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Fed-batch production of l-phenylalanine from glycerol and ammonia with recombinant Escherichia coli

Paper ID Volume ID Publish Year Pages File Format Full-Text
3191 156 2014 8 PDF Available
Title
Fed-batch production of l-phenylalanine from glycerol and ammonia with recombinant Escherichia coli
Abstract

•A specific rationally designed multi-phase fed-batch process was applied.•Therein recombinant Escherichia coli strains convert lactic acid and glycerol to biomass.•During production phase glycerol and ammonia are converted to l-phenylalanine.•l-Phenylalanine concentrations of up to 13.4 g L−1 can be achieved.•Exchange of ampicillin for kanamycin resistance leads to plasmid stabilization.

Glycerol was used as carbon source for l-phenylalanine production with recombinant Escherichia coli. In contrast to glucose, no consumption of the precursor phosphoenolpyruvate (PEP) is necessary for glycerol uptake. Additional lactic acid feeding was necessary for growth because the genes encoding the PEP consuming pyruvate kinase isoenzymes have been deleted. Thus a fed-batch process was developed with feeding of lactic acid and glycerol for biomass formation followed by feeding of glycerol and ammonia for l-phenylalanine production. Unfortunately, plasmid instability was observed in the first process. Plasmid stability could be successfully assured by replacing an ampicillin resistance gene by a kanamycin resistance gene cassette. The resulting maximum l-phenylalanine concentration of 13.4 g L−1 was improved by 26% and biomass specific productivity (22 mgL-phe gCDW−1 h−1) was raised by 69%. The final l-phenylalanine concentration of 13.4 g L−1 was thus improved by a factor of 2.4 compared to earlier reports.

Keywords
l-Phenylalanine; Glycerol; Escherichia coli; Fed-batch; Plasmid stability
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Fed-batch production of l-phenylalanine from glycerol and ammonia with recombinant Escherichia coli
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 83, 15 February 2014, Pages 62–69
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us