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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.

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.

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.

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...

This paper has demonstrated the valorization of inexpensive and readily available restaurant waste containing most consumed food and beverage residues as adsorbents for methylene blue dye. Coffee, tea, lettuce and citrus waste have been utilized without any pre-treatment, thus the adsorption capacities and dye removal efficiency were determined. Coffee waste showed the highest adsorbent capacity, followed by tea, lettuce and citrus waste. The dye removal was more effective as dye concentration increases from 5 up to 60 mg/L. The favorable results obtained for lettuce waste have been especially encouraged, as this material has not been commonly employed for sorption purposes. Equilibrium data fitted very well in a Freundlich isotherm model, whereas pseudo-second- order kinetic model describes the process behavior. Restaurant waste performed rapid dye removal at no cost, so it can be adopted and widely used in industries for contaminated water treatment., Metilen plavo je bazna boja sa strukturom heterocikličnog aromatičnog jedinjenja, koja se u dobu savremenog društva često koristi za bojenje raznih tipova materijala. Efluenti iz industrije boja predstavljaju jednu od najproblematičnijih vrsta otpadnih voda za tretiranje, usled njihove velike biološke i hemijske potrebe za kiseonikom. Pored toga, toksičnost i teško razgradiva priroda boja mogu značajno uticati na fotosintetičku aktivnost vodenog sveta. Adsorpcijom na čvrstim nosačima mogu se ukloniti, odnosno, svesti na minimum razni tipovi zagađivača, zbog čega ova tehnika ima široku primenu u kontroli zagađenja voda. S tim u vezi, ispitivana je mogućnost iskorišćenja sirovog otpada iz restorana za adsorpciju i uklanjanje boje metilen plavo iz vodenih rastvora. U radu su određivani adsorpcioni kapaciteti otpadnih sirovina najčešće konzumiranih namirnica, uključujući kafu, čaj, zelenu salatu i mešavinu citrusnog voća (citrusa). Proces adsorpcije izveden je u šaržnom režimu, uz mešanje na tresilici, u uslovima ambijentalne temperature. Efikasnost procesa praćena je u zavisnosti od promene koncentracije boje u radnim rastvorima. Pokazano je da otpadna kafa ispoljava najviši adsorpcioni kapacitet, a za njom otpadni čaj, zelena salata i citrusi, redom. Nakon 30 min odigravanja reakcije, na kafi se vezalo gotovo 90%, dok na čaju 80%, zelenoj salati 60% i citrusima 30% od početne koncentracije rastvora boje. Vezivanje boje na adsorbentima bilo je efikasnije u slučajevima kada je koncentracija rastvora boje rasla od 5 do 60 mg/L. Na osnovu ispitivanja najčešće primenjivanih modela izo- termi za definisanje adsorpcione ravnoteže, pronađeno je da su ravnotežni podaci, u slučajevima svih vrsta adsorbenata, bili u skladu sa Frojndlihovom adsorpcionom izotermom. S tim u vezi, smatra se da je proces odigravanja reakcije baziran na interakcijama između molekula boje i funkcionalnih grupa na heterogenoj površini adsorbenata. Kinetika i mehanizam reakcija opisani su po principu mod

Activated carbons from spent coffee grounds have been prepared for column adsorption of main green tea polyphenol (-)-epigallocatechingallate (EGCG). The response surface methodology was used to estimate the influence of testing variables on process effectiveness, and a good agreement was found between experimental and predicted data. Adsorption of EGCG occurred in a high ratio, and desorption process in predominantly water solutions was proven to be feasible, and thus, it recovered more than 80 % of the polyphenols. Further, the adsorbent has expressed the selectivity property, revealing the removal of EGCG in much higher content compared to other polyphenol's group. Obtained fractions of recovered EGCG have undergone just a slight bioactive loss, indicating that such adsorption/desorption performance was mild and appropriate for product stabilization. The kinetic data followed the pseudo-second-order model, and the equilibrium data fitted very well in a Freundlich isotherm equation. The investigation into binding of EGCG from green tea extract revealed that transfer of the results from model experiments to more complex real food systems may be feasible. The favorable results from the overall process suggest that coffee residues may be promising alternatives to organic resins for polyphenols recovery through improved cost efficiency.

The importance of coffee waste utilization is based on the fact that it contains a large amount of biologically valuable components. Preparation of espresso coffee produces substantial quantities of polyphenolic acids that have a significant antioxidant activity. In this work, the contents of polyphenols and antioxidant activity of extracts obtained from spent espresso coffee were analyzed using different solvent systems. A 70% solution of methanol and a 70% solution of ethanol and distilled water were used as solvents. The total amounts of polyphenols were determined by the Folin-Ciocalteu method, while the antioxidant activities were determined by DPPH inhibition (2,2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power). Both methods confirmed that the order of antioxidant activity of obtained dried extracts is as follows: water extract lt methanol extract lt ethanol extract, which was in accordance with their polyphenols content. Mild prooxidant activity was observed in the concentration of 200 μg/ml while investigating the DPPH inhibition. Prooxidant activity is a characteristic of some polypenolic acids that is considered to be one of the mechanisms of anticancer activity. The inhibition of DPPH radical, expressed by IC50 values, was compared with the results of the commercial antioxidants such are ascorbic acid and BHT (butylated hydroxytoluene). Comparing the IC50 values of ascorbic acid and BHT with the IC50 values of tested extracts it can be concluded that waste coffee extracts could be a good source of natural antioxidants., U radu je određivan sadržaj polifenola i antioksidativna aktivnost osušenih ekstrakata otpadne espreso kafe dobijenih primenom različitih rastvarača. Kao rastvarači, u ekstrakcijama su korišćeni 70% rastvor metanola, 70% rastvor etanola i destilovana voda. Određen je ukupan sadržaj polifenola i antioksidativna aktivnost metodama inhibicije DPPH (2,2-difenil-1-pikrilhidrazil) radikala i FRAP (engl. ferric reducing antioxidant power). Inhibicija DPPH radikala je izražena preko IC50 vrednosti, a rezultati su poređeni sa rezultatima komercijalnih antioksidanata, askorbinskom kiselinom i BHT (butil-hidroksi-toluen). Obe metode su potvrdile da je redosled antioksidativne aktivnosti dobijenih suvih ekstrakta sledeći: vodeni ekstrakt lt metanolni ekstrakt lt etanolni ekstrakt. Poređenjem sa vrednostima IC50 za askorbinsku kiselinu i BHT može se zaključiti da ekstrakti otpadne kafe mogu biti dobar izvor prirodnih antioksidanata.