Nashwa Hagagy

The accumulation of cerium oxide nanoparticles (CeO ₂ NPs) in the ecosystem adversely affects plant growth and development. Therefore, this study aimed to investigate the effects of Micromonospora sp. treatment, elevated CO ₂ (eCO ₂ ), and their combined application on the biomass, photosynthesis, oxidative stress markers, and anthocyanin metabolism in oat plants under CeO ₂ NPs contamination. CeO ₂ NPs contamination significantly reduced oat plant biomass (fresh weight by 49%, dry weight by 60%) and photosynthetic efficiency. However, Micromonospora sp. treatment substantially mitigated CeO ₂ NPs‐induced growth inhibition and oxidative damage by enhancing photosynthesis, antioxidant activity, and anthocyanin metabolism, particularly under eCO ₂ . CeO ₂ NPs exposure induced oxidative stress, as evidenced by increased H ₂ O ₂ and MDA levels and impaired redox status. While CeO ₂ NPs contamination suppressed antioxidant enzyme activities by up to 44%, treatment with Micromonospora sp. and CeO ₂ NPs mitigated this damage by significantly boosting enzyme levels, particularly increasing POX and APX activities. In line with increased proline and anthocyanins, their metabolism was also improved. Micromonospora sp. treatment significantly enhanced anthocyanin metabolism in oat plants, increasing PAL activity by 57% and 171% under uncontaminated and contaminated conditions, respectively. Additionally, phenylalanine, cinnamic acid, coumaric acid, and naringenin levels were notably elevated. While eCO ₂ also improved anthocyanin metabolism, the combined treatment with Micromonospora sp. and eCO ₂ was less effective than individual treatments. The findings highlight the complexity of plant responses to environmental and contamination stressors, with bacterial treatment emerging as a particularly effective strategy.

Biodegradable polyhydroxyalkanoates (PHAs), consisting of monomers and heteropolymers, this is an alternative for polymers generated by fossil fuels. Halophilic archaea produced polyhydroxyalkanoates (PHAs) as intracellular granules reserves energy in response to nutrients scarcity. Nevertheless, there is a scarcity of comprehensive understanding of these processes and the capacity of halophilic archaea to accumulate PHAs. This study focused on isolation of haloarchaea from Saudi Arabia's Red Sea solar saltern and investigate their growth and synthesis of polyhydroxybutyrate (PHB) under varying pH levels, temperatures, and NaCl concentrations. In addition, the study aimed to assess the accumulation of polyhydroxybutyrate (PHB) under nutrient-limited conditions utilizing cost-effective sources of carbon, like carboxymethyl cellulose (CMC), glycerol, glucose, starch and sucrose. Identification of candidate strains was achieved via 16S rRNA genome sequencing. Subsequently, the sequences were added to the NCBI GenBank and given accession numbers OQ366239-OQ366242.Haloferax sp. strain HSM17 produced the greatest quantity of PHB (50.94%) when starch was the only source of carbon. The best growth was shown at 65°C, a pH 7, and 10% salinity. The chemical combination of the biopolymer was evaluated by applying GC-MS. Hemolysis was then measured to determine the cytotoxicity of the extracted PHB towards red blood cells. The results showed a considerable decrease in damage to human red blood cells parallel to the positive control (P<0.05). Haloferax sp. strain HSM17 has great potential as a producer of polyhydroxybutyrate (PHB) using cheap carbon sources.

Light is arguably one of the most significant aspects of microgreen algae growth and lipid yields. Microgreen algae-based biodiesel production offers a pioneering method of producing renewable fuel. In this research, Chlorella sp. was cultivated in colorless (control), red, orange, yellow, blue, and green Erlenmeyer flasks. The BG11 medium was used with continuous illumination by cool white fluorescent light with a light intensity of 2,500 lux (35 µmol photon·m ⁻² ·s ⁻¹ ), and light: dark (12:12 h). After 14 days of cultivation, dry weight, pigments, and lipids % were measured. The results demonstrate that the red color was the best effect on Chlorella sp. growth under continuous light. Control enhanced the production of Chlorophyll- a and Chlorophyll- b in continuous illumination. Non-significant results among control, red, and blue colors in the case of algal dry weight, under dark: light. The quantity of saturated fatty acids was higher in algae cultivated in the red flask (42.9%), followed by blue with continuous illumination. Control with continuous illumination denotes a higher amount of monounsaturated fatty acids. Alga in the blue flask produced a high quantity (83.71%) of polyunsaturated fatty acids in the light: dark cycle. The color light can be used to enhance the lipid quality.

BACKGROUND: Most microorganisms that cause food decay and the lower the shelf life of foods are fungi. Nanotechnologies can combat various diseases and deal with the application of nanomaterial to target cells or tissues. In this study selenium nanoparticles (Se‐NPs) were synthesized using ascorbic acid and characterized by ultraviolet–visible spectroscopy, transmission electron microscopy (TEM), X‐ray diffraction and zeta potential. The different concentrations of As/Se‐NPs were tested against various fungi, including Alternaria linicola, Alternaria padwickii, Botrytis cinerea, Bipolaris sp., Cephalosporium acremonium, Fusarium moniliform and Fusarium semitectum. This study tested the influence of coated As/Se‐NPs on healthy strawberry fruits and those infected with Botrytis cinerea during 16 days of storage, with regard to shelf life, decay percentage, weight loss, total titratable acidity percentage, total soluble solids content (TSS) and anthocyanin content.RESULTS: Energy‐dispersive X‐ray analysis showed only two elements: selenium and oxygen. TEM images showed that the nanoparticles ranged in size between 26 to 39 nm and were rhombohedral in shape. Se‐NPs showed antifungal activity against all tested fungi, the most effective being against Botrytis cinerea, Cephalosporium acremonium and Fusarium semitectum. During storage periods of strawberries fruits coated with As/Se‐NPs, the shelf life was increased, and the number of decaying fruits was less than in control (uncoated) and coated infected fruits. The decline in weight loss was lower in coated fruits than in control fruits.CONCLUSION: These findings demonstrated that As/Se‐NPs could effectively maintain the postharvest quality of strawberries, even when the fruit was infected with B. cinerea. © 2024 Society of Chemical Industry.

BACKGROUND: The present study set out to evaluate the potential of plant growth‐promoting Actinobacteria (PGPB) in improving some physiological and molecular parameters of rapeseed (Brassica napus L.) plants under ambient and elevated CO₂ conditions by assessing some nitrogen‐ and sulfur‐containing metabolites, antioxidant defense system and antimicrobial activity. With this aim, a pot experiment was conducted where the rapeseed plants were treated with Actinobacterium sp. strain NCO2 (OQ451136) and were grown under two levels of air CO₂ concentrations: ambient CO₂ (aCO₂, 410 μmol CO₂ mol⁻¹); and elevated CO₂ (eCO₂, 710 μmol CO₂ mol⁻¹).RESULTS: There was an increase in the photosynthetic pigments (+35–80%) and photosynthesis rate (+20–34%) in PGPB‐treated plants under eCO₂ compared to control plants, resulting in further growth and biomass production (+53–294%). These results were associated with an enhancement in the content of total antioxidant capacity (+15–128%), polyphenols (+21–126%) and α‐tocopherols (+20–138%) under both eCO₂ and PGPB application (in combination or individual application), while only the combined treatment (eCO₂ + PGPB) led to a significantly higher accumulation of antioxidant enzymes (+88–197%), β‐tocopherols (+177%) and flavonoids (+155%). Moreover, nitrogen‐ and sulfur‐containing metabolites (glucosinolates and amino acids) were improved by PGPB treatment and/or CO₂ levels, in which PGPB increased the amino acid‐derived glucosinolate induction by eCO₂ with low levels of effective sulforaphane.CONCLUSIONS: Therefore, the interaction effects of beneficial Actinobacteria and eCO₂ are expected to boost the level of antioxidant molecules and to have a helpful role in improving plant biomass and adaptability to complicated climate changes in the future. © 2023 Society of Chemical Industry.

This work aims to characterize the haloarchaeal diversity of unexplored environmental salty samples from a hypersaline environment on the southern coast of Jeddah, Saudi Arabia, looking for new isolates able to produce polyhydroxyalkanoates (PHAs). Thus, the list of PHA producers has been extended by describing two species of Halolamina; Halolamina sediminis sp. strain NRS_35 and unclassified Halolamina sp. strain NRS_38. The growth and PHA-production were investigated in the presence of different carbon sources, (glucose, sucrose, starch, carboxymethyl cellulose (CMC), and glycerol), pH values, (5–9), temperature ranges (4–65 °C), and NaCl concentrations (100–350 g L⁻¹). Fourier-transform infra-red analysis (FT-IR) and Liquid chromatography–mass spectrometry (LC-MS) were used for qualitative identification of the biopolymer. The highest yield of PHB was 33.4% and 27.29% by NRS_35 and NRS_38, respectively, using starch as a carbon source at 37 °C, pH 7, and 25% NaCl (w/v). The FT-IR pattern indicated sharp peaks formed around 1628.98 and 1629.28 cm⁻¹, which confirmed the presence of the carbonyl group (C=O) on amides and related to proteins, which is typical of PHB. LC-MS/MS analysis displayed peaks at retention times of 5.2, 7.3, and 8.1. This peak range indicates the occurrence of PHB and its synthetic products: Acetoacetyl-CoA and PHB synthase (PhaC). In summary, the two newly isolated Halolamina species showed a high capacity to produce PHB using different sources of carbon. Further research using other low-cost feedstocks is needed to improve both the quality and quantity of PHB production. With these results, the use of haloarchaea as cell factories to produce PHAs is reinforced, and light is shed on the global concern about replacing plastics with biodegradable polymers.

The latest advancements in cellulose and its derivatives are the subject of this study. We summarize the characteristics, modifications, applications, and properties of cellulose. Here, we discuss new breakthroughs in modified cellulose that allow for enhanced control. In addition to standard approaches, improvements in different techniques employed for cellulose and its derivatives are the subject of this review. The various strategies for synthetic polymers are also discussed. The recent advancements in polymer production allow for more precise control, and make it possible to make functional celluloses with better physical qualities. For sustainability and environmental preservation, the development of cellulose green processing is the most abundant renewable substance in nature. The discovery of cellulose disintegration opens up new possibilities for sustainable techniques. Based on the review of recent scientific literature, we believe that additional chemical units of cellulose solubility should be used. This evaluation will evaluate the sustainability of biomass and processing the greenness for the long term. It appears not only crucial to dissolution, but also to the greenness of any process.