Enhanced production of dihydroxyacetone from glycerol by overexpression of glycerol dehydrogenase in an alcohol dehydrogenase-deficient mutant of Gluconobacter oxydans

Improved Utilization of Crude Glycerol By-Product from Biodiesel Production

“…They achieved up to about 30 g/L of dihydroxyacetone from 50 g/L of glycerol which was 20-40% more in comparison with control strains. Li et al (2010) also investigated the over expression of glycerol dehydrogenase (GDH) in an alcohol dehydrogenase (ADH)-deficient mutant of Gluconobacter oxydans M5AM/GDH in order to improve dihydroxyacetone productivity. It was found that absence of ADH together with over expression of GDH gene substantially improved dihydroxyacetone formation.…”

Effect of glycerol and dihydroxyacetone concentrations in the culture medium on the growth of acetic acid bacteria Gluconobacter oxydans ATCC 621

“…In recent years, some works have appeared [13,15,20,22] that addressed glycerol biotransformation to DHa by genetically modified strains of G. oxydans. The modifications consisted in, among other things, designing strains capable of glyDH overproduction, which ensured higher (compared to parental strain) concentrations of the product.…”

Use of Glycerol in Biotechnological Applications

“…In line with the notion that glyceric acid inhibits growth and DHA production by G. oxydans, it was found that addition of glyceric acid to the medium reduced growth and DHA production (Habe et al, 2010a) and that AdhA activity strongly increased when very high glycerol concentrations were used (Habe et al, 2009d). In the next step, the combination of adhA disruption and sldAB overexpression resulted in a strain with very high productivity and strongly increased tolerance towards glycerol (Li et al, 2010b). Since the production of DHA by the obligate aerobic G. oxydans is characterized by a very high demand for oxygen to oxidize reduced PQQ (Hekmat et al, 2003, Svitel & Sturdik, 1994, the gene encoding Vitreoscilla hemoglobin, an oxygen transporting protein, was shown to be beneficial .…”