with good thermal stability and antibacterial functions was fabricated by HA-CS-NP and poly (vinyl alcohol) (PVA). The tensile strength and elongation at break of HA-CS-NP/PVA composite film at the weight ratio of 3/7 were 20.32 ± 1.02 MPa and 65.73 ± 3.29%, respectively. And, the inhibition rates of HA-CS-NP (0.5%) on Mango C. lagenarium and Papaya C. gloeosporioides on day 6 were up to 80.92 ± 4.12%. Compared with CK group, the weight loss of experimental groups were 23.96 ± 2.46 g/206 ± 7.25 g (mangoes) and 59.45 ± 3.06 g/496 ± 6.37 g (papaya), reduced by 35.76 ± 1.15%. Moreover, the final hardness value of the fruits coated with composite films was 4.94 ± 0.23 kg/cm3 and increased by 20.79 ± 1.04%, and the rot index was reduced by 71.43 ± 3.24%. The multifunctional HA-CS-NP/PVA coating has broad prospects in the application of food packaging.

Transcriptional profiling of biomass degradation-related genes during Trichoderma reesei growth on different carbon sources.

To identify all the gene products involved in cellulosic biomass degradation, we employed RNA sequencing technology to perform a genome-wide comparison of gene expression during growth of Trichoderma reesei QM9414 on cellulose or glucose. Due to their important role in lignocellulose decomposition, we focused on CAZymes and other secreted proteins. In total, 122 CAZymes showed at least a two-fold change in mRNA abundance, and 97 of those were highly induced by cellulose. Compared to the well-characterized cellulases and hemicellulases, a majority of the other upregulated CAZymes showed lower transcriptional levels. In addition, 64 secreted proteins, including oxidoreductases, exhibited at least two-fold upregulation on cellulose medium. To better understand the potential roles of low-abundance CAZymes in cellulose breakdown, we compared the expression patterns of 25 glycoside hydrolase genes under different conditions via real-time PCR. Substantial differences for the 25 genes were observed for individual strains grown on different carbon sources, and between QM9414 and RUTC30 when grown on the same carbon source. Moreover, we identified 3 genes that are coregulated with known cellulases. Collectively, this study highlights a comprehensive transcriptional profile for biomass degradation-related proteins and provides a first step toward the identification of candidates to construct optimized enzyme cocktails.