Understanding bacterial diversity, infection dynamics, prevention of antibiotic resistance: an integrated study in an Algerian hospital context.

PURPOSE: Bacterial infections, particularly bacteremia, urinary tract infections (UTIs), and pus infections, remain among hospitals' most worrying medical problems. This study aimed to explore bacterial diversity, infection dynamics, and antibiotic resistance profiles of bacterial isolates. METHODS: We analyzed data from 1750 outpatients and 920 inpatients, of whom 1.6% and 8.47% respectively had various bacterial infections. RESULTS: The analysis revealed that UTIs were the most prevalent at 41.01%, particularly affecting women. UTIs also showed a distinct distribution across admission departments, notably in emergency (23.07%) and pediatric (14.10%) units. The most frequently isolated microorganisms were Escherichia coli (E. coli), followed by Klebsiella ornithinolytica. Skin infections followed UTIs, accounting for 35.88% of cases, more prevalent in men, with Staphylococcus aureus (S. aureus) being the primary pathogen (57%). Gram-negative bacteria (GNB) like E. coli and Pseudomonas aeruginosa contributed significantly to skin infections (43%). Bacteremia cases constituted 11.52% of bacterial infections, predominantly affecting women (67%) and linked to GNB (78%). A comparative study of antibiotic susceptibility profiles revealed more pronounced resistance in GNB strains isolated from inpatients, particularly to antibiotics such as Amoxicillin/clavulanic acid, Tetracyclin, Gentamicin, Chloramphenicol, and Ampicillin. In contrast, strains from ambulatory patients showed greater resistance to Colistin. Gram-positive bacteria from hospitalized patients showed higher resistance to quinolones and cephalosporins, while ambulatory strains showed high resistance to aminoglycosides, macrolides, fluoroquinolones, and penicillin. Furthermore, these analyses identified the most effective antibiotics for the empirical treatment of both community-acquired and nosocomial infections. Ciprofloxacin, aztreonam, and amikacin exhibited low resistance rates among GNB, with gentamicin and chloramphenicol being particularly effective for community-acquired strains. For S. aureus, ciprofloxacin, rifampicin, and cefoxitin were especially effective, with vancomycin showing high efficacy against community-acquired isolates and fosfomycin and chloramphenicol being effective for hospital-acquired strains. CONCLUSION: These results are essential for guiding antibiotic therapy and improving clinical outcomes, thus contributing to precision medicine and antimicrobial stewardship efforts.

Biological properties of extracts from the mixture of honey and berries of Pistacia lentiscus.

Background: Honey is a product of the hive elaborated by the bees of the species Apis mellifera. As well as Pistacia lentiscus, is a species widely used in traditional medicine that is part of a large family of Anacardiaceae. Aims: To determine the biological properties including the antioxidant activity of the mixture of the extract of P. lentiscus berries associated with honey at different concentrations (0.5%, 2%, 4%, 8% and 12%). Methods: Physicochemical parameters and phenolic compound amounts. The antioxidant activities (reducing power, FRAP, CUPRAC, TAC, DPPH, ABTS, and ferrozine) were also tested. Results: According to the physico-chemical parameters, the honey and the mixture analyzed are in conformity with the international standards. The results of the antioxidant assay gave a significant content of total phenolic compounds for the H/DP mixtures, the sample of honey alone analyzed exerts a weak antioxidant activity compared to the two mixtures made. Conclusion: The honey and Pistacia compound constitute an important source of antioxidants which intensifies very significantly the antioxidant activity of the blend.

Application of Rosmarinic Acid with Its Derivatives in the Treatment of Microbial Pathogens.

The emergence of the antimicrobial resistance phenomena on and the harmful consequences of the use of antibiotics motivate the necessity of innovative antimicrobial therapies, while natural substances are considered a promising alternative. Rosmarin is an original plant compound listed among the hydroxycinnamic acids. This substance has been widely used to fight microbial pathology and chronic infections from microorganisms like bacteria, fungi and viruses. Also, various derivatives of rosmarinic acid, such as the propyl ester of rosmarinic acid, rosmarinic acid methyl ester or the hexyl ester of rosmarinic acid, have been synthesized chemically, which have been isolated as natural antimicrobial agents. Rosmarinic acid and its derivatives were combined with antibiotics to obtain a synergistic effect. This review reports on the antimicrobial effects of rosmarinic acid and its associated derivatives, both in their free form and in combination with other microbial pathogens, and mechanisms of action.

Biological Properties, Phenolic Profile, and Botanical Aspect of Nigella sativa L. and Nigella damascena L. Seeds: A Comparative Study.

The use of Nigella seeds in the food, pharmaceutical, and cosmetic fields is common, since the iniquity and the virtues of these plants are directly related to their characteristic phytochemical composition. This investigation focused on the comparative study of the botanical aspect, phenolic profile, and in vitro and in vivo biological activities of Nigella sativa L. (NS) and Nigella damascena L. (ND) seeds. The macro- and micro-morphological properties of these seeds were studied, and the key dissimilarities between them were clearly illustrated. The phytochemical contents and phenolic profiles were determined, and the in vitro antioxidant activity was assessed using four methods. The in vivo antioxidant and biochemical parameters of the blood of supplemented mice were determined. The results of the macro- and micro-structure analysis revealed differences between the two plants. Here, ND is characterized by higher phytochemical contents and the best antioxidant activities. The HPLC analysis indicated the presence of nine compounds, namely seven phenolic acids, particularly hydroxybenzoic and caffeic acids, and two flavonoids. The administration of ND extract to mice for 21 days at a concentration of 500 mg/kg allowed a substantial amelioration of plasma antioxidant properties. In addition, the extracts ameliorate blood parameters (cholesterol, triglycerides, glycemia, and urea). Furthermore, the antimicrobial activity of extracts demonstrated their effects on Staphylococcus and Aspergillus. Nigella seeds, in particular ND, expressed considerable in vitro antioxidant properties and demonstrated significant amelioration of mice blood properties. Consequently, these species can serve as a valuable source of compounds with various applications.

A Hybrid Water Balance Machine Learning Model to Estimate Inter-Annual Rainfall-Runoff.

Watershed climatic diversity poses a hard problem when it comes to finding suitable models to estimate inter-annual rainfall runoff (IARR). In this work, a hybrid model (dubbed MR-CART) is proposed, based on a combination of MR (multiple regression) and CART (classification and regression tree) machine-learning methods, applied to an IARR predicted data series obtained from a set of non-parametric and empirical water balance models in five climatic floors of northern Algeria between 1960 and 2020. A comparative analysis showed that the Yang, Sharif, and Zhang's models were reliable for estimating input data of the hybrid model in all climatic classes. In addition, Schreiber's model was more efficient in very humid, humid, and semi-humid areas. A set of performance and distribution statistical tests were applied to the estimated IARR data series to show the reliability and dynamicity of each model in all study areas. The results showed that our hybrid model provided the best performance and data distribution, where the R2Adj and p-values obtained in each case were between (0.793, 0.989), and (0.773, 0.939), respectively. The MR model showed good data distribution compared to the CART method, where p-values obtained by signtest and WSR test were (0.773, 0.705), and (0.326, 0.335), respectively.

A Novel Interannual Rainfall Runoff Equation Derived from Ol'Dekop's Model Using Artificial Neural Networks.

In water resources management, modeling water balance factors is necessary to control dams, agriculture, irrigation, and also to provide water supply for drinking and industries. Generally, conceptual and physical models present challenges to find more hydro-climatic parameters, which show good performance in the assessment of runoff in different climatic regions. Accordingly, a dynamic and reliable model is proposed to estimate inter-annual rainfall-runoff in five climatic regions of northern Algeria. This is a new improvement of Ol'Dekop's equation, which models the residual values obtained between real and predicted data using artificial neuron networks (ANNs), namely by ANN1 and ANN2 sub-models. In this work, a set of climatic and geographical variables, obtained from 16 basins, which are inter-annual rainfall (IAR), watershed area (S), and watercourse (WC), were used as input data in the first model. Further, the ANN1 output results and De Martonne index (I) were classified, and were then processed by ANN2 to further increase reliability, and make the model more dynamic and unaffected by the climatic characteristic of the area. The final model proved the best performance in the entire region compared to a set of parametric and non-parametric water balance models used in this study, where the R2Adj obtained from each test gave values between 0.9103 and 0.9923.

Effect of Sonication on Microwave Inactivation Kinetics of Enterococcus faecalis in Dairy Effluent.

The aim of this study is to inactivate Enterococcus faecalis ATCC 29212 present in dairy wastewater effluent using microwave (MW) waves and/or ultrasound waves (US). The ultrasonic bath treatment (35 kHz) had no significant effect on the reduction of the survival rate (predominant declumping effect). At 650 W of microwave treatment, the total destruction was completed at 75 s, while at 350 W a 3 log reduction was achieved. The Weibull model was fitted to the survival curves to describe the inactivation kinetics, and the effect of the combined microwave-ultrasound treatments was evaluated. The scaling parameter α that was estimated from the inactivation kinetics for the microwaves combined with the ultrasound waves in pre-treatment was found to be lower than the scaling parameters obtained in post-treatment, which were in turn lower than those estimated for microwaves or ultrasound waves alone. The use of the ultrasound waves in pre-treatment was more effective than in post-treatment; a total reduction was achieved using a combination of US (30 min) followed by MW (650 W) with α = 28.3 s, while 4.0 log was obtained by reversing all processes with α = 34.5 s. The results from the protein assays indicate that the bacterial wall was damaged and that holes were formed from which protein leakage occurred.

Effects of Seed Roasting Temperature on Sesame Oil Fatty Acid Composition, Lignan, Sterol and Tocopherol Contents, Oxidative Stability and Antioxidant Potential for Food Applications.

Roasting is a key step for preparing sesame oil that leads to important changes in its organoleptic properties and quality. In this study, white sesame seeds were roasted for 20 min in an electric oven at different temperatures (120, 150, 180, 210, 250 and 300 °C). The oils extracted from unroasted and roasted seeds were compared for their chemical composition: fatty acids (including trans isomers), phytosterols, lignans (sesamin and sesamolin), tocopherols and total phenolic compounds, as well as their oxidative stability and antiradical capacity. There were no obvious differences in the oil densities, refractive indexes or iodine values, but the saponification values were affected by temperature. Relevant primary and secondary lipid oxidation were observed at T > 250 °C, resulting in a higher p-anisidine value and K232 as well as K268 values. Roasting improved oil yield (from 33.5 to 62.6%), increased its induction period (from 5.5 to 10.5 h) and enhanced the total phenolic content (from 152 to 194 mg/100 g) and antiradical activity of the extracted oil. Depending on roasting temperature, a gradual decline was recorded in total amounts of phytosterols (up to 17.4%), γ-tocopherol (up to 10.6%), sesamolin (maximum of 27.5%) and sesamin (maximum of 12.5%). All the investigated oils presented a low quantity in triglyceride polymers, clearly below the maximum tolerated quantity according to the European regulation. The optimal roasting temperature for obtaining high nutritional grade oil within the permissible values was 210 °C. The unsaponifiable components (including lignans and sterols) extracted from roasted seeds have been shown to be natural additives to fresh meatball products to extend shelf life. The results of this study may help to boost the nutritional content of plant-based diets by allowing for the use of roasted sesame seed oil and its components.

Prevention of 7-ketocholesterol-induced side effects by natural compounds.

Cholesterol oxidation products, also named oxysterols, can be formed either by cholesterol auto-oxidation, enzymatically or both. Among these oxysterols, 7-ketocholesterol (7KC) is mainly formed during radical attacks that take place on the carbon 7 of cholesterol. As increased levels of 7KC have been found in the tissues, plasma and/or cerebrospinal fluid of patients with major diseases, especially age-related diseases (cardiovascular diseases, eye diseases, neurodegenerative diseases), some cancers, and chronic inflammatory diseases, it is suspected that 7KC, could contribute to their development. Since 7KC, provided by the diet or endogenously formed, is not or little efficiently metabolized, except in hepatic cells, its cellular accumulation can trigger numerous side effects including oxidative stress, inflammation and cell death. To counteract 7KC-induced side effects, it is necessary to characterize the metabolic pathways activated by this oxysterol to identify potential targets for cytoprotection and geroprotection. Currently, several natural compounds (tocopherols, fatty acids, polyphenols, etc) or mixtures of compounds (oils) used in traditional medicine are able to inhibit the deleterious effects of 7KC. The different molecules identified could be valued in different ways (functional foods, recombinant molecules, theranostic) to prevent or treat diseases associated with 7KC.

Hemi-Synthesis of Chiral Imine, Benzimidazole and Benzodiazepines from Essential Oil of Ammodaucus leucotrichus subsp. leucotrichus.

The hemi-synthesis of chiral imine, benzimidazole and benzodiazepine structures is reported by the condensation of (S)-(-)-perillaldehyde, the major phytochemical of Ammodaucus leucotrichus subsp. leucotrichus essential oil, with different amine derivatives of 2,3-diaminomaleonitrile, o-phenylenediamine and 3-[(2-aminoaryl)amino]dimedone. The reaction proceeds in situ at ambient temperature without prior isolation of the natural (S)-(-)-perillaldehyde. Final products precipitate in the ethanolic reaction medium. 2D NMR and single-crystal X-ray diffraction studies were used to unequivocally characterize the structures in solution and in the solid state, respectively. Chiral HPLC analysis confirms the formation of unique enantiomers and diastereomeric mixtures.

Evidence of biological activity of Mentha species extracts on apoptotic and autophagic targets on murine RAW264.7 and human U937 monocytic cells.

CONTEXT: Mints (Lamiaceae) are used as traditional remedies for the treatment of several diseases. Their extracts are recognized as anti-inflammatory compounds. OBJECTIVE: This study characterized the cytotoxic effects of Mentha spicata L. (MS), Mentha pulegium L. (MP) and Mentha rotundifolia (L). Huds (MR) on macrophage cells (RAW264.7; U937) and determined their impact on apoptosis and autophagy, which can play a role in controlling inflammation. MATERIALS AND METHODS: The extracts were prepared in culture medium and tested from 25 to 400 µg/mL after 24-48 h of treatment. To show the effect of the aqueous ethanol (50%) extracts on apoptosis and authophagy, the presence of cleaved caspase-3, and the conversion of LC3-I to LC3-II was evaluated by Western blotting. RESULTS: Compared with the MTT assay, crystal violet showed a pronounced decrease in the number of cells with all extracts at 48 h. Calculated IC50 values were 257.31, 207.82 and 368.02 µg/mL for MS, MP and MR, respectively. A significant increase in PI positive cells was observed with all extracts at 200-400 µg/mL. Mitochondrial dysfunctions and nuclear morphological changes were detected with MS and MR extracts at 400 µg/mL. At this concentration, no cleaved caspase-3 was found whereas stabilized caspase-3 in its dimeric form was identified. MS and MR extracts also favour LC3-I to LC3-II conversion which is a criterion of autophagy. CONCLUSIONS: The cytotoxic profiles depend on the extracts considered; MS extract showed the strong activity. However, all the mint extracts studied interact with the apoptotic and autophagic pathways at elevated concentrations.

Feasibility study of date (Phoenix dactylifera L.) fruit syrup-based natural jelly using central composite design.

A feasibility study of natural fruit jelly from three Algerian raw materials, namely date (Phoenix dactylifera l.) fruit syrup and suspension of orange albedo powder (OAP) in lemon juice (LJ) was performed by response surface methodology (RSM) based on central composite design (CCD). The textural properties of the final jelly were investigated through two dependent variables: hardness and stickiness. The cooking temperature (X1), corresponding to that of thermo stated oil bath, and cooking time (X 2), taken for heating the initial fruit mixture in the oil bath (from ambient temperature without fixing however, the final temperature), were found to be the most influent factors, compared to °Brix of date syrup (X3) and temperature (X4) of the cooling stage following the cooking process. Results have also shown that the second-degree polynomial models correctly fit experimental data (R(2), adjusted R(2) (R(2) adj) and cross-validation (Q(2)) ≈ 1). Considering textural properties of commercial jellies as a reference, it was found that the cooking temperature of 155 °C for 10 min gave a jelly with suitable textural properties. On the other hand, FT-IR spectra revealed that the structure of such jelly was partially close to that of pectin molecules. Finally, the color analysis in the CIELab system of the fruit mixture over the cooking process showed that both lightness (L(*)) and a*/b* ratio were not affected by the experienced temperature range (80-155 °C).

Tentative characterisation of iridoids, phenylethanoid glycosides and flavonoid derivatives from Globularia alypum L. (Globulariaceae) leaves by LC-ESI-QTOF-MS.

INTRODUCTION: Globularia alypum L., belonging to the Globulariaceae family, is a perennial wild shrub found throughout the Mediterranean area, Europe, and Africa. This plant is widely used to treat many diseases, but no previous work on the phytochemical composition of the Algerian G. alypum species has yet been reported. OBJECTIVE: To investigate the phytoconstituents of the methanolic extract of G. alypum using an LC-ESI-QTOF-MS method. METHODS: Ground air-dried leaves of G. alypum were macerated with methanol at room temperature for 24 h. The supernatant was filtered and concentrated to dryness under reduced pressure in a rotary evaporator, and extracts were recovered with methanol and filtered. Afterwards, the G. alypum extract was injected into the LC-ESI-QTOF-MS system. RESULTS: The combined LC-MS/MS led to the tentative characterisation of 63 phytochemicals. In this work, a large number of compounds have been characterised in the leaf-extract analysis of this plant. Among others, 24 iridoids and secoiridoids were found, of which nine compounds have not previously been recorded in G. alypum. Also, nine unusual phenylethanoid glycosides were characterised for the first time in this species. CONCLUSION: The method used has proved to be a valued tool for the characterisation of a wide range of compounds from G. alypum leaves. This work constitutes a detailed investigation of the chemical composition of G. alypum leaves, which are widely used in different traditional systems of medicine.

Phenolic compounds profile of macerates of different edible parts of carob tree (Ceratonia siliqua L.) using UPLC-ESI-Q-TOF-MSE: Phytochemical screening and biological activities.

Locust bean pulp and gum extracts were prepared, and phytochemical tests based on color reactions and chromatographic analyzes were performed. A profile of seventy-six phenolic compounds was obtained by the ultra-high performance liquid chromatography with electrospray ionization and quadrupole time-of-flight mass spectrometry. The main groups of phenolic compounds identified in the both extracts of Ceratonia siliqua L., were flavonoids, tannins and phenolic acids. Moreover, carob pulp and gum extracts were tested for their antimicrobial activity using disk diffusion tests which showed sensitivity of the different strains to the analyzed extracts at a concentration of 100 mg/mL. Additionally, the antioxidant activity of Ceratonia siliqua L. extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl acid test, which confirmed stronger antioxidant properties in the case of the pulp extract. To sum up, carob pulp and gum extracts present promising alternatives to synthetic additives within the medicinal industry, serving as potential antioxidant agents and preservatives that combat bacterial contamination, thereby offering a more natural approach to enhancing product safety and efficacy.

Exploring the environmental and economic impact of fruits and vegetable loss quantification in the food industry.

Population growth has stimulated rising demand for agro-food products and economic activity for many years, negatively impacting the ecosystem and non-renewable resource consumption. Algeria confronts the monumental challenge of effectively choosing how to nourish everyone on a more congested globe. However, food loss is a significant issue that worsens as Algerians' population expands and food consumption increases. In Algeria, food production and processing of food items, which include fruits, vegetables, and cereals, generate a considerable amount of by-products, with no commercial exploitation and a negative environmental impact, generating enormous socioeconomic problems. These by-products are essential sources of products with high levels of added value that can be applied in different sectors. They have no studies to measure the scope of food loss in the Algerian food industry. In this background, our research aims to quantify the loss in the Algerian food industry generated by the transformation of various agricultural products, directly affecting the economy and food availability for the population. The research utilizes a mixed methods approach, including coefficients, production statistics transformed, and data analysis; the findings reveal that a significant portion of fruits and vegetables are lost in the Algerian food industry, suggesting that minimizing food loss can help companies minimize costs and mitigate the adverse environmental effects of food production. Finally, the study proposes practical options to minimize food loss to create a long-term food system in Algeria.

Effect of storage on bioactivity of an Algerian spice "paprika": optimization of phenolic extraction and study of antioxidant and antibacterial activities.

The effect of different storage methods (ambient temperature (A), refrigeration at 4 °C (R) and freezing at - 18 °C (F)), on the phytochemistry of an Algerian spice (paprika powder), was assessed. The optimized extract was obtained under the optimum conditions of ultrasound-assisted extraction (UAE) using response surface methodology (RSM) coupled with a Box-Behnken Design (BBD). This extract was evaluated for its total phenolics content (TPC), total flavonoids content (TFC) and its antioxidant and antibacterial activities. Under the optimum conditions (5 min for the irradiation time, 40% for the amplitude, 80% for ethanol concentration and 50% for solid-liquid ratio) the TPC was 12.23 ± 1.01 mg Gallic Acid Equivalent/gram of Dried Powder (mg GAE/g DP) which is very close with experimental assay. The TPC are better preserved at A whereas TFC and the antioxidant activity at F, and the antibacterial activity depend on the storage methods and the strains tested.

Sustainable gelatin-kappa carrageenan active packaging with Mekwiya date seeds to enhance goat meat quality and shelf life.

This research aimed to elaborate a gelatin-Kappa carrageenan-based packaging with 0.22 %, 0.44 %, and 0.88 % w/v of Mekwiya date palm seeds extract (DSEMK). This extract improved the mechanical, physical, and thermal properties of the films. Moisture content, water solubility, and water vapor permeability were reduced from 17.54 ±â€¯0.02 to 12.18 ±â€¯0.02, from 77.61 ±â€¯0.02 to 25.35 ±â€¯0.29 %, and from 5.28 ±â€¯0.29 to 1.69 ±â€¯0.03 g s-1 m-1 Pa-1 × 10-10, respectively. During thermal degradation, DSEMK4 film had a residual weight of 27.99 %, compared to 20.67 % for the control. Despite a decline in the film's tensile strength from 24.19 to 8.94 MPa with the incorporation of DSEMK, elongation at the breaking point increased from 37.66 ±â€¯0.16 to 46.17 ±â€¯0.25 %. The film containing DSEMK4 displayed the highest phenolic contents and illustrated the best antioxidant effects in DPPH and FRAP assays, with IC50s of 756 and 1445 µg/mL, respectively and inhibited pathogen growth on the meat surface. Over storage at 4 °C, monitoring of pH, lipid and protein oxidation parameters, microbial spoilage, optical properties, and sensory attributes disclosed that the DSEMK-films successfully enhanced the meat quality and safety. These findings were supported by principal component analysis and heat maps.

Qualitative and semi-quantitative analysis of phenolics in Eucalyptus globulus leaves by high-performance liquid chromatography coupled with diode array detection and electrospray ionisation mass spectrometry.

INTRODUCTION: Eucalyptus species are widely cultivated in Mediterranean regions. Moreover, plants of this family have been utilized for medicinal purposes. A number of studies have been devoted to the identification of eucalypt phenolics, all of them have focused on specific families of compounds, and no exhaustive profiling has been reported in leaves of this plant. OBJECTIVE: To develop methods that allows the identification and quantification of different classes of phenolics in Eucalyptus globulus leaf. METHODOLOGY: Acetonic extract was fractionated by chromatography on a Sephadex LH-20 column using consecutive elution with ethanol, methanol and aqueous acetone (60%). High-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI/MS) were applied to determine the structure of different compounds. Quantities were evaluated from peak areas in the HPLC profile, using external calibration curves. RESULTS: Fractionation of acetonic extract yielded three fractions: F1, F2 and F3. In total 39 phenolic compounds are detected. Among them: 16 hydrolyzable tannins, 3 terpenyl derivatives, 12 ellagic acid derivatives, 5 flavonols, 2 hydroxybenzoic acids and 1 formylated phloroglucinol. 26 compounds described in this study have not previously detected in leaves of this plant and this is the first report of quercetin 3-O-ß-galactoside-6"-O-gallate and cypellogin A and B, in E. globulus plant. Quantitatively, ellagic acid derivatives and sideroxylonal A or B are largely predominant. CONCLUSION: Fractionation of crude extract by chromatography on Sephadex LH-20 was efficient to separate different molecular weight compounds. HPLC-DAD-ESI/MS enabled detection of gallotannin, ellagitannin and flavonol derivatives, in leaves of E. globulus.

Statistical Optimization and Partial Characterization of Xylanases Produced by Streptomyces sp. S1M3I Using Olive Pomace as a Fermentation Substrate.

Xylanase production by Streptomyces sp. S1M3I was optimized by response surface methodology (RSM), followed by a partial characterization of these enzymes. Olive pomace was used as a substrate for growing Streptomyces sp. S1M3I in submerged fermentation. Effects of incubation time, pH, temperature, carbon source, nitrogen source, and inoculum size on xylanase production were studied, through the one-factor-at-a-time method. Then, a 33-factorial experimental design with RSM and the Box-Behnken design was investigated for the major influence factors. Maximum xylanase production (11.28 U/mL) was obtained when the strain was grown in mineral medium supplemented with 3% (w/v) of olive pomace powder and 0.3% (w/v) of ammonium sulfate, at a pH 7.4 and an incubation temperature of 40 °C. The xylanases in the supernatant degraded all tested substrates, with higher activity for the low-viscosity wheat arabinoxylan substrate. Two xylanases with close molecular masses were detected by zymogram analysis: Xyl-1 and Xyl-2 with molecular masses of 24.14 kDa and 27 kDa, respectively. The optimization of enzyme production parameters of Streptomyces sp. S1M3I and the characterization of these enzymes are prerequisites to enhancing xylanase production yield, which is crucial for further biotechnological processes.

A Global Overview of Dietary Supplements: Regulation, Market Trends, Usage during the COVID-19 Pandemic, and Health Effects.

Over the last 20 years, the use of dietary supplements (DS) has continued to grow in many countries. Due to the public health crisis brought on by the COVID-19 pandemic and amidst fears regarding COVID-19 vaccines and their low supply in many regions of the world, there has been a marked interest in the use of DS as alternative means of protecting against and treating this emerging disease, as well as boosting the immune system and minimizing the risk of inflammation. Despite a lack of evidence to suggest their efficacy, a surge in the sales of DS has been reported in many parts of the world. Questions have also been raised about the health effects associated with DS due to their increased use during the health crisis. Numerous scientific studies have demonstrated their beneficial properties as well as some adverse and even toxic effects. In addition, given the current global interest in this issue, a review is needed to establish the status of dietary supplements before and during the health crisis. The aim of this review is to summarize the current evidence on the impact of dietary supplements on the incidence of the COVID-19 pandemic, as well as their regulation and associated market trends. First, we provide an overview of DS, including a comprehensive review of the legislative and regulatory aspects of DS in the USA, China, the EU, and Algeria. Second, we describe the prevalence of the most commonly consumed DS and their efficacy as a prophylactic modality in the era of COVID-19. Additionally, we examine the structure and size of the DS market in the countries that predominantly produce and import them, its global market trend, and the impact of the COVID-19 pandemic on market growth. Finally, in this review, we also discuss the profile of DS users.