The novel bacteriocin BacYB1 produced by Leuconostoc mesenteroides YB1: From recent analytical characterization to biocontrol Verticillium dahliae and Agrobacterium tumefaciens.

Biocontrol of phytopathogens involving the use of bioactive compounds produced by lactic acid bacteria (LAB), is a promising approach to manage many diseases in agriculture. In this study, a lactic acid bacterium designated YB1 was isolated from fermented olives and selected for its antagonistic activity against Verticillium dahliae (V. dahliae) and Agrobacterium tumefaciens (A. tumefaciens). Based on the 16S rRNA gene nucleotide sequence analysis (1565 pb, accession number: OR714267), the new isolate YB1 bacterium was assigned as Leuconostoc mesenteroides YB1 (OR714267) strain. This bacterium produces an active peptide "bacteriocin" called BacYB1, which was purified in four steps. Matrix-assisted lasers desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) based approach was performed to identify and characterize BacYB1. The exact mass was 5470.75 Da, and the analysis of the N-terminal sequence (VTRASGASTPPGTASPFKTL) of BacYB1 revealed no significant similarity to currently available antimicrobial peptides. The BacYB1 displayed a bactericidal mode of action against A. tumefaciens. The potentiel role of BacYB1 to supress the growth of A. tumefaciens was confirmed by live-dead cells viability assay. In pot experiments, the biocontrol efficacy of BacYB1 against V. dahliae wilt on young olive trees was studied. The percentage of dead plants (PDP) and the final mean symptomes severity (FMS) of plants articifialy infected by V. dahliae and treated with the pre-purified peptide BacYB1 (preventive and curative treatments) were significantly inferior to untreated plants. Biochemical analysis of leaves of the plants has shown that polyophenols contents were highly detected in plants infected by V. dahliae and the highest contents of chlorophyl a, b and total chlorophyll were recorded in plants treated with the combination of BacYB1 with the biofertilisant Humivital. BacYB1 presents a promising alternative for the control of Verticillium wilt and crown gall diseases.

Exploring the bio-insecticidal activity of Eucalyptus globulus essential oil/ß-cyclodextrin inclusion complexes: In vitro and in silico assessment against Ephestia kuehniella larvae.

Owing to their beneficial functional capabilities, essential oils were largely used. However, their low aqueous solubility, instability, and high volatility urged scientists to their encapsulation with cyclodextrins (CDs) to tackle their shortcomings. In this study, the co-precipitation method was used to prepare ß-CD/Eucalyptus globulus essential oil (EGEO) inclusion complexes (ICs). ß-CD/EGEO ICs were prepared at ratios (w:w) 1:2 and 1:4 with an encapsulation efficiency of 93 and 96%, respectively. The ICs characterization using the Fourier transform Infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction, Dynamic Light Scattering, and Laser Doppler Velocimetry confirmed the formation of ß-CD/EGEO ICs. The insecticidal activity of the free EGEO and ICs was explored and displayed that the complex ß-CD/EGEO 1:4 had the highest activity with the lowest LC50 against Ephestia kuehniella larvae (5.03 ± 1.16 mg/g) when compared to the free oil (8.38 ± 1.95 mg/g). Molecular docking simulations stipulated that the compound α-Bisabolene epoxide had the best docking score (ΔG = -7.4 Kcal/mol) against the selected insecticidal target α-amylase. Additionally, toxicity evaluation of the studied essential oil suggested that it could be safely used as a potent bioinsecticide as compared to chemical insecticides. This study reveals that the formation of ß-CD/EGEO ICs enhanced the oil activity and stability and could be a promising and safe tool to boost its application in food or pharmaceutical fields.

Combined in†vitro/in silico approaches, molecular dynamics simulations and safety assessment of the multifunctional properties of thymol and carvacrol: A comparative insight.

Bioactive compounds derived from medicinal plants have acquired immense attentiveness in drug discovery and development. The present study investigated in vitro and predicted in silico the antibacterial, antifungal, and antiviral properties of thymol and carvacrol, and assessed their safety. The performed microbiological assays against Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica Typhimurium revealed that the minimal inhibitory concentration values ranged from (0.078 to 0.312 mg/mL) and the minimal fungicidal concentration against Candida albicans was 0.625 mg/mL. Molecular docking simulations, stipulated that these compounds could inhibit bacterial replication and transcription functions by targeting DNA and RNA polymerases receptors with docking scores varying between (-5.1 to -6.9 kcal/mol). Studied hydroxylated monoterpenes could hinder C. albicans growth by impeding lanosterol 14α-demethylase enzyme and showed a (ΔG=-6.2 and -6.3 kcal/mol). Computational studies revealed that thymol and carvacrol could target the SARS-Cov-2 spike protein of the Omicron variant RBD domain. Molecular dynamics simulations disclosed that these compounds have a stable dynamic behavior over 100 ns as compared to remdesivir. Chemo-computational toxicity prediction using Protox II webserver indicated that thymol and carvacrol could be safely and effectively used as drug candidates to tackle bacterial, fungal, and viral infections as compared to chemical medication.

Cupressus sempervirens Essential Oil: Exploring the Antibacterial Multitarget Mechanisms, Chemcomputational Toxicity Prediction, and Safety Assessment in Zebrafish Embryos.

Nowadays, increasing interest has recently been given to the exploration of new food preservatives to avoid foodborne outbreaks or food spoilage. Likewise, new compounds that substitute the commonly used synthetic food preservatives are required to restrain the rising problem of microbial resistance. Accordingly, the present study was conducted to examine the chemical composition and the mechanism(s) of action of the Cupressus sempervirens essential oil (CSEO) against Salmonella enterica Typhimuriumand Staphyloccocus aureus. The gas chromatography analysis revealed α-pinene (38.47%) and δ-3-carene (25.14%) are the major components of the CSEO. By using computational methods, such as quantitative structure-activity relationship (QSAR), we revealed that many CSEO components had no toxic effects. Moreover, findings indicated that α-pinene, δ-3-carene and borneol, a minor compound of CSEO, could inhibit the AcrB-TolC and MepR efflux pump activity of S. enterica Typhimurium and S. aureus, respectively. In addition, our molecular docking predictions indicated the high affinity of these three compounds with active sites of bacterial DNA and RNA polymerases, pointing to plausible impairments of the pathogenic bacteria cell replication processes. As well, the safety profile was developed through the zebrafish model. The in vivo toxicological evaluation of (CSEO) exhibited a concentration-dependent manner, with a lethal concentration (LC50) equal to 6.6 µg/mL.

Purification and characterization of seven bioactive compounds from the newly isolated Streptomyces cavourensis TN638 strain via solid-state fermentation.

The strain TN638 was isolated from Tunisian soil contaminated with industrial wastewater and selected for its potent antimicrobial activity against the tested Gram positive bacteria: Staphylococcus aureus (S. aureus) ATCC 6538 and Listeria monocytogenes (L. monocytogenes) ATCCC 19117, and Gram negative bacteria: Agrobacterium tumefaciens (A. tumefaciens) ATCC 23308 and Salmonella typhimurium (S. typhimurium) ATCC 14028 and fungi: Candida albicans (C. albicans) ATCC 10231, Rhizoctonia solani (R. solani) ATCC 58938 and Fusarium sp. Solide-state fermentation (SSF) dry crude extract of the TN638 strain presents a strong inhibitory activity notably against the phytopathogenic microorganism A. tumefaciens ATCC 23308 and the two pathogenic bacteria S. aureus ATCC 6538 and L. monocytogenes ATCCC 19117 with a zone of inhibition of 48, 34 and 34 mm respectively. According to the morphological characteristic, the complete 16S rRNA gene nucleotide sequence determination [1492 bp deposited in National Center of Biotechnology Information (NCBI) database under the accession no. LN854629.1; https://www.ncbi.nlm.nih.gov/nuccore/LN854629.1/], and the phylogenetic analysis, we can deduce that our isolate is an actinomycete bacterium belonging to the genus Streptomyces and the most closely related strain was Streptomyces cavourensis (S. cavourensis) NRRL 2740T (99.9%). We propose the assignment of our strain as Streptomyces cavourensis (S. cavourensis) TN638 strain. Work-up and purification of the strain extract using different chromatographic techniques afforded seven bio-compounds namely: Cyclo-(Leu-Pro) (1), Cyclo-(Val-Pro) (2), Cyclo-(Phe-Pro) (3), nonactin (4), monactin (5), dinactin (6) and trinactin (7). The chemical structures of compounds 1-7 were confirmed by nuclear magnetic resonance (NMR) 1D and 2D spectroscopy, mass spectrometry, and comparison with literature data. The three purified diketopiperazine (DKP) derivatives (1-3), demonstrated significant antibacterial activity against A. tumefaciens ATCC 23308 and S. typhimurium ATCC 14028. The four pure macrotetrolides (4-7), exhibited strong inhibitory effect against all tested Gram positive and Gram negative bacteria notably against A. tumefaciens ATCC 23308 and S. typhimurium ATCC 14028 with a minimum inhibitory concentration (MIC) around 8 µg/mL quite similar to that of ampicillin. Thus, we propose the use of the (SSF) active extract of the S. cavourensis TN638 strain as safe biological product to control disease caused by plant pathogen A. tumefaciens. Also, the purified active molecules produced by this strain could be used in pharmaceutical field.

Bioactive Compounds and Pharmacological Potential of Pomegranate (Punica granatum) Seeds - A Review.

The use of complementary medicine has recently increased in an attempt to find effective alternative therapies that reduce the adverse effects of drugs. Pomegranate (Punica granatum L.) by-products, such as seeds, is a rich source of phytochemicals with a high antioxidant activity, thus possessing health benefits. For the identification and quantification of the pomegranate seeds chemical compounds, particular attention has been drawn to the latest developments in the HPLC coupling with electrospray ionization (ESI) MS/MS detection. In fact, a wide range of phytochemicals including phenolic acid, anthocyanins, flavonoids, hydrolysable tannins and other polyphenols were characterized. Furthermore, an exhaustive review of the scientific literature on pomegranate seeds on biomedicine and pharmacotherapy was carried out. Indeed, both in vitro and in vivo studies have demonstrated how pomegranate seeds possess antioxidant, anti- cardiovascular diseases, anti-osteoporosis, antidiabetic, anti-inflammatory and anticancer activities. The present review describes a recent tendency in research focusing on the chemical and biomedical features of the pomegranate seeds to value them as natural additives or active compounds for first-order diseases.

Modeling-based optimization approaches for the development of Anti-Agrobacterium tumefaciens activity using Streptomyces sp TN71.

A new aerobic bacterium TN71 was isolated from Tunisian Saharan soil and has been selected for its antimicrobial activity against phytopathogenic bacteria. Based on cellular morphology, physiological characterization and phylogenetic analysis, this isolate has been assigned as Streptomyces sp. TN71 strain. In an attempt to increase its anti-Agrobacterium tumefaciens activity, GYM + S (glucose, yeast extract, malt extract and starch) medium was selected out of five different production media and the medium composition was optimized. Plackett-Burman design (PBD) was used to select starch, malt extract and glucose as parameters having significant effects on antibacterial activity and a Box-Behnken design was applied for further optimization. The analysis revealed that the optimum concentrations for anti-A. tumefaciens activity of the tested variables were 19.49 g/L for starch, 5.06 g/L for malt extract and 2.07 g/L for glucose. Several Artificial Neural Networks (ANN): the Multilayer perceptron (MLP) and the Radial basis function (RBF) were also constructed to predict anti-A. tumefaciens activity. The comparison between experimental with predicted outputs from ANN and Response Surface Methodology (RSM) were studied. ANN model presents an improvement of 12.36% in terms of determination coefficients of anti A. tumefaciens activity. To our knowledge, this is the first work reporting the statistical versus artificial intelligence based modeling for optimization of bioactive molecules against phytopathogens.

The use of newly isolated Streptomyces strain TN258 as potential biocontrol agent of potato tubers leak caused by Pythium ultimum.

An actinomycete strain designated TN258, was isolated from Tunisian Sahara soil and selected for its antagonistic activity, especially against Pythium ultimum (P. ultimum) causing potato tubers leak. Based on the results of cultural characteristic of TN258 strain, the 16S rRNA gene nucleotide sequence (1433 bp, accession n° HE600071) and the phylogenetic analysis, we propose the assignment of our new isolate bacterium as Streptomyces TN258 strain. After culture optimization, the inhibitory effect of TN258 free cell supernatant against P. ultimum was evaluated. As result, by application of 50% (v/v) from 25 mg ml-1 of concentration, mycelial growth was totally inhibited with hyphal destruction. At the same concentration, the oospores were distorted and the germination was completely stopped. In potato tubers, Streptomyces TN258 filtrated supernatant, applied 24 h before inoculation by P. ultimum (preventive treatment group) was able to significantly decrease pathogen penetration by 62% and to reduce the percentage of weight loss by 59.43%, in comparison with non-treated group.

A Palladium Catalyst System for the Efficient Cross-Coupling Reaction of Aryl Bromides and Chlorides with Phenylboronic Acid: Synthesis and Biological Activity Evaluation.

New benzimidazolium salts 1a-c and their palladium bis-N-heterocyclic carbene complexes 2a-c and palladium PEPPSI-type complexes 3a-c were designed, synthesized and structurally characterized by NMR (1H and 13C), IR, DART-TOF mass spectrometry and elemental analysis. Then these complexes 2-3 were employed in the Suzuki-Miyaura cross-coupling reaction of substituted arenes with phenylboronic acid under mild conditions in toluene and DMF/H2O (1/1) to afford functionalized biaryl derivatives in good to excellent yields. The antibacterial activity of palladium bis-N-heterocyclic carbene complexes 2a-c and palladium PEPPSI-type complexes 3a-c was measured by disc diffusion method against Gram positive and Gram negative bacteria. Compounds 2a, 2c and 3a-c exhibited potential antibacterial activity against four bacterial species among the five used indicator cells. The product 2b inhibits the growth of the all five tested microorganisms. Moreover, the antioxidant activity determination of these complexes 2-3, using 2.2-diphenyl-1-picrylhydrazyl (DPPH) as a reagent, showed that compounds 2a-c and 3b possess DPPH antiradical activity. The higher antioxidant activity was obtained from the product 2b which has radical scavenging activity comparable to that of the two used positive controls (gallic acid "GA" and tutylatedhydroxytoluene "BHT"). Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 2b, 3a, and 3b exhibited moderate activity at 100 µg/mL and product 2b is the most active.

An antilisterial bacteriocin BacFL31 produced by Enterococcus faecium FL31 with a novel structure containing hydroxyproline residues.

A new bacterium called FL31, which was selected for its antimicrobial activity against the pathogenic bacterium Listeria monocytogenes, was identified as Enterococcus faecium and noted to produce an antibacterial proteinaceous substance (BacFL31). The active peptide from the cell-free supernatant of E. faecium FL31 was purified in four steps and the results revealed a single band with an estimated molecular mass of approximately 3.5 kDa. The N-terminal amino acid sequence of the purified BacFL31 "GLEESXGHXGQXGPXGPXGAXGP" (X = hydroxyproline) showed the presence of six hydroxyproline residues. It displayed a bactericidal mode of action against L. monocytogenes. Its application at 400 AU/g was also noted to constitute an effective approach for preventing the contamination and growth of the pathogenic bacterium L. monocytogenes during the storage of minced beef meat at 4 °C.

Disclosing the Functional Potency of Three Oxygenated Monoterpenes in Combating Microbial Pathogenesis: From Targeting Virulence Factors to Chicken Meat Preservation.

During the last few decades, there has existed an increased interest in and considerable consumer preference towards using natural and safe compounds derived from medicinal plants as alternatives to synthetic preservatives to combat microbial pathogenicity. In this regard, the present study investigated the possible synergistic interactions of the anti-foodborne bacterial capacity of linalool (L), eucalyptol (E), and camphor (C). The antibacterial synergistic effect was determined against Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica Typhimurium, and Escherichia coli. The optimal predicted mixture showed the highest antibacterial activity at 33.5%, 33.2%, and 33.4% of L, E, and C, respectively. Molecular docking simulations displayed that the studied monoterpenes have effective antibacterial inhibitory effects by impeding specific virulence factors such as sortase A, listeriolysin O, L, D-Transpeptidase, and polyphosphate kinase. The selected triple combination of L, E, and C was applied as a natural preservative in minced chicken breast meat. In this regard, 1 MIC (16 µg/mL), 1.5 MIC (24 µg/mL), and 2 MIC (32 µg/mL) of L. monocytogenes were used, and the microbiological, physicochemical, and sensory analyses were monitored for 14 days of storage at 4 °C. The L/E/C mixture at different levels could delay lipid and protein oxidation, inhibit the microorganisms, and maintain the sensory attributes. Additionally, by using chemometric tools, strong connections between physicochemical properties, microbiological parameters, and organoleptic attributes were established. Concisely, this research confers the importance of the use of blended monoterpenes and highlights their antibacterial mode of action, effectiveness, and synergistic effects as a powerful and safe bio-preservative formulation in chicken meat products.

In-Depth Study of Thymus vulgaris Essential Oil: Towards Understanding the Antibacterial Target Mechanism and Toxicological and Pharmacological Aspects.

Questions have been raised apropos the emerging problem of microbial resistance, which may pose a great hazard to the human health. Among biosafe compounds are essential oils which captured consumer draw due to their multifunctional properties compared to chemical medication drugs. Here, we examined the chemical profile and the mechanism(s) of action of the Thymus vulgaris essential oil (TVEO) against a Gram-negative bacterium Salmonella enterica Typhimurium ATTCC 10028 (S. enterica Typhimurium ATTCC 10028) and two Gram-positive bacteria Staphyloccocus aureus ATCC 6538 (S. aureus ATCC 6538) and Listeria monocytogenes ATCC 19117 (L. monocytogenes ATCC 19117). Findings showed that TVEO was principally composed of thymol, o-cymene, and γ-terpinene with 47.44, 16.55, and 7.80%, respectively. Molecular docking simulations stipulated that thymol and ß-sesquiphellandrene (a minor compound at 1.37%) could target multiple bacterial pathways including topoisomerase II and DNA and RNA polymerases of the three tested bacteria. This result pointed plausible impairments of the pathogenic bacteria cell replication and transcription processes. Through computational approach, the VEGA quantitative structure-activity relationship (QSAR) model, we revealed that among twenty-six TVEO compounds, sixteen had no toxic effects and could be safe for human consumption as compared to the Food and Drug Administration (FDA) approved drugs (ciprofloxacin and rifamycin SV). Assessed by the SwissADME server, the pharmacokinetic profile of all identified TVEO compounds define their absorption, distribution, metabolism, and excretion (ADME) properties and were assessed. In order to predict their biological activity spectrum based on their chemical structure, all TVEO compounds were subjected to PASS (Prediction of Activity Spectra for Substances) online tool. Results indicated that the tested compounds could have multiple biological activities and various enzymatic targets. Findings of our study support that identified compounds of TVEO can be a safe and effective alternative to synthetic drugs and can easily combats hazardous multidrug-resistant bacteria.

Multiobjective response and chemometric approaches to enhance the phytochemicals and biological activities of beetroot leaves: an unexploited organic waste.

Research on medicinal plants is developing each day due to inborn phytochemicals, which can encourage the progress of novel drugs. Most plant-based phytochemicals have valuable effects on well-being. Among them, beetroot leaves (BL) are known for their therapeutic properties. Here, three solvents, namely, acetonitrile, ethanol, and water, and their combinations were developed for BL extraction and simultaneous assessment of phytochemical compounds and antioxidant and antifoodborne pathogen bacteria activities. By using the augmented simplex-centroid mixture design, 40.40% acetonitrile diluted in water at 38.74% and ethanol at 20.86% favored the recovery of 49.28 mg GAE/mL (total phenolic content (TPC)) and 0.314 mg QE/mL (total flavonoid content (TFC)), respectively. Acetonitrile diluted in water at 50% guarantees the best antioxidant activity, whereas the optimal predicted mixture for the highest antibacterial activity matches 24.58, 50.17, and 25.25% of acetonitrile, ethanol, and water, respectively. These extraction conditions ensured inhibition of Staphylococcus aureus, Salmonella enterica, and Escherichia coli, respectively, at 0.402, 0.497, and 0.207 mg/mL. Under optimized conditions, at three concentrations of BL, minimal inhibitory concentration (MIC), 2 × MIC, and 4 × MIC, a linear model was employed to investigate the inhibition behavior against the three tested bacteria. The early logarithmic growth phase of these bacteria illustrated the bactericidal effect of optimized extracted BL with a logarithmic growth phase inferior to 6 h. Therefore, BL extract at 4 × MIC, which corresponds to 1.608, 1.988, and 0.828 mg/mL, was more efficient against S. aureus, S. enterica, and E. coli.

Novel Active Food Packaging Films Based on Gelatin-Sodium Alginate Containing Beetroot Peel Extract.

Currently, the exploration of natural colorants from vegetal waste has gained particular attention. Furthermore, incorporation of these natural sources into biopolymers is an encouraging environmentally friendly approach to establishing active films with biological activities for food packaging. The present study developed bioactive antioxidant films based on gelatin-sodium alginate (NaAlg) incorporated with aqueous beetroot peel extract (BPE). Firstly, the effects of combining gelatin-NaAlg and BPE at 0.25, 0.5, and 1% on the mechanical, physical, antioxidant, and antibacterial properties of the films were analyzed. With increasing BPE, mechanico-physical properties and antioxidant and anti-foodborne pathogen capacities were enhanced. Likewise, when added to gelatin-NaAlg films, BPE remarkably increased the instrumental color properties. Moreover, during 14 days of storage at 4 °C, the impact of gelatin-NaAlg coating impregnated with BPE on microbial and chemical oxidation and on the sensory characteristics of beef meat samples was periodically assessed. Interestingly, by the end of the storage, BPE at 1% limited the microbial deterioration, enhanced the instrumental color, delayed chemical oxidation, and improved sensory traits. By practicing chemometrics tools (principal component analysis and heat maps), all data provided valuable information for categorizing all samples regarding microbiological and oxidative properties, sensory features, and instrumental color. Our findings revealed the ability of gelatin-NaAlg with BPE as an antioxidant to be employed as food packaging for meat preservation.

Novel 3-phenyl-1- (alkylphenyl)-9-oxa-4-azaphenanthren-10-ones as inhibitors of some enzymes: synthesis, characterization, biological evaluation and molecular docking studies.

A series of novel 3-phenyl-1-(alkylphenyl)-9-oxa-4-azaphenanthren-10-ones and (E)-1-phenyl-3-(aryl)prop-2-en-1-ones were synthesized and characterized by IR, 1H NMR, 13C spectroscopy and elemental analysis. The synthesized Compounds 5a-f were subjected to molecular docking simulation with three proteins, namely, tyrosyl-tRNA synthetase, heme oxygenase 1 and acetylcholinesterase to evaluate the antibacterial, antioxidant and acetylcholinesterase inhibition, respectively. Moreover, the docked poses of all compounds inside the proteins were subjected to further dynamic simulation through the calculation of the binding free energy using MM-GBSA analysis. Compound 5d exhibits high potential inhibition against antibacterial, antioxidant and acetylcholinesterase activities. Compounds 3d, 3f, 5a and 5d recorded an important scavenging activity in DPPH and ABTS assays. Investigation of the anti-acetylcholinesterase activity of the synthesized compounds showed that Compounds 5a and 3d are the most potent inhibitors against AchE, with percent inhibition values of 38 and 30%, respectively.Communicated by Ramaswamy H. Sarma.

Pistachio Hull Extract as a Practical Strategy to Extend the Shelf Life of Raw Minced Beef: Chemometrics in Quality Evaluation.

The agricultural processing industry produces a notable quantity of by-products rich in bioactive compounds, which can be exploited for agri-food applications. From pistachio industrial processing, pistachio's hull is one of the major by-products. This work aimed to evaluate the potential of pistachio hull, as a potential source of natural antioxidant, to preserve the meat quality. Here, we investigated the impact of aqueous pistachio hull extract (PHE) at 0.156% (PHE1), 0.312% (PHE2), and 0.625% (PHE3) on the quality of raw minced beef meat stored for 14 days at 4°C. At the end of storage, mesophilic total viable plate, psychotropic and Enterobacteriaceae counts, showed significantly lower (P < 0.05) microbial count in PHE samples. PHE3 revealed a powerful inhibitory effect on lipid/protein oxidation, and sensory characteristics were positively (P < 0.05) affected. Principal component analysis and heat map indicated complex and close synchronized relations among lipid/protein oxidation processes, microbial loads, and sensory attributes. Obtained results using univariate and multivariate statistical analysis underlined the importance of using different mathematical approaches, which are complementary to each other and could provide considerable information about the minced beef meat treated by PHE. Therefore, compared to synthetic antioxidants, PHE could be a clean-label alternative that can protect and enhance the quality of meat products.

Recent advancements in encapsulation of bioactive compounds as a promising technique for meat preservation.

Encapsulation is currently considered as one the most valuable methods for preserving aromatic compounds or hiding odors, enhancing their thermal and oxidative stability, and expanding their food applications. Indeed, this current article was aimed to provide an overview regarding the encapsulation of plant bioactive compounds and the spray-drying and extrusion processes with a focused discussion regarding the encountered challenges for meat and meat product preservation. Furthermore, different ranges of carbohydrates as wall materials (carriers) besides the process conditions' effects on the encapsulation effectiveness and the particle size of the encapsulated bioactive compounds have been discussed. The encapsulation of these compounds ameliorates the quality of the stored meat products by further delaying in microflora growth and lipid/protein oxidation. Therefore, the innovative technologies for plant active compounds encapsulation offer a prospective alternative for natural preservation development in the meat industry.

A New Endophytic Fusarium Oxysporum Gibberellic Acid: Optimization of Production Using Combined Strategies of Experimental Designs and Potency on Tomato Growth under Stress Condition.

This study reports the potential of the endophytic fungi identified as a Fusarium oxysporum to produce gibberellic acid (GA3). The GA3 production was confirmed by high performance liquid chromatography. To improve the production of this phytohormone under solid state fermentation (SSF), successive optimization strategies were used. Firstly, Plackett-Burman design was applied for screening medium components and culture condition. Under the optimized condition, GA3 yield (7.14 g/kg) was 2.62-fold higher than by the use of the initial condition (2.72 g/kg). The concentration of the most influential parameters and their interaction were optimized with a Box-Behnken experimental design. The optimized condition led to a 1.14-fold enhancement in GA3 production, reaching 8.16 g/kg. The GA3 crude extract obtained by SSF was then used to study its ameliorative role on adverse salinity effect on tomato plants (Solanum lycopersicum L.). The interactive effects of different GA3 concentrations were examined on morphological and physiological parameters of tomato plants. The application of GA3 (10-6 M) under salt stress condition (100 mM) was found to improve growth and physiological parameters including plant height, total chlorophyll, starch, and proline contents. The exogenous application of GA3 is a potent strategy to reverse abiotic stress that affect the agricultural productivity and limit plant growth and yield.

A biological clean processing approach for the valorization of speckled shrimp Metapenaeus monoceros by-product as a source of bioactive compounds.

The efficiency of the proteolytic strain Anoxybacillus kamchatkensis M1V in the fermentation of speckled shrimp by-product was investigated for the recovery of a deproteinized bioactive hydrolysate. The biological activities of the resulting hydrolysate were also examined by applying several antioxidant and enzyme inhibitory assays. The strain M1V was found to produce high level of protease activity (2000 U/mL) when grown in media containing only shrimp powder at 25 g/L. The crude protease displayed a significant deproteinization capabiliy, with the best efficiency (48%) being recorded for an enzyme to substrate (E/S) ratio of 30 U/mg. Following the deproteinization, chitin was recovered and the authenticity was confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis. On the other hand, the obtained hydrolysate showed a significant enzymatic inhibitory potential against acetylcholinesterase, tyrosinase, amylase, and angiotensin I convertase, and a strong antioxidant activity. Graphical Abstract.

Overproduction of Glucose Oxidase by Aspergillus tubingensis CTM 507 Randomly Obtained Mutants and Study of Its Insecticidal Activity against Ephestia kuehniella.

In order to enhance the production of glucose oxidase (GOD), random mutagenesis of Aspergillus tubingensis CTM 507 was performed using the chemical and physical mutagens: nitric acid and UV irradiation, respectively. The majority of the isolated mutants showed good GOD production, but only some mutants presented a significant overproduction, as compared with the parent strain. The selected mutants (19 strains), showing an overproduction larger than 200%, are quite stable after three successive subcultures. Among these, six strains revealed an important improvement in submerged fermentation. The insecticidal activity of GOD produced by the wild and the selected mutant strains was evaluated against the third larval instars of E. kuehniella. Mutant strains U11, U12, U20, and U21, presenting the most important effect, displayed an LC50 value of 89.00, 88.51, 80.00, and 86.00 U/cm2, respectively, which was 1.5-fold more important than the wild strain (61 U/cm2). According to histopathology observations, the GOD enzyme showed approximately similar damage on the E. kuehniella midgut including rupture and disintegration of the epithelial layer and cellular vacuolization. The data supports, for the first time, the use of GOD as a pest control agent against E. kuehniella.