title: Group II intron-mediated deletion of lactate dehydrogenase gene in an isolated 1,3-propanediol producer Hafnia alvei AD27.
abstract: 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.
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Celińska
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Drożdżyńska
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Wita
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Juzwa
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Białas
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Czaczyk
authors.affiliation: Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland.
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Grajek
mesh_terms: D001419:Bacteria / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D017353:Gene Deletion; D005990:Glycerol / Q000494:pharmacology; D020611:Hafnia alvei / Q000378:metabolism*; D007438:Introns / Q000235:genetics*; D007770:L-Lactate Dehydrogenase / Q000235:genetics*; D019344:Lactic Acid / Q000096:biosynthesis / Q000378:metabolism; D010084:Oxidation-Reduction; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D011409:Propylene Glycols; D019344:Lactic Acid; D000431:Ethanol; C041787:1,3-propanediol; D007770:L-Lactate Dehydrogenase; D005990:Glycerol
keywords: 1,3-propanediol; Enterobacteriaceae; gene knock-out; group II intron; lactate dehydrogenase; metabolic engineering