Glucose oxidase è un enzima che catalizza l'ossidazione del glucosio in acido gluconico e perossido di idrogeno. Viene ampiamente utilizzato in diverse applicazioni industriali, inclusi i processi alimentari, la diagnostica e i cosmetici, per la sua capacità di regolare i livelli di glucosio e, in alcuni casi, di stabilizzare i composti sensibili alla luce. Nel contesto della stabilizzazione della luce, la glucosio ossidasi può aiutare a ridurre i danni ossidativi causati dall'esposizione alla luce, migliorando così la durata e la stabilità di alcuni prodotti, in particolare nei cosmetici e nei prodotti per la cura della persona.

Composizione chimica e struttura

• Struttura dell'enzima: La glucosio ossidasi è una glicoproteina composta da aminoacidi, con un gruppo eme che facilita l'ossidazione del glucosio. L'enzima funziona utilizzando ossigeno per ossidare il glucosio, producendo perossido di idrogeno e acido gluconico come sottoprodotti.
• Sito attivo: Il sito attivo dell'enzima si lega al glucosio e facilita la reazione di ossidazione, rilasciando perossido di idrogeno, che gioca un ruolo nel controllare i processi ossidativi negli ambienti sensibili alla luce.

Funzione come stabilizzante della luce

La glucosio ossidasi può agire come stabilizzante della luce riducendo la presenza di radicali liberi e perossido di idrogeno che si generano con l'esposizione alla luce. Questa riduzione dello stress ossidativo aiuta a:

• Prevenire l'ossidazione foto-indotta: Ossidando il glucosio e producendo perossido di idrogeno in modo controllato, la glucosio ossidasi può ridurre gli effetti dannosi dell'esposizione alla luce sui composti sensibili.
• Migliorare la stabilità delle formulazioni: Nei cosmetici e nei prodotti per la cura della persona, questo enzima aiuta a prevenire la degradazione degli ingredienti attivi o dei composti sensibili in formulazioni che sono suscettibili al degrado indotto dalla luce.
• Prolungare la durata del prodotto: Stabilizzando i componenti sensibili alla luce, la glucosio ossidasi aiuta a prolungare la durata dei prodotti esposti alla luce durante lo stoccaggio o l'uso.

Applicazioni

Cosmetici e prodotti per la cura della persona

• Ingredienti sensibili alla luce: Nelle formulazioni contenenti ingredienti sensibili alla luce, come le vitamine (es. vitamina C), la glucosio ossidasi può aiutare a mantenere la loro stabilità riducendo i danni ossidativi.
• Conservazione: Viene utilizzata nei prodotti cosmetici come creme, sieri e lozioni per preservare la loro efficacia e garantire che gli ingredienti attivi non si degradino rapidamente quando esposti alla luce.
• Prodotti anti-invecchiamento: Nelle formulazioni anti-invecchiamento, la glucosio ossidasi può proteggere gli ingredienti delicati dalla degradazione, preservando i benefici anti-invecchiamento.

CAS   9001-37-0   EC number   232-601-0

Industria alimentare

• Controllo dell'ossidazione: Viene utilizzata nei prodotti alimentari per controllare l'ossidazione, specialmente nei prodotti sensibili alla luce, come succhi di frutta e bevande, aiutando a mantenere la freschezza e prolungare la durata del prodotto.

Farmaceutici

• Stabilizzazione dei principi attivi: Nelle formulazioni farmaceutiche, la glucosio ossidasi può essere utilizzata per stabilizzare gli ingredienti attivi sensibili alla luce, garantendone la potenza e l'efficacia durante tutta la durata del prodotto.

Considerazioni ambientali e di sicurezza

• Biodegradabilità: La glucosio ossidasi è un enzima naturale ed è biodegradabile, rendendola ecocompatibile quando smaltita correttamente.
• Profilo di sicurezza: Generalmente considerata sicura per l'uso nei cosmetici, nei prodotti per la cura della persona e negli alimenti, la glucosio ossidasi è non tossica. Tuttavia, è importante utilizzarla nelle concentrazioni appropriate poiché quantità eccessive di perossido di idrogeno possono causare irritazioni.
• Sostenibilità: Poiché la glucosio ossidasi è un enzima naturale, può essere ottenuta in modo sostenibile, in particolare se derivata da fonti non OGM, offrendo un'alternativa ecologica agli stabilizzatori della luce sintetici.

Bibliografia__________________________________________________________________________

Bankar SB, Bule MV, Singhal RS, Ananthanarayan L. Glucose oxidase--an overview. Biotechnol Adv. 2009 Jul-Aug;27(4):489-501. doi: 10.1016/j.biotechadv.2009.04.003. 

Abstract. Glucose oxidase (beta-D-glucose:oxygen 1-oxidoreductase; EC 1.1.2.3.4) catalyzes the oxidation of beta-D-glucose to gluconic acid, by utilizing molecular oxygen as an electron acceptor with simultaneous production of hydrogen peroxide. Microbial glucose oxidase is currently receiving much attention due to its wide applications in chemical, pharmaceutical, food, beverage, clinical chemistry, biotechnology and other industries. Novel applications of glucose oxidase in biosensors have increased the demand in recent years. Present review discusses the production, recovery, characterization, immobilization and applications of glucose oxidase. Production of glucose oxidase by fermentation is detailed, along with recombinant methods. Various purification techniques for higher recovery of glucose oxidase are described here. Issues of enzyme kinetics, stability studies and characterization are addressed. Immobilized preparations of glucose oxidase are also discussed. Applications of glucose oxidase in various industries and as analytical enzymes are having an increasing impact on bioprocessing.

Liang Z, Yan Y, Zhang W, Luo H, Yao B, Huang H, Tu T. Review of glucose oxidase as a feed additive: production, engineering, applications, growth-promoting mechanisms, and outlook. Crit Rev Biotechnol. 2023 Dec;43(5):698-715. doi: 10.1080/07388551.2022.2057275.

Abstract. The regulation and prohibition of antibiotics used as growth promoters (AGP) in the feed field are increasing because they cause antimicrobial resistance and drug residue issues and threaten community health. Recently, glucose oxidase (GOx) has attracted increasing interest in the feed industry as an alternative to antibiotics. GOx specifically catalyzes the production of gluconic acid (GA) and hydrogen peroxide (H2O2) by consuming molecular oxygen, and plays an important role in relieving oxidative stress, preserving health, and promoting animal growth. To expand the application of GOx in the feed field, considerable efforts have been made to mine new genetic resources. Efforts have also been made to heterologously overexpress relevant genes to reduce production costs and to engineer proteins by modifying enzyme properties, both of which are bottleneck problems that limit industrial feed applications. Herein, the: different sources, diverse biochemical properties, distinct structural features, and various strategies of GOx engineering and heterologous overexpression are summarized. The mechanism through which GOx promotes growth in animal production, including the improvement of antioxidant capacity, maintenance of intestinal microbiota homeostasis, and enhancement of gut function, are also systematically addressed. Finally, a new perspective is provided for the future development of GOx applications in the feed field.

Bauer JA, Zámocká M, Majtán J, Bauerová-Hlinková V. Glucose Oxidase, an Enzyme "Ferrari": Its Structure, Function, Production and Properties in the Light of Various Industrial and Biotechnological Applications. Biomolecules. 2022 Mar 19;12(3):472. doi: 10.3390/biom12030472. 

Abstract. Glucose oxidase (GOx) is an important oxidoreductase enzyme with many important roles in biological processes. It is considered an "ideal enzyme" and is often called an oxidase "Ferrari" because of its fast mechanism of action, high stability and specificity. Glucose oxidase catalyzes the oxidation of β-d-glucose to d-glucono-δ-lactone and hydrogen peroxide in the presence of molecular oxygen. d-glucono-δ-lactone is sequentially hydrolyzed by lactonase to d-gluconic acid, and the resulting hydrogen peroxide is hydrolyzed by catalase to oxygen and water. GOx is presently known to be produced only by fungi and insects. The current main industrial producers of glucose oxidase are Aspergillus and Penicillium. An important property of GOx is its antimicrobial effect against various pathogens and its use in many industrial and medical areas. The aim of this review is to summarize the structure, function, production strains and biophysical and biochemical properties of GOx in light of its various industrial, biotechnological and medical applications.

Leskovac V, Trivić S, Wohlfahrt G, Kandrac J, Pericin D. Glucose oxidase from Aspergillus niger: the mechanism of action with molecular oxygen, quinones, and one-electron acceptors. Int J Biochem Cell Biol. 2005 Apr;37(4):731-50. doi: 10.1016/j.biocel.2004.10.014.

Abstract. Glucose oxidase from the mold Aspergillus niger (EC 1.1.3.4) oxidizes beta-D-glucose with a wide variety of oxidizing substrates. The substrates were divided into three main groups: molecular oxygen, quinones, and one-electron acceptors. The kinetic and chemical mechanism of action for each group of substrates was examined in turn with a wide variety of kinetic methods and by means of molecular modeling of enzyme-substrate complexes. There are two proposed mechanisms for the reductive half-reaction: hydride abstraction and nucleophilic attack followed by deprotonation. The former mechanism appears plausible; here, beta-D-glucose is oxidized to glucono-delta-lactone by a concerted transfer of a proton from its C1-hydroxyl to a basic group on the enzyme (His516) and a direct hydride transfer from its C1 position to the N5 position in FAD. The oxidative half-reaction proceeds via one- or two-electron transfer mechanisms, depending on the type of the oxidizing substrate. The active site of the enzyme contains, in addition to FAD, three amino acid side chains that are intimately involved in catalysis: His516 with a pK(a)=6.9, and Glu412 with pK(a)=3.4 which is hydrogen bonded to His559, with pK(a)>8. The protonation of each of these residues has a strong influence on all rate constants in the catalytic mechanism.

Wong CM, Wong KH, Chen XD. Glucose oxidase: natural occurrence, function, properties and industrial applications. Appl Microbiol Biotechnol. 2008 Apr;78(6):927-38. doi: 10.1007/s00253-008-1407-4.

Abstract. Glucose oxidase (GOX) from Aspergillus niger is a well-characterised glycoprotein consisting of two identical 80-kDa subunits with two FAD co-enzymes bound. Both the DNA sequence and protein structure at 1.9 A have been determined and reported previously. GOX catalyses the oxidation of D: -glucose (C(6)H(12)O(6)) to D: -gluconolactone (C(6)H(10)O(6)) and hydrogen peroxide. GOX is produced naturally in some fungi and insects where its catalytic product, hydrogen peroxide, acts as an anti-bacterial and anti-fungal agent. GOX is Generally Regarded As Safe, and GOX from A. niger is the basis of many industrial applications. GOX-catalysed reaction removes oxygen and generates hydrogen peroxide, a trait utilised in food preservation. GOX has also been used in baking, dry egg powder production, wine production, gluconic acid production, etc. Its electrochemical activity makes it an important component in glucose sensors and potentially in fuel cell applications. This paper will give a brief background on the natural occurrence, functions as well as the properties of glucose oxidase. A good coverage on the diverse uses of glucose oxidase in the industry is presented with a brief outline on the working principles in the various settings. Furthermore, food grade GOX preparations are relatively affordable and widely available; the readers may be encouraged to explore other potential uses of GOX. One example is that GOX-catalysed reaction generates significant amount of heat (~200 kJ/mol), and this property has been mostly neglected in the various applications described so far.