Effects of mutation of 2,3-butanediol formation pathway on glycerol metabolism and 1,3-propanediol production by Klebsiella pneumoniae J2B.

The current study investigates the impact of mutation of 2,3-butanediol (BDO) formation pathway on glycerol metabolism and 1,3-propanediol (PDO) production by lactate dehydrogenase deficient mutant of Klebsiella pneumoniae J2B. To this end, BDO pathway genes, budA, budB, budC and budO (whole-bud operon), were deleted from K. pneumoniae J2B ΔldhA and the mutants were studied for glycerol metabolism and alcohols (PDO, BDO) production.

Production of 1,3-propanediol from glycerol using the newly isolated Klebsiella pneumoniae J2B.

Recently, novel Klebsiella pneumoniae J2B, which grows rapidly on glycerol as the carbon source without forming pathogenic and sticky lipopolysaccharides, was isolated. Current study examined the ability of K. pneumoniae J2B to produce 1,3-propanediol (PDO) from glycerol.

Simultaneous production of 3-hydroxypropionic acid and 1,3-propanediol from glycerol using resting cells of the lactate dehydrogenase-deficient recombinant Klebsiella pneumoniae overexpressing an aldehyde dehydrogenase.

In the present study, the lactate dehydrogenase-deficient (ldhA(-)) recombinant Klebsiella pneumoniae overexpressing an ALDH (KGSADH) was developed and the co-production of 3-HP and PDO from glycerol by this recombinant under resting cell conditions was examined. The new recombinant did not produce any appreciable lactate, which seriously inhibits the production of 3-HP and PDO. The final titers of 3-HP and PDO by the ldhA(-) recombinant strain at 60 h were 252.

Co-production of 3-hydroxypropionic acid and 1,3-propanediol from glycerol using resting cells of recombinant Klebsiella pneumoniae J2B strain overexpressing aldehyde dehydrogenase.

The co-production of 3-hydroxypropionic acid (3HP) and 1,3-propanediol (PDO) from glycerol was studied using the resting cells of a recombinant Klebsiella pneumoniae J2B strain that overexpresses an aldehyde dehydrogenase (KGSADH). Active biomass was produced in a mineral salt medium containing yeast extract and glycerol under a range of aeration conditions, and shifted to potassium phosphate buffer containing glycerol for bioconversion. The microaerobic or anaerobic conditions were favorable for both the production of active biomass and subsequent bioconversion.