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Polymers and copolymers of horseradish root peroxidase (HRP) and Penicillium funiculosum 46.1 glucose oxidase (GO) have been synthesized and their catalytic properties have been characterized (free and immobilized forms of each enzyme were studied). The cooxidation reaction of phenol and 4-aminoantipyrin (4-AAP), performed in an aqueous medium in the presence of equimolar amounts of GO and HRP, was characterized by effective KM and kcat of 0.58 mM and 20.9 s−1 (for phenol), and 14.6 mM and 18.4 s−1 (glucose), respectively. The catalytic efficiency of polymerization products (PPs) of GO (GO-PPs) depended on the extent of their aggregation. The combinations GO + HRP-PP and HRP + GO-PP, as well as the copolymer HRP*-GO-PP, proved promising as reagents for enzyme-based analytical systems. When adsorbed on aluminum hydroxide gels, GO-PPs exhibited higher catalytic activity than the non-polymeric enzyme. Maximum retention of GO-PP activity on the inorganic carrier was observed in the case of GO-PP copolymers with an activated HRP. Polymerization of HRP in the presence of a zinc hydroxide gel, paralleled by HRP-PP immobilization onto the gel, increased both the activity of the enzyme and its operational stability.

Different methods of immobilization of extracellular glucose oxidase (GO) from Penicillium funiculosum 46.1 on gels of aluminum or zinc hydroxides have been compared. GO from the culture liquid filtrate (CLF) associated with Zn(OH)2 but not Al(OH)3 gels. Preparation of samples of immobilized GO does not require isolation of the enzyme (CLF may be used). GO immobilized on Zn(OH)2 gels from CLF was 1.6 times more efficient in catalyzing D-glucose oxidation than the enzyme contained in the original culture liquid. Crosslinking of gel-adsorbed CLF proteins affected the properties of GO adversely and to a considerable extent. Various means of polymerization and immobilization of GO isolated from CLF have been studied. Optimum results were obtained when GO polymeric products were pre-synthesized in solution, followed by adsorption to Al(OH)3 but not Zn(OH)2 gels. The catalytic efficiency of GO immobilized on a Zn(OH)2 gel was significantly lower than that of the enzyme associated with Al(OH)3.

A procedure for purification of extracellular glucose oxidase (GO, EC 1.1.3.4) from a filtrate of culture liquid (CLF) of the fungus Penicillium funiculosum 46.1 has been developed using alluvial quartz sand as an adsorbent. Modifying the sand by changing the charge and polarity did not lead to a significant increase in its adsorption capacity towards GO. The effectiveness of sand and aluminum oxide used as adsorbents for GO isolation from CLF has been compared. Glucose oxidase isolated from CLF by adsorption on sand exhibited a greater catalytic activity than enzyme preparations obtained by column chromatography on CLF. Glucose oxidase from P. funiculosum 46.1 was adsorbed on sand more effectively than on aluminum oxide. It is concluded that sand may be used for fractionation of partially purified GO.

A method for isolation of extracellular glucose oxidase from Penicillium funiculosum 433 and its purification is proposed. The enzymatic preparation was produced with a yield of 56% and a specific activity of 3730 AU per 1 mg protein. The enzyme studied displayed a high thermostability, resistance to metal ions, and performance in a wide pH range and was equal in its properties to foreign analogues.

A method for isolating extracellular glucose oxidase from the fungus Penicillium funiculosum 46.1 using ultrafiltration membranes was developed. Two samples of the enzyme with a specific activity of 914–956 IU were obtained. The enzyme exhibited a high catalytic activity at pH above 6.0. The effective rate constant of glucose oxidase inactivation at pH 2.6 and 16°C was 2.74 × 10–6 s–1. This constant decreased significantly as the pH of the medium increased (4.0–10.0). The temperature optimum for glucose oxidase–catalyzed β-D-glucose oxidation was in the range 30–65°C. At temperatures below 30°C, the activation energy for β-D-glucose oxidation was 6.42 kcal/mol; at higher temperatures, this parameter was equal to 0.61 kcal/mol. Kinetic parameters of glucose oxidase–catalyzed β-D-glucose oxidation depended on the initial concentration of the enzyme in the solution. Glucose oxidase also catalyzed the oxidation of 2-deoxy-D-glucose, maltose, and galactose.

Metabolic inhibitors, riboflavin, and end products of glucose oxidation were shown to hold much promise for the selection of Penicillium funiculosum mutant strains with a high glucose oxidase activity. The incidence of positive mutations was highest in clones resistant to sodium azide, riboflavin, and beta-D-glucono-delta-lactone. Enzyme activity in Penicillium funiculosum mutants was studied under conditions of submerged cultivation. The intensity of glucose oxidase synthesis in seven cultures was 24-56% higher than that in the parent strain of Penicillium funiculosum NMM95.132.

Mycelial fungi Penicillium funiculosum, P. citrinum, P. expansum, P. chrysogenum, Aspergillus ochraceus, A. alliaceus, A. luchaensis, A. flavus, and A. niger were isolated from enrichment cultures. These fungi actively destruct carbon deposits formed during operation of aircraft. A biotechnological method for removing fouling from parts of aircraft engines (PAE) was developed. This method is less laborious, more rapid, and ecologically cleaner than contemporary chemical methods. Scanning microscopy was suggested for estimating the degree of decarbonization of PAE surfaces.