Inhibitory effects of glycerol on Gluconobacter oxydans

Ohrem, H. Leonhard; Voβ, Harald

doi:10.1007/bf00142939

Cited by 7 publications

(3 citation statements)

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“…Moreover, Ohrem and Voss showed that high glycerol concentration provoked cell elongation, interfering on cellular division, and Stasiak‐Rozanska et al also observed a great impact of glycerol concentration on growth. However, Ohrem and Merck analyzed separately glycerol inhibitory effects on cell and concluded that glycerol did not inhibit DHA production. In contrast, product inhibition in this process has been widely reported; bacterial growth rate decreases with DHA concentration, although total inhibition of growth does not block DHA production .…”

Section: Introductionmentioning

confidence: 99%

Dihydroxyacetone production from glycerol using Gluconobacter oxydans: Study of medium composition and operational conditions in shaken flasks

Morena

Acedos

Santos

et al. 2019

Biotechnology Progress

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The production of dihydroxyacetone from glycerol employing aerobic cultures of Gluconobacter oxydans is studied. Dihydroxyacetone is one of the most important value‐added products obtained from glycerol, a by‐product of biodiesel production. The effect of organic nitrogen source and initial substrate concentrations has been studied together with the possibility of product inhibition. Afterward, the influence of the main operating conditions (temperature, shaking speed, and initial biomass concentration) on in vivo glycerol dehydrogenase activity has also been considered. The results show no evidence of glycerol inhibition, but an important product inhibition was detected, which has been taken into account in a kinetic model for enzymatic activity description. In terms of operating conditions, pH was found to exert a great impact on glycerol conversion, being necessary to keep it above 4 to ensure complete glycerol conversion. The minimum temperature that maximized enzymatic activity was found to be 30°C. In addition, a surprising decoupling between biomass concentration and dihydroxyacetone production rate was observed when adding increasing nitrogen source concentrations at a fixed shaking speed. Glycerol dehydrogenase activity remains constant despite the increase in biomass concentration, contrary to what would be expected. This fact revealed the existence of a rate limiting factor, identified subsequently as oxygen transfer rate depending on the biomass concentration.

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Section: Introductionmentioning

confidence: 99%

Dihydroxyacetone production from glycerol using Gluconobacter oxydans: Study of medium composition and operational conditions in shaken flasks

Morena

Acedos

Santos

et al. 2019

Biotechnology Progress

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“…The production of DHA via a microbial pathway, achieved through aerobic fermentation by acetic acid bacteria, is more economical and environmentally friendly than the production via a chemical pathway . Gluconobacter strains are the most common acetic acid bacteria for DHA production . The conversion of glycerol to DHA by Gluconobacter strains is performed by membrane‐bound, pyrroloquinoline quinone (PQQ)‐dependent glycerol dehydrogenase in an oxidative reaction …”

Section: Introductionmentioning

confidence: 99%

Effect of NaCl removal from biodiesel‐derived crude glycerol by ion exchange to enhance dihydroxyacetone production by Gluconobacter thailandicus in minimal medium

Jittjang

Jiratthiticheep

Kajonpradabkul

et al. 2019

J of Chemical Tech & Biotech

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BACKGROUND: Chloride salts are major impurities in biodiesel-derived crude glycerol that can impact dihydroxyacetone (DHA) production. Ion exchange was performed to remove these salts. DHA production from crude glycerol was investigated, before and after an ion exchange treatment in shake-flask fermentation and batch fermentation. DHA production from treated crude glycerol was further studied in fed-batch fermentation. RESULTS:In shake-flask fermentation, the DHA production from the treated crude glycerol was 56.1 ± 1.87 g L −1 . This is 16.2 g L −1 (41%) higher than the DHA production from crude glycerol without the ion exchange treatment at 72 h. The DHA production from the treated crude glycerol was 61.9 ± 2.57 g L −1 , with a DHA production yield (DHA moles per glycerol moles) of > 99 ± 4.4% at 138 h in the batch fermentation. The DHA concentration from the treated crude glycerol was 8.1 g L −1 higher than in the crude glycerol fermentation. In fed-batch fermentation, the DHA production was not significantly higher than that in the batch fermentation due to product inhibition when the DHA concentration reaches 65.05 ± 4.52 g L −1 or more, after 156 h.CONCLUSION: This study shows that salt impurities in crude glycerol negatively impact the DHA production by Gluconobacter thailandicus TBRC 3351 cultured in crude glycerol minimal media. Removing chloride salts from crude glycerol can improve the DHA yield, both in the shake-flask and the batch fermentation. Fed-batch fermentation can also increase the DHA production, but to a lesser extent because of the product inhibition mechanism.

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“…In recent years, large-scale bio-production of biodiesel generates large amount of glycerol as by-product, which can be a promising and abundant carbon sources for industrial microbes (da Silva et al, 2009). P. putida S12 can efficiently use crude glycerol as a feedstock without effects of growth inhibition that have caused harmful effects to a number of other bacteria (da Silva et al, 2009;Ohrem and Voβ, 1996;Verhoef et al, 2014). In P. putida, glycerol metabolizes via a glycerol kinase (GlpK) and glycerol phosphate dehydrogenase (GlpD) to produce dihydroxyacetone phosphate which later enters into central metabolism (Nikel et al, 2014a).…”

Section: Introductionmentioning

confidence: 99%

Metabolic engineering and bio-electrochemical synthesis in Pseudomonas putida KT2440 for the production of p-hydroxybenzoate and 2-ketogluconate

Yu¹

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Bio-based chemicals have drawn research interests due to the need for sustainable development. Aromatics and the derived compounds are an important class of chemicals that are mostly derived from fossil resources. Microbial bio-production can produce many compounds from renewable feedstocks to reduce the current heavy dependency on fossil resources. The aromatic compound para-hydroxybenzoate (PHBA) is used to make parabens and high-value polymers (liquid crystal polymer). Biologically, this chemical can be derived from the shikimate pathway, the central pathway for the biosynthesis of aromatic amino acids in bacteria, plants and fungi and some protozoa. In recent years, the gram-negative soil bacterium Pseudomonas putida is becoming an interesting chassis for industrial biotechnology. The production of PHBA in recombinant P. putida KT2440 was engineered by overexpressing the chorismate lyase Ubic from Escherichia coli and a feedback resistant 3-Deoxy-D-arabinoheptulosonate 7-phosphate synthase (AroG D146N).Additionally, the pathways competing for the substrate chorismate (trpE and pheA) and the PHBA degradation pathway (pobA) were eliminated. Finally, deletion of the glucose metabolism repressor hexR led to an increase in erythrose-4-phosphate and NADPH supply. This resulted in a maximum titre of 1.73 g L -1 and a carbon yield of 18.1 % (C-mol) in a non-optimized fed-batch fermentation. This is to date the highest PHBA concentration produced by P. putida using a chorismate lyase route.Large-scale aerobic fermentations are more expensive due to the limiting gas transfer and lead to substrate loss in the form of CO2, whereas anaerobic processes are easier to scale up and achieve high carbon yield. In the case of aromatics, anaerobic production could be beneficial. Microbial electrosynthesis is an emerging technology for biosynthesis of chemicals and fuels by microorganisms in an anaerobic bio-electrochemical system (BES).These systems can provide electrons to electroactive microbes for reductive production processes in the cathode or drain excessive electrons in oxidative production processes in the anode. P. putida was tested for the first time for its ability to perform anoxic metabolism in BES with ferricyanide as the mediator and anode as the electron sink. A dual-phase fermentation was employed, where the cells grew aerobically in the first phase and then performed an anaerobic oxidation process in the second phase. In this way, P. putida ) with a 9 % lower productivity than that in TB-grown cells. The proteomics analysis suggested the GADH enzyme complex (PP_3382, PP_3383, and PP_3384) overexpression was limited by the subunit PP_3382 biosynthesis. The slight upregulation of PP_3382 in glycerol-grown cells may contribute to its better performance in this condition, suggesting that the aerobic growth condition can be optimized for a better performance in bio-electrochemical production.In summary, using a chorismate lyase route in P. putida is a suitable strategy to produce aromatics. The use of a bio-...

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Inhibitory effects of glycerol on Gluconobacter oxydans

Cited by 7 publications

References 7 publications

Dihydroxyacetone production from glycerol using Gluconobacter oxydans: Study of medium composition and operational conditions in shaken flasks

Dihydroxyacetone production from glycerol using Gluconobacter oxydans: Study of medium composition and operational conditions in shaken flasks

Effect of NaCl removal from biodiesel‐derived crude glycerol by ion exchange to enhance dihydroxyacetone production by Gluconobacter thailandicus in minimal medium

Metabolic engineering and bio-electrochemical synthesis in Pseudomonas putida KT2440 for the production of p-hydroxybenzoate and 2-ketogluconate

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