Effect of enzymatic hydrolysis

Figure 8. Effect of enzymatic hydrolysis on specific volume of foam obtained by whipping a heated whey protein sol (4% w/w, 85°C, 6 min whipping) (43)...

Qin, L., Xu, S., and Zhang, W. 2005. Effect of enzymatic hydrolysis on the yield of cloudy carrot juice and the effects of hydrocolloids on color and cloud stability during ambient storage. J. Sci. Food... 

Effect of Enzymatic Hydrolysis Using 3000 U of Xylanase from T. lanuginosus IOC-4145 g of Sugarcane Bagasse Under Different Conditions After 24 h of Incubation... 

Khoddami A, Morshed M, Tavani H (2001) Effects of enzymatic hydrolysis on drawn polyester filament yams. Iran Polym J 10 363-370... 

Resolution of Racemic Amines and Amino Acids. Acylases (EC3.5.1.14) are the most commonly used enzymes for the resolution of amino acids. Porcine kidney acylase (PKA) and the fungaly3.spet i//us acylase (AA) are commercially available, inexpensive, and stable. They have broad substrate specificity and hydrolyze a wide spectmm of natural and unnatural A/-acyl amino acids, with exceptionally high enantioselectivity in almost all cases. Moreover, theU enantioselectivity is exceptionally good with most substrates. A general paper on this subject has been pubUshed (106) in which the resolution of over 50 A/-acyl amino acids and analogues is described. Also reported are the stabiUties of the enzymes and the effect of different acyl groups on the rate and selectivity of enzymatic hydrolysis. Some of the substrates that are easily resolved on 10—100 g scale are presented in Figure 4 (106). Lipases are also used for the resolution of A/-acylated amino acids but the rates and optical purities are usually low (107). 

In a series of ten morphine 3-benzoates, large differences in rates of enzymatic hydrolysis were seen [122], In 80% human plasma at pH 7.4 and 37°, the unsubstituted 3-benzoate had a tm value of 0.6 h, whereas esters of 2,6-disubstituted benzoic acid were much more resistant to enzymatic attack (t1/2 ranging from 60 h for the dimethylbenzoate to 300 h for the dichloro-and dimethoxybenzoates). Although these results point to marked steric hindrance, electronic effects cannot be excluded but escape characterization because of the limited series. Furthermore, and as mentioned repeatedly in this text, the possibility of binding to plasma proteins is a complicating factor that should be kept in mind. 

Figure 5. Effect of vibratory ball milling on the rate and extent of enzymatic hydrolysis...

Draude, K. M., Kumiawan, C. B., and Duff, S. J. B., 2001, Effect of oxygen delignification on the rate and extend of enzymatic hydrolysis of lignocellulosic material, Biores. Technol.19 113-120. 

A major obstacle to the commercialization of enzymatic hydrolysis of biomass is the high cost of the enzymes. One way to reduce this cost is to use much less enzyme per unit of biomass hydrolyzed. Previous work has shown that the effective enzymatic hydrolysis of AFEX-treated biomass at enzyme loadings as low as 5 filter paper units (FPU)/g of dry biomass was achieved by adjusting the pretreatment parameters (6). The objectives of the present study, were to determine the best AFEX conditions for pretreatment of corn stover, to employ different enzyme loading levels (60,15, and 7.5, FPU/g of glucan), and to compare the enzymatic hydrolysis results and ethanol yield. 

A study was conducted to examine the effects of several parameters on the yields of enzymatic hydrolysis for two major MSW components namely, newspaper and corrugated cardboard [74], The primary aim was to try to determine the modifications of MSW that would lead to increased conversions to ethanol. A full complement cellulase system from T. reesei QM 9414G was used. The enzyme system consisted of endoglucanase,... 

Eriksson, T., Borjesson, J., and Tjerneld, F. 2002. Mechanism of surfactant effect in enzymatic hydrolysis of lignocellulose. Enz. Microbial Technol., 31, 353-364. 

As with pulping and bleaching, biotechnology too could have a considerable impact on the production of chemicals from wood and other forms of plant biomass. The effects of biotechnology probably will be noticed first in areas of enzymatic hydrolysis of polysaccharides and fermentation technology. 

The full structural determination of the structure of an oligosaccharide by this method includes complete sequencing by successive enzymatic digests using specific exoglycosi-dases and analysis of the products of each hydrolysis by mass spectrometry to observe the effectiveness of the hydrolysis by the decrease of molecular weight. [249]... 

Figure 16. The effect of heat treatment of soybean protein on the maximum extent of enzymatic hydrolysis by proteases of Aspergillus species (4)...

The (R)-amine 7 is a liquid, whereas the (S)-amide 6 is a solid. This difference in physical properties in effect enabled easy separation of the amine antipodes by filtration. The desired (S)-amide 6 needs to be deacylated prior to the synthesis of the final compound, xemilofiban 1. The slow rate of deacylation of the (S)-amide by the enzyme PGA can be enhanced significantly by using a high concentration of the enzyme. The temperature can also be raised to increase the rate of enzymatic hydrolysis. The (S)-amide 6 obtained was deacylated to liberate the free (S)-amine 9 using excess PGA (Fig. 5). 

Acetyl DL-methionine which is used as a substrate for amino acylase activity determination was prepared by acetylation of DL-methionine with acetic anhydride in acetic acid [5]. The rate of enzymatic hydrolysis was determined by measuring the liberated amino acid by ninhydrin method [6] where ascorbic acid was used as oxidizing agent instead of sodium cyanide. The activity curve of pure amino acylase enzyme is shown in Fig. 1 as a continuous line. For determining the effect of metal ions on the activity of amino acylase the following procedure was adopted. 

LEM systems have also been shown to be successful in separating commodity-type biochemicals such as propionic acid (10) and acetic acid (10,22) and have been used for the preparation of L-amino acids from racemic D,L mixtures by means of enzymatic hydrolysis of amino acid esters (23). In addition to biochemical separations, the work of Mohan and Li showed that enzymes could be encapsulated in liquid emulsion membranes with no deleterious effect on enzyme action (24). Later work by these authors indicated that encapsulated live cells could remain viable and function in the LEM interior phase for period as long as five days (25). 

The enzymatic hydrolysis and sampling procedures for Avicel was the same as described in Enhancement of Enzymatic Hydrolysis of Pretreated CWR by Additives. Based on the experimental result fiom Effect of Tween 20 Loading on Enzymatic Hydrolysis of Pretreated CWR, the ratio of Tween 20 to Avicel was decided to be 0.1 g Tween 20 to 1 g Avicel. A homogeneous aliquot of I ml was withdrawn at start and after 1, 2, 4, 8, 24, 48, and 72 h of hydrolysis. The aliquots were treated as Effect of Tween 20 and BSA on Enzyme Protein Concentration and Activity to obtain 500-ul supernatant samples. The... 

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