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Papers by siham ismail

Galactomanno-oligosaccharieds (GMO) and their sulfated derivatives (SGMO) were prepared from soyb... more Galactomanno-oligosaccharieds (GMO) and their sulfated derivatives (SGMO) were prepared from soybean hulls and evaluated for their biological activities as anticoagulant; antimicrobial; antitumor; fibrinoly tic and prebiotics. The results indicated that the sulfating process has positive effect on the anticoagulation and fibrinolytic activities of the galactomanno -oligosaccharieds. The SGMO have prolonged clotting time more than 24h at concentration resemble that of the standard heparin. It was also found that the SGMO have fibrinolytic activity as that of the standard hemoclar and 3times higher than that of the native GMO oligosaccharides. The pr epared oligosaccharides also preformed antitumor activity agains t human colon carcinoma cell line and the percentage of the dead cells increase from 28% to 72% by increase the concentration of the oligosaccharides from 0.005 to 0.02 mg/ml. The tested galactoma nnooligosaccharieds also act as good source for prebiotic a s they have the ab...

Galactomannans are naturally polysaccharides composed of β- (1→4)- mannose unit with α- (1→6) lin... more Galactomannans are naturally polysaccharides composed of β- (1→4)- mannose unit with α- (1→6) linked side chain of galactose unit in molar ratio depended on the

The quantitative effect of fermentation time, concentration of carbon and nitrogen sources and pH... more The quantitative effect of fermentation time, concentration of carbon and nitrogen sources and pH on mycelia growth and extracellular polysaccharides (EPS) produced by Scopularis spp. in shake flask were investigated by Box-Behnken experimental design. The low, middle and high levels of each variable were designated -1, 0, +1 and total of 30 experiments preformed in duplicate were conducted. The results indicated that the application of the design with the above variables almost increase the yield of EPS to 2.5 fold of that of the control (from 1.3 to 3.4 g/L) and double the mycelia growth (from 1.2 to 2.18 g/100 ml). The conditions for maximum mycelial growth were not the same as that for the maximum yield of EPS. The produced EPS from the 30 trials and their compositions were identified by: FT-IR, carbohydrate analysis, HPLC and TLC. Analysis data indicated the distinguish difference in the mono sugars composition and their ratio in the tested samples. However all the samples cont...

Egyptian Journal of Chemistry, 2021

Egyptian Pharmaceutical Journal, 2013

Background Microorganisms are better and cheaper sources for the production of polysaccharides. T... more Background Microorganisms are better and cheaper sources for the production of polysaccharides. Therefore, there has been an increasing interest in isolating and identifying new microbial polysaccharides. Objective The aim of this study was to produce new extracellular polysaccharides, with better rheological properties and varied applications, from the newly discovered fungal strain Scopularis spp., using different carbon sources. Methods Fourier transform infrared spectroscopy, carbohydrate analysis, and thin layer chromatography were the methods used for the preliminary characterizing of the produced polysaccharides. Results Among the 10 examined carbon sources, fructose, raffinose, sucrose, and maltose were found to produce an appreciable amount of extracellular polysaccharides (0.90, 0.87, 0.86, and 0.74 g/l, respectively), whereas arabinose, lactose, and mannitol produced a minimal amount of extracellular polysaccharides (0.22, 0.17, 0.12 g/l, respectively). However, all the t...

Egyptian Pharmaceutical Journal, 2019

Background and objective β-Mannanase is an enzyme that has great potential in many industrial app... more Background and objective β-Mannanase is an enzyme that has great potential in many industrial application including feed, food, pharmaceutical, cosmetics, production of mannan and manooligosaccharides, pulp and paper, bioethanol and biodiesel productions, and oil and textile industries. The aim of this study was to describe the potential of gamma and ultraviolet (UV) rays to optimize the production of industrially important β-mannanase enzyme by subjecting Penicillium citrinium Egy5LC368457 to these rays. Materials and methods Various doses and times of UV and gamma irradiation were used. Genetic diversity was resolved by mistreatment with the Random Amplified Polymorphic Polymer (RAPD-PCR) technique. Ten RAPD oligonucleotide primers amplifying DNA of β-mannanase showed reproducible banding patterns. Results and conclusion The results of this study revealed the highest β-mannanase activity was produced by gamma ray 150 Gy (37.42 IU/ml) with 2.27-fold higher than the wild type. A total of 64 bands were obtained from nine of these markers with 44% polymorphic bands. The size of the amplified bands ranged between ∼75 and 3000 bp. The genetic polymorphism value of each primer was determined, which ranged between 2 and 9 bands. The primer efficiency of amplification ranged between 3.13 and 23.44%, and the discriminatory power ranged from 4.5 to 25. In conclusion, UV and gamma ray irradiation can induct mutations, which can be carefully acclimatized and commercially propagated under suitable condition. RAPD technique could be successfully applied to the newly β-mannanase and can differentiate mutants.

Journal of Applied Pharmaceutical Science, 2018

Among the various methods used for the hydrolysis of chitosan, enzymatic hydrolysis was the most ... more Among the various methods used for the hydrolysis of chitosan, enzymatic hydrolysis was the most preferred method. Hence, in this research, the hydrolysis of chitosan to chito-oligosaccharides was performed using partially purified Dothideomycetes sp. chitosanase with a specific activity 16.7 IU/mg protein in a reaction mixture contained enzyme/ substrate ratio 0.2 IU/mg incubated for 1 hour at 45 ο C. The in vivo immunomodulatory effects of both chitosan and COS in low and high doses (10 and 20 mg/kg body weight) were studied using normal mice and lipopolysaccharide (LPS)-treated mice. In the case of their intraperitoneal injection in normal mice, they caused an increase in peritoneum cell infiltration, phagocytic activity of the peritoneal macrophage, and serum level of tumor necrotic factor-α, nitric oxide, lysozyme activity, and interleukin-6. Moreover, they significantly overcome LPS-induced severe activation of all the tested parameters. The results demonstrated that both had dual activities, immune-stimulatory activity and anti-inflammatory activity. Collectively, the present study suggests that chitosan and COS can be used as endotoxin scavenger and therapeutic agents in disorders where inflammation is one of the pathological features.

Pakistan journal of biological sciences : PJBS, 2018

Feather wastes are the most abundant keratinous material in the nature and its accumulation cause... more Feather wastes are the most abundant keratinous material in the nature and its accumulation causes multiple environmental problems. Nutritive value upgrading of such wastes through biological treatments may provide ruminant's rations with high quality and cost effective source of protein. Therefore, the main objective of this study was to investigate the potential uses of biologically treated feathers (BTF) as a feedstuff for ruminants through in vitro experiments. Keratinase production time course was performed by ten microbial isolates (3 fungal, 3 actinomyces and 4 bacterial isolates) under static and shaking conditions using turkey feather- synthetic medium. The chemical composition and amino acid analysis for the crude feathers, BTF and soybean meal were determined according to AOAC methods. Two in vitro experiments were conducted to study the effects of crude feathers, BTF and modified ruminant rations (in which soybean meal were substituted by the BTF in 10, 20 and 30%) o...

Malaysian Journal of Microbiology, 2013

Aim: Production of lactulose and other oligosaccharides by Lactobacillus acidophilus NRRL 4495 β-... more Aim: Production of lactulose and other oligosaccharides by Lactobacillus acidophilus NRRL 4495 β-galactosidase and their biological activity. Methodology and Results: The transgalactosylation activity of Lactobacillus acidophilus NRRL 4495 β-galactosidase was investigated under different conditions for synthesis of lactulose and oligosaccharides. The synthesis was optimized with respect to pH; time; enzyme concentration and substrates ratio (lactose: fructose). Maximum production for lactulose was found to be 25 g/L at pH 6.6 with 40: 20% (w/v) lactose to fructose, respectively and enzyme concentration 4 IU/mL after 7 h. With respect to the other oligosaccharides the maximum yield (19 .68 g/L) was obtained under the same conditions but with enzyme concentration 2 IU/mL and after 10 h. As a new pharmaceutical application the produced lactulose and oligosaccharide and their sulfated derivative were found to have fibrinolytic activity, but they failed to act as anticoagulant. Conclusion significance and impact of study: the research leads to increase the production of lactulose and other oligosaccharides with a significant yield and discovered a new pharmaceutical application for all the products.

Egyptian Pharmaceutical Journal, 2014

Objectives The aim of this research is to produce β-mannanases from a new microbial source using ... more Objectives The aim of this research is to produce β-mannanases from a new microbial source using wastes in their nutrition medium. The enzyme produced can be used for the production of galactomanno-oligosaccharides, which are very useful in the health and medical fields. Materials and methods Seven fungal strains and five bacterial strains were tested for the production of β-mannanases. Enzyme activity, protein content, and biomass production were determined in all the cultures produced using standard methods. Optimization studies to maximize enzyme production from the most potent microorganisms, including culture conditions and medium compositions, were also carried out. Preliminary studies for the production of galactomanno-oligosaccharides from locust bean gum using partially purified enzymes were also carried out and followed by thin-layer chromatography techniques and Somogyi methods. Results and conclusion The highest mannanase activities were produced by Penicillium humicola (8.8 U/ml) and Penicillium spp. v (7.75 U/ml) in shaking cultures after 10 days using gum locust bean as a carbon source. Among 13 carbon sources examined, coffee residue and ceratonia seeds were the best carbon sources (10.3 and 8.9 U/ml, respectively) for P. humicola, whereas the best nitrogen source was a mixture of peptone, urea, and ammonium sulfate for the same microorganism. The optimum temperature and pH for enzyme reaction was 55 and 5.5°C, respectively. The enzyme was thermostable and retained 80% of its activity after 1 h at 50°C. The highest reducing sugar of 8900 μg/ml was obtained from locust bean gum hydrolytes after 28 h.

Australian Journal of …, 2010

The production of â-galactosidase by Lactobacillus acidophilus NRRL 4495 was studied. The highest... more The production of â-galactosidase by Lactobacillus acidophilus NRRL 4495 was studied. The highest yield of intracellular â-galactosidase was achieved using acid whey (3.5%) as carbon source after 48h fermentation. Ammonium sulphate (3%) was the best nitrogen source. Addition of 2 MnCl at 0.02M optimized the production of the enzyme. In addition, the activity reached 51.46U/g cells when the temperature of the fermentation optimized at 40°C. The highest â-galactosidase activity was obtained by using mechanical disintegration of cells by mortar with sterile sea sand under cooling. By studying some properties of the produced enzyme, the enzyme activity was optimum at 40°C and pH 7.0. In absence of substrate and up to 45°C the enzyme was highly stable, at least for 60 min, retaining 83% of its original activity.

This study aimed the using of deep artificial neural network in the optimization of exochitinase ... more This study aimed the using of deep artificial neural network in the optimization of exochitinase production as an alternative method to response surface methodology. The isolated fungus Alternaria sp. strain Sha that was identified by its morphological features then by the 18S rDNA technique, was used for the production of the enzyme by solid state fermentation. A Plackett–Burman design was constructed to screen the effect of seven independent variables on the enzyme production. The overall enzyme production increased from 3.4 to 28.931U/g dry substrate by approximately 8.5 folds with the coefficient of determination (R) value being 0.996 using deep artificial neural network in comparison with the R value 0.76 using response surface methodology. It was clear that the deep artificial neural network was more accurate than the response surface methodology in predicting the enzyme activity. Finally, the produced exochitinase showed antifungal activity against the resistant controllable ...

Egyptian Pharmaceutical Journal, 2020

Background and objective β-Mannanase has potential industrial applications in pharmaceutical fiel... more Background and objective β-Mannanase has potential industrial applications in pharmaceutical field, bioethanol production, coffee extraction, food and feed technology, etc. So finding a new and promising enzyme source is a very important issue. The aim of this study was to improve the biosynthesis of β-mannanase by different techniques, such as mutation and optimization of the culture parameters. Materials and methods Five fungal isolates were tested for the production of β-mannanase. Enzyme activity, protein content, and specific activity were determined. The most potent isolated microorganism and its mutant were identified by using Transmission Electron Microscopy and 18SrDNA sequencing and phylogenetic analysis. Ultraviolet and gamma rays were used. Optimization studies were done to maximize enzyme production from the most potent microorganism and its highly productive and stable mutant, including culture conditions and medium compositions, and statistical optimization was also carried out. Primary characterization of β-mannanase was studied. Results and conclusion In our research, we found a stable mutant strain obtained by using gamma radiation at 150 GY. The first step of the fermentation, optimized by one-factor-at-a-time technique, increased the biosynthesis of β-mannanase for Penicillium citrinium 150 GY from 65.9 to 219 IU/ml compared with the wild strain, which increased from 16.82 to 26.5 IU/ml. Statistical optimization improved P. citrinium 150 GY β-mannanase from 219 to 296 IU/ml by applying Plackett–Burman design and increased the level of β-mannanase biosynthesis to 351 IU/ml. Primary characterization of β-mannanase produced by P. citrinium and P. citrinium 150 GY proved that they are almost the same, except in a little shift to higher value (5°C) in optimum temperature.

The optimum fermentation conditions for the production of intracellular α-galactosidase by P.chry... more The optimum fermentation conditions for the production of intracellular α-galactosidase by P.chrysogenum were investigated. The highest levels of the enzyme (4800 IU/g dry weight mycelia) were produced after 4 days in shaking cultures. Among 16 carbon sources examined, guar gum and locust bean gum were the best enzyme inducers .The results showed that the optimum fermentation medium should contain: 1% guar gum; 0.1% NaNO3 and 0.15% yeast extract. The enzyme displays a pH and temperature optima at 4 -5 and 50°C respectively. The enzyme was stable over pH range 4-7 and at temperature up to 60°C. The enzyme with a high specific activity (86 IU/mg protein/g dry weight of mycelia) has the ability to hydrolyze melibiose, raffinose and stachyose to their monoand di-monomers as proved by thin layer chromatography. The enzyme was also able to hydrolyze galactose from galactomannan polysaccharides (guar gum and locust bean gum).

Egyptian Journal of Chemistry, 2018

A MONG the methods used for the hydrolysis of chitosan, enzymatic hydrolysis using chitosanase wa... more A MONG the methods used for the hydrolysis of chitosan, enzymatic hydrolysis using chitosanase was selected in order to produce high yield of specific chitooligosaccharides with less environmental pollutions. The production of Dothideomycetes sp. NRC-SSW extracellular chitosanase was statistically optimized in which a two-phase experimental design was applied. Plackett-Burman design was used to evaluate the relative importance of culture conditions and medium components for chitosanase production. Chitosan concentration, agitation speed and incubation period were found to be the most significant variables that affected the chitosanase production and their optimal values were obtained by applying Box-Behnken design. The optimized medium composed of (g/L) chitosan, 30; K 2 HPO 4 , 1.5; MgSO 4 , 0.4; KCl, 4.0; yeast extract, 18.5 and FeSO 4 ,0.01; at pH 5.5, 30°C and 180rpm for 96h gave 13.9U/mL with 36.3% increase in the activity. The R 2 value was 0.954 and this indicated the aptness of the model. The optimization of the hydrolytic conditions required for chitooligosaccharides production was also performed by Box-Behnken design. The highest yield of chitooligosaccharides was obtained with enzyme/ substrate ratio 0.05U/mg in 0.2M Tris HCl buffer incubation at 60 ο C for 5h. The cytotoxic activity of the chitooligosaccharides was tested in vitro against Hep-G2 and MCF7.

Egyptian Journal of Chemistry

O PTIMIZATION of B. licheniformis ALW1 keratinase was investigated by using a Plackett-Burman des... more O PTIMIZATION of B. licheniformis ALW1 keratinase was investigated by using a Plackett-Burman design (PBD) and Central Composite Design (CCD). PBD showed that galactose, inoculum size and corn steep liquor were the most effective variables played a role in improving the enzyme productivity (87.65U/mL). CCD results recorded an increase in enzyme productivity to about1.4-fold compared to the basal medium (99.1 U/mL). The optimum activity for the partial purified enzyme was obtained at pH 8.5 and 70˚C. The activation and deactivation energy were calculated to be 25.37 kJmol-1 and 73.38 kJmol-1 respectively. The half-life time was 1380,690,530, and383 min. at 50˚C,55˚C,60˚C and 65˚C respectively. Also, D values were 4600,2300,1769, 1277min. at the same degree respectively. ∆G° (kJmol-1) kept relatively constant between 50-60˚C (191.49 kJmol-1-193.31 kJmol-1) and noticeably increase at 65˚C (212.86 kJmol-1). ∆H° (kJmol-1) recorded minor decrease by the increase of temperature. Approximately, most of the tested metals ions have stimulation effect in enzyme activity and MgSO 4 .H 2 O was the best (146%). Among all the tested detergents tween 80 retained 97% of original enzyme activity. DMSO increased the enzyme activity by about 11%, while propanol and acetonitrile reduced the enzyme activity to about 14% and 10% respectively. All the reducing agents had a stimulating effect on enzyme activity with variable degrees. The enzyme (980 U) had the ability to hydrolyze 74% of the feather to nutritional valuable protein.

Background and Objective: Feather wastes are the most abundant keratinous material in the nature ... more Background and Objective: Feather wastes are the most abundant keratinous material in the nature and its accumulation causes multiple environmental problems. Nutritive value upgrading of such wastes through biological treatments may provide ruminant's rations with high quality and cost effective source of protein. Therefore, the main objective of this study was to investigate the potential uses of biologically treated feathers (BTF) as a feedstuff for ruminants through in vitro experiments. Materials and Methods: Keratinase production time course was performed by ten microbial isolates (3 fungal, 3 actinomyces and 4 bacterial isolates) under static and shaking conditions using turkey feather- synthetic medium. The chemical composition and amino acid analysis for the crude feathers, BTF and soybean meal were determined according to AOAC methods. Two in vitro experiments were conducted to study the effects of crude feathers, BTF and modified ruminant rations (in which soybean meal...

Journal of Genetic Engineering and Biotechnology

Isolation and identification of newly microbial sources able to utilize keratinous wastes is the ... more Isolation and identification of newly microbial sources able to utilize keratinous wastes is the target to begin this research. Optimization of the medium composition and fermentation conditions was performed to maximize the production of keratinase and the properties of the produced crude keratinase were also carried out. Among ten microbial isolates screened for keratinase production, isolate identified as B. licheniformis ALW1 secreted a significant amount of keratinase (25.2 U/ml) under static condition. The optimization studies indicated that the medium consisted of (g/l): feather 10.0; NaCl 0.5; KH2PO4 0.7; K2HPO4 1.4; MgSO4.7H2O 0.1; galactose 1.0; corn steep liquor 9.2 at initial pH 6.0 with 5 % inoculum size and incubated at 42°C for four days under static condition increase the production of keratinase to 72.2 U/ml (2.9 fold). The crude extracellular keratinase was optimally active at pH 8.0 and temperature 65°C with 0.7 % soluble keratin as substrate. The produced B. licheniformis ALW1 keratinase exhibited a good stability over pH range from 7 to 9 and over a temperature range 50°C - 60°C for almost 90 min. The crude enzyme solution was able to degrade native feather up to 63% in redox free system.