The present study was targeted to; i) assess the production of Lysinibacillus sphaericus crude ex... more The present study was targeted to; i) assess the production of Lysinibacillus sphaericus crude extract (Ls CE) on different solid-state fermentation, ii) assess the acaricidal activity of Ls CE against Tetranychus urticae, iii) evaluate the prey mite mediated effects of Ls CE on the predatory mite, Neoseiulus zaheri, and iv) study the genetic diversity using ISSR marker. The bio-production of Ls CE was carried out on five medium substrates; and the most promising substrates for alkaline protease production were wheat bran and fodder yeast. The efficacy of Ls CE produced on wheat bran was investigated against eggs and females of both the prey and predatory mite species at different concentrations of 100%, 50%, 25% and 12.5%, and exposure times of 24h, 48h and 144h under laboratory conditions. Females were significantly influenced and mortality percentages increased as the Ls CE concentrations and exposure time increased. Mortality of T. urticae was 87.50 ± 2.06% and N. zaheri was 6.00 ± 1.07% at 100% concentration after 144h. Additionally, the population densities and reduction percentages of T. urticae stages were evaluated after 1, 3, 7, 10, and 16 days post-LC 50 values reported to T. urticae females by Ls CE treatment under semi-field-trials. The highest decrease was observed after 3-days of indirect exposure and 7-days post direct exposure. Also, the consumption rate and fecundity of N. zaheri females were conducted through prey mite mediated effects of the same LC 50 value. The consumption rate and fecundity of N. zaheri females were slightly influenced in indirect treatments. Finally, the genetic diversity of treated prey and predatory mites were resulted in 51% polymorphism in T. urticae, and 16% polymorphism in N. zaheri treatments. In conclusion, current findings recommend using Ls CE from wheat bran in biological control applications.
Global Journal of Engineering and Technology Advances, 2022
Photogrammetry can contribute not only with precision, but especially with speed and efficiency r... more Photogrammetry can contribute not only with precision, but especially with speed and efficiency regarding to documentation; it is an ideal system for producing 3D models, for creating data bases, and offering efficient solutions in emergency cases, etc. There are here some examples of the use of digital photogrammetry based on systems and methods which make possible to operate reducing the working time in the site, and operating very light and inexpensive equipment. This system is specially adapted to emergency works and archaeology, when it is needed to work on field without the full support of complete office equipment.
Functional foods are foods with a physiological function for body in addition to their role in nu... more Functional foods are foods with a physiological function for body in addition to their role in nutrition and satiation. With the increase in immune and emerging diseases, related to unhealthy nutrition, as it is strongly linked to digestive system diseases, which result in most other diseases. Therefore, it is incumbent upon us, each in his specialization, to point out the critical importance of functional nutrition in general, and fermented foods as one of the broadest sectors of functional foods especially; as microbial metabolism products after fermentation contribute to the production of many chemical compounds with important physiological functions. Using fermented foods has been known since ancient civilizations, folklore and some festive seasons, either because of its distinctive flavor or to increase the duration of preservation, or for its health importance, and this is in both animal and vegetable sources, and for being a special food as a religious custom or for vegetarians. Conclusion: This article aims to point out the importance of fermented foods and mention some of their sensitive functions, which may contribute to the advancement of humanity and take its hand to return to nature and a healthy life style.
Objective: Purify and classify alkaline protease (AP), produced by Bacillus thuringiensis (B.t.) ... more Objective: Purify and classify alkaline protease (AP), produced by Bacillus thuringiensis (B.t.) dendrolimus 4A/4B. Methods: Inoculum preparation, production media, enzymes assays, protein determination, ammonium sulfate precipitation, acetone fractionation, Sephadex Gel chromatography filtration. Results: The purification scheme, (a) ammonium sulfate fractionation, the most active fraction with 1.93 purification fold was at 60-75% saturation; (b) acetone precipitation, where the most active fraction was at 30-45% with purification fold of about 3.92 times; (c) Column chromatography on G-100 Sephadex with final purification folds 5.36 times of the crude enzyme with final yield recovery 1.9%. Purified AP showed stability against H2O2 1%, 5% and 10% (v/v), and retained 111%, 101% and 66% of its activity, respectively. AP retained 82%, 87% and 101% of its activity with 10, 5 and 1mM PMSF, respectively. Enzyme activity was completely inhibited by 10mM EDTA, while the enzyme retained abo...
Objective: This paper aims to, study the biochemical properties of the crude enzyme, extracted fr... more Objective: This paper aims to, study the biochemical properties of the crude enzyme, extracted from the bacterial strain Bacillus thuringiensis dendrolimus IP 4A/4B, such as the concentration of the enzyme, the duration of the enzymatic reaction, the effect of changing the temperature of the enzymatic reaction and the effect of the pH of the enzymatic reaction medium. Methods: Inoculum preparation, submerged and solid-state fermentation media, enzymes assays spectrophotometrically, protein determination were performed. Results: The results indicated that 0.181mg protein/mL of enzyme produced maximum alkaline protease activity (269U/mL/min) followed by 0.227mg protein/mL enzyme (260U/mL/min). The slope of the first period (up to 5min reaction time) exhibited steeper slope indicating reactions velocity near the theoretical initial velocity (Vmax) that has become lesser in value as the reaction was extended up to 120min. The maximum enzyme activity was at 60°C (246U/mL/min), while decr...
Objective: The study aims to produce alkaline protease and chitinase in the same fermentation pro... more Objective: The study aims to produce alkaline protease and chitinase in the same fermentation process in the most economical way possible so as to reduce production costs and to investigate the application of alkaline protease in detergents compatibility. Methods: Inoculums were prepared in nutrient yeast-extract standard medium, grown, and extracted from the solid medium, while the enzyme activities were measured using Lowry protein assay and high-performance liquid chromatography. Results: The culture of Bacillus thuringiensis subspecies dendrolimus IP 4A/4B was performed under solid-state fermentation conditions. The efficiency and performance of extraction using tap water outperformed other solutions. The crude protease enzyme was compatible with some detergents available in the local market, such as Persil, Tide, and Ariel, where the crude enzyme retained its activity at rates that varied between 113%, 110% and 83%. No microbial growth and therefore no chitinase enzymatic activ...
Functional foods are foods with a physiological function for body in addition to their role in nu... more Functional foods are foods with a physiological function for body in addition to their role in nutrition and satiation. With the increase in immune and emerging diseases, related to unhealthy nutrition, as it is strongly linked to digestive system diseases, which result in most other diseases. Therefore, it is incumbent upon us, each in his specialization, to point out the critical importance of functional nutrition in general, and fermented foods as one of the broadest sectors of functional foods especially; as microbial metabolism products after fermentation contribute to the production of many chemical compounds with important physiological functions. Using fermented foods has been known since ancient civilizations, folklore and some festive seasons, either because of its distinctive flavor or to increase the duration of preservation, or for its health importance, and this is in both animal and vegetable sources, and for being a special food as a religious custom or for vegetarians. Conclusion: This article aims to point out the importance of fermented foods and mention some of their sensitive functions, which may contribute to the advancement of humanity and take its hand to return to nature and a healthy life style.
Background and objective Pectin-degrading enzymes applied in the food industries are preferred to... more Background and objective Pectin-degrading enzymes applied in the food industries are preferred to be obtained from fungal origin because fungi are potent producers of pectic enzymes and the optimal pH of fungal enzymes is very close to the pH of many fruit juices, ranging from pH 3.0 to 5. Pectinolytic enzymes, have several industrial applications in different industries such as food industries to concentrate fruit juices. They increased the yield of fruit juice from the pulp and removal of haze from juices to get a clear product. Research to find microorganisms to produce high-quality polygalacturonase (PGase) and technical constraint include supply of cheap and pure raw materials needed to produce inexpensive enzymes. Utilization of agroindustrial residues offers potential benefits for solid-state fermentation, which is attractive for the implementation of sustainable bioprocesses. Materials and methods Fungal strain screening for PGase production was studied in 250 ml Erlenmeyer flasks containing 5 g of tested substrate moistened to 50% (v/w, ml/g) with distilled water. One milliliter of spore suspension (106 spores) from each fungus was used as inoculum. The cultures were incubated at 30°C for 4 days. At the end of the incubation period, 100 ml of distilled water was added to each flask, blended by shaking at 150 rpm for 30 min, and harvested by filtration. The filtrates were saved as sources of crude enzyme. The selected fungal strain and substrate were incubated for 120 h at 30°C and culture was taken at 24 h intervals to detect the optimum incubation period. Sugar beet pulp was moistened to different moisture levels, that is, 1 : 1, 1 : 2, 1 : 3, and 1 : 4 (v/w) under the optimum incubation period to determine the more suitable moisture content for enzyme production. Sodium phosphate buffer at 0.1 M was used for adjusting the initial pH of fermentation medium to different values from 3.5 to 7.5 to study the effect of pH on enzyme secretion. The fungus was incubated under different temperatures, that s, 20, 25, 30, 35, and 40°C to study the temperature effect on enzyme production. Inorganic nitrogen sources (at level 0.92 mg N/g solid substrate) were applied in the fermentation medium to study their effect on enzyme yield. Results and conclusion Aspergillus awamori NRC-F18 showed promising PGase’ production activity than other fungi screened. The study showed that the fungus gave promising results when the moisture content was adjusted to 70% (v/w), initial pH value 5.0, and incubation temperature at 35°C for 72 h. The enzyme activity was increased when urea was the sole nitrogen source at a level of 0.92 mg/g solid substrate supplemented to fermentation medium. Under the above conditions, 396.4 U/g original substrate was obtained. A study on the obtained PGase revealed that it has an optimum pH that ranged from 4.5 to 5.5, as well as it gave the highest activity when incubated at 50°C. Eighty percent ammonium sulfate (w/v) was applied to precipitate enzyme protein, as 24% of total protein involved 61% of total PGase activity obtained with a specific activity of 36.94 U/mg protein against 12.8 U/mg protein in the crude culture supernatant. After fermentation the mixture from unutilized raw material and fungal biomass after enzyme elution was 76% (w/w) from the original substrate dry weight involving 14.2% protein related to 9.2% before beet pulp fermentation which could be utilized as feedstuff component in rations for ruminant feed.
Background and objectives One of the important applications of dextranase enzyme is preventing de... more Background and objectives One of the important applications of dextranase enzyme is preventing dextran accumulation in sugarcane juice as well as, consequently, for enhancing the resultant fermentable reducing sugars and ethanol yield in the fermentation of sugarcane molasses by yeasts. Materials and methods Different materials and methods were used for fungal strains [screening, mutation ultraviolet (UV), inoculum preparation, cultivation type ‘solid-state fermentation,’, culture substrates], dextranase (production, assay, soluble protein determination), purification, characterization, application in ethanol production by fermentation from sugarcane molasses, dextran estimation, and determination of reducing sugars. Results and conclusion Six fungal strains (namely Aspergillus oryzae FK-923, Aspergillus niger F-93, A. niger F-258, Aspergillus awamori NRC-F18, Aspergillus fumigatus NRC-F103, and Trichoderma viride NRC-F107) were screened on sorghum, sugar beet pulp, wheat bran, and orange peels using the solid-state fermentation technique to produce dextranase enzyme. The fungus A. fumigatus NRC-F103 cultivated on orange peels showed promising enzyme yield than other tested fungal strains. Then, optimization of culture conditions for dextranase production was carried out. Moisture content, initial pH value, incubation temperature, and incubation period were optimized to be 2 : 1 (v/w), 5.0, 35°C and 96 h, respectively. Five inorganic nitrogen sources were trailed at equivalent levels as sole nitrogen in the fermentation medium did not result in any increase in enzyme activity. Subjecting the fungal to UV resulted in a 75% increase in enzyme activity corresponding to the mother strain before subjecting to UV. Under the above conditions, 118 U/g original substrate was obtained. Isopropanol 1 : 1 (v/v) was applied for precipitation enzyme protein, as 32% of total protein involving 68% of total enzyme activity was obtained and specific activity was 42.94 U/mg protein compared with 16.4 U/mg protein in the culture supernatant. A study on obtained dextranase showed that it has an optimum that pH ranged from 4.5 to 5.5 as well as it gave the highest activity when incubated between 35 and 40°C. Promising results were obtained when the enzyme was applied in cane juice to prevent accumulation of dextran. Enzyme supplementation to diluted sugarcane molasses (26%, w/v) resulted in an increase in reducing sugars by 2.64%. Ethanol was increased by about 2.36% (v/v) in the fermentation medium supplemented with an enzyme compared with the unsupplemented medium and the fermentation efficiency increased from 89 to 92.5%.
The objective of the current study was to purify and partially characterize an alkaline protease ... more The objective of the current study was to purify and partially characterize an alkaline protease (AP) from a newly isolated Egyptian Bacillus sphaericus strain. The enzyme was subjected to a 3-step purification scheme involving i) ammonium sulfate [(NH(4))(2)SO(4)] fractionation, ii) acetone precipitation and iii) Sephadex G-200 gel permeation chromatography. Fractions precipitated with 30 to 60% [(NH(4))(2)SO(4)] saturation levels exhibited the highest enzyme activities, whereas acetone in the ranges between 50 to 75% (v/v). Gel permeation utilizing Sephadex G-200 column resulted in approx. 50 fold purification level, as compared to the original crude enzyme, with a yield recovery of 27%. The AP enzyme was successfully purified to homogeneity as a monomeric band with an estimated molecular mass of similar to 29 kDa, based on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram activity staining analyses. While, the maximum enzymatic activity was record...
Thirty available bacterial cultures belonging to Bacillus thuringiensis (B.t.) obtained from vari... more Thirty available bacterial cultures belonging to Bacillus thuringiensis (B.t.) obtained from various culture collections were grown on two media, mainly NYSM & Soybean, and screened with respect to their ability to produce alkaline protease (AP) under shaking culture condition; they all were able to produce AP, except B.t. subsp. subtoxicus NRC16a. Growing high AP-Producers under solid-state fermentation (SSF) condition on an inexpensive substrate, wheat bran, as the main medium substrate, the highest AP yield was detected in culture of B.t. subspecies dendrolimus IP 4A/4B. Thus, it was selected for further studies. Optimum initial moisture content was 67% (v/w), inoculum size 60% (v/w), Incubation period 3 days, and incubation temperature 30°C for the production of AP from B.t. subspecies dendrolimus IP 4A/4B, under SSF condition. Investigating some agro-wastes as sole medium, wheat bran was the promising one for AP production. On the other hand, addition of different carbon source...
The present study was targeted to; i) assess the production of Lysinibacillus sphaericus crude ex... more The present study was targeted to; i) assess the production of Lysinibacillus sphaericus crude extract (Ls CE) on different solid-state fermentation, ii) assess the acaricidal activity of Ls CE against Tetranychus urticae, iii) evaluate the prey mite mediated effects of Ls CE on the predatory mite, Neoseiulus zaheri, and iv) study the genetic diversity using ISSR marker. The bio-production of Ls CE was carried out on five medium substrates; and the most promising substrates for alkaline protease production were wheat bran and fodder yeast. The efficacy of Ls CE produced on wheat bran was investigated against eggs and females of both the prey and predatory mite species at different concentrations of 100%, 50%, 25% and 12.5%, and exposure times of 24h, 48h and 144h under laboratory conditions. Females were significantly influenced and mortality percentages increased as the Ls CE concentrations and exposure time increased. Mortality of T. urticae was 87.50 ± 2.06% and N. zaheri was 6.00 ± 1.07% at 100% concentration after 144h. Additionally, the population densities and reduction percentages of T. urticae stages were evaluated after 1, 3, 7, 10, and 16 days post-LC 50 values reported to T. urticae females by Ls CE treatment under semi-field-trials. The highest decrease was observed after 3-days of indirect exposure and 7-days post direct exposure. Also, the consumption rate and fecundity of N. zaheri females were conducted through prey mite mediated effects of the same LC 50 value. The consumption rate and fecundity of N. zaheri females were slightly influenced in indirect treatments. Finally, the genetic diversity of treated prey and predatory mites were resulted in 51% polymorphism in T. urticae, and 16% polymorphism in N. zaheri treatments. In conclusion, current findings recommend using Ls CE from wheat bran in biological control applications.
Global Journal of Engineering and Technology Advances, 2022
Photogrammetry can contribute not only with precision, but especially with speed and efficiency r... more Photogrammetry can contribute not only with precision, but especially with speed and efficiency regarding to documentation; it is an ideal system for producing 3D models, for creating data bases, and offering efficient solutions in emergency cases, etc. There are here some examples of the use of digital photogrammetry based on systems and methods which make possible to operate reducing the working time in the site, and operating very light and inexpensive equipment. This system is specially adapted to emergency works and archaeology, when it is needed to work on field without the full support of complete office equipment.
Functional foods are foods with a physiological function for body in addition to their role in nu... more Functional foods are foods with a physiological function for body in addition to their role in nutrition and satiation. With the increase in immune and emerging diseases, related to unhealthy nutrition, as it is strongly linked to digestive system diseases, which result in most other diseases. Therefore, it is incumbent upon us, each in his specialization, to point out the critical importance of functional nutrition in general, and fermented foods as one of the broadest sectors of functional foods especially; as microbial metabolism products after fermentation contribute to the production of many chemical compounds with important physiological functions. Using fermented foods has been known since ancient civilizations, folklore and some festive seasons, either because of its distinctive flavor or to increase the duration of preservation, or for its health importance, and this is in both animal and vegetable sources, and for being a special food as a religious custom or for vegetarians. Conclusion: This article aims to point out the importance of fermented foods and mention some of their sensitive functions, which may contribute to the advancement of humanity and take its hand to return to nature and a healthy life style.
Objective: Purify and classify alkaline protease (AP), produced by Bacillus thuringiensis (B.t.) ... more Objective: Purify and classify alkaline protease (AP), produced by Bacillus thuringiensis (B.t.) dendrolimus 4A/4B. Methods: Inoculum preparation, production media, enzymes assays, protein determination, ammonium sulfate precipitation, acetone fractionation, Sephadex Gel chromatography filtration. Results: The purification scheme, (a) ammonium sulfate fractionation, the most active fraction with 1.93 purification fold was at 60-75% saturation; (b) acetone precipitation, where the most active fraction was at 30-45% with purification fold of about 3.92 times; (c) Column chromatography on G-100 Sephadex with final purification folds 5.36 times of the crude enzyme with final yield recovery 1.9%. Purified AP showed stability against H2O2 1%, 5% and 10% (v/v), and retained 111%, 101% and 66% of its activity, respectively. AP retained 82%, 87% and 101% of its activity with 10, 5 and 1mM PMSF, respectively. Enzyme activity was completely inhibited by 10mM EDTA, while the enzyme retained abo...
Objective: This paper aims to, study the biochemical properties of the crude enzyme, extracted fr... more Objective: This paper aims to, study the biochemical properties of the crude enzyme, extracted from the bacterial strain Bacillus thuringiensis dendrolimus IP 4A/4B, such as the concentration of the enzyme, the duration of the enzymatic reaction, the effect of changing the temperature of the enzymatic reaction and the effect of the pH of the enzymatic reaction medium. Methods: Inoculum preparation, submerged and solid-state fermentation media, enzymes assays spectrophotometrically, protein determination were performed. Results: The results indicated that 0.181mg protein/mL of enzyme produced maximum alkaline protease activity (269U/mL/min) followed by 0.227mg protein/mL enzyme (260U/mL/min). The slope of the first period (up to 5min reaction time) exhibited steeper slope indicating reactions velocity near the theoretical initial velocity (Vmax) that has become lesser in value as the reaction was extended up to 120min. The maximum enzyme activity was at 60°C (246U/mL/min), while decr...
Objective: The study aims to produce alkaline protease and chitinase in the same fermentation pro... more Objective: The study aims to produce alkaline protease and chitinase in the same fermentation process in the most economical way possible so as to reduce production costs and to investigate the application of alkaline protease in detergents compatibility. Methods: Inoculums were prepared in nutrient yeast-extract standard medium, grown, and extracted from the solid medium, while the enzyme activities were measured using Lowry protein assay and high-performance liquid chromatography. Results: The culture of Bacillus thuringiensis subspecies dendrolimus IP 4A/4B was performed under solid-state fermentation conditions. The efficiency and performance of extraction using tap water outperformed other solutions. The crude protease enzyme was compatible with some detergents available in the local market, such as Persil, Tide, and Ariel, where the crude enzyme retained its activity at rates that varied between 113%, 110% and 83%. No microbial growth and therefore no chitinase enzymatic activ...
Functional foods are foods with a physiological function for body in addition to their role in nu... more Functional foods are foods with a physiological function for body in addition to their role in nutrition and satiation. With the increase in immune and emerging diseases, related to unhealthy nutrition, as it is strongly linked to digestive system diseases, which result in most other diseases. Therefore, it is incumbent upon us, each in his specialization, to point out the critical importance of functional nutrition in general, and fermented foods as one of the broadest sectors of functional foods especially; as microbial metabolism products after fermentation contribute to the production of many chemical compounds with important physiological functions. Using fermented foods has been known since ancient civilizations, folklore and some festive seasons, either because of its distinctive flavor or to increase the duration of preservation, or for its health importance, and this is in both animal and vegetable sources, and for being a special food as a religious custom or for vegetarians. Conclusion: This article aims to point out the importance of fermented foods and mention some of their sensitive functions, which may contribute to the advancement of humanity and take its hand to return to nature and a healthy life style.
Background and objective Pectin-degrading enzymes applied in the food industries are preferred to... more Background and objective Pectin-degrading enzymes applied in the food industries are preferred to be obtained from fungal origin because fungi are potent producers of pectic enzymes and the optimal pH of fungal enzymes is very close to the pH of many fruit juices, ranging from pH 3.0 to 5. Pectinolytic enzymes, have several industrial applications in different industries such as food industries to concentrate fruit juices. They increased the yield of fruit juice from the pulp and removal of haze from juices to get a clear product. Research to find microorganisms to produce high-quality polygalacturonase (PGase) and technical constraint include supply of cheap and pure raw materials needed to produce inexpensive enzymes. Utilization of agroindustrial residues offers potential benefits for solid-state fermentation, which is attractive for the implementation of sustainable bioprocesses. Materials and methods Fungal strain screening for PGase production was studied in 250 ml Erlenmeyer flasks containing 5 g of tested substrate moistened to 50% (v/w, ml/g) with distilled water. One milliliter of spore suspension (106 spores) from each fungus was used as inoculum. The cultures were incubated at 30°C for 4 days. At the end of the incubation period, 100 ml of distilled water was added to each flask, blended by shaking at 150 rpm for 30 min, and harvested by filtration. The filtrates were saved as sources of crude enzyme. The selected fungal strain and substrate were incubated for 120 h at 30°C and culture was taken at 24 h intervals to detect the optimum incubation period. Sugar beet pulp was moistened to different moisture levels, that is, 1 : 1, 1 : 2, 1 : 3, and 1 : 4 (v/w) under the optimum incubation period to determine the more suitable moisture content for enzyme production. Sodium phosphate buffer at 0.1 M was used for adjusting the initial pH of fermentation medium to different values from 3.5 to 7.5 to study the effect of pH on enzyme secretion. The fungus was incubated under different temperatures, that s, 20, 25, 30, 35, and 40°C to study the temperature effect on enzyme production. Inorganic nitrogen sources (at level 0.92 mg N/g solid substrate) were applied in the fermentation medium to study their effect on enzyme yield. Results and conclusion Aspergillus awamori NRC-F18 showed promising PGase’ production activity than other fungi screened. The study showed that the fungus gave promising results when the moisture content was adjusted to 70% (v/w), initial pH value 5.0, and incubation temperature at 35°C for 72 h. The enzyme activity was increased when urea was the sole nitrogen source at a level of 0.92 mg/g solid substrate supplemented to fermentation medium. Under the above conditions, 396.4 U/g original substrate was obtained. A study on the obtained PGase revealed that it has an optimum pH that ranged from 4.5 to 5.5, as well as it gave the highest activity when incubated at 50°C. Eighty percent ammonium sulfate (w/v) was applied to precipitate enzyme protein, as 24% of total protein involved 61% of total PGase activity obtained with a specific activity of 36.94 U/mg protein against 12.8 U/mg protein in the crude culture supernatant. After fermentation the mixture from unutilized raw material and fungal biomass after enzyme elution was 76% (w/w) from the original substrate dry weight involving 14.2% protein related to 9.2% before beet pulp fermentation which could be utilized as feedstuff component in rations for ruminant feed.
Background and objectives One of the important applications of dextranase enzyme is preventing de... more Background and objectives One of the important applications of dextranase enzyme is preventing dextran accumulation in sugarcane juice as well as, consequently, for enhancing the resultant fermentable reducing sugars and ethanol yield in the fermentation of sugarcane molasses by yeasts. Materials and methods Different materials and methods were used for fungal strains [screening, mutation ultraviolet (UV), inoculum preparation, cultivation type ‘solid-state fermentation,’, culture substrates], dextranase (production, assay, soluble protein determination), purification, characterization, application in ethanol production by fermentation from sugarcane molasses, dextran estimation, and determination of reducing sugars. Results and conclusion Six fungal strains (namely Aspergillus oryzae FK-923, Aspergillus niger F-93, A. niger F-258, Aspergillus awamori NRC-F18, Aspergillus fumigatus NRC-F103, and Trichoderma viride NRC-F107) were screened on sorghum, sugar beet pulp, wheat bran, and orange peels using the solid-state fermentation technique to produce dextranase enzyme. The fungus A. fumigatus NRC-F103 cultivated on orange peels showed promising enzyme yield than other tested fungal strains. Then, optimization of culture conditions for dextranase production was carried out. Moisture content, initial pH value, incubation temperature, and incubation period were optimized to be 2 : 1 (v/w), 5.0, 35°C and 96 h, respectively. Five inorganic nitrogen sources were trailed at equivalent levels as sole nitrogen in the fermentation medium did not result in any increase in enzyme activity. Subjecting the fungal to UV resulted in a 75% increase in enzyme activity corresponding to the mother strain before subjecting to UV. Under the above conditions, 118 U/g original substrate was obtained. Isopropanol 1 : 1 (v/v) was applied for precipitation enzyme protein, as 32% of total protein involving 68% of total enzyme activity was obtained and specific activity was 42.94 U/mg protein compared with 16.4 U/mg protein in the culture supernatant. A study on obtained dextranase showed that it has an optimum that pH ranged from 4.5 to 5.5 as well as it gave the highest activity when incubated between 35 and 40°C. Promising results were obtained when the enzyme was applied in cane juice to prevent accumulation of dextran. Enzyme supplementation to diluted sugarcane molasses (26%, w/v) resulted in an increase in reducing sugars by 2.64%. Ethanol was increased by about 2.36% (v/v) in the fermentation medium supplemented with an enzyme compared with the unsupplemented medium and the fermentation efficiency increased from 89 to 92.5%.
The objective of the current study was to purify and partially characterize an alkaline protease ... more The objective of the current study was to purify and partially characterize an alkaline protease (AP) from a newly isolated Egyptian Bacillus sphaericus strain. The enzyme was subjected to a 3-step purification scheme involving i) ammonium sulfate [(NH(4))(2)SO(4)] fractionation, ii) acetone precipitation and iii) Sephadex G-200 gel permeation chromatography. Fractions precipitated with 30 to 60% [(NH(4))(2)SO(4)] saturation levels exhibited the highest enzyme activities, whereas acetone in the ranges between 50 to 75% (v/v). Gel permeation utilizing Sephadex G-200 column resulted in approx. 50 fold purification level, as compared to the original crude enzyme, with a yield recovery of 27%. The AP enzyme was successfully purified to homogeneity as a monomeric band with an estimated molecular mass of similar to 29 kDa, based on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram activity staining analyses. While, the maximum enzymatic activity was record...
Thirty available bacterial cultures belonging to Bacillus thuringiensis (B.t.) obtained from vari... more Thirty available bacterial cultures belonging to Bacillus thuringiensis (B.t.) obtained from various culture collections were grown on two media, mainly NYSM & Soybean, and screened with respect to their ability to produce alkaline protease (AP) under shaking culture condition; they all were able to produce AP, except B.t. subsp. subtoxicus NRC16a. Growing high AP-Producers under solid-state fermentation (SSF) condition on an inexpensive substrate, wheat bran, as the main medium substrate, the highest AP yield was detected in culture of B.t. subspecies dendrolimus IP 4A/4B. Thus, it was selected for further studies. Optimum initial moisture content was 67% (v/w), inoculum size 60% (v/w), Incubation period 3 days, and incubation temperature 30°C for the production of AP from B.t. subspecies dendrolimus IP 4A/4B, under SSF condition. Investigating some agro-wastes as sole medium, wheat bran was the promising one for AP production. On the other hand, addition of different carbon source...
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Papers by Amira Mohammed-Roshdy Ibrahim Ibrahim Asar