Application of microbial levan as a new component for production of graft copolymer with polystyrene

Polysaccharides based on fructose, also called fructans, are synthetized from sucrose by some plant species and many bacteria, fungi and Archaea. Levan is an exopolysaccharide composed of fructose units and has numerous applications in personal care and cosmetics, medicine and food industry. Polystyrene is the most widespread polymer for plastic production due to its low costing and easy production. Degradation of polystyrene is longterm process, therefore incorporating natural polymers is the desirable approach. In the present study, levan-polystyrene graft copolymer (L-g-PS) was synthetized, characterized and influence of reaction time on grafting reaction at two temperatures was investigated. Levan was isolated after cultivation Bacillus licheniformis NS032. Syntheses of L-g-PS were performed by the free radical reaction using K2S2O8 as initiator. Grafting reactions proceeded in nitrogen atmosphere, at 55ºC and 70ºC and reaction time ranged between 15 and 210 min. FTIR spectra and XRD patterns were recorded using a Thermo Nicolet 6700 Spectrophotometer and Philips PW-1710 automated diffractometer, respectively. The formation of L-d-g-PS was confirmed by FTIR spectra which displayed the presence of all characteristic peaks for both component and X-ray diffractograms which showed amorphous nature of copolymer. Compared to other reaction parameters, the temperature of 70ºC and time of 45 min was more optimal showing higher percentage of grafting

Fina strukturna analiza fungalnog polisaharida pululana dobijenog pomoću Aureobasidium pullulans, soj CH-1

The structure of pullulan, the extracellular α-D-glucan elaborated by the yeast-like fungus Aureobasidium pullulans, may be described as a linear α-D-glucan consisting of maltotriosyl repeat units connected terminally by (1->6)-α-D-glucosidic bonds. Occasionally some of maltotriosyl residues are replaced by higher oligosaccharide units, most frequently with maltotetraosyl residues. Using the susceptibility of pullulan CH-1 (obtained from strain CH-1 of Aureobasidium pullulans) to hydrolysis catalysed by porcine alpha-amylase, the polysaccharide was cleaved and the fragments obtained fractionated by gel-permeation chromatography. The heterogenous size of the fragments indicates that there is no apparent regular distribution of tetrasaccharide units in the pullulan chain. Enzymatic digestion of pullulan CH-1 using pullulanase, followed by gel-permeation chromatography of the resulting digest confirmed these results as did preparative paper chromatography and CI mass spectrometry of the separated components, i.e., that maltotetraosyl units (about 7 %) are building units of pullulan CH-1.Pululan, ekstracelularni polisaharid koji proizvodi kvascu slična gljiva Aureobasidium pullulans, jeste linearni glukan čiju strukturu pretežno čine polimaltotriozil ostatci povezani međusobno α-(1->6)-glikozidnim vezama. Varijacije u strukturi ovog polisaharida mogu nastati usled zamene maltotrioznih ostataka na pojedinim mestima polimernog lanca oligosaharidnim fragmentima dužeg niza, najčešće maltotetraoznim ostacima. U ovom radu ispitan je pululan koji proizvodi A. pullulans, soj CH-1, enzimskom hidrolizom sa pankreasnom α-amilazom i pululanazom, sa ciljem da se utvrdi da li i u kom odnosu ovaj polisaharid sadrži oligosaharidne fragmente, kao i da se odredi dužina oligosaharidnog niza, odnosno broj monosaharidnih ostataka koji ulaze u njegov sastav. Primenom uobičajenih analitičkih metoda (gel-filtraciona hromatografija, metilaciona analiza, preparativna hromatografija kombinovana sa masenom spektrometrijom metilovanih oligosaharidnih alditola), utvrđeno je da su maltotetraozne jedinice (oko 7 %) integralni deo polisaharidnog lanca pululana CH-1. Raspored ovih jedinica je nasumičan

Antioxidant and antimicrobial potentials of champignon mushroom

Fruiting bodies of some wild and cultivatable mushrooms contain medicinal compounds which are being used in traditional medicines and cosmetics. Champignon mushroom (Agaricus bisporus) is the most widely cultivated species of edible mushroom worldwide. This paper focuses on antioxidant and antimicrobial importance of A bisporus. Water-soluble polysaccharide-enriched fraction was isolated from the dry carpophores of Agaricus bisporus. Antioxidant activities were investigated using in vitro assay systems: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and chelating ability on ferrous ions. Antimicrobial activity was tested against Gram positive and Gram negative bacteria in vitro by disk diffusion method in order to determine the zones of inhibition. At concentrations of 0.1-10 mg/ml, the scavenging abilities of A bisporus ranged between 12.3-75.5 %. The radical scavenging ability of the positive controls-tocopherol and ascorbic acid, at the concentrations of 0.1-20 mg/ml, were between 79.9-80.8 and 80.6-91.1 %, respectively. Polysaccharide extract from A bisporus showed steadily increasing chelating ability as concentrations increased to 88.2 % at 20 mg/ml. The chelating ability of the citric acid was between 7.2-10.7 %, at the concentrations of 0.1-20 mg/ml. The study of antimicrobial potential of polysaccharide extract showed more potent activity against Gram-positive Enterococcus faecalis ATCC 49532 (26.7 ± 0.2 mm), Bacillus cereus 10876 (27.5 ± 0.4 mm), Geobacillus stearothermophylus ATCC 7953 (22.8 ± 0.3 mm) than Gram-negative bacteria Pseudomonas aeruginosa ATCC 35032 (10.4 ± 0.6 mm), Proteus hauseri ATCC 13315 (12.1 ± 0.1 mm) Escherichia coli (0157:H7) 35150 (12.7 ± 0.4 mm) with exception of Klebsiella pneumoniae ATCC 27736 (22.3 ± 0.2 mm)

Study of copper adsorption on aminofunctionalized macroporous poly(gma-co-egdma)

Macroporous crosslinked copolymer of glycidyl methacrylate and ethylene glycoldimethacrylate (PGME) was synthesized by suspension copolymerisation and modified by ring-opening reaction of epoxy groups with ethylene diamine, diethylene triamine and triethylene tetramine. The uptake of copper ions by amino-functionalized macroporous PGME from aqueous solutions was investigated in batch experiments. The equilibrium data fitted well with the Langmuir model.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Kinetics of heavy metal sorption on macroporous vinylpyridine based copolymer

Sorption of copper, nickel and cobalt on macroporous crosslinked copolymer of 4- vinylpyridine and ethylene glycol dimethacrylate, PVPE, was studied. The kinetics models (pseudo-first and pseudo-second order equations) were applied to the data obtained from batch sorption experiments at room temperature. The sorption of heavy metals was found to proceed according to pseudo-second order kinetics.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Čimbenici predispozicije odgovorni za pojavu bakterijskog purulentnog meningoencefalitisa

Bacterial purulent meningoencephalitis (BPME) is a life-threatening infectious disease caused by various pyogenic bacteria. The disease is defined as the inflammatory process of leptomeninges (visceral layer, pia mater and arachnoid membrane) and brain parenchyma with exudates in the subarachnoid space and surrounding brain structures. The aim of the study was to define the predisposing factors responsible for the occurrence of BPME, as well as the possible correlation between the presence of predisposing factors and patient demographic characteristics, etiology and outcome of the disease. This retrospective-prospective study included 90 patients with BPME confirmed by clinical, neuroradiological and laboratory findings. Multivariate logistic regression models were fitted to analyze the impact of the predisposing factors on the disease outcomes. Predisposing factors that were related to BPME were found in 61% of patients. Cranial trauma as the leading factor was recorded in 23.3% of patients, followed by previous neurological disease in 14.4% of patients, while 13 patients were exposed to previous chemotherapy or long-term corticosteroid therapy. Cardiovascular diseases were reported in 12.2% and diabetes in 7.8% of patients. The existence of cardiovascular diseases significantly influenced unfavorable outcome of the disease, i.e. ”deceased” in comparison to ”cured” (OR=8.418; 95% CI=1.007-76.270), independently of age and gender. None of the examined predisposing factors was significantly related to the ”recovered with sequels” outcome as compared with ”cured” outcome. Older age and presence of cardiovascular disease as a predisposing factor significantly increased the odds of the BPME unfavorable outcome ”deceased” as compared to ”cured” outcome.Bakterijski gnojni (purulentni) meningoencefalitis (BPME) je za život opasna zarazna bolest uzrokovana različitim piogenim bakterijama. Bolest je definirana kao upalni proces leptomeninga (visceralni sloj, pia mater i arahnoidna membrana), parenhima mozga s eksudatom u subarahnoidnom prostoru i okolnim strukturama mozga. Cilj istraživanja bio je definirati predisponirajuće čimbenike koji su odgovorni za pojavu BPME, kao i moguću povezanost prisutnosti predispozicije i demografskih karakteristika bolesnika, etiologije i ishoda bolesti. Ovo retrospektivno-prospektivno istraživanje je obuhvatilo 90 bolesnika različite dobi s BPME kod kojih je bolest potvrđena na osnovi kliničkih, neuroradioloških i laboratorijskih nalaza. Utjecaj predisponirajućih čimbenika na ishod bolesti analiziran je logističkom regresijom. Čimbenici predispozicije vezani za pojavu BPME su pronađeni u 61% bolesnika. Vodeći čimbenik je bila trauma lubanje zabilježena u 23,3% bolesnika, zatim prethodna neurološka bolest u 14,4% bolesnika, dok je 13 bolesnika bilo na kemoterapiji ili dugotrajnoj terapiji kortikosteroidima. Kardiovaskularne bolesti bile su prisutne u 12,2%, a dijabetes u 7,8% bolesnika. Postojanje kardiovaskularnih bolesti bilo je značajan predskazatelj smrtnosti kao nepovoljnog ishoda bolesti u usporedbi s ozdravljenjem (OR=8,418; 95% CI=1,007-76,270), nezavisno od spola i dobi. Nijedan predisponirajući čimbenik nije bio statistički značajno povezan s pojavom drugog nepovoljnog ishoda bolesti, “oporavka s posljedicama” u usporedbi s ozdravljenjem. U zaključku, bolesnici s BPME starije životne dobi i s postojećim kardiovaskularnim bolestima imali su značajno veću vjerojatnost nepovoljnog ishoda ”smrti” u usporedbi s ozdravljenjem

Polisaharidi viših gljiva - bioloska uloga, struktura i antioksidativna aktivnost

The fungal polysaccharides attract a lot of attention due to their multiple challenging biological properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypolipidemic, immunomodulatory and immune-stimulatory activities, which all together make them suitable for application in many quite distinctive areas, such as food industry, biomedicine, cosmetology, agriculture, environmental protection and waste water management. This article presents results with respect to biological properties, structure and procedures related to the isolation and activation of polysaccharides of higher fungi. It is considered and presented along with a review of the critical antioxidative activity and possible influence of the structural composition of polysaccharide extracts (isolated from these higher fungi) upon their antioxidative properties.Polisaharidi gljiva privlače veliku pažnju zbog svojih interesantnih bioloskih svojstava kao sto su: antitumorno, antivirusno, antikomplementarno, antikoagulaciono, hipolipidemijsko dejstvo, kao i imunomodulatorska i imunostimulativna aktivnost, sto ih sve čini pogodnim za primenu u mnogim oblastima, među kojima su i prehrambena industrija, kozmetika, biomedicina, poljoprivreda, zastita životne sredine i otpadnih voda. Oksidativna ostecenja prirodnih i industrijski pripremljenih namirnica predstavljaju veliki ekonomski problem na globalnom nivou, s obzirom da direktno utiču na promenu organoleptičkih osobina proizvoda, pri čemu dolazi i do stvaranja potencijalno toksičnih jedinjenja. Zbog toga se danas sve veća pažnja posvećuje istraživanjima novih prirodnih izvora antioksidanasa, među kojima su veoma značajni i polisaharidni ekstrakti različitih bazidiomiceta. U ovom radu su prikazana bioloska svojstva, struktura, kao i postupci izolovanja i aktivacije polisaharida visih gljiva. Dat je i pregled antioksidativne aktivnosti polisaharidnih ekstrakata visih gljiva i razmatran je uticaj strukturnih karakteristika ovih ekstrakata na antioksidativna svojstva

Termalna stabilnost konjugata polienskog antibiotika sa polisaharidom

Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5057

Termalna stabilnost konjugata polienskog antibiotika sa polisaharidom

Poster presented at XLIX Savetovanja Srpskog hemijskog društva, (13-14. maj 2011., Kragujevac)Abstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5056

Synthesis of gum Arabic-natamycin conjugate

In this work, natamycin, a polyene antibiotic belonging to the family of macrolides, was coupled to the periodate oxidized polysaccharide gum Arabic. Resulting conjugate was characterized by UV-Vis and FT-IR data