Dynamic behavior of glycerol–glucose co-fermentation for 1,3-propanediol production by Klebsiella pneumoniae under micro-aerobic conditions

ABSTRACT The capacity to both ferment and oxidize l-ascorbate has been widely documented for a number of enteric bacteria. Here we present evidence that all the strains of Klebsiella pneumoniae tested in this study ferment l-ascorbate using the ula regulon-encoded proteins. Under aerobic conditions, several phenotypes were observed for the strains. Our results showed that the yiaK-S system is required for this aerobic metabolic process. Gel shift experiments performed with UlaR and YiaJ and probes corresponding to the specific promoters indicated that l-ascorbate-6-phosphate is the effector molecule recognized by both regulators, since binding of the repressors to their recognition sites was impaired by the presence of this compound. We demonstrated that in K. pneumoniae cells l-ascorbate-6-phosphate is formed only by the action of the UlaABC phosphotransferase system. This finding explains why strains that lack the ula genetic system and therefore are unable to form the inducer intracellularly cannot efficiently use this vitamin as a carbon source under either anaerobic or aerobic conditions. Thus, efficient aerobic metabolism of l-ascorbate in K. pneumoniae is dependent on the presence of both the yiaK-S and ula systems. The expression of the yiaK-S operon, but not the expression of the ula regulon, is controlled by oxygen availability. Both systems are regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex and by IHF.

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Effects of over-expression of glycerol dehydrogenase and 1,3-propanediol oxidoreductase on bioconversion of glycerol into 1,3-propandediol by Klebsiella pneumoniae under micro-aerobic conditions

Bioprocess and Biosystems Engineering ◽

10.1007/s00449-008-0250-4 ◽

2008 ◽

Vol 32 (3) ◽

pp. 313-320 ◽

Cited By ~ 31

Author(s):

Li Zhao ◽

Yu Zheng ◽

Xingyuan Ma ◽

Dongzhi Wei

Keyword(s):

Klebsiella Pneumoniae ◽

Glycerol Dehydrogenase ◽

Aerobic Conditions ◽

Over Expression

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Propanediol oxidoreductases of Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. Aspects of interspecies structural and regulatory differentiation

Biochemical Journal ◽

10.1042/bj2310145 ◽

1985 ◽

Vol 231 (1) ◽

pp. 145-149 ◽

Cited By ~ 1

Author(s):

J Ros ◽

J Aguilar

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Klebsiella Pneumoniae ◽

Salmonella Typhimurium ◽

Peptide Mapping ◽

Considerable Extent ◽

Anaerobic Conditions ◽

Aerobic Conditions ◽

One Dimensional ◽

E Coli

The enzyme propanediol oxidoreductase, which converts the lactaldehyde formed in the metabolism of fucose and rhamnose into propane-1,2-diol under anaerobic conditions, was investigated in Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. Structural analysis indicated that the enzymes of E. coli and K. pneumoniae have the same Mr and pI, whereas that of Salm. typhimurium also has the same Mr but a slightly different pI. One-dimensional peptide mapping showed identity between the E. coli and K. pneumoniae enzymes when digested with α-chymotrypsin, Staphylococcus aureus V8 proteinase or subtilisin. In the case of Salm. typhimurium, this held only for the subtilisin-digested enzymes, indicating that the hydrophobic regions were preserved to a considerable extent. Anaerobically, the three species induced an active propanediol oxidoreductase when grown on fucose or rhamnose. An inactive propanediol oxidoreductase was induced in Salm. typhimurium by either fucose or rhamnose under aerobic conditions, and this was activated once anaerobiosis was established. An inactive propanediol oxidoreductase was also induced in E. coli under aerobic conditions, but only by growth on fucose. The inactive enzyme was not induced by either of the sugars in K. pneumoniae.

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