Tweens, hydrolysis

SG sols were synthesized by hydrolysis of tetraethyloxysilane in the presence of polyelectrolyte and surfactant. Poly (vinylsulfonic acid) (PVSA) or poly (styrenesulfonic acid) (PSSA) were used as cation exchangers, Tween-20 or Triton X-100 were used as non- ionic surfactants. Obtained sol was dropped onto the surface of glass slide and dried over night. Template extraction from the composite film was performed in water- ethanol medium. The ion-exchange properties of the films were studied spectrophotometrically using adsorption of cationic dye Rhodamine 6G or Fe(Phen) and potentiometrically by sorption of protons. 

Cellulase and all chemicals used in this work were obtained from Sigma. Hydrolysis experiments were conducted by adding a fixed amount of 2 x 2 mm oflSce paper to flasks containing cellulase in 0.05 M acetate buffer (pH = 4.8). The flasks were placed in an incubator-shaker maintained at 50 °C and 100 rpm. A Box-Behnken design was used to assess the influence of four factors on the extent of sugar production. The four factors examined were (i) reaction time (h), (ii) enzyme to paper mass ratio (%), (iii) amount of surfactant added (Tween 80, g/L), and (iv) paper pretreatment condition (phosphoric add concentration, g/L), as shown in Table 1. Each factor is coded according to the equation... 

Egelrud and Olivecrona (1973) studied the catalytic activity against several substrates of bovine milk enzyme preparations that had been purified about 7000-fold to a purity higher than 80% (Egelrud and Olivecrona 1972). The enzyme catalyzed the hydrolysis of emulsified trioleate, trioctanoate, monooleate, Tween 20 (polyoxyethylene sorbitan monolaurate), and p-nitrophenyl acetate. It was concluded that the enzyme had rather low substrate specificity and that the presence of activating serum factors is not needed for catalysis to occur. 

Castanon, M., and Wilke, C. R. 1981. Effects of the Surfactant Tween 80 on Enzymatic Hydrolysis of Newspaper. Biotech. Bioeng., 23,1365-1372. 

Fig. 4 Mechanism of action (MOA) and inhibition studies of ML119 (compound 1) with HePTP and HePTP mutants, (a) Progress curves of HePTP (6.25 nM) activity in the presence of different doses of compound 1 (0, 0.078,0.156,0.313,0.625,1.25 /jM) and 0.3 mM OMFP in 20 mM Bis-Tris, pH 6.0,150 mM NaCI, 1 mM DH, and 0.005 % Tween-20 in 20 /jL totai assay voiume in biack 384-weii microtiter plates. No time-dependent inhibition was observed as demonstrated by the linear progress curves of the HePTP phosphatase reaction, (b) Eadie-Hofstee plot of the Michaelis-Menten kinetic study with compound I.The HePTP-catalyzed hydrolysis of OMFP was assayed at room temperature in a 60 /jL 96-well format reaction system in 50 mM Bis-Tris, pH 6.0 assay buffer containing 1.7 mM DTT, 0.005 % Tween-20, and 5 % DMSO. Recombinant HePTP (5 nM) was preincubated with various fixed concentrations of inhibitor (0,0.1,0.2,0.4,0.8,1.6 /jM) for 10 min. The reaction was initiated by addition of various concentrations of substrate (0,12.5,25,50,100,200,400 pM) to the...

Lv et al. have demonstrated the ability of the microemulsions to improve the hydrolytic stability of a known anti-microbial agent chloramphenicol [5]. The components of mi-croemulsion included IPM, Tween 20 and Span 20, which have good ocular acceptability. The accelerated stability studies on chloramphenicol microemulsions and commercial solution were carried out for 3 months demonstrated significantly lower hydrolysis of chloramphenicol (14.38%) as compared to that of solutions (27.11%). H NMR studies on microemulsions confirmed that the chloramphenicol was embedded in the surfactant chains that may provide higher stability. 

The mechanism of action of this activator has not been established, but it is known (Fischer and Jatzkewitz, 1978 Mitsuyama et al., 1985) that the activator forms an equimolar complex with cerebroside 3-sulfate prior to hydrolysis by arylsulfohydrolase A. Similar heat-stable activator proteins are also known for other acid hydrolases (Li and Li, 1983 Inui and Wenger, 1983 Wenger and Inui, 1984 Conzelmann et al., 1982 Christomanou and Kleinschmidt, 1985 Burg et al., 1985). It is becoming increasingly evident that many lysosomal hydrolases have specific activators, although some of these activators may be common to more than one enzyme (Li and Li, 1983, 1984 Li et al., 1985). The desulfation of cerebroside 3-sulfate also occurs in the absence of activator protein. In these experiments, Tween-20 or sodium... 

Keywords Saline Creeping Wild Ryegrass Cellulase P-Glucosidase Tween 20 Tween 80 Bovine serum albumin - Enzymatie hydrolysis Avicel PH 101-Lignaceous residue... 

Enzyme activity loss because of non-productive adsorption on lignin surface was identified as one of the important factors to decrease enzyme effectiveness, and the effect of surfactants and non-catalytic protein on the enzymatic hydrolysis has been extensively studied to increase the enzymatic hydrolysis of cellulose into fermentable sugars [7, 9 19]. The reported study showed that the non-ionic surfactant poly(oxyethylene)2o-sorbitan-monooleate (Tween 80) enhanced the enzymatic hydrolysis rate and extent of newspaper cellulose by 33 and 14%, respectively [20]. It was also found that 30% more FPU cellulase activity remained in solution, and about three times more recoverable FPU activity could be recycled with the presence of Tween 80. Tween 80 enhanced enzymatic hydrolysis yields for steam-exploded poplar wood by 20% in the simultaneous saccharification and fermentation (SSF) process [21]. Helle et al. [22] reported that hydrolysis yield increased by as much as a factor of 7, whereas enzyme adsorption on cellulose decreased because of the addition of Tween 80. With the presence of poly(oxyethylene)2o-sorbitan-monolaurate (Tween 20) and Tween 80, the conversions of cellulose and xylan in lime-pretreated com stover were increased by 42 and 40%, respectively [23]. Wu and Ju [24] showed that the addition of Tween 20 or Tween 80 to waste newsprint could increase cellulose conversion by about 50% with the saving of cellulase loading of 80%. With the addition of non-ionic, anionic, and cationic surfactants to the hydrolysis of cellulose (Avicel, tissue paper, and reclaimed paper), Ooshima et al. [25] subsequently found that Tween 20 was the most effective for the enhancement of cellulose conversion, and anionic surfactants did not have any effect on cellulose hydrolysis. With the addition of Tween 20 in the SSF process for... 

Although lots of work has been done on additives for enhancement of enzymatic hydrolysis of various substrates such as wood, com stover, and wheat straw, saline Creeping Wild Ryegrass (CWR) has not previously been studied with addition of additives. Furthermore, the mechanisms for the enhancement of enzymatic hydrolysis by additives are not clear. Thus, more in-depth studies are needed to investigate such mechanisms. Two non-ionic surfactants (Tween 20 and 80) and a non-catalytic protein (BSA) were employed to do this study. 

Non-ionic surfactants (Tween 20 and 80) and non-catalytic protein (BSA) were used to investigate if the enzymatic hydrolysis of pretreated CWR can be improved with various surface-active additives. The enzyme protein concentration and activities in solution were measured during enzymatic hydrolysis. Based on these data, the effect of additives on enzyme protein and activity was determined. All the experiments and experimental conditions are summarized in Table 1. 

Effect of Tween 20 Loading on Enzymatic Hydrolysis of Pretreated CWR... 

The effect of Tween 20 loading on enzymatic hydrolysis of pretreated CWR was studied at five different loading levels, including 0, 0.05, 0.1, 0.15, and 0.2 g Tween 20/g-dry solid. At the end of 72 h hydrolysis, a 1-ml aliquot was withdrawn for sugars measurement. At the same time, another 1-ml aliquot was withdrawn for protein and enzyme activity measurement. For enzyme protein concentration and activity measurements, the sample pretreatment procedures before measurement were the same as described in Effect of Tween 20 and BSA on Enzyme Protein Concentration and Activity. ... 

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... 

Enzymatic Hydrolysis of Pretreated CWR With and Without the Presence of Tween 20 Added After 8 h of Hydrolysis... 

To investigate how the interaction between Tween 20 and pretreated CWR affect the enzymatic hydrolysis efficiency, the enzymatic hydrolysis of pretreated CWR with 0.1 g Tween 20/g dry solid added after 8 h of hydrolysis was studied. The results of this section were compared to those obtained in Enhancement of Enzymatic Hydrolysis of Pretreated... 

CWR by Additives, in which Tween 20 was added before the addition of en2ymes. During hydrolysis, 1-ml aliquots were taken at start and after 1, 2, 4, 8, 24, 48, and 72 h of hydrolysis. The sugars, enzyme protein concentration, and activity were measured. 

As shown in Fig. 1, the presence of Tween 80, Tween 20, BSA or (BSA + Tween 20) improved the enzymatic hydrolysis of pretreated CWR by 8 to 14% after 72 h of hydrolysis. The initial hydrolysis rate was also increased to some extent The cellulose conversion was increased from approximately 75% (no additives) to 89, 88, and 83% with the presence of Tween 20, Tween 80, and BSA, respectively. Of all three additives. Tween 20 was the most effective additive on the improvement of cellulose conversion, followed by Tween 80 and BSA. The treatment of Tween 20, Tween 80, or BSA gave similar results at an enzyme loading of 15 FPU/g cellulose to those at enzyme loading of 30 FPU/g cellulose but without additive addition (Fig. 1). Therefore, the addition of surfactants and/or non-catalytic protein could help save enzyme loading without decreasing the hydrolysis yield. In addition, it was found that Tween 20 and BSA gave no further increase in cellulose conversion. Thus, the effect of Tween 20 on the hydrolysis of pretreated CWR might be similar to that of BSA [7]. 

Fig. 2 Free enzyme protein in solution with and without Tween 20 during enzymatic hydrolysis...

Fig. 5 Changes in free enzyme activities and protein concentration in the solution during enzymatic hydrolysis of pretreated CWR after 72 h as a function of Tween 20 loading...

Considering the result from Fig. 1 that (0.1 g Tween 20 + 0.1 g BSA)/g dry solid gave no further increase of cellulose conversion compared with the addition of Tween 20 alone, a conclusion could be drawn that the mechanisms of Tween 20 and BSA on the improvement of enzymatic hydrolysis of pretreated CWR might be similar. If Tween 20 and BSA had significantly different mechanisms on the improvement of enzymatic hydrolysis, higher cellulose conversion should be expected after BSA was added to the solution with Tween 20 at saturation loading of 0.1 g/g dry solid. 

The changes in enzyme protein concentration and activities in the solution during hydrolysis of Avicel were measured as funetions of the addition of Tween 20 (Fig. 7). 

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