Petroleum-based plastic is widely used in almost all fields. However, it causes serious threats to the environment owing to its non-biodegradable properties, which necessitates finding biodegradable alternatives. Here, date palm rachis (DPR) waste was used as a filler (30, 40, and 50 wt%) to form a biodegradable composite with polylactic acid (PLA) and achieve cost–performance balance. DPR–PLA composites were prepared using a melt-mixing extruder at 180 °C by varying mixing time, DPR composition, and plasticizer type and composition. The biodegradable testing specimens were prepared by compression molding and analyzed using physical, thermal, and mechanical characterizations. Scanning electron microscopy images indicated a uniform dispersion of DPR (90 μm) in the PLA matrix. The esterification reaction resulting from this interaction between DPR and PLA was confirmed by Fourier transform infrared spectroscopy. The 30 wt% DPR–PLA composite was considered the optimal composite with the lowest melt flow index (16 g/10 min). This work confirmed the superior effect of addition of 10 wt% of triethyl citrate (TEC) compared with polybutylene adipate terephthalate (PBAT) by the improvement in the elongation at break of the optimal composite from 2.10% to 4.20%. Moreover, the addition of 10 wt% of PBAT to the optimal composite resulted in a lower tensile strength (21.80 MPa) than that of the composite with 10 wt% of TEC (33.20 MPa). These results show the potential of using the proposed composite as an alternative material for single-use plastics such as cutlery.

There is a wide biomass spectrum in the United Arab Emirates (UAE). Twenty three different biomass and fractions local to the UAE including lignocellulose (date palm, Moringa peregrina, mangroves, and garden trimmings), halophytes (Salicornia sinus-persica, Salicornia bigelovii, Halodule uninervis, Halophila ovalis, and Halophila stipulacea), macroalgae (Ulva Sp., Padina boergesenii, and Colppmenia sinuosa), and wastes (municipal and manures) were analyzed for bioenergy potential. Bioethanol potential of studied biomass is ranging from 55 to 359 kg ethanol / ton dry biomass. The biomethane potential is ranging from 72 to 288 L CH4 / kg VS biomass. The analysis shows that lignocellulosic biomass tends to give the highest bioethanol potential. Macroalgae (P. boergesenii) offers the least bioethanol potential compared with others, while washed Salicornia bigelovii, lignocellulosic garden trimmings, and camel manure are best suited for biomethane production. Significant variations in bioethanol and biomethane potential are noticed between different biomass fractions.

Bacterial contamination is one of the major challenges faced by yeast fermentation industries as the contaminating microorganisms produce lactic acid and acetic acid, which reduces the viability of yeast, and hence fermentation yields. The primary bacterial contaminants of yeast fermentations are lactic acid bacteria (LAB). This study aims to identify potential natural antibacterial fractions from raw and pretreated lignocellulosic biomasses found in Abu Dhabi, UAE, in terms of LAB inhibition capacity, allowing growth of the yeast. The analysis was carried out using plating technique. Pretreatment liquid of the mangrove stem Avicennia marina hydrothermally pretreated at 210 °C exhibited the widest inhibition zone with an average diameter of 14.5 mm, followed by the pretreatment liquid of mangrove leaf pretreated at 190 °C, Salicornia bigelovii pretreated at 202 °C and rachis of date palm Phoenix dactylifera pretreated at 200 °C. The compounds responsible for the antibacterial activity will be characterized in further study.

Avicennia marina is the only naturally occurring mangrove specie in the arid Arabian Gulf coast of the United Arab Emirates (UAE). Due to the water scarcity of this arid-region, A. marina is a precious biomass resource for the UAE that does not require fresh water for growing, and is able to grow in the Arabian Gulf high salinity conditions, over 40g/kg. This non-fresh water lignocellulosic arid-region bioresource may be used for the production of high valuable chemicals. The objective of the present manuscript is to characterize the lignocellulosic composition of Arabian Gulf A. marina, as a first attempt to highlight its importance in a biobased economy in arid regions. Avicennia marina stem, leaves and pneumatophors samples were collected from two locations in the United Arab Emirates. A. marina samples were chemically characterized for sugar composition, ash content and byproducts using standardized protocols. The analysis revealed that A. marina arabinan, xylan, glucan and lignin composition ranges, in g/100g_TS (TS: total solids), between 1-22, 5-18, 10-31, and 21-48, respectively. The highest composition of xylan and glucan (g/100g_TS) was obtained for stems and pneumatophors, 45 and 38, respectively. Xylan and glucan are the polymeric precursors for the production of high value chemicals, e.g. furfural and hydroxymethylfurfural (HMF), respectively. Under the characterization conditions, it was obtained furfural and HMF (g/100g_TS) in the ranges of 0.05-0.42, and 0.45-2.1, respectively.