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Cilj rada je bio da se ispita antioksidativna aktivnost etanolnog ekstrakta zrna cerealija i njihovih morfoloških frakcija. Ispitivani se : pšenica (Triticum durum L.), ječam (Hordeum vulgare L.), raž (Secale cereale L.) i heljda (Fagopyrum esculentum). Određivan je sadržaj ukupnih fenola (TPC) metodom po Folin-Ciocalteu i antioksidativna aktivnost (AOA) po tri najčešće korišćene metode: DPPH (sposobnost neutralizacije 2,2-difenil-1-pikrilhidrazil radikala), FRAP (antioksidativna sposobnost redukcije Fe III jona) i TBA ( metoda sa tiobarbiturnom kiselinom). Antioksidativna aktivnost etanolnog ekstrakta celog zrna opada u sledećem nizu: heljda gt ječam gt pšenica gt raž. Isti odnos je dobijen i za mekinje. Spoljni slojevi zrna imaju veći sadržaj polifenola, pa sledstveno tome i veću antioksidativnu aktivnost. Heljda sadrži najviše polifenola i ima najveću antioksidativnu aktivnost određenu DPPH i FRAP metodom, ali ima najmanju sposobnost inhibicije lipidne peroksidacije., The purpose of this study was to examine the antioxidant properties of 70% ethanolic extracts of cereal grains and their different morphological fractions. Wheat (Triticum durum L.), barley (Hordeum vulgare L.), rye (Secale cereale L.), and buckwheat (Fagopyrum esculentum) were used. The total phenolic content (TPC), determined by the Folin-Ciocalteu method and antioxidant activities (AOA) were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, ferric ion-reducing antioxidant power (FRAP) and thiobarbituric acid (TBA) methods. The following hierarchy of antioxidant activity was provided for 70% ethanolic extracts originated from whole grain: buckwheat gt barley gt wheat gt rye. In respect to hulls, the antioxidant hierarchy was the same. The outer layers of grains had higher amount of phenolic compounds and subsequently higher antioxidant activity. Buckwheat had the highest amount of total phenolics, with the highest DPPH radical scavenging activity and capacity for Fe3+ reduction, but it had the lowest lipid peroxidation inhibition ability.

The use of the microwave-activated sugar beet pulp as an alternative adsorbent material in combination with biological processes has been applied for the colored wastewater treatment. The maximum adsorption capacity of the crystal violet dye has been achieved relatively fast, during 315 s, with no dependence of the pH, when the adsorbent mass was 15 and 0.2 g/L of the initial dye concentration. The adsorption equilibrium data fully complied with the Temkin isotherm. The afterward biological decontamination of the adsorbed dye was related to the biodegradable potential of Streptomyces microflavus CKS6 cells. The microorganism revealed strong affinity toward the dye and minimal nutritional requirements for the metabolic activity expressions. Total dye decomposition occurred after 9 h, whereby lignin peroxidase enzyme has been recognized to be mainly involved in the process. According to the phytotoxicity analysis, no harmful residues were found in the decolorized working medium.

This study has explored the possibility to reuse the waste, spent coffee material for the cellulase enzyme immobilization. By the coffee surface modification with different activating agents, it was attempted to develop the convenient method for creation of a capable porous carrier for this purpose. Among the most common activating agents, glutaraldehyde, chlorine dioxide and hydrogen peroxide provided the most acceptable choice for the coffee surface modification. The changes that occurred on the coffee surface due to agents' treatment exposure were recorded by using of the FTIR spectra and SEM micrographs. The highest immobilization yield (55%) and immobilization efficiency (45%) were attained during 30 min of the treatment time, by employing of 30% chlorine dioxide aqueous solution within 6 mL/g activator/carrier ratio. The kinetic process was found to be predicted by the pseudo-second-order model. The cellulase immobilization onto the coffee surface provides an excellent base for increasing the enzyme availability to the substrate and enhancing the enzyme productivity, by offering the new perspectives to the industrial sector.

Predmet ove disertacije je iskorišćenje otpadnih sirovina koje su dobijene u procesu prerade jagorčevine (Primula veris), rastavića (Equisetum arvense) i hajdučke trave (Achillea millefolium) za dobijanje biološki aktivnih ekstrakata bogatih polifenolima..., The subject of this dissertation is the utilization of waste materials from the processing of primrose (Primula veris), horsetail (Equisetum arvense) and yarrow (Achillea millefolium) for obtaining biologically active and polyphenol-rich extracts...

Predmet ove doktorske disertacije je valorizacija nus-proizvoda agroindustrije: otpadnih rezanaca iz prerade šećerne repe i otpadne kafe, odnosno taloga, koji ostaje nakon pripreme napitaka u ugostiteljskim objektima..., The subject of this doctoral dissertation is the valorization of the by-products of agro-industry: sugar beet pulp waste, which remains after sugar processing, and spent coffee waste, which remains after preparing coffee in the industrial conditions...

U ovom radu proučavana je primena mehanohemije u sintezi prekursora aktivnih katalizatora reakcije transesterifikacije suncokretovog ulja. Ispitivan je uticaj različitih metoda sinteze – mehanohemijske, sa i bez dodatka vode i, radi poređenja, taložne – na osobine dobijenog prekursora CaZn2(OH)6·2H2O. Smeša prahova Ca(OH)2 i ZnO u molskom odnosu od 1:2 je podvrgnuta mlevenju u planetarnom mlinu tokom vremenskog perioda od 7 h, uz dodatak stehiometrijski potrebne količine vode, kao i bez dodatka vode. Izvršena je i sinteza prekursora katalizatora koprecipitacijom Ca(OH)2 i ZnO u vodenom rastvoru KOH radi poređenja. Prekursorski prahovi dobijeni u sve tri sinteze su višefazni, a njihova aktivacija izvršena je na temperaturi od 700 °C, čime su prevedeni u mešoviti oksid CaO·ZnO. Nakon kalcinacije, katalizatori su primenjeni u sintezi metil estara masnih kiselina (MEMK) suncokretovog ulja. Izvršena je i detaljna fizičko-hemijska karakterizaciju pripremljenih prahova, pre i posle kalcinacije: strukturna karakterizacija dobijenih prahova urađena je metodom rendgenske strukturne analize (XRD), dok je morfološka karakterizacija prahova nakon žarenja urađena skenirajućom elektronskom mikroskopijom (SEM/EDS). Takođe, primenjivana je i termijska analiza (TGA/DSC), i infracrvena (IC) spektroskopija radi dobijanja dodatnih informacija o strukturi i sastavu katalizatora. Kako pomenuti katalizatori daju različite prinose u reakciji transesterifikacije triglicerida sa metanolom, utvrđena je bitna povezanost između baznosti katalizatora pripremljenih različitim metodama i katalitičke efikasnosti. Mehanohemijska sinteza se, u odnosu na konvencionalnu koprecipitaciju, pokazala kao jednostavnija metoda koja ne uključuje rastvarač i dodatak alkalija koje mogu ometati uvid u stvarnu katalitičku aktivnost, a ujedno i kao efikasnija metoda za dobijanje aktivnih prekursora mešovitih oksida. Pored Ca(OH)2, kao polazni prah korišćen je i CaO, dobijen nakon žarenja Ca(OH)2 na 700 °C, kao i neg, The use of mechanochemical synthesis to obtain active catalyst precursors and testing their activity in transesterification of sunflower oil with methanol was investigated. The effect of different methods for preparation of catalytic precursor (CaZn2(OH)6·2H2O) – mechanochemical, with or without the addition of water and coprecipitation were investigated. A powder mixture of Ca(OH)2 and ZnO, with the molar ratio of 1:2, with, as well as without stoichiometrically required addition of water were milled in a planetary ball mill for a period of 7 hours. The classical coprecipitation procedure of Ca(OH)2 and ZnO powders in KOH solution was also performed for comparison. Precursor powders obtained after above mentioned procedures were multiphase, and their activation was carried out at temperature of 700 °C, in order to convert them to CaO·ZnO mixed oxide. After calcination, the catalytic activity was tested in the synthesis of fatty acid methyl esters (FAME) from sunflower oil. Structural characterization of obtained powders was done by X-ray diffraction (XRD) analysis, while morphology was observed by scanning electron microscopy (SEM/EDS). Thermal analysis (TG / DSC) was also applied, as well as infrared spectroscopy (IR) in order to obtain additional information on the structure and composition of the catalysts. The difference in the activity of mechanochemically synthesized catalysts and catalyst prepared by coprecipitation procedure could be related to the difference in their basicity. Mechanochemical synthesis has an advantage over the coprecipitation due to its relative simplicity – solid phase reactions without usage of solvents or precipitants which can interfere with catalytic activity. Using CaO, obtained after calcination of Ca(OH)2 at 700 °C, and lime as a starting powders was investigated in order to reduce the amount of carbonates present in the synthesized precursors. Influence of promoter (K2CO3) added to starting mixture of lime and ZnO for mechanochem

The subject of this dissertation is the utilization of waste materials from the processing of primrose (Primula veris), horsetail (Equisetum arvense) and yarrow (Achillea millefolium) for obtaining biologically active and polyphenol-rich extracts..., Predmet ove disertacije je iskorišćenje otpadnih sirovina koje su dobijene u procesu prerade jagorčevine (Primula veris), rastavića (Equisetum arvense) i hajdučke trave (Achillea millefolium) za dobijanje biološki aktivnih ekstrakata bogatih polifenolima...

This study has investigated the biodegradable potential of the Streptomyces microflavus CKS6 growing microbial cells for the colored waste water treatment. The Crystal violet and Safranin T basic dyes have been employed as a model compounds for decolorization evaluation by exploring the correlation with the other rate-dependent environmental parameters. Through the measuring of color reduction by UV Vis spectroscopic monitoring analysis, the results revealed well operational properties of Streptomyces microflavus CKS6 for the successful refinement of dyes contaminate water solutions. Optimized process parameters were found to be apparently mild, involving the use of the reaction temperature of 27-30 degrees C and pH 6-7. With the lower dye concentrations, the decolorization efficiency was found to be more effective and rapid, wherein the 1 mg/L of Crystal violet was removed within the 2.5 h of the treatment time, while the solution with the same content of the Safranin T dye required 30 h. A possible mechanism for the working medium decolorization was accomplished in two consecutive steps, by the primarily dye adsorption onto the bacterial cells surface, followed to biodegradation by the active microbial enzymatic system, wherein the lignin peroxidase acts a notable role. The phytotoxicity analysis of the degradation products revealed less toxicity to the plants, compared to parental chemicals. In addition, the adaptation of individual dye optimized parameters was effectively implemented in the real waste water system containing the mixture of these two dyes. The overall results may postulate that Streptomyces microflavus CKS6 may be promising applicants for dye contaminated Water treatment.

The production of dextransucrase (DS) by Leuconostoc mesenteroides T3, novel isolate from water kefir grain, was studied and optimized. Bacterial supernatant reached activity of 3.1 U/ml when the culture was grown at 23 degrees C and under static culture condition using classical Tsuchiya medium for DS production. The increase of sucrose concentration to 7% led to an increase of DS activity by 52% compared to the control. Medium with 2% beef extract and 1% yeast extract resulted in 4.52 U/ml, which was 47% higher than in the control (with 2% yeast extract). Finally, the increase of K2HPO4 concentration from 2 to 3% resulted in the increased enzyme activity by 28%. Enzyme purified by polyethylene glycol 400 fractionation displayed maximum activity at 30 degrees C and pH 5.4. Zymogram analysis confirmed the presence of DS of approximately 180 kDa. The addition of divalent cations Ca2+, Mg2+, Fe2+ and Co2+ led to a minor increase of DS activity, while the addition of Mn2+ was the most prominent with 73% increase. These findings classify dextransucrase from Leuconostoc mesenteroides T3 as promising candidate for production of dextran, which has numerous applications in various industries.

The purpose of this study was to examine the antioxidant properties of 70% ethanolic extracts of cereal grains and their different morphological fractions. Wheat (Triticum durum L.), barley (Hordeum vulgare L.), rye (Secale cereale L.), and buckwheat (Fagopyrum esculentum) were used. The total phenolic content (TPC), determined by the Folin-Ciocalteu method and antioxidant activities (AOA) were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, ferric ion-reducing antioxidant power (FRAP) and thiobarbituric acid (TBA) methods. The following hierarchy of antioxidant activity was provided for 70% ethanolic extracts originated from whole grain: buckwheat gt barley gt wheat gt rye. In respect to hulls, the antioxidant hierarchy was the same. The outer layers of grains had higher amount of phenolic compounds and subsequently higher antioxidant activity. Buckwheat had the highest amount of total phenolics, with the highest DPPH radical scavenging activity and capacity for Fe3+ reduction, but it had the lowest lipid peroxidation inhibition ability., Cilj rada je bio da se ispita antioksidativna aktivnost etanolnog ekstrakta zrna cerealija i njihovih morfoloških frakcija. Ispitivani se : pšenica (Triticum durum L.), ječam (Hordeum vulgare L.), raž (Secale cereale L.) i heljda (Fagopyrum esculentum). Određivan je sadržaj ukupnih fenola (TPC) metodom po Folin-Ciocalteu i antioksidativna aktivnost (AOA) po tri najčešće korišćene metode: DPPH (sposobnost neutralizacije 2,2-difenil-1-pikrilhidrazil radikala), FRAP (antioksidativna sposobnost redukcije Fe III jona) i TBA ( metoda sa tiobarbiturnom kiselinom). Antioksidativna aktivnost etanolnog ekstrakta celog zrna opada u sledećem nizu: heljda gt ječam gt pšenica gt raž. Isti odnos je dobijen i za mekinje. Spoljni slojevi zrna imaju veći sadržaj polifenola, pa sledstveno tome i veću antioksidativnu aktivnost. Heljda sadrži najviše polifenola i ima najveću antioksidativnu aktivnost određenu DPPH i FRAP metodom, ali ima najmanju sposobnost inhibicije lipidne peroksidacije.

U radu je ispitivana antioksidativna aktivnost nativnog i fermentisanog crvenog pasulja, odnosno njihovih polifenolnih i peptidnih frakcija. Utvrđeno je da antioksidativna aktivnost, određena metodom DPPH, FRAP i TBA, značajnije raste kod uzoraka fermentisanih bakterijom L. rhamnosus u odnosu na uzorak ferementisan S. cerevisiae. Proteinski izolat ima malu antioksidativnu aktivnost, koja raste sa stepenom hidrolize proteina. Proteolitički enzim Savinse™ u koncentraciji 2,5% se može uspešno koristiti za hidrolizu proteina pasulja. Pod optimalnim uslovima za delovanje enzima, stepen hidrolize posle 3h je 44%. Dobijeni hidrolizat ima znatno bolji antioksidativni potencijal, koji je rezultat helirajućeg delovanja nekih aminokiselina, ali i sinergističkog delovanja aminokiselina i zaostalih polifenola. Potpuni kiselinski hidrolizat ima najmanji sadržaj polifenola, ali i najveći antioksidativni potencijal., In this study we investigated the antioxidant activity of native and fermented red bean, or their polyphenol and peptide fractions. It was found that the antioxidant activity determined by DPPH, FRAP and TBA, significant increases in samples fermented by bacteria L. rhamnosus in relation to the sample with S. cerevisiae. Protein isolate has a low antioxidant activity, which increases with the degree of hydrolysis of proteins. Proteolytic enzyme Savinse ™ at 2.5% concentration can be successfully used for the hydrolysis of protein in beans. Under optimal conditions for enzyme activity, the degree of hydrolysis after 3h was 44%. The obtained hydrolyzate has a much better antioxidant potential, which is the result of chelate action of some amino acid and synergistic effects of amino acids and polyphenols backlog. Complete acid hydrolyzate had the lowest polyphenol content, but also the greatest antioxidant potential.

Predmet ove disertacije je iskorišćenje otpadnih sirovina, poljoprivrednog i industrijskog porekla, za proizvodnju enzima celulaza i amilaza pomoću novoizolovanog bakterijskog soja Paenibacillus chitinolyticus CKS1. Optimizacija procesa proizvodnje hidrolitiĉkih enzima celulaza i amilaza vršena je korišćenjem komercijalnih supstrata i otpadnih sirovina ivariranjem uticaja pojedinaĉnih parametara primenom metode planiranog eksperimenta i matematiĉko-statistiĉka obrade eksperimentalnih podataka – metode odzivnih površina (RSM). Proces proizvodnje celulalaza (endoglukanaza i egzoglukanaza) je optimizovan na razliĉitim komercijalnim podlogama ali i na otpadnim sirovinama. Soj CKS1 je pokazao predominantnu aktivnost egzoglukanaza (iskazanih kao Avicelazna aktivnost) što je netipiĉno za većinu bakterijskih vrsta. Rezultati su pokazali da se P. chitinolyticus CKS1 moţe koristiti za dobijanje celulazau komercijalnoj podlozi (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,532 U/mL i 1,83 U/mL, pojedinaĉno), ali i na otpadnim sirovinama: otpadnom lekovitom bilju (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,203 U/mL i 1,94 U/mL, pojedinaĉno) i piljevini (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,145 U/mL i 1,75 U/mL, pojedinaĉno). Soj CKS1 je pokazao mogućnost rasta i proizvodnje dve vrste celulaza: endoglukanaza (iskazanih kao karboksimetil celulazna (CMC-azna) aktivnost i egzoglukanaza (iskazanih kao Avicelazna) aktivnost tokom svog rasta na ĉvrstom otpadnom supstratu- repinom rezancu (maksimalna CMC-azna i Avicelazna aktivnost iznosi 3,159 U/g i 4,840 U/g). Metodom odzivnih površina optimizovana je proizvodnja endoglukanaza i egzoklukanaza u podlozi obogaćenoj jeĉmenim mekinjama (maksimalna CMC-aza i Avicelazna aktivnost iznosi 0,405 U/mL i 0,433 U/mL, pojedinaĉno). Dobijena je nešto niţa vrednostAvicelazne aktivnosti, ali optimizovani procesi jasno ukazuju na mogućnost njihovog korišćenja, pošto su u skladu sa principima odrţive proizvodnje i brige o, The subject of this thesis is the utilization of waste materials of agricultural and industrial origin, for the production of enzymes cellulases and amylases using a novel isolated bacterial strain Paenibacillus chitinolyticus CKS1. Optimization of the process of production of hydrolytic enzymes cellulases and amylases was performed using commercial substrates and waste materials by varying the influence of individual parameters but also by employing the method of the planned experiment and mathematical-statistical processing of experimental data - Response Surface Methodology (RSM). The process of producing cellulase (CMC-ase and Avicelase) was optimized using various commercial substrates but also using waste materials.The strain CKS1 showed predominant exoglucanase (Avicelase) activity which is not typical for most bacterial species. Results showed that P.chitinolyticus CKS1 could be used for cellulase (CMC-ase and Avicelase) production, in a liquid medium with comercial substrates (with maximum CMCase and Avicelase activity of 0,532 U/mL and 1,83 U/mLrespectively), but also in a medium with waste substrates: waste medicinal herbs (with maximum CMCase and Avicelase activityof 0,203 U/mL and 1,94 U/mL, respectively) and sawdust (with maximum CMCase and Avicelase activity of 0,145 U/mL and 1,75 U/mL, respectively)...

The subject of this thesis is the utilization of waste materials of agricultural and industrial origin, for the production of enzymes cellulases and amylases using a novel isolated bacterial strain Paenibacillus chitinolyticus CKS1. Optimization of the process of production of hydrolytic enzymes cellulases and amylases was performed using commercial substrates and waste materials by varying the influence of individual parameters but also by employing the method of the planned experiment and mathematical-statistical processing of experimental data - Response Surface Methodology (RSM). The process of producing cellulase (CMC-ase and Avicelase) was optimized using various commercial substrates but also using waste materials.The strain CKS1 showed predominant exoglucanase (Avicelase) activity which is not typical for most bacterial species. Results showed that P.chitinolyticus CKS1 could be used for cellulase (CMC-ase and Avicelase) production, in a liquid medium with comercial substrates (with maximum CMCase and Avicelase activity of 0,532 U/mL and 1,83 U/mLrespectively), but also in a medium with waste substrates: waste medicinal herbs (with maximum CMCase and Avicelase activityof 0,203 U/mL and 1,94 U/mL, respectively) and sawdust (with maximum CMCase and Avicelase activity of 0,145 U/mL and 1,75 U/mL, respectively)..., Predmet ove disertacije je iskorišćenje otpadnih sirovina, poljoprivrednog i industrijskog porekla, za proizvodnju enzima celulaza i amilaza pomoću novoizolovanog bakterijskog soja Paenibacillus chitinolyticus CKS1. Optimizacija procesa proizvodnje hidrolitiĉkih enzima celulaza i amilaza vršena je korišćenjem komercijalnih supstrata i otpadnih sirovina ivariranjem uticaja pojedinaĉnih parametara primenom metode planiranog eksperimenta i matematiĉko-statistiĉka obrade eksperimentalnih podataka – metode odzivnih površina (RSM). Proces proizvodnje celulalaza (endoglukanaza i egzoglukanaza) je optimizovan na razliĉitim komercijalnim podlogama ali i na otpadnim sirovinama. Soj CKS1 je pokazao predominantnu aktivnost egzoglukanaza (iskazanih kao Avicelazna aktivnost) što je netipiĉno za većinu bakterijskih vrsta. Rezultati su pokazali da se P. chitinolyticus CKS1 moţe koristiti za dobijanje celulazau komercijalnoj podlozi (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,532 U/mL i 1,83 U/mL, pojedinaĉno), ali i na otpadnim sirovinama: otpadnom lekovitom bilju (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,203 U/mL i 1,94 U/mL, pojedinaĉno) i piljevini (maksimalna CMC-azna i Avicelazna aktivnost iznose 0,145 U/mL i 1,75 U/mL, pojedinaĉno). Soj CKS1 je pokazao mogućnost rasta i proizvodnje dve vrste celulaza: endoglukanaza (iskazanih kao karboksimetil celulazna (CMC-azna) aktivnost i egzoglukanaza (iskazanih kao Avicelazna) aktivnost tokom svog rasta na ĉvrstom otpadnom supstratu- repinom rezancu (maksimalna CMC-azna i Avicelazna aktivnost iznosi 3,159 U/g i 4,840 U/g). Metodom odzivnih površina optimizovana je proizvodnja endoglukanaza i egzoklukanaza u podlozi obogaćenoj jeĉmenim mekinjama (maksimalna CMC-aza i Avicelazna aktivnost iznosi 0,405 U/mL i 0,433 U/mL, pojedinaĉno). Dobijena je nešto niţa vrednostAvicelazne aktivnosti, ali optimizovani procesi jasno ukazuju na mogućnost njihovog korišćenja, pošto su u skladu sa principima odrţive proizvodnje i brige o

This study aims to investigate the biological processes related to the biodegradable potential of growing microbial cells for contaminated water treatment. Thus, the use of the Streptomyces fulvissimus CKS 7 (CKS7) has been evaluated for decolorizing efficiency of a solution containing a cationic triphenylmethane dye, crystal violet. The color reduction was monitored by UV-Vis spectroscopic analysis, through changes in their absorption spectrum and comparing the results with those of the respective controls. It was found that the CKS7 performed well and reached up to 100% effectiveness. The required process parameters have been apparently mild and include the reaction temperature of 27-30 degrees C, 10% inoculum size, under shaking conditions, whereas the time course of decolorization had been concentration dependent. A possible mechanism for removing dye from the working medium was accomplished in two steps: the binding of the dye on the bacterial cell surface, in addition to the dye biodegradation by the bacterial intracellular enzymes. After one cycle of the complete dye removal, the adapted culture was successfully reused for the same purpose. The phytotoxicity analysis revealed that non-toxic compounds were present in decolorized medium, indicating that the CKS7 bacteria seem to be a promising application for contaminated water treatment.

Molasses and sugar beet pulp, by-products in sugar industry, are produced in large amounts annually which create disposal problems. High sugar content in sugar beet molasses enables its use for fermentations while sugar beet pulp represents an interesting cheap raw material source for enzyme production. beta-amylase production by a new strain Paenibacillus chitinolyticus CKS1 was performed using a molasses and sugar beet pulp. Two different pretreatments of SBP were investigated while scanning electron microscopy (SEM) showed immobilization of P. chitinolyticus CKS1 cells onto alkali treated SBP. The statistical model was design via Central Composite Design (CCD) under the Response Surface Methodology (RSM) using three variables (inoculum concentration, time of incubation and sugar beet pulp concentration) for obtaining maximum beta-amylase activity. An approximately 3.66-fold increase in beta-amylase production was achieved in the optimized medium as compared with the nonoptimized medium. A maximum beta-amylase production 2.237 U/ml was achieved under optimal conditions inoculum concentration 10%, incubation time 83.07 h and SBP concentration 3%. A high performance liquid chromatography showed that P. chitinolyticus CKS1 hydrolyzed starch to form maltose as a major product. These results indicate that beta-amylase production could be improved using these kind of processes. Also, taking into consideration cheap substrates, economic side of the process is justified.

Cellulases are industrially important enzymes with a potential to convert cellulose into fermentable sugars. Novel bacterial isolate Paenibacillus sp. CKS1 was tested for cellulase activity and the optimal conditions for carboxymethyl cellulase (CMCase) production were determined. Maximum CMCase activity was obtained in the third passage of the bacterial culture after 3 days of incubation at 30 degrees C. Cellobiose and yeast extract was the optimal source of carbon and nitrogen for induction of CMCase activity. In addition, with initial pH 7 of the medium and 40 ml of working volume in 500 ml culture flasks with shaking at 150 rpm, the maximum CMCase activity in a crude culture supernatant reached value of 0.532 +/- 0.006 U/ml. For crude CMCase, optimal temperature was 50 degrees C and optimal pH 4.8, respectively. HPLC analysis confirmed the bacterium is capable to hydrolise CMC to glucose and other soluble sugars.

This study has explored the feasibility of using spent coffee grounds as a good supporting material for the Paenibacillus chitinolyticus CKS1 cellulase immobilization. An optimal operational conditions in a batch-adsorption system were found to be: carrier mass of 12 g/L, under the temperature of 45 degrees C and no pH adjustments. The immobilization yield reached about 71%. An equilibrium establishment between the cellulase and the carrier surface occurred within 45 min, whereas the process kinetics may be predicted by the pseudo-second-order model. An immobilized cellulase preparation expressed very good avicelase activity, this reached up to 2.67 U/g, and revealed an improved storage stability property, compared to free enzyme sample counterpart. The addition of metal ions, such as K+ and Mg2+ did not affect positively immobilization yield results, but on the contrary, contributed to an improved bio-activities of the immobilized cellulase, thus may be employed before each enzyme application. The method developed in this study offers a cheap and effective alternative for immediate enzyme isolation from the production medium and its stabilization, compared to other carriers used for the immobilization.

Predmet ove disertacije je valorizacija otpadne kafe zaostale nakon pripreme napitaka i razmatranje mogućnosti njene praktične primene. Kafa i njeni produkti, već godinama unazad, se smatraju nutritivno bogatim, usled prisustva bioaktivnih jedinjenja sa izrazitim antioksidativnim potencijalom. Antioksidativni kapacitet kafe pripisuje se, u najvećoj meri, visokom sadržaju jedinjenja koja pripadaju grupi polifenola. Njihova koncentracija u sirovim zrnima varira u zavisnosti od vrste, porekla i uslova gajenja, a u pečenoj kafi od načina obrade i termičkog tretmana. Glavna polifenolna komponenta u kafi je hlorogenska kiselina, koja putem ove sirovine predstavlja i najznačajniji hranljivi izvor za čoveka. Izolovanjem ovih jedinjenja, otvara se mogućnost zamene sintetičkih aditiva u hrani sastojcima prirodnog porekla. Dobijeni ekstrakti se mogu inkorporirati u hranu i/ili farmaceutske proizvode sa ciljem povećanja njihove nutritivne vrednosti i stabilnosti. Mogu, takođe, biti i sastojci nove funkcionalne hrane..., This thesis explores the valorization of spent coffee grounds, the solid waste remained after coffee beverage preparation, thus considering the possibility of its practical application. Coffee and its products are considered to be nutritionally rich, due to the presence of bioactive compounds with distinctive antioxidant potential. The antioxidant capacity of coffee is mainly attributed to the high content of compounds belonging to the group of polyphenols. Their concentration in the raw grains varies depending on the type, origin and growing conditions, whereas in roasted coffee by means of processing and heat treatment. The main polyphenol component in coffee is chlorogenic acid; wherein, coffee represents a major source of chlorogenic acid in the human diet. By isolating of these compounds, there is the great possibility of replacing synthetic additives in food ingredients with ones of natural origin. The obtained extracts may be incorporated into food and/or pharmaceutical products in order to increase their nutritional value and stability, or may also be the ingredients of new functional foods...