ABSTRACT Es wurden Zellmasseertrag, Effizienz der Stickstoffbindung und Zellhauptbestandteile, wi... more ABSTRACT Es wurden Zellmasseertrag, Effizienz der Stickstoffbindung und Zellhauptbestandteile, wie Proteine, Kohlenhydrate und Lipide, einiger Azotobacter-Stämme untersucht, die in einem stickstofffreien flüssigen Medium als Schüttel- oder statische Kultur vermehrt worden waren. Das bakterielle Wachstum sowie der Stickstoffgehalt wurden stark durch die Azotobacter-Species und die spezifischen Eigenschaften der Stämme sowie durch die Kult urbedingungen beeinflußt. Unter den isolierten Organismen zeigtet, chroococcum-Stamm 12 nach 7 d in Schüttelkultur die höchsten Werte an Zellmasse (5,5 g Trockenmasse/l), im Gesamt-Stickstoffgehalt (324 ppm) und bei der N2-Fixierung (54 mg N/g oxid. C). Alle Stämme zeigten in den belüfteten Kulturen gegenüber den unbelüfteten eine Erhöhung des YER-Wertes (g Zelltrockenmasse/100 g oxid. C). Die Effizienz der N-Bindung (ENF) korrelierte hingegen negativ mit dem verfügbaren Sauerstoffgehalt des Substrates. Beträchtliche Unterschiede gab es in der Höhe des CPER-Wertes (g Roheiweiß/100 g oxid. C), des TCER-Wertes (g Kohlenhydrate/100 g oxid. C) und des TLER-Wertes (g Lipide/100 g oxid. C) in Abhängigkeit von Species, Stamm und Kulturbedingungen. In den statischen Kulturen wurden höhere Gehalte an Zellhauptbestandteilen und höhere Energiewerte als in Schüttelkulturen festgestellt. Eiweiß war der Hauptbestandteil der organischen Substanz der Azotobacter-Zellen. Die am Eiweißaufbau beteiligten Aminosäuren sind ein stabiles Charakteristikum einer unter bestimmten Bedingungen aufwachsenden Kultur. Die chromatographische Analyse von Azotobactfer-Zellen ergab 20 Aminosäuren; es fehlte keine essentielle.
ABSTRACT The accessibility of different carbon compounds to Azotobacter vinelandii and the produc... more ABSTRACT The accessibility of different carbon compounds to Azotobacter vinelandii and the productivity of nitrogen fixation were studied under static and shaking culture conditions. The nature of the carbon source applied was found to affect the yield of bacterial mass and nitrogen metabolism of the tested organism. On the basis of the efficiency of dinitrogen fixation and the yield efficiency ratio it was obvious that (sucrose + mannitol) as a source of carbon is optimum for both growth and dinitrogen fixation by A. vinelandii grown under static and shaking culture conditions. Furthermore, it was found that the highest crude protein efficiency ratio (14.6) and total carbohydrates efficiency ratio (4.3) were obtained with (sucrose + mannitol) as energy source for this organism under shaking culture condition. The experimental organism is able to convert the soluble nitrogenus substances present in molasses into more complex protein as well as to utilize the molasses as a source of energy for the fixtion of atmospheric nitrogen. The tested organism was unable to utilize sodium salicylate as the sole source of carbon.
Eleven fungal cultures belonging to Trichoderma, Penicillium and Aspergillus were grown on corn f... more Eleven fungal cultures belonging to Trichoderma, Penicillium and Aspergillus were grown on corn flour as main substrate of solid-state fermentation "SSF". Highest productions of α-amylase by T. koningii, A. fumigatus strain KF993 and Penicillium sp. F1 were 43.5, 38.5 and 37.8 U, respectively. Whereas, maximum productions of cellulase (as filter-paperase activity) were attained by A. niger F93 (96.5 U), A. fumigatus KF256 (80.1 U), T. koningii (86.1 U), T. reesei (84.5 U), and Penicillium sp. F2 (76.9 U). Hence, in general, Aspergillus & Trichoderma species produced more cellulase and α-amylase enzymes than did Penicillium spp. On the other hand, Aspergillus spp. produced, in general, higher amounts of cellulase, but lower amounts of αamylase, than those of Trichoderma. Supplementing the SSF substrate corn flour with sugarcane molasses has initiated the production of cellulase by five fungal cultures of A. oryzae (~245%), T. koningii (~7%), T. viride F416 (~20%), Penicillium sp. F1 and F2 (~248 & 3%, respectively). Also, supplementation with molasses has initiated the production of α-amylase by A. oryzae (~13%). Thermophilic A. fumigatus KF993 was grown on different agro-industrial residues as main SSF substrates. It produced different amounts of cellulase as filterpaperase activity when grown on corn flour (55.8 U), fodder yeast (52.2 U), fine wheat bran (48.4 U), sugar beet pulp (42.7 U), olive cake (22.7 U), coarse wheat bran (11.7 U), and potato starch (1.7 U). On the other hand, the fungus produced different amounts of α-amylase when grown on corn flour (36.4 U), sugar beet pulp (34.8 U), coarse wheat bran (29.9 U), potato starch (18.2 U), fodder yeast (16.5 U), olive cake (11.6 U), and fine wheat bran (4.1 U). So, using corn flour as SSF substrate showed the highest co-production of both cellulase and αamylase from thermophilic A. fumigatus KF993. In addition, the effect of particle size of SSF agro-industrial residue substrate (wheat bran) on cellulase (a filter-paperas activity) and α-amylase productions by thermophilic A. fumigatus KF993 was tested. Applying fine particles of wheat bran has increased the production of filterpaperase (up to 4x); in contrast, the coarse wheat bran initiated the production of α-amylase (up to 7x). Thermophilic A. awamori AF727 was grown, for 72 h, on different agro-industrial residues as main SSF substrates. It produced different amounts of cellulase as filter-paperase activity; 76.9 U (from sugar beet pulp), 64.7 U (from corn flour), 59.8 U (from olive cake), and 52.6 U (from fodder yeast). On the other hand, it produced different quantities of α-amylase, 37.3 U (from sugar beet pulp), 33 U (from corn flour), 32.1 U (from fodder yeast), and 1.9 U (from olive cake). Thus, applying sugar beet pulp as SSF substrate resulted in the highest co-production of both cellulase and α-amylase from thermophilic Aspergillus awamori AF727. On the other hand, most A. awamori AF727 SSF-cultures has attained their highest production of α-amylase after 24 hours. As for cellulase production, most of A. awamori cultures reached their maximum production of cellulase after 48 h (grown on corn flour) or 72 h (grown on olive cake or sugar beet pulp).
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...
Feeding only with a highly lignified material such as rice straw does not provide enough nutrient... more Feeding only with a highly lignified material such as rice straw does not provide enough nutrients to ruminants due to the low-produced nutritive value. To improve the feeding value of rice straw for ruminants, to overcome their inherent barriers to rumen microbial fermentation, farm scaling up for fifty tons of rice straw was subjected to biological treatment by Trichodermaharzianium F-418 for 8 days under solid state fermentation system. Chemical analysis revealed that, acid detergent fiber, natural detergent fiber, cellulose and hemicellulose were decreased during treatment by 13.80, 20.06, 16.81, and 32.79% respectively. The enzymes: Fpase, CMCase, cellobiase and xylanase included during fermentation were estimated at periodic intervals, and reached 237.40, 144.72, 11.22, and 3490.35 U/g DM, respectively, after 8 days. Soluble sugars increased by fermentation time from 6.47 to 17.63 mg/g DM. The dry matter loss was 12.27 %. The end product contained 9.92% crude protein. Using ligninolytic fungi may be one potential alternative to provide more practical and environmental-friendly approach for enhancing the nutritive value of rice straw.
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...
Glucoamylase production has been investigated by solid-state fermentation of corn flour by Asperg... more Glucoamylase production has been investigated by solid-state fermentation of corn flour by Aspergillus oryzae FK-923. Highest glucoamylase production (5582.4 µmoles of glucose produced per minute per gram of dry fermented substrate) was observed on corn flour supplemented with 30% (w/w) wheat bran, 1% soluble starch, 0.1% (w/w) urea pH 5.5, 60 % (v/w) initial moisture and 30°C after incubation for 72 hrs using 0.2M phosphate buffer as eluting solvent. Ammonium sulfate 80% (w/w) saturation could recovered 76.4% from total enzyme activity of crude enzyme extract involved in 36.8% of total protein precipitated, rising the specific activity from126.30 U/mg protein present in crude enzyme solution to 262.2 U/mg protein present in ammonium sulfate precipitate. Optimum enzyme activity was observed at 55°C and pH 5.5. Enzyme was applied for hydrolyzing 25 % w/v slurry of potato starchy waste resulting 86% saccharification. Enzymatic hydrolyzate 20% glucose was utilized for bioethanol production by Saccharomyces cerevisiae F-727 yielded 11.4% v/v ethanol and 12gl dry yeast biomass. S. cerevisiae F-707 was grown on enzymatic hydolyzate for baker's yeast 1 production giving 0.42 g/g utilized glucose. The residual mixture contained unutilized medium and fungal biomass was 42% from original weight was analyzed, showed increase in organic matter (OM) crude protein(CP), ether extract (EE) and dietary crude fiber (CF) from 96.98, 9.81, 3.10 and 7.61% to 98.11, 18.45, 10.13 and 27.07% respectively. On the other hand a decrease was seen in both ash and hemicellulose from 4.01 and 17.54% to 1.89 and12.59%, respectively. The gross energy was increased from 454 to 485 Kcal/100g DM. Enzymes assay showed that the residual fermented substrate loaded with glucoamylase 556, alpha-amylase 216, xylanase 224 and celullases (FPase 36 and CMCase 28) U/g. and can be used as concentrates feed for cattle and poultry as a source of protein, energy and feed fortification.
Cellulases find extensive applications in food, fermentation, textile industries and the hydrolys... more Cellulases find extensive applications in food, fermentation, textile industries and the hydrolysis of cellulosic wastes to useable carbon source for most of the microbes in food, fuel and chemical production. Trichoderma reesei is an efficient producer of exoglucanase enzyme. Physiological factors affecting the production of enzyme were studied in shake flask to obtain the optimum parameters for enzyme production. Batch fermentations were performed in 7 liter fermentor using an initial cellulose concentration corresponding to 10g/l. Results obtained indicate that adjusting the fermentation process at a pH range of 4-5 and agitation speed to 350 rpm resulted to an increase in enzyme activity about 15 folds and 1.8 fold respectively. In addition Monod growth kinetics and Leudeking Piret product formation kinetics were studied using Trichoderma reesei with best medium under optimized conditions of inoculum concentration, agitator speed, temperature and pH value.
In the present study, characteristics of free and in situ immobilized (pellets of Mucor rouxii) c... more In the present study, characteristics of free and in situ immobilized (pellets of Mucor rouxii) chitosanases were investigated. Tests included chitosanase from the culture filtrate (free form) and in situ chitosanase as an immobilized form. Growth parameters of M. rouxii revealed that maximum yield of biomass and enzyme activity (2.6 g /100 and 2.4 U/ml) occurred when molasses was used in the growth medium at a 3% concentration. Effect of pH greatly affected the fungus growth; maximum production of biomass and enzyme activity was obtained at pH 5.5, however, at pH 3.0 a formation of an exopolysaccharide bioflocculant was occurred as a form of self-protection by the fungus under the abiotic stress condition. Optimum pH for free and in situ immobilized enzymes was 6.0, whereas optimum temperature range for activity of free and in situ immobilized enzymes were 30-50°C and 40-65°C, respectively. Free and in situ immobilized enzymes display broad specificity towards colloidal chitin, chitosans with different degree of acetylation and Avicel. Values of K and V , for the extracted chitosanase are nearly the same for hydrolyzing of chitosans with different degree m max of acetylation.
Ten, non-producing mycotoxin, fungal strains, belonging to Aspergillus spp., Trichoderma spp. and... more Ten, non-producing mycotoxin, fungal strains, belonging to Aspergillus spp., Trichoderma spp. and Penicellium spp., were screened for clean production of xylanase using white corn flour (WCF) by solid state fermentation. A. fumigates F-993 showed promising xylanase production activity. Culture conditions, i.e., moisture content, initial pH value, temperature, incubation time were optimized to be 60 % (v/w), 3.5, 32°C and 48 hrs, respectively. Solid: solvent ratio of 1:10 was more suitable for enzyme extraction as well as a saline solution of 0.3 M sodium chloride, was more efficient to elute enzyme from fermented substrate. Under the above conditions 720 U/g original WCF was obtained. The enzyme is active at a wide range of pH values, from4.0-6.5 and a temperature range from 35-70°C. Forty percent (v/v)of cold acetone was more efficient for precipitating the enzyme than ethanol or ammonium sulfate, as 32% of total protein contained 86 % of total xylanase activity was obtained with a specific activity of 38U/mg protein. The precipitated enzyme involved considerable activities of cellulases and glucoamylase. The precipitate was applied for hydrolyzing 15% (w/v) of delignified sugarcane bagasse, wheat straw and rice straw, where reducing sugars reached 46,44,52 g l , 1 containing 16,15and 12% (w/w) glucose in the enzymatic hydrolysates of wheat straw, rice straw and sugar cane bagasse, respectively. The remainder fermented substrate, corresponded to 47% (w/w) from the original WCF, was found to be pounded with xylanase, cellulases and glucoamylase and contained 17% crude protein which can be used for fortification at concentrated rations in both poultry and ruminant feed.
International Journal of Biotechnology for Wellness Industries, 2014
Honey isolate Aspergillus niger EM77 was a good halophilic invertase producer in the presence of ... more Honey isolate Aspergillus niger EM77 was a good halophilic invertase producer in the presence of wheat bran as a complete medium (114.55 U/g), using solid state fermentation technique. Different parameters influence the enzyme productivity such as different pH values, temperature, incubation period, nitrogen and carbon sources were investigated. The optimum pH, temperature and incubation period for enzyme production were 5.5, 30 o C and 72 hrs, respectively. Sucrose at 2 % was more suitable carbon source for invertase production (144.39 U/g) and (NH4)2SO4 at 0.15 % was the ideal nitrogen source. Among different metals ions MnSO4 enhanced the enzyme productivity than other tested ions to 194.71 U/g. The partially purified enzyme was successfully entrapped in polyvinyl alcohol sponge shielded with agar starch layer (PVAsp Gs) and achieved 71% immobilization yield. The optimum conditions for immobilization were: pH 5.2, an incubation time of 15 min and a protein concentration of 250 mg/ml. Immobilized enzyme was reused 12 times with 29% activity loss. The free enzyme lost its activity completely at 70˚C after 45 minute and the immobilized form retained 80% of its activity at the same condition.The free and immobilized form reported extreme halophilic property since the highest enzyme activity was obtained between 3.5-5 M.
HAEA and EKAEH have designed the study and managed the literature searches at the beginning. Auth... more HAEA and EKAEH have designed the study and managed the literature searches at the beginning. Author MAE and TK have wrote the first draft of manuscript and author EKAEH has carried out the experiments. All other authors have supervised the thesis and experimental work and managed the literature searches needed during writing the script, discussing the results and publishing. All authors read and approved the final manuscript.
ABSTRACT Es wurden Zellmasseertrag, Effizienz der Stickstoffbindung und Zellhauptbestandteile, wi... more ABSTRACT Es wurden Zellmasseertrag, Effizienz der Stickstoffbindung und Zellhauptbestandteile, wie Proteine, Kohlenhydrate und Lipide, einiger Azotobacter-Stämme untersucht, die in einem stickstofffreien flüssigen Medium als Schüttel- oder statische Kultur vermehrt worden waren. Das bakterielle Wachstum sowie der Stickstoffgehalt wurden stark durch die Azotobacter-Species und die spezifischen Eigenschaften der Stämme sowie durch die Kult urbedingungen beeinflußt. Unter den isolierten Organismen zeigtet, chroococcum-Stamm 12 nach 7 d in Schüttelkultur die höchsten Werte an Zellmasse (5,5 g Trockenmasse/l), im Gesamt-Stickstoffgehalt (324 ppm) und bei der N2-Fixierung (54 mg N/g oxid. C). Alle Stämme zeigten in den belüfteten Kulturen gegenüber den unbelüfteten eine Erhöhung des YER-Wertes (g Zelltrockenmasse/100 g oxid. C). Die Effizienz der N-Bindung (ENF) korrelierte hingegen negativ mit dem verfügbaren Sauerstoffgehalt des Substrates. Beträchtliche Unterschiede gab es in der Höhe des CPER-Wertes (g Roheiweiß/100 g oxid. C), des TCER-Wertes (g Kohlenhydrate/100 g oxid. C) und des TLER-Wertes (g Lipide/100 g oxid. C) in Abhängigkeit von Species, Stamm und Kulturbedingungen. In den statischen Kulturen wurden höhere Gehalte an Zellhauptbestandteilen und höhere Energiewerte als in Schüttelkulturen festgestellt. Eiweiß war der Hauptbestandteil der organischen Substanz der Azotobacter-Zellen. Die am Eiweißaufbau beteiligten Aminosäuren sind ein stabiles Charakteristikum einer unter bestimmten Bedingungen aufwachsenden Kultur. Die chromatographische Analyse von Azotobactfer-Zellen ergab 20 Aminosäuren; es fehlte keine essentielle.
ABSTRACT The accessibility of different carbon compounds to Azotobacter vinelandii and the produc... more ABSTRACT The accessibility of different carbon compounds to Azotobacter vinelandii and the productivity of nitrogen fixation were studied under static and shaking culture conditions. The nature of the carbon source applied was found to affect the yield of bacterial mass and nitrogen metabolism of the tested organism. On the basis of the efficiency of dinitrogen fixation and the yield efficiency ratio it was obvious that (sucrose + mannitol) as a source of carbon is optimum for both growth and dinitrogen fixation by A. vinelandii grown under static and shaking culture conditions. Furthermore, it was found that the highest crude protein efficiency ratio (14.6) and total carbohydrates efficiency ratio (4.3) were obtained with (sucrose + mannitol) as energy source for this organism under shaking culture condition. The experimental organism is able to convert the soluble nitrogenus substances present in molasses into more complex protein as well as to utilize the molasses as a source of energy for the fixtion of atmospheric nitrogen. The tested organism was unable to utilize sodium salicylate as the sole source of carbon.
Eleven fungal cultures belonging to Trichoderma, Penicillium and Aspergillus were grown on corn f... more Eleven fungal cultures belonging to Trichoderma, Penicillium and Aspergillus were grown on corn flour as main substrate of solid-state fermentation "SSF". Highest productions of α-amylase by T. koningii, A. fumigatus strain KF993 and Penicillium sp. F1 were 43.5, 38.5 and 37.8 U, respectively. Whereas, maximum productions of cellulase (as filter-paperase activity) were attained by A. niger F93 (96.5 U), A. fumigatus KF256 (80.1 U), T. koningii (86.1 U), T. reesei (84.5 U), and Penicillium sp. F2 (76.9 U). Hence, in general, Aspergillus & Trichoderma species produced more cellulase and α-amylase enzymes than did Penicillium spp. On the other hand, Aspergillus spp. produced, in general, higher amounts of cellulase, but lower amounts of αamylase, than those of Trichoderma. Supplementing the SSF substrate corn flour with sugarcane molasses has initiated the production of cellulase by five fungal cultures of A. oryzae (~245%), T. koningii (~7%), T. viride F416 (~20%), Penicillium sp. F1 and F2 (~248 & 3%, respectively). Also, supplementation with molasses has initiated the production of α-amylase by A. oryzae (~13%). Thermophilic A. fumigatus KF993 was grown on different agro-industrial residues as main SSF substrates. It produced different amounts of cellulase as filterpaperase activity when grown on corn flour (55.8 U), fodder yeast (52.2 U), fine wheat bran (48.4 U), sugar beet pulp (42.7 U), olive cake (22.7 U), coarse wheat bran (11.7 U), and potato starch (1.7 U). On the other hand, the fungus produced different amounts of α-amylase when grown on corn flour (36.4 U), sugar beet pulp (34.8 U), coarse wheat bran (29.9 U), potato starch (18.2 U), fodder yeast (16.5 U), olive cake (11.6 U), and fine wheat bran (4.1 U). So, using corn flour as SSF substrate showed the highest co-production of both cellulase and αamylase from thermophilic A. fumigatus KF993. In addition, the effect of particle size of SSF agro-industrial residue substrate (wheat bran) on cellulase (a filter-paperas activity) and α-amylase productions by thermophilic A. fumigatus KF993 was tested. Applying fine particles of wheat bran has increased the production of filterpaperase (up to 4x); in contrast, the coarse wheat bran initiated the production of α-amylase (up to 7x). Thermophilic A. awamori AF727 was grown, for 72 h, on different agro-industrial residues as main SSF substrates. It produced different amounts of cellulase as filter-paperase activity; 76.9 U (from sugar beet pulp), 64.7 U (from corn flour), 59.8 U (from olive cake), and 52.6 U (from fodder yeast). On the other hand, it produced different quantities of α-amylase, 37.3 U (from sugar beet pulp), 33 U (from corn flour), 32.1 U (from fodder yeast), and 1.9 U (from olive cake). Thus, applying sugar beet pulp as SSF substrate resulted in the highest co-production of both cellulase and α-amylase from thermophilic Aspergillus awamori AF727. On the other hand, most A. awamori AF727 SSF-cultures has attained their highest production of α-amylase after 24 hours. As for cellulase production, most of A. awamori cultures reached their maximum production of cellulase after 48 h (grown on corn flour) or 72 h (grown on olive cake or sugar beet pulp).
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...
Feeding only with a highly lignified material such as rice straw does not provide enough nutrient... more Feeding only with a highly lignified material such as rice straw does not provide enough nutrients to ruminants due to the low-produced nutritive value. To improve the feeding value of rice straw for ruminants, to overcome their inherent barriers to rumen microbial fermentation, farm scaling up for fifty tons of rice straw was subjected to biological treatment by Trichodermaharzianium F-418 for 8 days under solid state fermentation system. Chemical analysis revealed that, acid detergent fiber, natural detergent fiber, cellulose and hemicellulose were decreased during treatment by 13.80, 20.06, 16.81, and 32.79% respectively. The enzymes: Fpase, CMCase, cellobiase and xylanase included during fermentation were estimated at periodic intervals, and reached 237.40, 144.72, 11.22, and 3490.35 U/g DM, respectively, after 8 days. Soluble sugars increased by fermentation time from 6.47 to 17.63 mg/g DM. The dry matter loss was 12.27 %. The end product contained 9.92% crude protein. Using ligninolytic fungi may be one potential alternative to provide more practical and environmental-friendly approach for enhancing the nutritive value of rice straw.
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...
Glucoamylase production has been investigated by solid-state fermentation of corn flour by Asperg... more Glucoamylase production has been investigated by solid-state fermentation of corn flour by Aspergillus oryzae FK-923. Highest glucoamylase production (5582.4 µmoles of glucose produced per minute per gram of dry fermented substrate) was observed on corn flour supplemented with 30% (w/w) wheat bran, 1% soluble starch, 0.1% (w/w) urea pH 5.5, 60 % (v/w) initial moisture and 30°C after incubation for 72 hrs using 0.2M phosphate buffer as eluting solvent. Ammonium sulfate 80% (w/w) saturation could recovered 76.4% from total enzyme activity of crude enzyme extract involved in 36.8% of total protein precipitated, rising the specific activity from126.30 U/mg protein present in crude enzyme solution to 262.2 U/mg protein present in ammonium sulfate precipitate. Optimum enzyme activity was observed at 55°C and pH 5.5. Enzyme was applied for hydrolyzing 25 % w/v slurry of potato starchy waste resulting 86% saccharification. Enzymatic hydrolyzate 20% glucose was utilized for bioethanol production by Saccharomyces cerevisiae F-727 yielded 11.4% v/v ethanol and 12gl dry yeast biomass. S. cerevisiae F-707 was grown on enzymatic hydolyzate for baker's yeast 1 production giving 0.42 g/g utilized glucose. The residual mixture contained unutilized medium and fungal biomass was 42% from original weight was analyzed, showed increase in organic matter (OM) crude protein(CP), ether extract (EE) and dietary crude fiber (CF) from 96.98, 9.81, 3.10 and 7.61% to 98.11, 18.45, 10.13 and 27.07% respectively. On the other hand a decrease was seen in both ash and hemicellulose from 4.01 and 17.54% to 1.89 and12.59%, respectively. The gross energy was increased from 454 to 485 Kcal/100g DM. Enzymes assay showed that the residual fermented substrate loaded with glucoamylase 556, alpha-amylase 216, xylanase 224 and celullases (FPase 36 and CMCase 28) U/g. and can be used as concentrates feed for cattle and poultry as a source of protein, energy and feed fortification.
Cellulases find extensive applications in food, fermentation, textile industries and the hydrolys... more Cellulases find extensive applications in food, fermentation, textile industries and the hydrolysis of cellulosic wastes to useable carbon source for most of the microbes in food, fuel and chemical production. Trichoderma reesei is an efficient producer of exoglucanase enzyme. Physiological factors affecting the production of enzyme were studied in shake flask to obtain the optimum parameters for enzyme production. Batch fermentations were performed in 7 liter fermentor using an initial cellulose concentration corresponding to 10g/l. Results obtained indicate that adjusting the fermentation process at a pH range of 4-5 and agitation speed to 350 rpm resulted to an increase in enzyme activity about 15 folds and 1.8 fold respectively. In addition Monod growth kinetics and Leudeking Piret product formation kinetics were studied using Trichoderma reesei with best medium under optimized conditions of inoculum concentration, agitator speed, temperature and pH value.
In the present study, characteristics of free and in situ immobilized (pellets of Mucor rouxii) c... more In the present study, characteristics of free and in situ immobilized (pellets of Mucor rouxii) chitosanases were investigated. Tests included chitosanase from the culture filtrate (free form) and in situ chitosanase as an immobilized form. Growth parameters of M. rouxii revealed that maximum yield of biomass and enzyme activity (2.6 g /100 and 2.4 U/ml) occurred when molasses was used in the growth medium at a 3% concentration. Effect of pH greatly affected the fungus growth; maximum production of biomass and enzyme activity was obtained at pH 5.5, however, at pH 3.0 a formation of an exopolysaccharide bioflocculant was occurred as a form of self-protection by the fungus under the abiotic stress condition. Optimum pH for free and in situ immobilized enzymes was 6.0, whereas optimum temperature range for activity of free and in situ immobilized enzymes were 30-50°C and 40-65°C, respectively. Free and in situ immobilized enzymes display broad specificity towards colloidal chitin, chitosans with different degree of acetylation and Avicel. Values of K and V , for the extracted chitosanase are nearly the same for hydrolyzing of chitosans with different degree m max of acetylation.
Ten, non-producing mycotoxin, fungal strains, belonging to Aspergillus spp., Trichoderma spp. and... more Ten, non-producing mycotoxin, fungal strains, belonging to Aspergillus spp., Trichoderma spp. and Penicellium spp., were screened for clean production of xylanase using white corn flour (WCF) by solid state fermentation. A. fumigates F-993 showed promising xylanase production activity. Culture conditions, i.e., moisture content, initial pH value, temperature, incubation time were optimized to be 60 % (v/w), 3.5, 32°C and 48 hrs, respectively. Solid: solvent ratio of 1:10 was more suitable for enzyme extraction as well as a saline solution of 0.3 M sodium chloride, was more efficient to elute enzyme from fermented substrate. Under the above conditions 720 U/g original WCF was obtained. The enzyme is active at a wide range of pH values, from4.0-6.5 and a temperature range from 35-70°C. Forty percent (v/v)of cold acetone was more efficient for precipitating the enzyme than ethanol or ammonium sulfate, as 32% of total protein contained 86 % of total xylanase activity was obtained with a specific activity of 38U/mg protein. The precipitated enzyme involved considerable activities of cellulases and glucoamylase. The precipitate was applied for hydrolyzing 15% (w/v) of delignified sugarcane bagasse, wheat straw and rice straw, where reducing sugars reached 46,44,52 g l , 1 containing 16,15and 12% (w/w) glucose in the enzymatic hydrolysates of wheat straw, rice straw and sugar cane bagasse, respectively. The remainder fermented substrate, corresponded to 47% (w/w) from the original WCF, was found to be pounded with xylanase, cellulases and glucoamylase and contained 17% crude protein which can be used for fortification at concentrated rations in both poultry and ruminant feed.
International Journal of Biotechnology for Wellness Industries, 2014
Honey isolate Aspergillus niger EM77 was a good halophilic invertase producer in the presence of ... more Honey isolate Aspergillus niger EM77 was a good halophilic invertase producer in the presence of wheat bran as a complete medium (114.55 U/g), using solid state fermentation technique. Different parameters influence the enzyme productivity such as different pH values, temperature, incubation period, nitrogen and carbon sources were investigated. The optimum pH, temperature and incubation period for enzyme production were 5.5, 30 o C and 72 hrs, respectively. Sucrose at 2 % was more suitable carbon source for invertase production (144.39 U/g) and (NH4)2SO4 at 0.15 % was the ideal nitrogen source. Among different metals ions MnSO4 enhanced the enzyme productivity than other tested ions to 194.71 U/g. The partially purified enzyme was successfully entrapped in polyvinyl alcohol sponge shielded with agar starch layer (PVAsp Gs) and achieved 71% immobilization yield. The optimum conditions for immobilization were: pH 5.2, an incubation time of 15 min and a protein concentration of 250 mg/ml. Immobilized enzyme was reused 12 times with 29% activity loss. The free enzyme lost its activity completely at 70˚C after 45 minute and the immobilized form retained 80% of its activity at the same condition.The free and immobilized form reported extreme halophilic property since the highest enzyme activity was obtained between 3.5-5 M.
HAEA and EKAEH have designed the study and managed the literature searches at the beginning. Auth... more HAEA and EKAEH have designed the study and managed the literature searches at the beginning. Author MAE and TK have wrote the first draft of manuscript and author EKAEH has carried out the experiments. All other authors have supervised the thesis and experimental work and managed the literature searches needed during writing the script, discussing the results and publishing. All authors read and approved the final manuscript.
Uploads
Papers by Tarek Kahil