scholarly journals A tunable l-arabinose-inducible expression plasmid for the acetic acid bacterium Gluconobacter oxydans

2020 ◽  
Vol 104 (21) ◽  
pp. 9267-9282
Author(s):  
Philipp Moritz Fricke ◽  
Tobias Link ◽  
Jochem Gätgens ◽  
Christiane Sonntag ◽  
Maike Otto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Stationary Phase ◽  
Gene Knockout ◽  
Glucose Dehydrogenase ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacteria ◽  
Acetic Acid Bacterium ◽  
Basal Expression ◽  
Fold Induction ◽  
Membrane Bound

Abstract The acetic acid bacterium (AAB) Gluconobacter oxydans incompletely oxidizes a wide variety of carbohydrates and is therefore used industrially for oxidative biotransformations. For G. oxydans, no system was available that allows regulatable plasmid-based expression. We found that the l-arabinose-inducible PBAD promoter and the transcriptional regulator AraC from Escherichia coli MC4100 performed very well in G. oxydans. The respective pBBR1-based plasmids showed very low basal expression of the reporters β-glucuronidase and mNeonGreen, up to 480-fold induction with 1% l-arabinose, and tunability from 0.1 to 1% l-arabinose. In G. oxydans 621H, l-arabinose was oxidized by the membrane-bound glucose dehydrogenase, which is absent in the multi-deletion strain BP.6. Nevertheless, AraC-PBAD performed similar in both strains in the exponential phase, indicating that a gene knockout is not required for application of AraC-PBAD in wild-type G. oxydans strains. However, the oxidation product arabinonic acid strongly contributed to the acidification of the growth medium in 621H cultures during the stationary phase, which resulted in drastically decreased reporter activities in 621H (pH 3.3) but not in BP.6 cultures (pH 4.4). These activities could be strongly increased quickly solely by incubating stationary cells in d-mannitol-free medium adjusted to pH 6, indicating that the reporters were hardly degraded yet rather became inactive. In a pH-controlled bioreactor, these reporter activities remained high in the stationary phase (pH 6). Finally, we created a multiple cloning vector with araC-PBAD based on pBBR1MCS-5. Together, we demonstrated superior functionality and good tunability of an AraC-PBAD system in G. oxydans that could possibly also be used in other AAB. Key points • We found the AraC-PBADsystem from E. coli MC4100 was well tunable in G. oxydans. •  In the absence of AraC orl-arabinose, expression from PBADwas extremely low. • This araC-PBADsystem could also be fully functional in other acetic acid bacteria.

Identifying membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria that produce lactobionic and cellobionic acids

2019 ◽  
Vol 83 (6) ◽  
pp. 1171-1179 ◽  
Author(s):  
Takaaki Kiryu ◽  
Taro Kiso ◽  
Daisuke Koma ◽  
Shigemitsu Tanaka ◽  
Hiromi Murakami
Keyword(s):  
Acetic Acid ◽  
Glucose Dehydrogenase ◽  
Acetic Acid Bacteria ◽  
Membrane Bound

scholarly journals Characterization and inactivation of the membrane-bound polyol dehydrogenase in Gluconobacter oxydans DSM 7145 reveals a role in meso-erythritol oxidation

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1890-1899 ◽  
Author(s):  
Jörn Voss ◽  
Armin Ehrenreich ◽  
Wolfgang Liebl
Keyword(s):  
Acetic Acid ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacteria ◽  
Second Phase ◽  
Growth Substrate ◽  
Whole Cell ◽  
Polyol Dehydrogenase ◽  
Membrane Bound ◽  
Two Stages ◽  
Substrate Spectrum

The growth of Gluconobacter oxydans DSM 7145 on meso-erythritol is characterized by two stages: in the first stage, meso-erythritol is oxidized almost stoichiometrically to l-erythrulose according to the Bertrand–Hudson rule. The second phase is distinguished from the first phase by a global metabolic change from membrane-bound meso-erythritol oxidation to l-erythrulose assimilation with concomitant accumulation of acetic acid. The membrane-associated erythritol-oxidizing enzyme was found to be encoded by a gene homologous to sldA known from other species of acetic acid bacteria. Disruption of this gene in the genome of G. oxydans DSM 7145 revealed that the membrane-bound polyol dehydrogenase not only oxidizes meso-erythritol but also has a broader substrate spectrum which includes C3–C6 polyols and d-gluconate and supports growth on these substrates. Cultivation of G. oxydans DSM 7145 on different substrates indicated that expression of the polyol dehydrogenase was not regulated, implying that the production of biomass of G. oxydans to be used as whole-cell biocatalysts in the biotechnological conversion of meso-erythritol to l-erythrulose, which is used as a tanning agent in the cosmetics industry, can be conveniently carried out with glucose as the growth substrate.

scholarly journals Highly tunable TetR-dependent target gene expression in the acetic acid bacterium Gluconobacter oxydans

2021 ◽  
Author(s):  
Philipp Moritz Fricke ◽  
Martha Lürkens ◽  
Max Hünnefeld ◽  
Christiane K. Sonntag ◽  
Michael Bott ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acetic Acid ◽  
Dna Binding ◽  
Target Gene ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacterium ◽  
Antibiotics Resistance ◽  
Target Gene Expression ◽  
Fold Induction ◽  
Plasmid Backbone

Abstract For the acetic acid bacterium (AAB) Gluconobacter oxydans only recently the first tight system for regulatable target gene expression became available based on the heterologous repressor-activator protein AraC from Escherichia coli and the target promoter ParaBAD. In this study, we tested pure repressor-based TetR- and LacI-dependent target gene expression in G. oxydans by applying the same plasmid backbone and construction principles that we have used successfully for the araC-ParaBAD system. When using a pBBR1MCS-5-based plasmid, the non-induced basal expression of the Tn10-based TetR-dependent expression system was extremely low. This allowed calculated induction ratios of up to more than 3500-fold with the fluorescence reporter protein mNeonGreen (mNG). The induction was highly homogeneous and tunable by varying the anhydrotetracycline concentration from 10 to 200 ng/mL. The already strong reporter gene expression could be doubled by inserting the ribosome binding site AGGAGA into the 3’ region of the Ptet sequence upstream from mNG. Alternative plasmid constructs used as controls revealed a strong influence of transcription terminators and antibiotics resistance gene of the plasmid backbone on the resulting expression performance. In contrast to the TetR-Ptet-system, pBBR1MCS-5-based LacI-dependent expression from PlacUV5 always exhibited some non-induced basal reporter expression and was therefore tunable only up to 40-fold induction by IPTG. The leakiness of PlacUV5 when not induced was independent of potential read-through from the lacI promoter. Protein-DNA binding simulations for pH 7, 6, 5, and 4 by computational modeling of LacI, TetR, and AraC with DNA suggested a decreased DNA binding of LacI when pH is below 6, the latter possibly causing the leakiness of LacI-dependent systems hitherto tested in AAB. In summary, the expression performance of the pBBR1MCS-5-based TetR-Ptet system makes this system highly suitable for applications in G. oxydans and possibly in other AAB. Key Points • A pBBR1MCS-5-based TetR-Ptet system was tunable up to more than 3500-fold induction. • A pBBR1MCS-5-based LacI-PlacUV5 system was leaky and tunable only up to 40-fold. • Modeling of protein-DNA binding suggested decreased DNA binding of LacI at pH < 6.

scholarly journals Microbial Production of Glyceric Acid, an Organic Acid That Can Be Mass Produced from Glycerol

2009 ◽  
Vol 75 (24) ◽  
pp. 7760-7766 ◽  
Author(s):  
Hiroshi Habe ◽  
Yuko Shimada ◽  
Toshiharu Yakushi ◽  
Hiromi Hattori ◽  
Yoshitaka Ano ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Growth Parameters ◽  
Operating Time ◽  
Enantiomeric Excess ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacteria ◽  
Culture Broth ◽  
Glyceric Acid ◽  
Bacterial Strains ◽  
Biotechnological Production

ABSTRACT Glyceric acid (GA), an unfamiliar biotechnological product, is currently produced as a small by-product of dihydroxyacetone production from glycerol by Gluconobacter oxydans. We developed a method for the efficient biotechnological production of GA as a target compound for new surplus glycerol applications in the biodiesel and oleochemical industries. We investigated the ability of 162 acetic acid bacterial strains to produce GA from glycerol and found that the patterns of productivity and enantiomeric GA compositions obtained from several strains differed significantly. The growth parameters of two different strain types, Gluconobacter frateurii NBRC103465 and Acetobacter tropicalis NBRC16470, were optimized using a jar fermentor. G. frateurii accumulated 136.5 g/liter of GA with a 72% d-GA enantiomeric excess (ee) in the culture broth, whereas A. tropicalis produced 101.8 g/liter of d-GA with a 99% ee. The 136.5 g/liter of glycerate in the culture broth was concentrated to 236.5 g/liter by desalting electrodialysis during the 140-min operating time, and then, from 50 ml of the concentrated solution, 9.35 g of GA calcium salt was obtained by crystallization. Gene disruption analysis using G. oxydans IFO12528 revealed that the membrane-bound alcohol dehydrogenase (mADH)-encoding gene (adhA) is required for GA production, and purified mADH from G. oxydans IFO12528 catalyzed the oxidation of glycerol. These results strongly suggest that mADH is involved in GA production by acetic acid bacteria. We propose that GA is potentially mass producible from glycerol feedstock by a biotechnological process.

scholarly journals Formation of 4-Keto-D-aldopentoses and 4-Pentulosonates (4-Keto-D-pentonates) with Unidentified Membrane-Bound Enzymes from Acetic Acid Bacteria

2011 ◽  
Vol 75 (9) ◽  
pp. 1801-1806 ◽  
Author(s):  
Osao ADACHI ◽  
Roque A. HOURS ◽  
Emiko SHINAGAWA ◽  
Yoshihiko AKAKABE ◽  
Toshiharu YAKUSHI ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Bacteria ◽  
Membrane Bound ◽  
Membrane Bound Enzymes

scholarly journals Saccharibacter floricola gen. nov., sp. nov., a novel osmophilic acetic acid bacterium isolated from pollen

2004 ◽  
Vol 54 (6) ◽  
pp. 2263-2267 ◽  
Author(s):  
Yasuko Jojima ◽  
Yasuhiro Mihara ◽  
Sonoko Suzuki ◽  
Kenzo Yokozeki ◽  
Shigeru Yamanaka ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Phylogenetic Analyses ◽  
Acetic Acid Bacteria ◽  
Cellular Fatty Acid ◽  
Acetic Acid Bacterium ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Growth Properties ◽  
Novel Genus And Species ◽  
Straight Chain Acid

Three Gram-negative, aerobic, rod-shaped bacterial strains were isolated, from the pollen of Japanese flowers, as producers of xylitol; these strains were subjected to a polyphasic taxonomic study. Phylogenetic analyses of the 16S rRNA gene sequences demonstrated that these three isolates formed a new cluster within a group of acetic acid bacteria in the α-Proteobacteria. The characteristics of the three isolates were as follows: (i) their predominant quinone was Q-10; (ii) their cellular fatty acid profile contained major amounts of 2-hydroxy acids and an unsaturated straight-chain acid (C18 : 1 ω7c); and (iii) their DNA G+C contents were in the range 51·9–52·3 mol%, which is around the lower limit of the reported range for the genera of acetic acid bacteria. The negligible or very weak productivity of acetic acid from ethanol and the osmophilic growth properties distinguished these strains from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the three isolates should be classified within a novel genus and species with the proposed name Saccharibacter floricola gen. nov., sp. nov. The type strain is strain S-877T (=AJ 13480T=JCM 12116T=DSM 15669T).

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