الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
Summary
In the present work, the lignocellulosic materials of Faba bean straw and pea pods have been investigated and more information were obtained about their pretreatment and chemical features of these agricultural wastes. Cellulase complex enzymes were evaluated to obtain optimum conditions. Saccharification process was carried out using the produced cellulase enzymes to convert cellulose of the above mentioned lignocellulosic materials to glucose and cellobiose syrup. The obtained glucose has been converted by
fermentation to ethanol alcohol.
The results indicated that Faba bean straw and pea pods contained a high percentage of cellulose and hemicellulose i.e. 32.3, 29.2 % and 23.0, 20.4 % respectively. Pretreatment of the above mentioned lignocellulosic materials with NaOH and glacial acetic acid was achieved to convert the crystallinity structure of these polymers to amorphous state to enhance the enzymatic attack toward these polysaccharides. The results indicated that pretreatment of lignocellulosic materials with glacial acetic acid (4 %, VN) showed the highest yield of cellulose in case of faba bean straw. But the lignocellulosic materials with NaOH (1 %, W/V) showed the highest yield of cellulose in case of pea pods at different concentrations and temperatures comparing the obtained results. Trichoderma Reesei; Trichoderma Harzianum and Aspergillus Niger were used for the production of cellulase enzyme by using Carboxy Methyl Cellulose (CMC) as sole carbon source to develop the above mentioned fungi.
The best results of enzyme production was recorded by using cellulose as carbon source after 9 days fermentation period. Effect of different parameters on the reaction velocity and activity of cellulase enzyme:
(i) Effect of enzyme concentration :
The effect of enzyme concentration on the reaction activity by using carboxymethylcellulose (CMC) as standard and extracted cellulose from lignocellulosic materials were studied. The obtained results indicated that the reaction activity increased gradually until reached its maximum i.e. 84.7 & 74.2 limM/L/min with cellulase enzyme produced by T.Reesei; 46.6 & 43.2 .i.mM/Umin with cellulase enzyme produced by T.Harzianum and 73.3 & 23.9 ,trnM/Umin with cellulase enzyme produced by A.Niger cellulase enzyme at the same concentration of cellulase enzyme which equalled to 0.5 mg/100 buffer by using CMC and F.P. as substrates. Cellulase enzyme of T.Reesei; T.Harzianum reached its maximum reaction activity i.e. 38.2 & 41.2 iimM/Umin; 34.9 & 34.3 gmM/L/min at concentration of equalled 0.5 mg/100 buffer 0.5 mg/100 buffer by using CMC and Faba bean straw and pea pods as substrates. While cellulase of A.Niger reached its maximum i.e. at 39.3 limM/L/min values with faba bean straw and 37.5 pmM/Umin for pea pods at concentration of enzyme equaled to 0.6 mg/ 100 buffer for the first substrate and 0.5
mg/100 buffer for the latter ones.
(ii) Effect of temperature
The obtained results of the effect of temperature on the reaction activity of cellulase enzyme produced by T.Reesei and ia:4r]uL’n indicated that the optimum temperature was 55 °C with CMC; and lignocellulosic materials. While in case of A.Niger the optimum temperature was 50 °C with CMC, Faba bean straw and pea
pods. (iii)Effect of pH
The effect of pH values on the enzyme activity on the same above mentioned cellulase complex enzyme indicated that the optimum pH was 0.5 by using CMC and lignocellulosic materials. (iv)Effect of substrate concentration
The effect of substrate concentration using CMC as standard and extracted cellulose of faba bean and pea pods on the activity of cellulase enzyme complex were studied. The obtained results indicated that the maximum reaction velocity (Vmax) of cellulase
enzyme produced by T.Reesei were 185.2, 173.8 & 165.8 p.mM/Umin respectively. While for cellulase of T.Harzianum these values equalled 132.7, 128.5 and 133.2 limM/L/min. On the other hand cellulase of A.Niger achieved maximum velocities amounted to 135.9, 129.2 & 136.2 p.rnM/L/min at concentration of 1.8 % CMC and previously mentioned pretreated lignocellulosic polymers.
The results illustrate that Michaelis Constant (Km) values of T.Reesei were 0.34 on CMC as substrate and 0.40; 0.41 by using
Faba bean straw and pea pods. But, Km values of cellulase enzyme
of T.Harzianum were 0.19; 0.26 and 0.25 by using CMG; faba bean straw and pea pods respectively. Finally, Km values of cellulase
enzyme of A.Niger equalled to 0.19; 0.25 and 0.23 at concentration of 1.8 % CMC and previous mentioned pretreated lignocellulosic
materials.
The results of saccharification process for different lignocellulsic materials indicated that the maximum values of saccharification process were 62.2; 59.9 and 56.2% by previous fungi enzymes for extracted cellulose of Faba bean straw at substrate concentration of 8 % after 6 h. under optimum conditions of cellulase enzyme. While these maximum values for extracted cellulose of pea pods amounted to 66.3; 58.8 and 65.0% at concentration of 10 % for 6 h. by using the same enzymes under the above mentioned conditions. Immobilization of cellulase enzyme
Immobilization of cellulase enzyme on solid supports is an important advantage, since it enables the continuous reutilization and recyclation of the enzyme support system.
The cellulase enzyme from T.Reesei, T.Harzianum and A.Niger have been immobilized on two different support materials, i.e. gel fertilizer and chitin support. Kinetic studies of the immobilized enzymes with the different supports were characterized. The results indicated that the rate of immobilized enzyme reaction activity increased up to a certain point with increasing concentration of substrate (Vmax)• The obtained results indicated that a slight changes
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for Km of native and T.Harzianum immobilized enzyme on both
supports occurred . While the highest changes had been achieved in case of immobilized cellulase enzyme of A.Niger (0.52) if compared with the native enzyme (0.19). Km value of cellulase T.Reesei
increased to (0.42) after its immobilization on gel fertilizer support. On the contrary Km value of this enzyme decreased to (0.22) after its
immobilization on chitin. The results illustrates that there are a slight decrement in the (Vmax) values of cellulase enzyme after its
immobilization on gel fertilizer. While a great decrement occurred after immobilization of the free enzyme and its conversion to cellulase - chitin complex. Production of ethanol by fermentation of the lignocellulosic substances
The obtained results indicated that the high efficiency of the conversion of the resultant glucose which produced from saccharification process to ethanol alcohol had been achieved by yeast strain saccharomyces cervisia. The percentages of this conversion were 89.5; 84.7; and 85.7 % by using hydrolyzed CMC of T.Reesei, T.Harzianum and A.Niger .
Besides, the produced ethanol and methanol was produced in different quantities. The highest yield of methanol alcohol i.e. 7.4 % had been achieved with the fermentation process of the hydrolyzed CMC of A.Niger .This point needs more investigation, since this result is very important from economical point of view.