scholarly journals Enzyme-catalyzed reactions in different types of high-pressure enzymatic reactors

2006 ◽  
Vol 12 (3) ◽  
pp. 159-163
Author(s):  
Mateja Primozic ◽  
Maja Habulin ◽  
Muzafera Paljevac ◽  
Zeljko Knez

The enzyme-catalyzed hydrolysis of carboxy-methyl cellulose (CMC) was performed in three different types of reactors; in a batch stirred-tank reactor (BSTR) operating at atmospheric pressure, in a high-pressure batch stirred-tank reactor (HP BSTR) and in a high-pressure continuous tubular-membrane reactor (HP CTMR). In the high-pressure reactors aqueous SC CO2 was used as the reaction medium. The aim of our research was optimization of the reaction parameters for reaction performance. All the reactions were catalyzed by cellulase from Humicola insolens. Glucose production in the high-pressure batch stirred-tank reactor was faster than in the BSTR at atmospheric pressure. The optimal temperature for the reaction performed in the BSTR at atmospheric pressure was 30?C, while the optimal temperature for the reaction performed in SC CO2 was 32?C. The influence of the application of tubular ceramic membranes in the high-pressure reaction system was studied on the model reaction of CMC hydrolysis at atmospheric pressure and in SC CO2. The reaction was catalyzed by cellulase from Humicola insolens covalently linked to the surface of the ceramic membrane. The hydrolysis of CMC in SC CO2 and at atmospheric pressure was performed for a long time period. The reaction carried out in SC CO2 was more productive than the reaction performed at atmospheric pressure.

2021 ◽  
Author(s):  
Ejaz Khan

In an attempt to elucidate the effect of some operating conditions on the rate and extent of enzymatic hydrolysis of lignocellulosic materials in a stirred tank reactor, wheat straw was hydrolyzed by mixing with two pitched-blade impellers mounted on a shaft under various atmospheric conditions: static air in headspace, N₂ gas flowing over the surface of the medium, and minimal static air by a lid touching the surface of the medium. The presence of N₂ gas over the reaction medium produced by the highest 6.9 % (w/w) conversion in 36 hours. The initial conversion when N₂ gas flowed in the headspace (2.9 % w/w), and when a lid was used (2.9 % w/w) as compared to conversion in air presence (2.3 % w/w), seems to indicate that the enzyme activity was affected due to oxidation in the presence of air. The observed low conversion yield was probably the result of the non sterile conditions imposed by industrial requirements for the production of biofuel ethanol from agricultural lignocellulosics.


2021 ◽  
Author(s):  
Ejaz Khan

In an attempt to elucidate the effect of some operating conditions on the rate and extent of enzymatic hydrolysis of lignocellulosic materials in a stirred tank reactor, wheat straw was hydrolyzed by mixing with two pitched-blade impellers mounted on a shaft under various atmospheric conditions: static air in headspace, N₂ gas flowing over the surface of the medium, and minimal static air by a lid touching the surface of the medium. The presence of N₂ gas over the reaction medium produced by the highest 6.9 % (w/w) conversion in 36 hours. The initial conversion when N₂ gas flowed in the headspace (2.9 % w/w), and when a lid was used (2.9 % w/w) as compared to conversion in air presence (2.3 % w/w), seems to indicate that the enzyme activity was affected due to oxidation in the presence of air. The observed low conversion yield was probably the result of the non sterile conditions imposed by industrial requirements for the production of biofuel ethanol from agricultural lignocellulosics.


2004 ◽  
Vol 39 (12) ◽  
pp. 2179-2182 ◽  
Author(s):  
J. Vásquez-Bahena ◽  
M.C. Montes-Horcasitas ◽  
J. Ortega-López ◽  
I. Magaña-Plaza ◽  
L.B. Flores-Cotera

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