TY  - JOUR
AU  - Jakovetić, Sonja
AU  - Knežević-Jugović, Zorica
AU  - Grbavčić, Sanja
AU  - Bezbradica, Dejan
AU  - Avramović, Nataša
AU  - Karadžić, Ivanka
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2329
AB  - Pseudomonas aeruginosa has been repeatedly reported as a powerful producer of rhamnolipid biosurfactants as well as hydrolytic enzymes. In this study, the effects of four fermentation factors were evaluated using response surface methodology and experiments were performed in accordance with a four-factor and five-level central composite experimental design. The investigated factors were: fermentation temperature, time of fermentation, concentration of sunflower oil and concentration of Tween® 80. The most important finding was that regression coefficients of the highest values were those that describe interactions between factors and that they differ for lipase and rhamnolipid production, which were both investigated in this study. Production of both metabolites was optimized and response equations were obtained, making it possible to predict rhamnolipid concentration or lipase activity from known values of the four factors. The highest achieved rhamnolipid concentration and lipase activity were 138 mg dm-3 (sunflower oil concentration: 0.8%, Tween® 80 concentration: 0.05%, temperature: 30 °C and fermentation time: 72 h) and 11111 IU dm-3 (sunflower concentration: of 0.4%, Tween® 80 concentration: 0.05%, temperature: 30 °C and fermentation time: 120 h), respectively.
AB  - Pseudomonas aeruginosa san-ai, izolovan je iz izrazito alkalne emulzije koja je korišćena kao mazivo u industriji pri obradi metala. Sposobnost da preživi u visoko alkalnoj sredini (pH 10) učinila je ovaj mikroorganizam veoma interesantnim za istraživanje, budući da je za preživljavanje u tako ekstremnim uslovima neophodno da mikroorganizam proizvodi enzime specifičnih karakteristika. Prethodna istraživanja su pokazala da ovaj ekstremofilni mikroorganizam ekstracelularno produkuje hidrolitičke enzime, koji zbog izuzetno atraktivnih karakteristika imaju potencijal za primenu u nizu biotehnoloških postupaka. Ipak, iako je pokazano da ovaj atraktivni soj produkuje industrijski veoma interesantne biomolekule (proteaze i lipaze), produkcija ramnolipida, jedinjenja čija oblast primene svakodnevno raste, pomoću ovog soja je malo ispitana. Ramnolipidi su amfifilna jedinjenja, koja se sastoje iz hidrofilne šećerne komponente i hidrofobne komponente koju čine β-hidroksi masne kiseline. Spadaju u grupu mikrobioloških surfaktanata ili biosurfaktanata, koji bi trebalo u budućnosti da se koriste kao zamena za sintetičke surfaktante koji nisu biodegradabilni i kao takvi predstavljaju opasnost za životnu sredinu. Sve veće interesovanje za industrijsku primenu ramnolipida, dovelo je do potrebe za optimizacijom njihove proizvodnje. Cilj ovog rada bila je optimizacija produkcije ramnolipida kao i lipaze pomoću Pseudomonas aeruginosa san-ai. Ispitan je uticaj četri fermentaciona faktora: koncentracije suncokretovog ulja u intervalu: 0,2-1,0 % (w/v), Tween® 80 u intervalu: 0-0,2 % (v/v), temperature: 20­60 °C i vremena trajanja fermentacije: 48-144 h. Uticaj fermentacionih faktora na prinos navedenih metabolita ispitan je pomoću centralnog kompozitnog rotatabilnog eksperimentalnog plana, na pet nivoa vrednosti ispitivanih faktora. Analizom dobijenih regresionih koeficijenata ustanovljeno je da su vrlo izražena interaktivna dejstva nekoliko parova faktora. Kod produkcije ramnolipida, najveća je vrednost koeficijenta koji opisuje negativnu interakciju između koncentracije suncokretovog ulja i temperature, a kao bitne pokazale su se i pozitivna interakcija između koncentracije Tween® 80 i temperature, kao i negativna interakcija između koncentracija suncokretovog ulja i Tween® 80. Interesantno je da su se kod produkcije lipaze kao značajni faktori pokazali samo temperatura i vreme fermentacije. Najveći prinos ramnolipida, 138 mg dm-3, postignut je pri niskoj koncentraciji Tween® 80 (0,05 %) i visokoj koncentraciji ulja (0,8 %) na 30 °C posle 72 h, dok je najveća lipolitička aktivnost, 11111 IU dm-3, ostvarena pri istoj koncentraciji Tween® 80 (0,05 %) i istoj temperaturi od 30 °C, nešto nižoj koncentraciji suncokretovog ulja (0,4 %) i dužem vremenu fermentacije od 120 h.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Rhamnolipid and lipase production by Pseudomonas aeruginosa san-ai: The process comparison analysis by statistical approach
T1  - Proizvodnja ramnolipida i lipaze iz Pseudomonas aeruginosa san-ai - optimizacija procesa primenom metode odzivnih površina
EP  - 685
IS  - 4
SP  - 677
VL  - 67
DO  - 10.2298/HEMIND121008114J
ER  - 

@article{
author = "Jakovetić, Sonja and Knežević-Jugović, Zorica and Grbavčić, Sanja and Bezbradica, Dejan and Avramović, Nataša and Karadžić, Ivanka",
year = "2013",
abstract = "Pseudomonas aeruginosa has been repeatedly reported as a powerful producer of rhamnolipid biosurfactants as well as hydrolytic enzymes. In this study, the effects of four fermentation factors were evaluated using response surface methodology and experiments were performed in accordance with a four-factor and five-level central composite experimental design. The investigated factors were: fermentation temperature, time of fermentation, concentration of sunflower oil and concentration of Tween® 80. The most important finding was that regression coefficients of the highest values were those that describe interactions between factors and that they differ for lipase and rhamnolipid production, which were both investigated in this study. Production of both metabolites was optimized and response equations were obtained, making it possible to predict rhamnolipid concentration or lipase activity from known values of the four factors. The highest achieved rhamnolipid concentration and lipase activity were 138 mg dm-3 (sunflower oil concentration: 0.8%, Tween® 80 concentration: 0.05%, temperature: 30 °C and fermentation time: 72 h) and 11111 IU dm-3 (sunflower concentration: of 0.4%, Tween® 80 concentration: 0.05%, temperature: 30 °C and fermentation time: 120 h), respectively., Pseudomonas aeruginosa san-ai, izolovan je iz izrazito alkalne emulzije koja je korišćena kao mazivo u industriji pri obradi metala. Sposobnost da preživi u visoko alkalnoj sredini (pH 10) učinila je ovaj mikroorganizam veoma interesantnim za istraživanje, budući da je za preživljavanje u tako ekstremnim uslovima neophodno da mikroorganizam proizvodi enzime specifičnih karakteristika. Prethodna istraživanja su pokazala da ovaj ekstremofilni mikroorganizam ekstracelularno produkuje hidrolitičke enzime, koji zbog izuzetno atraktivnih karakteristika imaju potencijal za primenu u nizu biotehnoloških postupaka. Ipak, iako je pokazano da ovaj atraktivni soj produkuje industrijski veoma interesantne biomolekule (proteaze i lipaze), produkcija ramnolipida, jedinjenja čija oblast primene svakodnevno raste, pomoću ovog soja je malo ispitana. Ramnolipidi su amfifilna jedinjenja, koja se sastoje iz hidrofilne šećerne komponente i hidrofobne komponente koju čine β-hidroksi masne kiseline. Spadaju u grupu mikrobioloških surfaktanata ili biosurfaktanata, koji bi trebalo u budućnosti da se koriste kao zamena za sintetičke surfaktante koji nisu biodegradabilni i kao takvi predstavljaju opasnost za životnu sredinu. Sve veće interesovanje za industrijsku primenu ramnolipida, dovelo je do potrebe za optimizacijom njihove proizvodnje. Cilj ovog rada bila je optimizacija produkcije ramnolipida kao i lipaze pomoću Pseudomonas aeruginosa san-ai. Ispitan je uticaj četri fermentaciona faktora: koncentracije suncokretovog ulja u intervalu: 0,2-1,0 % (w/v), Tween® 80 u intervalu: 0-0,2 % (v/v), temperature: 20­60 °C i vremena trajanja fermentacije: 48-144 h. Uticaj fermentacionih faktora na prinos navedenih metabolita ispitan je pomoću centralnog kompozitnog rotatabilnog eksperimentalnog plana, na pet nivoa vrednosti ispitivanih faktora. Analizom dobijenih regresionih koeficijenata ustanovljeno je da su vrlo izražena interaktivna dejstva nekoliko parova faktora. Kod produkcije ramnolipida, najveća je vrednost koeficijenta koji opisuje negativnu interakciju između koncentracije suncokretovog ulja i temperature, a kao bitne pokazale su se i pozitivna interakcija između koncentracije Tween® 80 i temperature, kao i negativna interakcija između koncentracija suncokretovog ulja i Tween® 80. Interesantno je da su se kod produkcije lipaze kao značajni faktori pokazali samo temperatura i vreme fermentacije. Najveći prinos ramnolipida, 138 mg dm-3, postignut je pri niskoj koncentraciji Tween® 80 (0,05 %) i visokoj koncentraciji ulja (0,8 %) na 30 °C posle 72 h, dok je najveća lipolitička aktivnost, 11111 IU dm-3, ostvarena pri istoj koncentraciji Tween® 80 (0,05 %) i istoj temperaturi od 30 °C, nešto nižoj koncentraciji suncokretovog ulja (0,4 %) i dužem vremenu fermentacije od 120 h.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Rhamnolipid and lipase production by Pseudomonas aeruginosa san-ai: The process comparison analysis by statistical approach, Proizvodnja ramnolipida i lipaze iz Pseudomonas aeruginosa san-ai - optimizacija procesa primenom metode odzivnih površina",
pages = "685-677",
number = "4",
volume = "67",
doi = "10.2298/HEMIND121008114J"
}

Jakovetić, S., Knežević-Jugović, Z., Grbavčić, S., Bezbradica, D., Avramović, N.,& Karadžić, I.. (2013). Rhamnolipid and lipase production by Pseudomonas aeruginosa san-ai: The process comparison analysis by statistical approach. in Hemijska industrija
Association of Chemical Engineers of Serbia., 67(4), 677-685.
https://doi.org/10.2298/HEMIND121008114J

Jakovetić S, Knežević-Jugović Z, Grbavčić S, Bezbradica D, Avramović N, Karadžić I. Rhamnolipid and lipase production by Pseudomonas aeruginosa san-ai: The process comparison analysis by statistical approach. in Hemijska industrija. 2013;67(4):677-685.
doi:10.2298/HEMIND121008114J .

Jakovetić, Sonja, Knežević-Jugović, Zorica, Grbavčić, Sanja, Bezbradica, Dejan, Avramović, Nataša, Karadžić, Ivanka, "Rhamnolipid and lipase production by Pseudomonas aeruginosa san-ai: The process comparison analysis by statistical approach" in Hemijska industrija, 67, no. 4 (2013):677-685,
https://doi.org/10.2298/HEMIND121008114J . .

TY  - JOUR
AU  - Grbavčić, Sanja
AU  - Bezbradica, Dejan
AU  - Izrael-Zivković, Lidija
AU  - Avramović, Nataša
AU  - Milosavić, Nenad
AU  - Karadžić, Ivanka
AU  - Knežević-Jugović, Zorica
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1895
AB  - An indigenous Pseudomonas aeruginosa strain has been studied for lipase and protease activities for their potential application in detergents. Produced enzymes were investigated in order to assess their compatibility with several surfactants, oxidizing agents and commercial detergents. The crude lipase appeared to retain high activity and stability in the presence of several surfactants and oxidizing agents and it was insusceptible to proteolysis. Lutensol (R) XP80 and Triton (R) X-100 strongly activated the lipase for a long period (up to 40 and 30% against the control after 1 h) while the protease activity was enhanced by the addition of Triton (R) WR1339 and Tween (R) 80. The washing performance of the investigated surfactants was significantly improved with the addition of the crude enzyme preparation. Studies were further undertaken to improve enzymes production. The optimization of fermentation conditions led to an 8-fold increase of lipase production, while the production of protease was enhanced by 60%.
PB  - Elsevier Sci Ltd, Oxford
T2  - Bioresource Technology
T1  - Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance
EP  - 11233
IS  - 24
SP  - 11226
VL  - 102
DO  - 10.1016/j.biortech.2011.09.076
ER  - 

@article{
author = "Grbavčić, Sanja and Bezbradica, Dejan and Izrael-Zivković, Lidija and Avramović, Nataša and Milosavić, Nenad and Karadžić, Ivanka and Knežević-Jugović, Zorica",
year = "2011",
abstract = "An indigenous Pseudomonas aeruginosa strain has been studied for lipase and protease activities for their potential application in detergents. Produced enzymes were investigated in order to assess their compatibility with several surfactants, oxidizing agents and commercial detergents. The crude lipase appeared to retain high activity and stability in the presence of several surfactants and oxidizing agents and it was insusceptible to proteolysis. Lutensol (R) XP80 and Triton (R) X-100 strongly activated the lipase for a long period (up to 40 and 30% against the control after 1 h) while the protease activity was enhanced by the addition of Triton (R) WR1339 and Tween (R) 80. The washing performance of the investigated surfactants was significantly improved with the addition of the crude enzyme preparation. Studies were further undertaken to improve enzymes production. The optimization of fermentation conditions led to an 8-fold increase of lipase production, while the production of protease was enhanced by 60%.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Bioresource Technology",
title = "Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance",
pages = "11233-11226",
number = "24",
volume = "102",
doi = "10.1016/j.biortech.2011.09.076"
}

Grbavčić, S., Bezbradica, D., Izrael-Zivković, L., Avramović, N., Milosavić, N., Karadžić, I.,& Knežević-Jugović, Z.. (2011). Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance. in Bioresource Technology
Elsevier Sci Ltd, Oxford., 102(24), 11226-11233.
https://doi.org/10.1016/j.biortech.2011.09.076

Grbavčić S, Bezbradica D, Izrael-Zivković L, Avramović N, Milosavić N, Karadžić I, Knežević-Jugović Z. Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance. in Bioresource Technology. 2011;102(24):11226-11233.
doi:10.1016/j.biortech.2011.09.076 .

Grbavčić, Sanja, Bezbradica, Dejan, Izrael-Zivković, Lidija, Avramović, Nataša, Milosavić, Nenad, Karadžić, Ivanka, Knežević-Jugović, Zorica, "Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: Compatibility study with detergent ingredients and washing performance" in Bioresource Technology, 102, no. 24 (2011):11226-11233,
https://doi.org/10.1016/j.biortech.2011.09.076 . .

TY  - JOUR
AU  - Bradić, Milena R.
AU  - Ognjanović, Nevena
AU  - Bezbradica, Dejan
AU  - Grbavčić, Sanja
AU  - Avramović, Nataša
AU  - Mijin, Dušan
AU  - Knežević-Jugović, Zorica
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1632
AB  - Monoacylglycerols are non-ionic surfactants widely used in the food industry. They are also important in cosmetic and pharmaceutical industries as drug carriers and for consistency improvements in creams and lotions. The current process for their production is based on the glycerolysis of natural fats and oils in the presence of inorganic catalysts at temperatures higher than 220°C. The major drawbacks of this process include high-energy consumption, low yield, and poor product quality. The use of lipases for monoacylglycerols production offers environmental advantages and a reduction in energy consumption. Besides, the same surfactants prepared by the enzymatic synthesis may be labeled as 'natural'. Recent progress in the application of highly-stable lipases in the organic solvents offers the possibility of employing various methods to the enzyme-catalyzed synthesis of monoacylglycerols, such as selective hydrolysis of fats and oils using 1,3-regiospecific lipases, the esterification of glycerol with fatty acids and the glycerolysis of fats or oils. In this review, different reaction systems such as aqueous-organic two-phase systems, microemulsions and reverse micelles systems, anhydrous organic solvents, solvent-free systems with free or immobilized lipases, as well as the use of two-phase membrane reactor systems are presented. We discuss some of the key factors, such as control of water content, removal of products from reaction system, and the effects of solvent on the lipase activity and selectivity, that must be addressed in order to obtain an efficient reaction system with high yields of monoacylglycerols. Engineering of the enzymatic monoacylglycerols synthesis processes requires also optimization of other factors such as: molar ratio of substrates, temperature, type of lipase immobilization and supports (if any), reactor design and operating regime.
AB  - Monoacilgliceroli (MAG), zahvaljujući svojoj amfipatičnoj strukturi, imaju veliki značaj i primenu kao emulgatori u prehrambenoj industriji. Koriste se i u kozmetičkoj i farmaceutskoj industriji za pripremu emulzija ulje/voda (U/V) i za poboljšanje konzistencije krema i losiona. Konvencionalni hemijski postupci hidrolize masti imaju značajnih nedostataka jer se odvijaju na visokim temperaturama i pritiscima uz korišćenje neorganskih katalizatora. Pri ovako drastičnim procesnim uslovima, obrazuju se proizvodi promenjene boje i neprijatne arome, koji se moraju naknadno prečišćavati što poskupljuje proizvodnju. Enzimski postupci za dobijanje monoacilglicerola imaju značajnih prednosti, a to su pre svega blagi reakcioni uslovi, usmerenost reakcije kao i znatno manji troškovi za energiju. U ovom radu razmatrani su osnovni načini enzimskog dobijanja monoacilglicerola kao što su parcijalna hidroliza masti i ulja poziciono specifičnim lipazama, esterifikacija masnih kiselina i alkohola i gliceroliza masti i ulja, sa posebnim osvrtom na prednosti i nedostatke svakog od njih.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Synthesis of monoacylglycerols by enzymatic methods
T1  - Enzimska sinteza monoacilglicerola
EP  - 388
IS  - 5
SP  - 375
VL  - 64
DO  - 10.2298/HEMIND100510040B
ER  - 

@article{
author = "Bradić, Milena R. and Ognjanović, Nevena and Bezbradica, Dejan and Grbavčić, Sanja and Avramović, Nataša and Mijin, Dušan and Knežević-Jugović, Zorica",
year = "2010",
abstract = "Monoacylglycerols are non-ionic surfactants widely used in the food industry. They are also important in cosmetic and pharmaceutical industries as drug carriers and for consistency improvements in creams and lotions. The current process for their production is based on the glycerolysis of natural fats and oils in the presence of inorganic catalysts at temperatures higher than 220°C. The major drawbacks of this process include high-energy consumption, low yield, and poor product quality. The use of lipases for monoacylglycerols production offers environmental advantages and a reduction in energy consumption. Besides, the same surfactants prepared by the enzymatic synthesis may be labeled as 'natural'. Recent progress in the application of highly-stable lipases in the organic solvents offers the possibility of employing various methods to the enzyme-catalyzed synthesis of monoacylglycerols, such as selective hydrolysis of fats and oils using 1,3-regiospecific lipases, the esterification of glycerol with fatty acids and the glycerolysis of fats or oils. In this review, different reaction systems such as aqueous-organic two-phase systems, microemulsions and reverse micelles systems, anhydrous organic solvents, solvent-free systems with free or immobilized lipases, as well as the use of two-phase membrane reactor systems are presented. We discuss some of the key factors, such as control of water content, removal of products from reaction system, and the effects of solvent on the lipase activity and selectivity, that must be addressed in order to obtain an efficient reaction system with high yields of monoacylglycerols. Engineering of the enzymatic monoacylglycerols synthesis processes requires also optimization of other factors such as: molar ratio of substrates, temperature, type of lipase immobilization and supports (if any), reactor design and operating regime., Monoacilgliceroli (MAG), zahvaljujući svojoj amfipatičnoj strukturi, imaju veliki značaj i primenu kao emulgatori u prehrambenoj industriji. Koriste se i u kozmetičkoj i farmaceutskoj industriji za pripremu emulzija ulje/voda (U/V) i za poboljšanje konzistencije krema i losiona. Konvencionalni hemijski postupci hidrolize masti imaju značajnih nedostataka jer se odvijaju na visokim temperaturama i pritiscima uz korišćenje neorganskih katalizatora. Pri ovako drastičnim procesnim uslovima, obrazuju se proizvodi promenjene boje i neprijatne arome, koji se moraju naknadno prečišćavati što poskupljuje proizvodnju. Enzimski postupci za dobijanje monoacilglicerola imaju značajnih prednosti, a to su pre svega blagi reakcioni uslovi, usmerenost reakcije kao i znatno manji troškovi za energiju. U ovom radu razmatrani su osnovni načini enzimskog dobijanja monoacilglicerola kao što su parcijalna hidroliza masti i ulja poziciono specifičnim lipazama, esterifikacija masnih kiselina i alkohola i gliceroliza masti i ulja, sa posebnim osvrtom na prednosti i nedostatke svakog od njih.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Synthesis of monoacylglycerols by enzymatic methods, Enzimska sinteza monoacilglicerola",
pages = "388-375",
number = "5",
volume = "64",
doi = "10.2298/HEMIND100510040B"
}

Bradić, M. R., Ognjanović, N., Bezbradica, D., Grbavčić, S., Avramović, N., Mijin, D.,& Knežević-Jugović, Z.. (2010). Synthesis of monoacylglycerols by enzymatic methods. in Hemijska industrija
Association of Chemical Engineers of Serbia., 64(5), 375-388.
https://doi.org/10.2298/HEMIND100510040B

Bradić MR, Ognjanović N, Bezbradica D, Grbavčić S, Avramović N, Mijin D, Knežević-Jugović Z. Synthesis of monoacylglycerols by enzymatic methods. in Hemijska industrija. 2010;64(5):375-388.
doi:10.2298/HEMIND100510040B .

Bradić, Milena R., Ognjanović, Nevena, Bezbradica, Dejan, Grbavčić, Sanja, Avramović, Nataša, Mijin, Dušan, Knežević-Jugović, Zorica, "Synthesis of monoacylglycerols by enzymatic methods" in Hemijska industrija, 64, no. 5 (2010):375-388,
https://doi.org/10.2298/HEMIND100510040B . .