•Gluconic acid and its derivatives, uses and production methods.•Importance of gluconic acid derivatives as food additives.•Use of renewable resources for the biobased production of gluconic ...acid.•Comparison between fungi and bacteria for gluconic acid bioproduction.•Optimized gluconic acid production by genetically modified acetic acid bacteria.
Agro-industrial by-products and wastes pose serious, widespread problems with considerable economic and environmental consequences in developed countries. However, many of the by-products contain large amounts of sugars that make them potentially excellent raw materials for the biotechnological production of added value products; in particular, by-products from perishables such as fruits can be highly useful for this aim. The growing significance and demand for gluconic acid have promoted an interest in integrating both issues as a strategy for the revalorization of these resources.
The pertinence of this strategy can be better understood by examining the properties of gluconic acid and its derivatives and their uses and production methods, especially biotechnological methods, to update the existing reviews on the topic.
Future advances in this direction may be promoted by the development of genetically modified organisms for the generation of new technological processes and the optimization of existing ones. Particular attention is paid to acetic acid bacteria.
•HAc could promote 2-KGA accumulation in the process of glucose with G. oxydans.•The yield of 2-KGA was increased from 38.0% to 80.5% with addition of 5 g/L HAc.•A 2-KGA yield of 83.5% was achieved ...using enzymatic hydrolysate as feedstock.
An acetic acid-mediated bio-oxidation strategy with Gluconobacter oxydans was developed to produce valuable 2-ketogluconic acid from lignocellulosic biomass. Metabolically, glucose is firstly oxidized to gluconic acid and further oxidized to 2-keto-gluconic acid by Gluconobacter oxydans. As a specific inhibitor for microbial fermentation generated from pretreatment, acetic acid was validated to have a down-regulated effect on bio-oxidizing glucose to gluconic acid. Nevertheless, it significantly facilitated 2-keto-gluconic acid accumulation and improved gluconate dehydrogenase activity. In the presence of 5.0 g/L acetic acid, the yield of 2-keto-gluconic acid increased from 38.0% to 80.5% using pure glucose as feedstock with 1.5 g/L cell loading. Meanwhile, 44.6 g/L 2-keto-gluconic acid with a yield of 83.5% was also achieved from the enzymatic hydrolysate. 2-keto-gluconic acid production, found in this study, laid a theoretical foundation for the industrial production of 2-keto-gluconic acid by Gluconobacter oxydans using lignocellulosic materials.
Over the past 3 years, glucose oxidase (GOx) has aroused great research interest in the context of cancer treatment due to its inherent biocompatibility and biodegradability, and its unique catalytic ...properties against β‐d‐glucose. GOx can effectively catalyze the oxidation of glucose into gluconic acid and hydrogen peroxide. This process depletes oxygen levels, resulting in elevated acidity, hypoxia, and oxidative stress in the tumor microenvironment. All of these changes can be readily harnessed to develop a multimodal synergistic cancer therapy by combining GOx with other therapeutic approaches. Herein, the representative studies of GOx‐instructed multimodal synergistic cancer therapy are introduced, and their synergistic mechanisms are discussed systematically. The current challenges and future prospects to advance the development of GOx‐based nanomedicines in this cutting‐edge research area are highlighted.
The rapid developments in GOx‐instructed multimodal synergistic cancer therapy and their synergistic mechanisms are systematically discussed; the current challenges and future prospects are also highlighted to expedite the development of GOx‐based nanomedicines.
Gluconic acid (GA) has been widely applied as a value-added platform biochemical, and the whole-cell catalysis of glucose for GA bioproduction by Gluconobacter sp. NL71 has shown great commercial ...competitiveness. In bioprocess, GA will be further dehydrogenated by Gluconobacter sp. NL71 to generate the by-products of 2-/5-/2,5-ketogluconic acid (keto-GA) that leads yield decrease and troublesome impurity problems. In this paper, the bi-directional switch regulation strategy of three metals on whole-cell catalysis was explored and developed to cleaner production of GA without by-products. With the couple dance performance of three metals of Ca2+, Mg2+ and Cu2+, a precise two-switch controlling on whole-cell catalysis and bio-oxidation was successfully achieved that results in the complete bio-conversion of glucose to GA without any keto-GA. Ca2+ and Mg2+ plays a positive activator to glucose dehydrogenation to GA, while Cu2+ works as a strong negative inhibitor to GA further oxidation to 2-/5-/2,5-keto-GA. Under the intensification with the superimposition of 100 mmol/L Mg2+, 60 mmol Ca2+ and the auxiliary regulation with 40 mmol Cu2+, 52.3 g/L glucose was transformed into 48.9 g/L GA by whole-cell catalysis with the yield of 93.5%. 58.4 g/L glucose obtained by enzymatic hydrolysate of sulfuric acid-pretreated corncob could effectively produce 54.2 g/L GA without by-product. The results verify that bi-directional switch regulation of three metals could vigorously promote the industrial bioproduction of GA, as well as provide some technical approach for fermentation engineering controlling.
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•Bi-directional regulation on whole-cell catalysis of glucose for GA bioproduction.•54.2 g/L GA with 93% yield were produced from enzymatic hydrolysate of LCB.•The effect of metal ions on dehydrogenase activity of NL71 were explored.
Four-component coupling of amines, aldehydes, 1,3-dicarbonyl compounds, and nitromethane has been achieved in gluconic acid aqueous solution (GAAS) to produce polysubstituted pyrroles in high yield. ...Gluconic acid aqueous solution could be recycled and reused several times without significant loss of its efficiency.
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Glucose is a key energy supplier and nutrient for tumor growth. Herein, inspired by the glucose oxidase (GOx)‐assisted conversion of glucose into gluconic acid and toxic H2O2, a novel treatment ...paradigm of starving‐like therapy is developed for significant tumor‐killing effects, more effective than conventional starving therapy by only cutting off the energy supply. Furthermore, the generated acidic H2O2 can oxidize l‐Arginine (l‐Arg) into NO for enhanced gas therapy. By using hollow mesoporous organosilica nanoparticle (HMON) as a biocompatible/biodegradable nanocarrier for the co‐delivery of GOx and l‐Arg, a novel glucose‐responsive nanomedicine (l‐Arg‐HMON‐GOx) has been for the first time constructed for synergistic cancer starving‐like/gas therapy without the need of external excitation, which yields a remarkable H2O2–NO cooperative anticancer effect with minimal adverse effect.
Synergistic therapy: A biocompatible and biodegradable nanomedicine based on glucose oxidase/l‐arginine co‐loaded hollow mesoporous organosilica nanoparticles has been successfully constructed for converting intratumoral glucose into high concentrations of toxic hydrogen peroxide and nitric oxide. An endogenous synergistic cancer therapy for efficient tumor eradication has been developed.
Chemodynamic therapy (CDT), enabling selective therapeutic effects and low side effect, attracts increasing attention in recent years. However, limited intracellular content of H2O2 and acid at the ...tumor site restrains the lasting Fenton reaction and thus the anticancer efficacy of CDT. Herein, a nanoscale Co–ferrocene metal–organic framework (Co‐Fc NMOF) with high Fenton activity is synthesized and combined with glucose oxidase (GOx) to construct a cascade enzymatic/Fenton catalytic platform (Co‐Fc@GOx) for enhanced tumor treatment. In this system, Co‐Fc NMOF not only acts as a versatile and effective delivery cargo of GOx molecules to modulate the reaction conditions, but also possesses excellent Fenton effect for the generation of highly toxic •OH. In the tumor microenvironment, GOx delivered by Co‐Fc NMOF catalyzes endogenous glucose to gluconic acid and H2O2. The intracellular acidity and the on‐site content of H2O2 are consequently promoted, which in turn favors the Fenton reaction of Co‐Fc NMOF and enhances the generation of reactive oxygen species (ROS). Both in vitro and in vivo results demonstrate that this cascade enzymatic/Fenton catalytic reaction triggered by Co‐Fc@GOx nanozyme enables remarkable anticancer properties.
A cascade nanozyme, named Co–ferrocene, combined with glucose oxidase (Co‐Fc@GOx) is successfully constructed, presenting a unique cascade enzymatic/Fenton effect for promoted chemodynamic therapy. In this platform, the Co–ferrocene metal–organic framework (Co‐Fc NMOF) shows unique Fenton activity, and GOx molecules are delivered significantly and amplify the Fenton reaction. This study offers another potential therapeutic platform for synergetic cancer treatment.
To produce gluconic acid from sodium gluconate, three types of cell configurations of bipolar membrane electrodialysis (BMED) and two types of cell configurations of electrodialysis (ED) were applied ...and the factors such as the current variation, conversion rate, current efficiency and energy consumption were compared. The results indicated that the BMED2C–C cell configuration (two-chamber BMED with cation exchange membrane) had the better overall performance than the BMED2C-A configuration (two-chamber BMED with anion exchange membrane) and the BMED3C configuration (three-chamber BMED), and the ED3C configuration (three-chamber ED) had the better overall performance than ED4C configuration (four-chamber ED). An industrial production model was set, and the production cost of gluconic acid was estimated to be 0.25 US$/kg for BMED2C–C and 0.067 $/kg for ED3C, respectively. Taking account of the calculated value for sodium hydroxide, the cost of BMED2C–C will be 0.104 $/kg, which was less than the one of traditional production. Though ED3C has the lowest production cost, it produces the by-product sodium sulfate which needs to be handled further.
•Sodium gluconate is acidified into gluconic acid by BMED and ED.•BMED2C–C is the best choice within three BMED configurations.•ED3C is the better choice within two ED configurations.•ED3C is the best choice in all configurations with product cost 0.067$ per kilogram gluconic acid.
Efficient antimicrobials are urgently needed for the treatment of bacterial biofilms due to their resistance to traditional drugs. Photodynamic therapy (PDT) is a new strategy that has been used to ...combat bacteria and biofilms. Cationic photosensitizers, particularly cationic photodynamic nanoagents, are usually chosen to enhance photodynamic antimicrobial activity. However, positively charged nanoparticles (NPs) are beneficial to cellular internalization, which causes increased cell cytotoxicity. Herein, a pH‐sensitive photodynamic nanosystem is designed. Rose Bengal (RB) polydopamine (PDA) NPs are decorated in a layer‐by‐layer fashion with polymyxin B (PMB) and gluconic acid (GA) to generate functionally adaptive NPs (RB@PMB@GA NPs). RB@PMB@GA NPs remain negative at physiological pH and exhibit good biocompatibility. When RB@PMB@GA NPs are exposed to an acidic infectious environment, the surface charge of the NPs is, in turn, positively charged as a result of pH‐sensitive electrostatic interactions. This surface charge conversion allows the RB@PMB@GA to effectively bind to the surfaces of bacteria and enhance photoinactivation efficiency against gram‐negative bacteria. Most importantly, RB@PMB@GA NPs exhibit good biofilm penetration and eradication under acidic conditions. Furthermore, RB@PMB@GA NPs efficiently eliminate biofilm infections in vivo. This study provides a promising strategy for safely treating biofilm‐associated infections in vivo.
A pH‐sensitive photodynamic nanosystem is proposed. RB@PMB@GA nanoparticles (NPs) remain negatively charged at physiological pH and convert to be positively charged NPs in an acidic infectious environment. The conversion of the surface charge allows the NPs to effectively bind to the surfaces of negatively charged bacteria and significantly enhance their penetration and antibacterial photodynamic efficiency in biofilms of gram‐negative bacteria.
The root microbiome consists of commensal, pathogenic, and plant-beneficial microbes 1. Most members of the root microbiome possess microbe-associated molecular patterns (MAMPs) similar to those of ...plant pathogens 2. Their recognition can lead to the activation of host immunity and suppression of plant growth due to growth-defense tradeoffs 3, 4. We found that 42% of the tested root microbiota, including the plant growth-promoting rhizobacteria Pseudomonas capeferrum WCS358 5, 6 and Pseudomonas simiae WCS417 6, 7, are able to quench local Arabidopsis thaliana root immune responses that are triggered by flg22 8, an immunogenic epitope of the MAMP flagellin 9, suggesting that this is an important function of the root microbiome. In a screen for WCS358 mutants that lost their capacity to suppress flg22-induced CYP71A12pro:GUS MAMP-reporter gene expression, we identified the bacterial genes pqqF and cyoB in WCS358, which are required for the production of gluconic acid and its derivative 2-keto gluconic acid. Both WCS358 mutants are impaired in the production of these organic acids and consequently lowered their extracellular pH to a lesser extent than wild-type WCS358. Acidification of the plant growth medium similarly suppressed flg22-induced CYP71A12pro:GUS and MYB51pro:GUS expression, and the flg22-mediated oxidative burst, suggesting a role for rhizobacterial gluconic acid-mediated modulation of the extracellular pH in the suppression of root immunity. Rhizosphere population densities of the mutants were significantly reduced compared to wild-type. Collectively, these findings show that suppression of immune responses is an important function of the root microbiome, as it facilitates colonization by beneficial root microbiota.
•42% of the tested root microbiota are able to quench local root immune responses•Beneficial Pseudomonas can suppress root immunity by lowering environmental pH•Suppression of immunity facilitates root colonization by these beneficial microbes
Many plant-root-associated microbes can trigger plant defenses. Yu et al. show that the production of gluconic acid and its derivative 2-keto gluconic acid acidifies the plant growth medium, suppressing flg22-induced root immunity to facilitate colonization by beneficial root microbiota.
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