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Hypothetical glycerol pathways of newly isolated strains capable of 1,3-propanediol production

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Leja K., Samul D., Drożdżyńska A., Myszka K., Juzwa W., Pawlicka J., Czaczyk K.

2014

vol. 61

issue 4

759-763

Study presented here demonstrates the ability of three newly isolated strains, obtained from environmental probes (manure, bottom sediment, and food waste) and identified as Clostridium bifermentans, Clostridium butyricum, and Hafnia alvei, to synthesize 1,3-propanediol (1,3-PD), organic acids (such as lactic, acetic, fumaric, succinic, and butyric acids), and ethanol from glycerol. The production of 1,3-PD as well as the glycerol pathways in C. bifermentans and H. alvei cells have not been investigated and described yet by others. Moreover, there is no data in the available literature on the products of glycerol utilization by H. alvei and there is only some incoherent data (mainly from the first half of the twentieth century) about the ability of C. bifermentans to carry out glycerol degradation. Additionally, this study presents complete hypothetical glycerol pathways and the basic fermentation kinetic parameters (such as yield and productivity) for both strains as well as for the newly isolated C. butyricum strain.

Group II intron-mediated deletion of lactate dehydrogenase gene in an isolated 1,3-propanediol producer Hafnia alvei AD27

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Celińska E., Drożdżyńska A., Wita A., Juzwa W., Białas W., Czaczyk K., Grajek W.

2017

vol. 64

issue 1

123-133

Our previous studies showed that glycerol fermentation by Hafnia alvei AD27 strain was accompanied by formation of high quantities of lactate. The ultimate aim of this work was the elimination of excessive lactate production in the 1,3-propanediol producer cultures. Group II intron-mediated deletion of ldh (lactate dehydrogenase) gene in an environmental isolate of H. alvei AD27 strain was conducted. The effect of the Δldh genotype in H. alvei AD27 strain varied depending on the culture medium applied. Under lower initial glycerol concentration (20 gL-1), lactate and 1,3-propanediol production was fully abolished, and the main carbon flux was directed to ethanol synthesis. On the other hand, at higher initial glycerol concentrations (40 gL-1), 1,3-propanediol and lactate production was recovered in the recombinant strain. The final titers of 1,3-propanediol and ethanol were similar for the recombinant and the WT strains, while the Δldh genotype displayed significantly decreased lactate titer. The by-products profile was altered upon ldh gene deletion, while glycerol utilization and biomass accumulation remained unaltered. As indicated by flow-cytometry analyses, the internal pH was not different for the WT and the recombinant Δldh strains over the culture duration, however, the WT strain was characterized by higher redox potential.

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2 Acta Biochimica Polonica

1 2017

1 2014

2 Czaczyk K.

2 Drożdżyńska A.

2 Juzwa W.

1 Białas W.

1 Celińska E.

1 Grajek W.

1 Leja K.

1 Myszka K.

1 Pawlicka J.

1 Samul D.

1 Wita A.

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Hypothetical glycerol pathways of newly isolated strains capable of 1,3-propanediol production

Group II intron-mediated deletion of lactate dehydrogenase gene in an isolated 1,3-propanediol producer Hafnia alvei AD27