In:
Biotechnology Journal, Wiley, Vol. 2, No. 11 ( 2007-11), p. 1408-1416
Kurzfassung:
An in vivo system was developed for the biotransformation of D ‐fructose into D ‐mannitol by the expression of the gene mdh encoding mannitol dehydrogenase (MDH) from Leuconostoc pseudomesenteroides ATCC12291 in Bacillus megaterium . The NADH reduction equivalents necessary for MDH activity were regenerated via the oxidation of formate to carbon dioxide by coexpression of the gene fdh encoding Mycobacterium vaccae N10 formate dehydrogenase (FDH). High‐level protein production of MDH in B. megaterium required the adaptation of the corresponding ribosome binding site. The fdh gene was adapted to B. megaterium codon usage via complete chemical gene synthesis. Recombinant B. megaterium produced up to 10.60 g/L D ‐mannitol at the shaking flask scale. Whole cell biotransformation in a fed‐batch bioreactor increased D ‐mannitol concentration to 22.00 g/L at a specific productivity of 0.32 g D ‐mannitol (gram cell dry weight) –1 h –1 and a Dmannitol yield of 0.91 mol/mol. The nicotinamide adenine dinucleotide (NAD(H)) pool of the B. megaterium producing D ‐mannitol remained stable during biotransformation. Intra‐ and extracellular pH adjusted itself to a value of 6.5 and remained constant during the process. Data integration revealed that substrate uptake was the limiting factor of the overall biotransformation. The information obtained identified B. megaterium as a useful production host for D ‐mannitol using a resting cell biotransformation approach.
Materialart:
Online-Ressource
ISSN:
1860-6768
,
1860-7314
DOI:
10.1002/biot.200700055
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2007
ZDB Id:
2214038-4
