Document Detail


Scale-up of enzymatic production of lactobionic acid using the rotary jet head system.
MedLine Citation:
PMID:  17154315     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Enzymatic oxidation of lactose to lactobionic acid (LBA) by a carbohydrate oxidase from Microdochium nivale was studied in a pilot-scale batch reactor of 600 L working volume using a rotary jet head (RJH) for mixing and mass transfer (Nordkvist et al., 2003, Chem Eng Sci 58:3877-3890). Both lactose and whey permeate were used as substrate, air was used as oxygen source, and catalase was added to eliminate the byproduct hydrogen peroxide. More than 98% conversion to LBA was achieved. Neither enzyme deactivation nor enzyme inhibition was observed under the experimental conditions. The dissolved oxygen tension (DOT) was constant throughout the tank for a given set of operating conditions, indicating that liquid mixing was sufficiently good to avoid oxygen gradients in the tank. However, at a given oxygen tension measured in the tank, the specific rate of reaction found in the RJH system was somewhat higher than previously obtained in a 1 L mechanically stirred tank reactor (Nordkvist et al., 2007, in this issue, pp. 694-707). This can be ascribed to a higher pressure in the recirculation loop which is part of the RJH system. Compared to mechanically stirred systems, high values of the volumetric mass transfer coefficient, k(L)a, were obtained when lactose was used as substrate, especially at low values of the specific power input and the superficial gas velocity. k(L)a was lower for experiments with whey permeate than with lactose due to addition of antifoam. The importance of mass transfer and of the saturation concentration of oxygen on the volumetric rate of reaction was demonstrated by simulations.
Authors:
Ling Hua; Mikkel Nordkvist; Per Munk Nielsen; John Villadsen
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Biotechnology and bioengineering     Volume:  97     ISSN:  0006-3592     ISO Abbreviation:  Biotechnol. Bioeng.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-05-30     Completed Date:  2007-07-17     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7502021     Medline TA:  Biotechnol Bioeng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  842-9     Citation Subset:  IM    
Copyright Information:
(c) 2006 Wiley Periodicals, Inc.
Affiliation:
Department of Chemical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
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MeSH Terms
Descriptor/Qualifier:
Ascomycota / enzymology
Bioreactors / microbiology
Carbohydrate Dehydrogenases / metabolism*
Catalase / pharmacology
Computer Simulation
Disaccharides / biosynthesis*
Equipment Design / instrumentation*
Hydrogen Peroxide / metabolism
Kinetics
Lactose / metabolism
Milk Proteins / metabolism
Oxidation-Reduction
Oxygen / metabolism
Pilot Projects
Substrate Specificity
Chemical
Reg. No./Substance:
0/Disaccharides; 0/Milk Proteins; 0/whey protein; 63-42-3/Lactose; 7722-84-1/Hydrogen Peroxide; 7782-44-7/Oxygen; 96-82-2/lactobionic acid; EC 1.1.-/Carbohydrate Dehydrogenases; EC 1.1.-/lactose oxidase; EC 1.11.1.6/Catalase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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