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The agricultural raw industry generates large amounts of annually by- -products that create disposal problems. Hitherto, there have been no reported papers about the simultaneous production of cellulase and β-amylase from these raw materials using Paenibacillus sp. that would reduce the costs. Thus, in this paper simultaneous cellulase (CMC-ase and avicelase) and β-amylase production using barley bran and the application of the natural isolate Paenibacillus chitinolyticus CKS1 and potential enzymes in the hydrolysis process was studied. Response surface methodology was used to obtain the maximum enzyme activity (CMC-ase 0.405 U mL-1, avicelase 0.433 U mL-1 and β-amylase 1.594U mL-1). Scanning electron microscopy showed degradation of the lignocellulosic–starch structure of barley bran after fermentation. The CKS1 bacterial supernatant, which contains cellulases and β-amylase, could hydrolyze cotton fibres and barley bran, respectively. The main products after enzymatic hydrolysis of cotton fibres and barley bran, glucose (0.117 g gmat -1) and maltose (0.347 g gmat -1), were quantified by high performance liquid chromatography (HPLC). The produced enzymes could be used for hydrolysis of cotton fabric and barley bran to glucose and maltose, respectively. Application of simultaneous enzymes production using an agricultural by-product is economically and environmentally accepted and moreover, valuable biotechnological products, such as glucose and maltose, were obtained in this investigation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31035 and Grant no. III 45020]

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.

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.

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°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°C and optimal pH 4.8, respectively. HPLC analysis confirmed the bacterium is capable to hydrolise CMC to glucose and other soluble sugars. [Projekat Ministarstva nauke Republike Srbije, br. TR 31035]