44 research outputs found

    Uklanjanje fenola i fenolnih derivata iz vode imobilizovanom polifenol-oksidazom iz krompira

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    Phenols containing halogens, which tend to deactivate the aromatic nuclei, constitute a significant category of highly toxic and difficult-to-degrade pollutants, which arise from a wide variety of industries. The main purpose of this study was to obtain an inexpensive immobilized enzyme for the removal of phenols. Partially purified potato polyphenol oxidase (PPO) was immobilized onto different commercial and laboratory produced carriers. Three of the obtained biocatalysts, with the highest PPO activities, namely Eupergit C250L-PPO; Celite-PPO and CelluloseM-PPO, were tested in a batch reactor for the removal of phenol, 4-chlorophenol and 4-bromophenol. In the case of 2.5 mM substrates with Eupergit C250L-PPO, an around 45 % removal of 4-bromophenol was achieved, while the removals 4-chlorophenol and phenol were 35 and 20 %, respectively. The reusability of Eupergit C250L-PPO for the removal of 4-chlorophenol was tested. After eight repeated tests, the efficiency of 4-chlorophenol removal by Eupergit C250L-PPO immobilisate had decreased to 55 %.Halogenovani fenoli imaju dezaktivirano aromatično jezgro i čine značajnu kategoriju veoma toksičnih i teÅ”ko razgradivih zagađivača u raznim industrijskim granama. Glavni cilj ovog rada je bio dobijanje jeftinog imobilizovanog enzima za uklanjanje fenola. Delimično prečiŔćena polifenol-oksidaza (PFO) iz krompira je imobilizovana na različitim komercijalnim i laboratorijski sintetizovanim nosačima. Od dobijenih biokatalizatora, tri sa najvećim aktivnostima PPO, nazvani Eupergit C250L-PFO; Celit-PFO i CelulozaM-PFO, testirani su u reaktoru za uklanjanje fenola, 4-hlorfenola i 4-bromfenola. U slučaju 2,5 mM supstrata sa Eupergit C250L-PFO, postignuto je oko 45 % razgradnje 4-bromfenola, dok su 4-hlorfenol i fenol razgrađeni 35, odnosno 20 %. Testirana je i sposobnost viÅ”estruke upotrebe Eupergit C250L-PFO imobilizata za uklanjanje 4-hlorfenola. Nakon osam ponovljenih ciklusa efikasnost Eupergit C250L-PFO imobilizata za uklanjanje 4-hlorfenola je pala na 55%

    Mixed-mode resins: taking shortcut in downstream processing of raw-starch digesting alpha-amylases

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    Bacillus licheniformis 9945a alpha-amylase is known as a potent enzyme for raw starch hydrolysis. In this paper, a mixed mode Nuvia cPrime (TM) resin is examined with the aim to improve the downstream processing of raw starch digesting amylases and exploit the hydrophobic patches on their surface. This resin combines hydrophobic interactions with cation exchange groups and as such the presence of salt facilitates hydrophobic interactions while the ion-exchange groups enable proper selectivity. alpha-Amylase was produced using an optimized fed-batch approach in a defined media and significant overexpression of 1.2 g L-1 was achieved. This single step procedure enables simultaneous concentration, pigment removal as well as purification of amylase with yields of 96% directly from the fermentation broth.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3384

    Uporedna analiza izoformi Ī±-amilaze iz srednjeg creva larvi Cerambyx cerdo L. (Coleoptera: Cerambycidae) iz prirode i gajenih na veÅ”tačkoj podlozi

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    alpha-Amylase isoforms of Cerambyx cerdo larvae from the wild (ML and SL) and reared in the laboratory (ADL) were compared. Three amylase isoforms were presented in the SL and ML extracts while two isoforms were presented in the ADL according to zymogram after isoelectric focusing (IEF). All C. cerdo amylase isoforms were acidic proteins (pI lt 3.5). Seven amylase isoforms (ACC 1-7) from the midgut of C. cerdo larvae were found in the ML midgut extract, six in the SL extract, and four in the ADL extract according to native PAGE zymogram. The ADL amylase had the highest activity. All crude midgut extracts of C. cerdo larvae were fractionated on a Superose 12 HR column. The molecular mass of the ACC was estimated to be 34 kDa.Upoređene su izoforme Ī±-amilaze larvi Cerambyx cerdo sakupljenih iz prirode (ML i SL) i gajenih na veÅ”tačkoj podlozi u laboratoriji (ADL). Zimogramskom detekcijom posle IEF-a po tri izoforme su detektovane u ML i SL ekstraktima, a u ADL dve izoforme. Sve amilazne izoforme iz C. cerdo su bile kisele (pI lt 3.5). Zimogramskom detekcijom posle nativne elektroforeze sedam izoformi je detektovano u ML ekstraktu, Å”est u SL ekstraktu i četiri u ADL ekstraktu. Najveća amilazna aktivnost je detektovana u ADL ekstraktu. Svi ekstrakti srednjih creva larvi C. cerdo su frakcionisani na koloni Superose 12 HR. Molekulska masa ACC-a je bila 34 kDa

    Supplementary data for the article: Loncar, N.; Bozic, N.; Vujcic, Z. Expression and Characterization of a Thermostable Organic Solvent-Tolerant Laccase from Bacillus Licheniformis ATCC 9945a. J. Mol. Catal. B-Enzym. 2016, 134, 390ā€“395. https://doi.org/10.1016/j.molcatb.2016.06.005

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    Supplementary material for: [https://doi.org/10.1016/j.molcatb.2016.06.005]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2375]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3517

    Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: synthesis, antioxidant activity, cytotoxicity and DNA interaction studies

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    Hybrid compounds that combine the 1,3,4-thiadiazole-containing catechol moiety with a chalcone motif were synthesized and examined for their antioxidant activity, cytotoxicity, and DNA-binding activity. A series of thirteen compounds showed strong antioxidant and cytotoxic effects on human acute promyelocytic leukemia HL-60 cells. Several compounds exerted good cytotoxic activities on cervical adenocarcinoma HeLa cells. The treatment of HeLa cells with IC50 and double IC50 concentrations of the compounds 5a, 5c, 5f, and 5m induced a statistically significant increase in the percentage of cells within a subG1 cell cycle phase. The examined compounds caused G2/M cell cycle arrest in HeLa cells. Each of these compounds triggered apoptosis in HeLa cells through activation of caspase-3, the main effector caspase, caspase-8, which is involved in the extrinsic apoptotic pathway, and caspase-9, which is involved in the intrinsic apoptotic pathway. All of the examined compounds decreased the expression levels of MMP2 in HeLa cells and levels of protumorigenic miR-133b. Compounds 5a and 5m lowered the expression level of oncogenic miR-21 in HeLa cells. In addition, compounds 5a, 5f, and 5m decreased the expression levels of oncogenic miR-155 while the treatment of HeLa cells with compounds 5a, 5c, and 5f increased expression of tumor-suppressive miR-206. Observed effects of these compounds on expression levels of four examined miRNAs suggest their prominent cancer-suppressive activity. An investigation by absorption and fluorescence spectroscopy showed more efficient calf thymus DNA binding activity of the compound 5m in comparison to other tested compounds. Results of a pUC19 plasmid cleavage study and comet assay showed DNA damaging activities of compounds 5a and 5c.Related to published version:[https://imagine.imgge.bg.ac.rs/handle/123456789/1168]This is the peer reviewed version of the paper: Jakovljević, K., Joksović, M. D., Matić, I., Petrović, N., Stanojković, T., Sladić, D., Vujčić, M., Janović, B., Joksović, L., Trifunović, S., & Marković, V. (2018). Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: Synthesis, antioxidant activity, cytotoxicity and DNA interaction studies. Medchemcomm, 9(10), 1679ā€“1697. [https://doi.org/10.1039/c8md00316e

    Abdominal aortic aneurysm volume and relative intraluminal thrombus volume might be auxiliary predictors of ruptureā€”an observational cross-sectional study

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    Objectives: The study aimed to identify differences and compare anatomical and biomechanical features between elective and ruptured abdominal aortic aneurysms (AAAs). Methods: Data (clinical, anatomical, and biomechanical) of 98 patients with AAA, 75 (76.53%) asymptomatic (Group aAAA) and 23 (23.46%) ruptured AAA (Group rAAA), were prospectively collected and analyzed. Anatomical, morphological, and biomechanical imaging markers like peak wall stress (PWS) and rupture risk equivalent diameter (RRED), comorbid conditions, and demographics were compared between the groups. Biomechanical features were assessed by analysis of Digital Imaging and Communication in Medicine images by A4clinics (Vascops), and anatomical features were assessed by 3Surgery (Trimensio). Binary and multiple logistic regression analysis were used and adjusted for confounders. Accuracy was assessed using receiving operative characteristic (ROC) curve analysis. Results: In a multivariable model, including gender and age as confounder variables, maximal aneurysm diameter [MAD, odds ratio (OR) = 1.063], relative intraluminal thrombus (rILT, OR = 1.039), and total aneurysm volume (TAV, OR = 1.006) continued to be significant predictors of AAA rupture with PWS (OR = 1.010) and RRED (OR = 1.031). Area under the ROC curve values and correct classification (cc) for the same parameters and the model that combines MAD, TAV, and rILT were measured: MAD (0.790, cc = 75%), PWS (0.713, cc = 73%), RRED (0.717, cc = 55%), TAV (0.756, cc = 79%), rILT (0.656, cc = 60%), and MAD + TAV + rILT (0.797, cc = 82%). Conclusion: Based on our results, in addition to MAD, other important predictors of rupture that might be used during aneurysm surveillance are TAV and rILT. Biomechanical parameters (PWS, RRED) as valuable predictors should be assessed in prospective clinical trials. Similar studies on AAA smaller than 55ā€…mm in diameter, even difficult to organize, would be of even greater clinical value. 2023 Koncar, Nikolic, Milosevic, Bogavac-Stanojevic, Ilic, Dragas, Sladojevic, Markovic, Vujcic, Filipovic and Davidovic
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