Prisustvo i rasprostranjenost virusa žute prugavosti praziluka u usevima različitih vrsta lukova u Srbiji

Leek yellow stripe virus (LYSV) is one of the most frequent and important viruses in leek and garlic crops worldwide. In Serbia this virus is found both in leek and garlic, and often at high percentages. During two consecutive years, 2012 and 2013, a total 92 samples were collected from 11 inspected leek-, garlic- and onion-growing locations and they were analyzed for the presence of LYSV using DAS-ELISA. LYSV was detected in 31.5% of the tested samples. In 2012, the presence of LYSV was only detected in leek plants, and in 55.6% of the tested samples. During 2013, LYSV was detected in 85% of leek and 58.3% of garlic samples. In total, LYSV was detected in 56.4% of leek samples and 17.1% garlic samples. LYSV incidence was confirmed using RT-PCR with LYSV specific primers amplifying 1020 bp fragment representing coat protein and part of nuclear inclusion B genes. Molecular identification was confirmed by sequencing of two selected isolates, 181-13 (MG242625) from garlic and 298-13 (MG242624) from leek, and comparing them to the GenBank sequences of LYSV. Phylogenetic analysis of 55 sequences of LYSV from all over the world showed some correlation between host plant and geographical origin of the isolates, forming five separate clades. Two Serbian LYSV isolates fell into distant clades. The Serbian leek isolate 298-13 of LYSV belongs to clade B, while isolate 181-13 originating from garlic belongs in clade E.Virus žute prugavosti praziluka (Leek yellow stripe virus, LYSV) je jedan od najčešćih i najznačajnijih virusa na praziluku i belom luku. U Srbiji je virus detektovan na obe kulture, i praziluku i belom luku, a često se javlja u visokim procentima. Tokom dve uzastopne godine (2013. i 2014.) pregledano je 11 lokaliteta gajenja praziluka, belog i crnog luka i sakupljena su 92 uzorka koja su DAS-ELISA metodom testirana na prisustvo LYSV. Prisustvo LYSV je dokazano u 31,5% testiranih uzoraka. Tokom 2012., prisustvo LYSV dokazano je samo u praziluku, u 55,6% testiranih uzoraka. Tokom 2013., LYSV je dokazan u 85% uzoraka praziluka i 58,3% uzoraka belog luka. Ukupno, prisustvo LYSV je dokazano u 56,4% uzoraka praziluka i 17,1% uzoraka belog luka. Prisustvo LYSV u testiranim uzorcima potvrđeno je primenom RT-PCR metode i specifičnih prajmera za LYSV koji umnožavaju fragment od 1020 bp koji obuhvata gen za proteinski omotač i deo gena za nuklearne inkluzije B. Molekularna identifikacija LYSV obavljena je sekvenciranjem dva odabrana izolata iz belog luka 181-13 (MG242625) i praziluka 298-13 (MG242624) i poređenjem dobijenih sekvenci sa sekvencama LYSV iz GenBank baze podataka. Filogenetske analize 55 sekvenci izolata LYSV iz različitih delova sveta ukazale su na delimičnu korelaciju između biljke domaćina i geografskog porekla izolata, formiranjem pet odvojenih grupa izolata u stablu. Dva izolata iz Srbije grupisala su se u udaljene grupe. Izolat iz Srbije iz praziluka 298-13 grupisao se u grupu B, dok se izolat iz belog luka 181-13 grupisao u grupu E

Bioethanol production from milling industry by-product in a laboratory-scale bioreactor

Bioethanol produced by biomass fermentation is a renewable and environmentally friendly energy source and has significant potential as a replacement for liquid fossil fuels. Due to the world moving toward more sustainable energy sources, the production of bioethanol has been steadily increasing. This research aims to investigate the efficiency of bioethanol fermentation from a milling industry by-product in a laboratory-scale bioreactor. Prior to fermentation in a bioreactor, for preparation of a milling industry by-product, two different thermo-enzymatic procedures were investigated and compared, and based on the obtained results the more efficient procedure was selected and used for the experiment in a bioreactor. The bioethanol fermentation was carried out in a 14-litre bioreactor in batch mode under anaerobic conditions at 30°C. The obtained results showed that this by-product can be used for the production of bioethanol but that further optimization is necessary to improve the overall efficiency of the bioprocess

Effect of different conditions on Saccaromyces cerevisiae immobilization onto sugar beet pulp in ethanol production

The use of yeast cells immobilized on sugar beet pulp as support for ethanol production employs a cheap and simple method of retaining high cells densities. The present work describes the effect of yeast concentration and ammount of support on immobilization of Saccharomyces cerevisiae onto sugar beet pulp (SBP). Further, the efficiency of immobilized biocatalyst for batch ethanol fermentation of sugar beet thin juice was investigated with goal to examine the optimum conditions of its potential application. The hvdratet SBP showed highes cells retention capacity of 0.117 g/g. A maximum sugar conversion of 97.69%, ethanol concentration of 75.66 g/I, ethanol yield per consumed sugar of 0.499 g/g (equal to 97.71% of its theoretical value) was achieved in the batch fermentation of thin juice substrate. This study demonstrates that the efficient ethanol fermentation from sugar beet thin juice using S. cerevisiae immobilized by natural adhesion on sugar beet pulp (SBP) is possible even without any nutrient supplementation. The novelty of the approach lies in the effectiveness of exploitation of thin juice and sugar beet pulp with purpose to obtain efficient ethanol production from and to lower high operating cost

Diverzitet, biološka i molekularna karakterizacija virusa tikava i epidemologija oboljenja u Srbiji

In the period from 2007 to 2011 constant high levels of viral infections were detected in 61 cucurbit growing localities in Serbia. The frequency of viral infection fluctuated over the years, ranging from 30-50% in 2007, to the extremely high 80% in the epidemic year of 2008, while it was constant and around 40% in the next two years. In the last year of investigation, the frequency reached a very high level of 60%. Serological testing of 1100 collected samples proved the presence of three viruses: Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV) and Cucumber mosaic virus (CMV). Additional testing of symptomatic samples revealed the presence of Cucurbit aphid-borne yellows virus (CABYV), which represents the first detection of CABYV in Serbia, and Tomato spotted wilt virus (TSWV), which is the first report of TSWV on cucurbits in Serbia and the first report of Cucurbita maxima as natural host plant worldwide. ZYMV was the most prevalent virus during this five year survey. Mixed infections were the most frequent infection type in the first two years, while single infection prevailed in the last three years of investigation. During this investigation, transmission of ZYMV by seeds of C. pepo var. styriaca, C. maxima and C. moschata was proved. Both annual and perennial weeds, which are present during the establishment of cucurbit crops, and in the beginning stages of vegetation, were infected with ZYMV, WMV, CMV and TSWV. The most prevalent was TSWV which was detected in eight different weed species, the second most prevalent virus in weeds was CMV, detected in seven different weed species, while the prevalence of ZYMV and WMV was similar and they were detected in five and four weed species, respectively. A high diversity of aphids which are visiting cucurbit crops was detected through the determination of 57 aphid taxons. The most common aphid species were Aphis fabae, Anoecia corni, Aphis gossypii, Myzus persicae and Acyrthosiphon pisum. The greatest diversity and the largest number of aphids were detected in the first few weeks after plant sprouting. The detection and identification of the species level for all five cucurbit viruses in Serbia were confirmed by RT-PCR method and suitable specific primers. Bioassay on 45 test plants was used to determine phenotypic variability and host range for ZYMV, WMV and CMV...U periodu od 2007. do 2011. godine na 61 lokalitetu gajenja tikava u Srbiji utvrđeno je stalno prisustvo virusa sa visokim intenzitetom zaraze. Učestalost virusne zaraze se po godinama mijenjala i kretala od 30-50% u 2007. godini, preko izuzetno visokih 80% u epidemijskoj 2008. godini, da bi tokom naredne dvije godine bila konstantna i kretala se oko 40%. U posljednjoj godini ispitivanja zaraza je ponovo dostigla čak 60%. Serološkim testiranjem 1100 uzoraka sakupljenih sa 19 vrsta, sorti i varijeteta tikava detektovano je prisustvo tri virusa: virusa žutog mozaika cukinija (Zucchini yellow mosaic virus, ZYMV), virusa mozaika lubenice (Watermelon mosaic virus, WMV) i virusa mozaika krastavca (Cucumber mosaic virus, CMV). Dodatnim testiranjem simptomatičnih uzoraka detektovano je prisustvo virusa žutila tikava perzistentno prenosivog vašima (Cucurbit aphid-borne yellows virus, CABYV), što predstavlja prvi nalaz ovog virusa u Srbiji i virusa bronzavosti paradajza (Tomato spotted wilt virus, TSWV), što je prvi nalaz ovog virusa na tikvama u Srbiji, ali i prvi nalaz u prirodnoj infekciji na Cucurbita maxima u svijetu. Najzastupljeniji virus tokom pet godina ispitivanja bio je ZYMV. Tokom prve dvije godine najčešće su bile detektovane miješane infekcije, a u poslednje tri godine pojedinačne. U okviru ovih istraživanja dokazano je prenošenje ZYMV sjemenom Cucurbita pepo var. styriaca, C. maxima i C. moschata. Utvrđena je zaraženost jednogodišnjih i višegodišnjih korovskih biljaka, koje su prisutne u vrijeme zasnivanja usjeva tikava i u početnim fazama vegetacije, sa ZYMV, WMV, CMV i TSWV. Najzastupljeniji je bio TSWV, a njegovo prisustvo je dokazano u osam različitih korovskih vrsta, sljedeći po zastupljenosti je bio CMV, dokazan u sedam vrsta korova, dok su ZYMV i WMV bili slični po zastupljenosti, a dokazani su u pet, odnosno četiri korovske vrste. Pokazan je visok diverzitet biljnih vaši koje posjećuju usjeve tikava kroz determinaciju 57 taksona. Najzastupljenije vrste vaši bile su Aphis fabae, Anoecia corni, Aphis gossypii, Myzus persicae i Acyrthosiphon pisum. Najveći diverzitet i najveća brojnost vrsta vaši bila je u prvim nedjeljama po nicanju biljaka. Detekcija i identifikacija do nivoa vrste svih prouzrokovača virusnih oboljenja na tikvama u Srbiji potvrđena je primjenom RT-PCR metode i odgovarajućih specifičnih prajmera i sekvencioniranjem. Fenotipska varijabilnost i krug domaćina za ZYMV, WMV i CMV ispitivani su primjenom biotesta na ukupno 45 test biljaka..

Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp

Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP) is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l), inoculum concentration (5, 10 and 15 g/l dry mass) and temperature (25, 30, 35 and 40°C). In order to estimate the optimal immobilization conditions the yeast cells retention (R), after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30°C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98%) of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

Ethanol production from sugar beet thin juice by immobilized Saccharomyces cerevisiae : characterization of volatile compounds

The potential of by-products and intermediate products of sugar beet processing as rawmaterials for bioethanol production in Serbia has a big scope in view of the demand of ethanol as an alternative for fossil fuels. The production of bioethanol from sugar beet thin juice by Saccharomyces cerevisiae immobilized on sugar beet pulp (SBP) enables one more opportunity for achieving the zerowaste goal, through a rational use of intermediate and by-products of sugar beet processing. The effect of inoculum concentration on volatile compounds content of distillate was examined. The increase of inoculum concentration from 2.0 g/1 to 2.6 g/l (dry mass basis) increased ethanol and aldehyde content of the distillate from 9.34 % v/v to 9.60 % v/v and from 238.6 mg/l a.a. to 301.5 mg/l a.a., but decreased methanol, acetic acid and ester content from 650.0 mg/l a.a. to 232.3 mg/l a.a., from 73.4 to 51.3 mg/l a.a., and from 272.0 mg/l a.a. to 220.8 mg/l a.a., respectively. The increase in inoculum concentration of SBP-immobilized yeast indicated improvement of distillate quality

Examining submerged and solid-state cultivation course of hydrolytic enzymes production from wheat chaff

Agricultural waste represents an interesting raw material for biotechnological processes nowadays, due to its low price, favorable composition and availability. Wheat chaff, as a lignocellulosic by-product of wheat processing could be a suitable renewable source for producing hydrolytic enzymes for second generation ethanol production technologies. The aim of this work was to investigate the course of Trichoderma reesei cultivation for hydrolytic enzymes production by submerged and solid-state techniques on medium based on wheat chaff. Results show that the monitored values (hydrolytic enzymes activities, total protein content and reducing sugars content) vary significantly with cultivation time, thus there is a need for further optimization of this process parameter

Bioprocess model of ethanol production from sugar beet processing intermediates and byproducts

Istraživanja iz okvira ove doktorske disertacije obuhvatila su optimizaciju, kinetičko modelovanje i simulaciju dobijanja etanola fermentacijom izluženih repinih rezanaca ili ekstrakcionog, retkog i gustog soka primenom metode odzivne površine, različitih kinetičkih modela i programa SuperPro Designer, redosledom. Optimizacijom bioprocea doprineto je razumevanju različitih operativnih uslova, kao i međusobnih interakcija ispitanih varijabli na predtretman, hirolizu i fermentaciju date biomase. Izvođenjem procesa pod optimalnim uslovima definisana kinetika proizvodnog procesa, a dobijeni kinetički modeli su omogućili projektovanje čitavog bioprocesa kroz simulaciju. Krajnji model bioprocesa može olakšati definisanje materijalnih i energetskih bilansa, dimenzionisanje opreme, pravljenje plana proizvodnje, analizu produktivnosti i uklanjanje „uskih grla“, analizu troškova, ekonomske isplativosti i kapaciteta proizvodnje, sprečavanje zagađenja i njenu kontrolu, itd. Na osnovu toga se mogu dobiti konkretni podaci koji olakšavaju donošenje odluka o ulaganju, odnosno realizaciji projekta datog bioprocesa.Research from this framework of this study included optimization, kinetic modeling and simulation of obtaining ethanol by fermentation of spent sugar beet pulp or raw, thin and thick juice by using RSM (Response Sruface Methodology), different kinetic equations and software SuperPro Designer, respctively. Bioprocess optimization contrbuted to better understanding of different operating conditions, as well as the interactions of examined parameters on pretreatment, hydrolysis and fermentation of lignocellulosic feedstock. Running the process under optimal conditions made it possible to define the kinetics of the production process, and tha obtained kinetic models were used to design the entire process through simulations. The obtained final model of the bioprocess can faciliatate defining the material and energy balances, equipment sizing, production planing, productivity analysis, debottlenecking, cost analysis, economic feasibility and production capacity, pollution prevention and control, etc. Based on that, concrete data could be obtained which facilitate decision making about investing, i.e. this bioproces project realisation

Primena bakar-selektivne elektrode tipa prekrivena žica za određivanje bakra(II) potenciometrijskom titracijom sa etilendiaminom u vodenim i nevodenim rastvorima

In this work, potentiometric titrations of the solution of the Cu(II) ione have been executed with ethylenediamine as complexing agent and the copper selective electrode coated wire type/SCE indicator system in aqueous and nonaqueous solvents. Because of the difficult conditions of the forma­tion of the Cu (II) ethylenediamine complex, due to the presence of parallel reactions influencing the position of the basic balance of the formation of the complex, this study discusses and deduces the equations for the calculation of the constant of the formation of the complex as well as the equations for the calculation of the free ethylenediamine. In all the cases a pronounced extreme of the curve of titration has been remarked in the final phase of the titration, whatever diluent was used. Similar results have been obtained using solvents such as: water, alcohol (methanol, ethanol, buthanol), which was expected having in mind the chemical resemblance of these compounds (polar mollecules), while a sharper extreme was obtained in N,N-dymethylformamide, which was expected as well because of the similar basic characteristics with ethylenediamine. The results obtained by this study show the exceptional advantage of ethylenediamine as complexing agent and also the possibility of the application of the copper selective electrode coated wire type/SCE indicating system for the determina­tion of Cu(II) in aqueous and non-aqueous solvents and for the determination of the constants of the determination of the formation of the ethylenediamine complex. .Formiranje kompleksa Cu(II) sa etilendiaminom otežano je postojanjem paralelnih ravnoteža sa reaktantima, koji reagujući sa ligandom, etilendiaminom, ili Cu(II) jonom utiču na položaj osnovne ravnoteže građenja kompleksa. Polazeći od konstatacije da svojstva etilendiaminada gradi stabilne komplekse sa mnogobrojnim jonima u analitičkoj hemiji nisu dovoljno iskorišćena, u ovome radu izvršena je analiza mogućih efekata na položaj ravnoteže građenja kompleksa kao i izvođenje jednačina za ukupnu konstantu obrazovanja B2 i za izračunavanje koncentracije slobodnog etilendiamina. U radu su izvršena potenciometrijska ispitivanja rastvora Cu(II) jona sa etilendiaminom kao kompleksirajućim agensom uz bakar-selektivna elektroda/zasićena kalomelova elektroda (ZKE) indikatorski sistem u vodenim i nevodenim rastvorima. Dobijeni rezultati pokazali su izuzetnu vrednost etilendiamina kao kompleksirajućeg agensa u poređenju sa drugim, konvencionalnim kompleksirajućima agensima, a takođe i mogućnost primene bakar-selektivna elektroda/ZKE indikatorskog sistema za određivanje konstante obrazovanja Cu(en)22+ kompleksa.

Diversity, biological and molecular characterization of cucurbit viruses and disease epidemiology in Serbia

U periodu od 2007. do 2011. godine na 61 lokalitetu gajenja tikava u Srbiji utvrđeno je stalno prisustvo virusa sa visokim intenzitetom zaraze. Učestalost virusne zaraze se po godinama mijenjala i kretala od 30-50% u 2007. godini, preko izuzetno visokih 80% u epidemijskoj 2008. godini, da bi tokom naredne dvije godine bila konstantna i kretala se oko 40%. U posljednjoj godini ispitivanja zaraza je ponovo dostigla čak 60%. Serološkim testiranjem 1100 uzoraka sakupljenih sa 19 vrsta, sorti i varijeteta tikava detektovano je prisustvo tri virusa: virusa žutog mozaika cukinija (Zucchini yellow mosaic virus, ZYMV), virusa mozaika lubenice (Watermelon mosaic virus, WMV) i virusa mozaika krastavca (Cucumber mosaic virus, CMV). Dodatnim testiranjem simptomatičnih uzoraka detektovano je prisustvo virusa žutila tikava perzistentno prenosivog vašima (Cucurbit aphid-borne yellows virus, CABYV), što predstavlja prvi nalaz ovog virusa u Srbiji i virusa bronzavosti paradajza (Tomato spotted wilt virus, TSWV), što je prvi nalaz ovog virusa na tikvama u Srbiji, ali i prvi nalaz u prirodnoj infekciji na Cucurbita maxima u svijetu. Najzastupljeniji virus tokom pet godina ispitivanja bio je ZYMV. Tokom prve dvije godine najčešće su bile detektovane miješane infekcije, a u poslednje tri godine pojedinačne. U okviru ovih istraživanja dokazano je prenošenje ZYMV sjemenom Cucurbita pepo var. styriaca, C. maxima i C. moschata. Utvrđena je zaraženost jednogodišnjih i višegodišnjih korovskih biljaka, koje su prisutne u vrijeme zasnivanja usjeva tikava i u početnim fazama vegetacije, sa ZYMV, WMV, CMV i TSWV. Najzastupljeniji je bio TSWV, a njegovo prisustvo je dokazano u osam različitih korovskih vrsta, sljedeći po zastupljenosti je bio CMV, dokazan u sedam vrsta korova, dok su ZYMV i WMV bili slični po zastupljenosti, a dokazani su u pet, odnosno četiri korovske vrste. Pokazan je visok diverzitet biljnih vaši koje posjećuju usjeve tikava kroz determinaciju 57 taksona. Najzastupljenije vrste vaši bile su Aphis fabae, Anoecia corni, Aphis gossypii, Myzus persicae i Acyrthosiphon pisum. Najveći diverzitet i najveća brojnost vrsta vaši bila je u prvim nedjeljama po nicanju biljaka. Detekcija i identifikacija do nivoa vrste svih prouzrokovača virusnih oboljenja na tikvama u Srbiji potvrđena je primjenom RT-PCR metode i odgovarajućih specifičnih prajmera i sekvencioniranjem. Fenotipska varijabilnost i krug domaćina za ZYMV, WMV i CMV ispitivani su primjenom biotesta na ukupno 45 test biljaka...In the period from 2007 to 2011 constant high levels of viral infections were detected in 61 cucurbit growing localities in Serbia. The frequency of viral infection fluctuated over the years, ranging from 30-50% in 2007, to the extremely high 80% in the epidemic year of 2008, while it was constant and around 40% in the next two years. In the last year of investigation, the frequency reached a very high level of 60%. Serological testing of 1100 collected samples proved the presence of three viruses: Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV) and Cucumber mosaic virus (CMV). Additional testing of symptomatic samples revealed the presence of Cucurbit aphid-borne yellows virus (CABYV), which represents the first detection of CABYV in Serbia, and Tomato spotted wilt virus (TSWV), which is the first report of TSWV on cucurbits in Serbia and the first report of Cucurbita maxima as natural host plant worldwide. ZYMV was the most prevalent virus during this five year survey. Mixed infections were the most frequent infection type in the first two years, while single infection prevailed in the last three years of investigation. During this investigation, transmission of ZYMV by seeds of C. pepo var. styriaca, C. maxima and C. moschata was proved. Both annual and perennial weeds, which are present during the establishment of cucurbit crops, and in the beginning stages of vegetation, were infected with ZYMV, WMV, CMV and TSWV. The most prevalent was TSWV which was detected in eight different weed species, the second most prevalent virus in weeds was CMV, detected in seven different weed species, while the prevalence of ZYMV and WMV was similar and they were detected in five and four weed species, respectively. A high diversity of aphids which are visiting cucurbit crops was detected through the determination of 57 aphid taxons. The most common aphid species were Aphis fabae, Anoecia corni, Aphis gossypii, Myzus persicae and Acyrthosiphon pisum. The greatest diversity and the largest number of aphids were detected in the first few weeks after plant sprouting. The detection and identification of the species level for all five cucurbit viruses in Serbia were confirmed by RT-PCR method and suitable specific primers. Bioassay on 45 test plants was used to determine phenotypic variability and host range for ZYMV, WMV and CMV..