TY  - JOUR
AU  - Kaličanin, Nevena
AU  - Kovačević, Gordana
AU  - Spasojević, Milica
AU  - Prodanović, Olivera
AU  - Jovanović-Šanta, Suzana
AU  - Škorić, Dušan
AU  - Opsenica, Dejan
AU  - Prodanović, Radivoje
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1768
AB  - The aim of this research was to improve the operational stability and enable the reusability of ω-transaminase for synthesis of new enantiopure chiral amines of steroids. Dihydrotestosterone was used to optimize the synthetic procedure of corresponding amino-steroid on a larger scale. The obtained product 3α-amino-5α-androstan-17β-ol was isolated and characterized. The enzyme was immobilized on a methacrylate-based carrier, giving the specific activity of 1.84 U/g of dry polymer. Higher residual activity of the immobilized enzyme in comparison to the soluble form (100 % versus 35%) after 24 h incubation in 35 % dimethylformamide (DMF) was obtained. The soluble enzyme retained 19 % of the initial activity after 2 h incubation in 35 % DMF at 70 °C, while the activity of the immobilized enzyme decreased only to 75 %. Immobilized retained 85 % of initial activity after ten consecutive cycles of 3α-amino-5α-androstan-17β-ol synthesis. We have tested the specificity of the ArRMut11 variant, further increased its stability by immobilization, and used it in several cycles for the synthesis of 3α-amino-5α-androstan-17β-ol. We showed that the enzyme previously evolved for higher stability as the immobilized variant showed more increased stability and high reusability that can more effectively be applied for the biosynthesis of amino steroids.
PB  - Elsevier
T2  - Process Biochemistry
T1  - Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol
EP  - 680
SP  - 674
VL  - 121
DO  - 10.1016/j.procbio.2022.08.016
ER  - 

@article{
author = "Kaličanin, Nevena and Kovačević, Gordana and Spasojević, Milica and Prodanović, Olivera and Jovanović-Šanta, Suzana and Škorić, Dušan and Opsenica, Dejan and Prodanović, Radivoje",
year = "2022",
abstract = "The aim of this research was to improve the operational stability and enable the reusability of ω-transaminase for synthesis of new enantiopure chiral amines of steroids. Dihydrotestosterone was used to optimize the synthetic procedure of corresponding amino-steroid on a larger scale. The obtained product 3α-amino-5α-androstan-17β-ol was isolated and characterized. The enzyme was immobilized on a methacrylate-based carrier, giving the specific activity of 1.84 U/g of dry polymer. Higher residual activity of the immobilized enzyme in comparison to the soluble form (100 % versus 35%) after 24 h incubation in 35 % dimethylformamide (DMF) was obtained. The soluble enzyme retained 19 % of the initial activity after 2 h incubation in 35 % DMF at 70 °C, while the activity of the immobilized enzyme decreased only to 75 %. Immobilized retained 85 % of initial activity after ten consecutive cycles of 3α-amino-5α-androstan-17β-ol synthesis. We have tested the specificity of the ArRMut11 variant, further increased its stability by immobilization, and used it in several cycles for the synthesis of 3α-amino-5α-androstan-17β-ol. We showed that the enzyme previously evolved for higher stability as the immobilized variant showed more increased stability and high reusability that can more effectively be applied for the biosynthesis of amino steroids.",
publisher = "Elsevier",
journal = "Process Biochemistry",
title = "Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol",
pages = "680-674",
volume = "121",
doi = "10.1016/j.procbio.2022.08.016"
}

Kaličanin, N., Kovačević, G., Spasojević, M., Prodanović, O., Jovanović-Šanta, S., Škorić, D., Opsenica, D.,& Prodanović, R.. (2022). Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol. in Process Biochemistry
Elsevier., 121, 674-680.
https://doi.org/10.1016/j.procbio.2022.08.016

Kaličanin N, Kovačević G, Spasojević M, Prodanović O, Jovanović-Šanta S, Škorić D, Opsenica D, Prodanović R. Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol. in Process Biochemistry. 2022;121:674-680.
doi:10.1016/j.procbio.2022.08.016 .

Kaličanin, Nevena, Kovačević, Gordana, Spasojević, Milica, Prodanović, Olivera, Jovanović-Šanta, Suzana, Škorić, Dušan, Opsenica, Dejan, Prodanović, Radivoje, "Immobilization of ArRMut11 omega-transaminase for increased operational stability and reusability in the synthesis of 3α-amino-5α-androstan-17β-ol" in Process Biochemistry, 121 (2022):674-680,
https://doi.org/10.1016/j.procbio.2022.08.016 . .

TY  - JOUR
AU  - Pantić, Nevena
AU  - Spasojević, Milica
AU  - Stojanović, Zeljko P
AU  - Veljović, Đorđe
AU  - Krstic, Jugoslav
AU  - Balaž, Ana Marija
AU  - Prodanović, Radivoje
AU  - Prodanović, Olivera
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1530
AB  - Novel macroporous copolymers of glycidyl methacrylate and ethylene glycol dimethacrylate with mean pore size diameters ranging from 150 to 310 nm were synthesized by dispersion polymerization and modified with ethylenediamine. The glutaraldehyde and periodate method were employed to immobilize horseradish peroxidase (HRP) onto these carriers. The activity of the immobilized enzyme was greatly affected by the pore size of the carrier. The highest specific activities of 9.65 and 8.94 U/g of dry weight were obtained for HRP immobilized by the periodate-route onto poly(GMA-co-EGDMA) carriers with pore size diameters of 234 and 297 nm, respectively. Stability studies showed an improved operational stability of immobilized peroxidase at 65 degrees C and in an organic solvent. HRP immobilized on a copolymer with a pore size of 234 nm, showing the highest specific activity and good stability, had higher activities at almost all pH values than the native enzyme and the increased K-m value for pyrogallol oxidation. Immobilized HRP retained 80% of its original activity after five consecutive cycles of the pyrogallol oxidation and 98% of its initial activity in a storage stability study. Enzyme immobilized onto the macroporous copolymer with the pore size diameter of 234 nm showed a substantial degree of phenol removal achieved by immobilized peroxidase.
PB  - Springer, New York
T2  - Journal of Polymers and the Environment
T1  - Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol
DO  - 10.1007/s10924-021-02364-3
ER  - 

@article{
author = "Pantić, Nevena and Spasojević, Milica and Stojanović, Zeljko P and Veljović, Đorđe and Krstic, Jugoslav and Balaž, Ana Marija and Prodanović, Radivoje and Prodanović, Olivera",
year = "2022",
abstract = "Novel macroporous copolymers of glycidyl methacrylate and ethylene glycol dimethacrylate with mean pore size diameters ranging from 150 to 310 nm were synthesized by dispersion polymerization and modified with ethylenediamine. The glutaraldehyde and periodate method were employed to immobilize horseradish peroxidase (HRP) onto these carriers. The activity of the immobilized enzyme was greatly affected by the pore size of the carrier. The highest specific activities of 9.65 and 8.94 U/g of dry weight were obtained for HRP immobilized by the periodate-route onto poly(GMA-co-EGDMA) carriers with pore size diameters of 234 and 297 nm, respectively. Stability studies showed an improved operational stability of immobilized peroxidase at 65 degrees C and in an organic solvent. HRP immobilized on a copolymer with a pore size of 234 nm, showing the highest specific activity and good stability, had higher activities at almost all pH values than the native enzyme and the increased K-m value for pyrogallol oxidation. Immobilized HRP retained 80% of its original activity after five consecutive cycles of the pyrogallol oxidation and 98% of its initial activity in a storage stability study. Enzyme immobilized onto the macroporous copolymer with the pore size diameter of 234 nm showed a substantial degree of phenol removal achieved by immobilized peroxidase.",
publisher = "Springer, New York",
journal = "Journal of Polymers and the Environment",
title = "Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol",
doi = "10.1007/s10924-021-02364-3"
}

Pantić, N., Spasojević, M., Stojanović, Z. P., Veljović, Đ., Krstic, J., Balaž, A. M., Prodanović, R.,& Prodanović, O.. (2022). Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol. in Journal of Polymers and the Environment
Springer, New York..
https://doi.org/10.1007/s10924-021-02364-3

Pantić N, Spasojević M, Stojanović ZP, Veljović Đ, Krstic J, Balaž AM, Prodanović R, Prodanović O. Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol. in Journal of Polymers and the Environment. 2022;.
doi:10.1007/s10924-021-02364-3 .

Pantić, Nevena, Spasojević, Milica, Stojanović, Zeljko P, Veljović, Đorđe, Krstic, Jugoslav, Balaž, Ana Marija, Prodanović, Radivoje, Prodanović, Olivera, "Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol" in Journal of Polymers and the Environment (2022),
https://doi.org/10.1007/s10924-021-02364-3 . .

TY  - CONF
AU  - Tomić, Katarina
AU  - Šokrda Slavić, Marinela
AU  - Kojić, Milan
AU  - Stanisavljević, Nemanja
AU  - Nikolić, Stefan
AU  - Vujčić, Zoran
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1771
AB  - One of the most abundant natural polymers with multidimensional and multifaceted application is starch. Due to energy fuel sustainability concern, the world is focusing on renewable energy including energy from renewable biological materials like starch1. The importance of the enzymatic hydrolysis of granular starch below the temperature of gelatinization has been well recognized, mainly due to energy savings and the effective utilization of biomass, which reduces the overall cost of starch processing2. A new α-amylase gene (Amy35) was cloned from newly isolated thermophilic Anoxybacillus sp. ST4 and expressed in Escherichia coli. The purified recombinant α-amylase had an wide pH optimum range from 4.5 to 8.5 and optimum temperature of 75°C. The enzyme retained 95% of its activity after 3h of incubation at 50 and 60°C. Hydrolysis rates of potato, horseradish and corn starches, at 1% concentration were 20, 70 and 65%, respectively, in a period of 16 h. Analysis of the enzyme properties proved its high efficacy for the digestion of diverse raw starches below gelatinization temperature and, therefore, its potential commercial value for use as an industrial enzyme.
PB  - Faculty of Chemistry, Serbian Biochemical Society
C3  - Serbian Biochemical Society Eleventh Conference
T1  - Cloning and characterization of new raw starch digestion α-amylase from thermophilic Anoxybacillus sp.
SP  - 147
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_1771
ER  - 

@conference{
author = "Tomić, Katarina and Šokrda Slavić, Marinela and Kojić, Milan and Stanisavljević, Nemanja and Nikolić, Stefan and Vujčić, Zoran",
year = "2022",
abstract = "One of the most abundant natural polymers with multidimensional and multifaceted application is starch. Due to energy fuel sustainability concern, the world is focusing on renewable energy including energy from renewable biological materials like starch1. The importance of the enzymatic hydrolysis of granular starch below the temperature of gelatinization has been well recognized, mainly due to energy savings and the effective utilization of biomass, which reduces the overall cost of starch processing2. A new α-amylase gene (Amy35) was cloned from newly isolated thermophilic Anoxybacillus sp. ST4 and expressed in Escherichia coli. The purified recombinant α-amylase had an wide pH optimum range from 4.5 to 8.5 and optimum temperature of 75°C. The enzyme retained 95% of its activity after 3h of incubation at 50 and 60°C. Hydrolysis rates of potato, horseradish and corn starches, at 1% concentration were 20, 70 and 65%, respectively, in a period of 16 h. Analysis of the enzyme properties proved its high efficacy for the digestion of diverse raw starches below gelatinization temperature and, therefore, its potential commercial value for use as an industrial enzyme.",
publisher = "Faculty of Chemistry, Serbian Biochemical Society",
journal = "Serbian Biochemical Society Eleventh Conference",
title = "Cloning and characterization of new raw starch digestion α-amylase from thermophilic Anoxybacillus sp.",
pages = "147",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_1771"
}

Tomić, K., Šokrda Slavić, M., Kojić, M., Stanisavljević, N., Nikolić, S.,& Vujčić, Z.. (2022). Cloning and characterization of new raw starch digestion α-amylase from thermophilic Anoxybacillus sp.. in Serbian Biochemical Society Eleventh Conference
Faculty of Chemistry, Serbian Biochemical Society., 147.
https://hdl.handle.net/21.15107/rcub_rimsi_1771

Tomić K, Šokrda Slavić M, Kojić M, Stanisavljević N, Nikolić S, Vujčić Z. Cloning and characterization of new raw starch digestion α-amylase from thermophilic Anoxybacillus sp.. in Serbian Biochemical Society Eleventh Conference. 2022;:147.
https://hdl.handle.net/21.15107/rcub_rimsi_1771 .

Tomić, Katarina, Šokrda Slavić, Marinela, Kojić, Milan, Stanisavljević, Nemanja, Nikolić, Stefan, Vujčić, Zoran, "Cloning and characterization of new raw starch digestion α-amylase from thermophilic Anoxybacillus sp." in Serbian Biochemical Society Eleventh Conference (2022):147,
https://hdl.handle.net/21.15107/rcub_rimsi_1771 .

TY  - JOUR
AU  - Pantić, Nevena
AU  - Prodanović, Radivoje
AU  - Ilic-Durdic, Karla
AU  - Polović, Natalija
AU  - Spasojević, Milica
AU  - Prodanović, Olivera
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1476
AB  - Removal of phenolic compounds from water is of major interest over the years, since they are one of the most common pollutants in aqueous systems. Horseradish peroxidase (HRP) is the most investigated biocatalyst for this purpose. Inactivation of the enzyme is a major issue which can be successfully overcome by the enzyme immobilization on different polymers. In this study, tyramine-alginate micro-beads were used as carriers for the immobilization of horseradish peroxidase. The effect of the oxidation degree of tyramine-alginates on a specific activity of the enzyme was tested. An increase in the concentration of oxidized alginate from 2.5 to 20% resulted in a gradual increase in the specific activity from 0.05 to 0.67 U/mL. HRP immobilized within these microbeads was tested for the phenol removal in a batch reactor. Reaction conditions were optimized to achieve a high removal efficiency and substantial reusability of the system. In this study, for the first time, an internal generation of hydrogen peroxide from glucose and glucose oxidase was employed in the phenol removal process with HRP immobilized on tyramine-alginate. Within 6 h of repeated use 96% of phenol was removed when the system for internal delivery of H2O2, composed of 0.187 U/mL of glucose oxidase and 4 mmol/L of glucose was employed. A common straightforward addition of hydrogen peroxide provided the removal efficiency of only 42%, under the same reaction conditions. The highest efficiency of the phenol removal (96%) was obtained with HRP immobilized within 20 mol% oxidized tyramine-alginate microbeads. Fifteen mol% oxidized tyramine-alginate showed lower removal efficiency in the first cycle of use (73%) but more promising reusability, since the immobilized enzyme retained 61% of its initial activity even after four consecutive cycles of use.
PB  - Elsevier, Amsterdam
T2  - Environmental Technology & Innovation
T1  - Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads
VL  - 21
DO  - 10.1016/j.eti.2020.101211
ER  - 

@article{
author = "Pantić, Nevena and Prodanović, Radivoje and Ilic-Durdic, Karla and Polović, Natalija and Spasojević, Milica and Prodanović, Olivera",
year = "2021",
abstract = "Removal of phenolic compounds from water is of major interest over the years, since they are one of the most common pollutants in aqueous systems. Horseradish peroxidase (HRP) is the most investigated biocatalyst for this purpose. Inactivation of the enzyme is a major issue which can be successfully overcome by the enzyme immobilization on different polymers. In this study, tyramine-alginate micro-beads were used as carriers for the immobilization of horseradish peroxidase. The effect of the oxidation degree of tyramine-alginates on a specific activity of the enzyme was tested. An increase in the concentration of oxidized alginate from 2.5 to 20% resulted in a gradual increase in the specific activity from 0.05 to 0.67 U/mL. HRP immobilized within these microbeads was tested for the phenol removal in a batch reactor. Reaction conditions were optimized to achieve a high removal efficiency and substantial reusability of the system. In this study, for the first time, an internal generation of hydrogen peroxide from glucose and glucose oxidase was employed in the phenol removal process with HRP immobilized on tyramine-alginate. Within 6 h of repeated use 96% of phenol was removed when the system for internal delivery of H2O2, composed of 0.187 U/mL of glucose oxidase and 4 mmol/L of glucose was employed. A common straightforward addition of hydrogen peroxide provided the removal efficiency of only 42%, under the same reaction conditions. The highest efficiency of the phenol removal (96%) was obtained with HRP immobilized within 20 mol% oxidized tyramine-alginate microbeads. Fifteen mol% oxidized tyramine-alginate showed lower removal efficiency in the first cycle of use (73%) but more promising reusability, since the immobilized enzyme retained 61% of its initial activity even after four consecutive cycles of use.",
publisher = "Elsevier, Amsterdam",
journal = "Environmental Technology & Innovation",
title = "Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads",
volume = "21",
doi = "10.1016/j.eti.2020.101211"
}

Pantić, N., Prodanović, R., Ilic-Durdic, K., Polović, N., Spasojević, M.,& Prodanović, O.. (2021). Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads. in Environmental Technology & Innovation
Elsevier, Amsterdam., 21.
https://doi.org/10.1016/j.eti.2020.101211

Pantić N, Prodanović R, Ilic-Durdic K, Polović N, Spasojević M, Prodanović O. Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads. in Environmental Technology & Innovation. 2021;21.
doi:10.1016/j.eti.2020.101211 .

Pantić, Nevena, Prodanović, Radivoje, Ilic-Durdic, Karla, Polović, Natalija, Spasojević, Milica, Prodanović, Olivera, "Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads" in Environmental Technology & Innovation, 21 (2021),
https://doi.org/10.1016/j.eti.2020.101211 . .