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result(s) for
"Emam, Maha T. H."
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Safe production of Aspergillus terreus xylanase from Ricinus communis: gene identification, molecular docking, characterization, production of xylooligosaccharides, and its biological activities
by
Taie, Hanan A.A.
,
Emam, Maha T.H.
,
Nour, Shaimaa A.
in
Activation energy
,
agricultural wastes
,
ammonium sulfate
2022
The production of industrial enzymes such as xylanase using sufficient cost-effective substrates from potent microorganisms is considered economically feasible. Studies have reported castor cake (Ricinus communis) as the most potent and inexpensive alternative carbon source for production of xylanase C by using Aspergillus terreus (A. terreus). A. terreus strain RGS Eg-NRC, a local isolate from agro-wastes, was first identified by sequencing the internal transcribed spacer region of a nuclear DNA encoding gene cluster deposited in GenBank (accession number MW282328). Before optimization of xylanase production, A. terreus produced 20.23 U/g of xylanase after 7 days using castor cake as a substrate in a solid-state fermentation (SSF) system that was employed to achieve ricin detoxification and stimulate xylanase production. Physicochemical parameters for the production of xylanase were optimized by using a one-variable-at-a-time approach and two statistical methods (two-level Plackett-Burman design and central composite design, CCD). The maximum xylanase yield after optimization was increased by 12.1-fold (245 U/g). A 60-70% saturation of ammonium sulfate resulted in partially purified xylanase with a specific activity of 3.9 IU/mg protein. At 60 °C and pH 6, the partially purified xylanase had the highest activity, and the activation energy (Ea) was 23.919 kJmol. Subsequently, antioxidant capacity and cytotoxicity tests in normal Ehrlich ascites carcinoma human cells demonstrated xylooligosaccharides produced by the xylanase degradation of xylan as a potent antioxidant and moderate antitumor agent. Further investigations with sodium dodecyl sulfate polyacrylamide gel electrophoresis then determined the molecular weight of partially purified xylanase C to be 36 kDa. Based on the conserved regions, observations revealed that xylanase C belonged to the glycosyl hydrolase family 10. Next, the xylanase-encoding gene (xynC), which has an open reading frame of 981 bp and encodes a protein with 326 amino acids, was isolated, sequenced, and submitted to the NCBI GenBank database (accession number LC595779.1). Molecular docking analysis finally revealed that Glu156, Glu262, and Lys75 residues were involved in the substrate-binding and protein-ligand interaction site of modeled xylanase, with a binding affinity of -8.7 kcal. mol.sup.-1. The high production of safe and efficient xylanase could be achieved using economical materials such as Ricinus communis.
Journal Article
Gene Cloning, Heterologous Expression, and In Silico Analysis of Chitinase B from Serratia marcescens for Biocontrol of Spodoptera frugiperda Larvae Infesting Maize Crops
2024
Spodoptera frugiperda, the fall armyworm (FAW), is a highly invasive polyphagous insect pest that is considered a source of severe economic losses to agricultural production. Currently, the majority of chemical insecticides pose tremendous threats to humans and animals besides insect resistance. Thus, there is an urgent need to develop new pest management strategies with more specificity, efficiency, and sustainability. Chitin-degrading enzymes, including chitinases, are promising agents which may contribute to FAW control. Chitinase-producing microorganisms are reported normally in bacteria and fungi. In the present study, Serratia marcescens was successfully isolated and identified from the larvae of Spodoptera frugiperda. The bacterial strain NRC408 displayed the highest chitinase enzyme activity of 250 units per milligram of protein. Subsequently, the chitinase gene was cloned and heterologously expressed in E. coli BL21 (DE3). Recombinant chitinase B was overproduced to 2.5-fold, driven by the T7 expression system. Recombinant chitinase B was evaluated for its efficacy as an insecticidal bioagent against S. frugiperda larvae, which induced significant alteration in subsequent developmental stages and conspicuous malformations. Additionally, our study highlights that in silico analyses of the anticipated protein encoded by the chitinase gene (ChiB) offered improved predictions for enzyme binding and catalytic activity. The effectiveness of (ChiB) against S. frugiperda was evaluated in laboratory and controlled field conditions. The results indicated significant mortality, disturbed development, different induced malformations, and a reduction in larval populations. Thus, the current study consequently recommends chitinase B for the first time to control FAW.
Journal Article
Utilizing chitooligosaccharides from shrimp waste biodegradation via recombinant chitinase A: a promising approach for emulsifying hydrocarbon and bioremediation
by
Sakr, Ebtehag A. E.
,
Emam, Maha T. H.
,
Nour, Shaimaa A.
in
Animals
,
Applied Microbiology
,
Biodegradation, Environmental
2024
Background
Hydrocarbon pollution stemming from petrochemical activities is a significant global environmental concern. Bioremediation, employing microbial chitinase-based bioproducts to detoxify or remove contaminants, presents an intriguing solution for addressing hydrocarbon pollution. Chitooligosaccharides, a product of chitin degradation by chitinase enzymes, emerge as key components in this process. Utilizing chitinaceous wastes as a cost-effective substrate, microbial chitinase can be harnessed to produce Chitooligosaccharides. This investigation explores two strategies to enhance chitinase productivity, firstly, statistical optimization by the Plackett Burman design approach to evaluating the influence of individual physical and chemical parameters on chitinase production, Followed by response surface methodology (RSM) which delvs into the interactions among these factors to optimize chitinase production. Second, to further boost chitinase production, we employed heterologous expression of the chitinase-encoding gene in
E. coli
BL21(DE3) using a suitable vector. Enhancing chitinase activity not only boosts productivity but also augments the production of Chitooligosaccharides, which are found to be used as emulsifiers.
Results
In this study, we focused on optimizing the production of chitinase A from
S. marcescens
using the Plackett Burman design and response surface methods. This approach led to achieving a maximum activity of 78.65 U/mL. Subsequently, we cloned and expressed the gene responsible for chitinase A in
E. coli
BL21(DE3). The gene sequence, named
SmChiA
, spans 1692 base pairs, encoding 563 amino acids with a molecular weight of approximately 58 kDa. This sequence has been deposited in the NCBI GenBank under the accession number \"OR643436\". The purified recombinant chitinase exhibited a remarkable activity of 228.085 U/mL, with optimal conditions at a pH of 5.5 and a temperature of 65 °C. This activity was 2.9 times higher than that of the optimized enzyme. We then employed the recombinant chitinase A to effectively hydrolyze shrimp waste, yielding chitooligosaccharides (COS) at a rate of 33% of the substrate. The structure of the COS was confirmed through NMR and mass spectrometry analyses. Moreover, the COS demonstrated its utility by forming stable emulsions with various hydrocarbons. Its emulsification index remained stable across a wide range of salinity, pH, and temperature conditions. We further observed that the COS facilitated the recovery of motor oil, burned motor oil, and aniline from polluted sand. Gravimetric assessment of residual hydrocarbons showed a correlation with FTIR analyses, indicating the efficacy of COS in remediation efforts.
Conclusions
The recombinant chitinase holds significant promise for the biological conversion of chitinaceous wastes into chitooligosaccharides (COS), which proved its potential in bioremediation efforts targeting hydrocarbon-contaminated sand.
Journal Article
Gene Cloning, Heterologous Expression, and In Silico Analysis of Chitinase B from ISerratia marcescens/I for Biocontrol of ISpodoptera frugiperda/I Larvae Infesting Maize Crops
by
Emam, Maha T. H
,
El-Sayed, Ghada M
,
Hammad, Maher A
in
Agricultural industry
,
Amino acids
,
Analysis
2024
Spodoptera frugiperda, the fall armyworm (FAW), is a highly invasive polyphagous insect pest that is considered a source of severe economic losses to agricultural production. Currently, the majority of chemical insecticides pose tremendous threats to humans and animals besides insect resistance. Thus, there is an urgent need to develop new pest management strategies with more specificity, efficiency, and sustainability. Chitin-degrading enzymes, including chitinases, are promising agents which may contribute to FAW control. Chitinase-producing microorganisms are reported normally in bacteria and fungi. In the present study, Serratia marcescens was successfully isolated and identified from the larvae of Spodoptera frugiperda. The bacterial strain NRC408 displayed the highest chitinase enzyme activity of 250 units per milligram of protein. Subsequently, the chitinase gene was cloned and heterologously expressed in E. coli BL21 (DE3). Recombinant chitinase B was overproduced to 2.5-fold, driven by the T7 expression system. Recombinant chitinase B was evaluated for its efficacy as an insecticidal bioagent against S. frugiperda larvae, which induced significant alteration in subsequent developmental stages and conspicuous malformations. Additionally, our study highlights that in silico analyses of the anticipated protein encoded by the chitinase gene (ChiB) offered improved predictions for enzyme binding and catalytic activity. The effectiveness of (ChiB) against S. frugiperda was evaluated in laboratory and controlled field conditions. The results indicated significant mortality, disturbed development, different induced malformations, and a reduction in larval populations. Thus, the current study consequently recommends chitinase B for the first time to control FAW.
Journal Article
Band-like calcification with simplified gyration and polymicrogyria: report of 10 new families and identification of five novel OCLN mutations
by
Abdel-Hamid, Mohamed S
,
Emam, Bayoumi A
,
Abdel-Salam, Ghada M H
in
Adolescent
,
Anus
,
Basal ganglia
2017
Band-like calcification with simplified gyration and polymicrogyria (BLC-PMG) is an extremely rare autosomal recessive disorder with distinctive clinical and neuroimaging findings. To date, only 17 patients from 9 unrelated families with BLC-PMG have been reported worldwide. Herein, we describe a series of 13 new patients derived from 10 unrelated Egyptian families. Patients presented at early life with the classic phenotype including severe microcephaly, failure to acquire developmental skills, growth failure and the distinguished calcification patterns involving the cortex, thalami, basal ganglia and pons. Additional features not reported before included calcification of the cerebellum (eight patients: 61.5%) and imperforate anus and undescended testis in a single patient. Molecular studies of the OCLN gene (NM_001205254) identified six distinct candidate mutations. Interestingly, the deletion mutation of the transmembrane domain in exons 3 and 4 (c.51-?_730-?del, p.Lys18_Glu243) was found in five unrelated families (50%), suggesting a founder mutation in our population. On the other hand, five novel truncating mutations (c.809delA (p.K270Rfs*62), c.858_861delTTAT (p.I286Mfs*45), c.1037+5G>C, c.1169C>G (p.S390*) and c.1180delG (p.E394Sfs*91)) were detected, each in one family. To our knowledge, this is the largest series of patients with BLC-PMG. Cerebellum calcification is an additional relevant finding in our series, thus expanding the neuroradiological phenotype of this syndrome.
Journal Article
Adropin/Tirzepatide Combination Mitigates Cardiac Metabolic Aberrations in a Rat Model of Polycystic Ovarian Syndrome, Implicating the Role of the AKT/GSK3β/NF-κB/NLRP3 Pathway
by
El-Horany, Hemat El-sayed
,
Abdallah, Hanan M.
,
Fouda, Mohamed H.
in
Animals
,
Antidiabetics
,
Biomarkers
2025
Polycystic ovarian syndrome (PCOS) is a multifaceted metabolic and hormonal disorder in females of reproductive age, frequently associated with cardiac disturbances. This research aimed to explore the protective potential of adropin and/or tirzepatide (Tirze) on cardiometabolic aberrations in the letrozole-induced PCOS model. Female Wistar non-pregnant rats were allotted into five groups: CON; PCOS; PCOS + adropin; PCOS + Tirze; and PCOS + adropin+ Tirze. The serum sex hormones, glucose, and lipid profiles were securitized. Cardiac phosphorylated levels of AKT(pAKT), glycogen synthase kinase-3 beta (pGSK-3β), NOD-like receptor family pyrin domain containing 3 (NLPR3), IL-1β and IL-18 were assayed. The cardiac redox status and endoplasmic reticulum stress (ER) parameters including relative glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) gene expressions were detected. Finally, the immunoreactivity of cardiac NF-κB, Bcl2, and BAX were assessed. Our results displayed that adropin and/or Tirze intervention successfully alleviated the PCOS-provoked cardiometabolic derangements with better results recorded for the combination treatment. The synergistic effect of adropin and Tirze is mostly mediated via activating the cardiac Akt, which dampens the GSK3β/NF-κB/NLRP3 signaling pathway, with a sequel of alleviating oxidative damage, inflammatory response, ER stress, and related apoptosis, making them alluring desirable therapeutic targets in PCOS-associated cardiac complications.
Journal Article
Oxazolone-Induced Immune Response in Atopic Dermatitis Using a Goat Model and Exploration of the Therapeutic Potential of Pomegranate Peel Extract
by
Aljameel, Suhailah S.
,
Hetta, Helal F.
,
Samir, Haney
in
Advertising executives
,
Atopic dermatitis
,
Cytokines
2025
Atopic dermatitis (AD) remains a challenging condition, necessitating effective models for investigation and therapeutic exploration. In this study, we employed a goat skin model to assess the immune response triggered by topical oxazolone (OX) application. The OX simulates a Th2-driven immune reaction typified by elevated Th2 cytokine (IL-4 and IL-13) expression and the infiltration of mononuclear cells magnified by the presence of CD3+ and CD4+ T-cells in the epidermal and dermal layers. Additionally, the application of pomegranate peel extract (PPE) demonstrated a mitigating effect on OX-induced skin alterations, suggesting potential therapeutic benefits. This study underscores the value of goats as a reliable and accessible model for studying AD in humans and/or large animals. While the therapeutic potential of PPE dosage requires further exploration.
Journal Article
Subpleural versus Deep Lung Biopsies Obtained during Pleuroscopy for Histological Examination: An Experimental Animal Study
2012
Background: Lung biopsies obtained during medical pleuroscopy using coagulating forceps could represent a cost-effective alternative to surgical lung biopsies in patients with diffuse parenchymal lung diseases (DPLD). However, it is not clear whether these patients should undergo deeplung biopsies rather than more superficial subpleural lung biopsies. Objectives: The aim of this experimental animal study was to compare gross and microscopic features of deep and subpleural pleuroscopic lung biopsy samples. Methods: Six male sheep (median weight 40 kg) underwent lung biopsies via pleuroscopy under general anesthesia. The following parameters were studied: weight, size, quality of the parenchyma and visceral pleura, parenchymal vessels and bronchial tissue. Results: The mean number of biopsies taken per animal was 4.5 ± 1.22 and 4.83 ± 1.33 (p = 0.36) for deep and subpleural biopsies, respectively. The mean size of deep and subpleural biopsies was 1.758 ± 0.478 and 1.283 ± 0.851 cm 2 , respectively (p = 0.0006). The mean weight of deep biopsies and subpleural biopsies was 0.156 ± 0.092 and 0.145 ± 0.047 mg, respectively (p = 0.83). No statistically significant difference was found between subpleural and deep biopsies regarding the mean quality scores of parenchyma-pleura (p = 0.36), vessels (p = 0.36), or bronchial tissue (p = 0.20). Conclusion: Both subpleural biopsies obtained during pleuroscopy and deep lung biopsy specimens obtained by electrocautery in animal subjects provided satisfactory material for histologic examination. Therefore, in DPLD, where the subpleural layers are involved, subpleural biopsies obtained during pleuroscopy might be sufficient for establishing an accurate diagnosis.
Journal Article