Biosyntesis
of L-Lysin from Methanol
This project was initiated in 2001 in colaboration with SINTEF Applied
Biotechnology and the BioTechnology Institute at the University of Minnesota.
L-Lysine is an essential amino acid widely used as an additive in food and
feed, and the global L-Lysine market is large and growing. Today, commercial
L-Lysine production is made fermentative by
using bacteria growing on sugars as carbon and energy source. However, the
need for new and better production processes is emerging, and in particular
the possibility to utilize alternative carbon sources has both economical
and ecological advantages. One-carbon (C1)-compounds such as methanol are
highly interesting in this regard, due to low price, high abundance and high
purity. The unusual metabolic capabilities of thermotolerant methylotrophic
bacteria make them interesting candidates for the bioproduction of amino acids,
as well as recombinant proteins, vitamins, coenzymes, and cytochromes. The
Gram-positive bacterium Bacillus methanolicus can produce high levels
(55 g/l) of glutamate at 50oC using methanol as a carbon source in fed-batch
fermentations, and by classical mutagenesis a B. methanolicus mutant
secreting 35 g/l of L-Lysine has been made at the University of Minnesota.
Our goal in this project is to develop and apply recombinant DNA technology
to make B. methanolicus mutants producing L-Lysine at industrial
competitive levels.
Key Papers
Brautaset,
T., Williams, M.D., Dillingham, R.D., Kaufmann, C., Bennaars, A., Crabbe,
E., and Flickinger, M.C. (2003). The role of the Bacillus methanolicus
citrate synthase synthase II gene, citY, in regulating the secretion of glutamate
in L-lysine secreting mutants. Applied and Environmental Microbiology
69: 3986-3995.
Brautaset
T, Jakobsen M O, Flickinger MC, Valla S, Ellingsen TE. (2004). Plasmid-Dependent
Methylotrophy in Thermotolerant Bacillus methanolicus. J Bacteriol.
Mar 1;186(5):1229-1238.
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Biopolymers
Bioprospecting
of marine microorganisms
Engineered
antibiotic synthesis
Gene
Expression
Osmoregulation
Metabolic
Engineering