Variety Of Renewable Resources Research Articles

Facile Green Synthesis of Zingerone Based Tissue‐Like Biodegradable Polyester with Shape‐Memory Features for Regenerative Medicine

AbstractThe abundance of plants as a renewable bioresource has captured the significant attention of researchers, driving them to explore new biodegradable polymeric materials. However, there are still many biobased materials with untapped potential, offering opportunities to synthesize novel biodegradable polymers with multifunctional properties. This work provides a unique solvent and catalyst‐free melt polycondensation process to prepare a series of polyesters using zingerol (Zing‐OH), a reduced form of zingerone, as a primary component for the first time. Briefly, Zing‐OH (a ginger‐based component) is employed in conjunction with a variety of renewable resources, such as citric acid (CA), sebacic acid (SA), and xylitol (Xy), to synthesize multifunctional soft tissue‐like ZCSX polyesters. Fourier‐transform infrared (FTIR) and 1H‐nuclear magnetic resonance (NMR) spectroscopy are used to validate the synthesis of the polyesters, while thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and universal testing machine (UTM) are employed to investigate their physicochemical properties. Moreover, the synthesized polyester's thermal, mechanical, and biodegradation properties can be fine‐tuned by simply varying the Zing‐OH feed ratio. The mechanical properties of the synthesized polymer resemble various human tissues, including the liver, uterus, bladder, breast, and temporal and nasal cartilage. This suggests that the synthesized polyesters can potentially be useful in tissue engineering applications. Furthermore, the polyester demonstrated exceptional recovery responses and good shape memory behavior at ambient body temperature. Additionally, as observed from Alamar blue, live/dead assays, and time‐dependent in vitro wound images, the synthesized polyester demonstrated antibacterial activity, good in vitro cytocompatibility, cell proliferation, and wound healing capabilities against mouse fibroblast cells (NIH/3T3). The developed biocompatible polyester also exhibits excellent hemocompatibility for human blood, indicating its potential use in the field of regenerative medicine.

Efficient free fatty acid production in engineered Escherichia coli strains using soybean oligosaccharides as feedstock.

To be competitive with current petrochemicals, microbial synthesis of free fatty acids can be made to rely on a variety of renewable resources rather than on food carbon sources, which increase its attraction for governments and companies. Industrial waste soybean meal is an inexpensive feedstock, which contains soluble sugars such as stachyose, raffinose, sucrose, glucose, galactose, and fructose. Free fatty acids were produced in this report by introducing an acyl-ACP carrier protein thioesterase and (3R)-hydroxyacyl-ACP dehydratase into E. coli. Plasmid pRU600 bearing genes involved in raffinose and sucrose metabolism was also transformed into engineered E. coli strains, which allowed more efficient utilization of these two kinds of specific oligosaccharide present in the soybean meal extract. Strain ML103 (pRU600, pXZ18Z) produced ~1.60 and 2.66 g/L of free fatty acids on sucrose and raffinose, respectively. A higher level of 2.92 g/L fatty acids was obtained on sugar mixture. The fatty acid production using hydrolysate obtained from acid or enzyme based hydrolysis was evaluated. Engineered strains just produced ~0.21 g/L of free fatty acids with soybean meal acid hydrolysate. However, a fatty acid production of 2.61 g/L with a high yield of 0.19 g/g total sugar was observed on an enzymatic hydrolysate. The results suggest that complex mixtures of oligosaccharides derived from soybean meal can serve as viable feedstock to produce free fatty acids. Enzymatic hydrolysis acts as a much more efficient treatment than acid hydrolysis to facilitate the transformation of industrial waste from soybean processing to high value added chemicals.

Production of Hydrogen via Biological Processes

This article reviews biological production processes of hydrogen as a renewable and alternative energy source. Biological hydrogen produced from renewable sources (biomass, water, and organic wastes) either biologically or photo-biologically is called “biohydrogen.” The phenomenon of biological hydrogen production was observed one century ago. When the oil crisis broke out in 1970s, the technology started receiving attention, especially in hydrogen production by photosynthetic process. Biological hydrogen production is one of the alternative methods where processes can be operated at ambient temperatures and pressures, and are less energy intensive and more environmentally friendly. Biological production of hydrogen as a by-product of microorganism metabolism is an exciting new area of technology development that offers the potential production of usable hydrogen from a variety of renewable resources.