Određivanje mikrobiološke aktivnosti i biomase u različitim zemljištima nakon primene nikosulfurona

The effects of the herbicide nicosulfuron on the abundance of cellulolytic and proteolytic microorganisms, activity of β-glucosidase and protease enzymes, and microbial phosphorus biomass were examined. A laboratory bioassay was set up on two types of agricultural soils differing in physicochemical properties. The following concentrations were tested: 0.3, 0.6, 3.0 and 30.0 mg a.i./kg of soil. Samples were collected 3, 7, 14, 30 and 45 days after treatment with nicosulfuron. The results showed that nicosulfuron significantly reduced the abundance of cellulolytic microorganisms in both soils, as well as microbial biomass phosphorus in sandy loam soil. The herbicide was found to stimulate β-glucosidase and protease activity in both types of soil and microbial biomass phosphorus in loamy soil. Proteolytic microorganisms remained unaffected by nicosulfuron.Ispitivan je uticaj herbicida nikosulfurona na brojnost celulolitskih i proteolitskih mikroorganizama, aktivnost enzima β-glukozidaze i proteaze i mikrobiološku biomasu fosfora. Ogled je postavljen u laboratorijskim uslovima na dva poljoprivredna zemljišta koja se razlikuju po svojim fizičko-hemijskim karakteristikama. Primenjene su koncentracije od 0,3, 0,6, 3,0 i 30,0 mg a.s/kg zemljišta. Uzorci za analizu uzeti su 3, 7, 14, 30 i 45 dana nakon primene nikosulfurona. Dobijeni rezultati su pokazali da je nikosulfuron značajno smanjio broj celulolizatora kod oba tipa zemljišta, kao i vrednost mikrobiološke biomase fosfora u peskuši. Stimulativno delovanje ovog herbicida zabeleženo je kod enzima β-glukozidaze i proteaze kod oba tipa zemljišta kao i kod mikrobiološke biomase fosfora u ilovači. Na brojnost proteolitičkih mikroorganizama nikosulfuron nije ispoljio nikakav uticaj

Efikasnost različitih metoda za određivanje ostataka organofosfata u fermentisanim uzorcima žita

In the present work, the efficiencies of three different sample preparation methods for GC/ MS determination of pirimiphos-methyl and chlorpyrifos-methyl residues in wheat (Triticum spelta) samples fermented by Lactobacillus plantarum were compared. All three methods were based on methanol:acetone=1:1 extraction, while further purification of the obtained samples was altered. First purification was through a column containing a mixture of aluminium oxide and activated charcoal slurry-packed and eluted with dichlormethane, the second was purification on a florisil column slurry-packed and eluted with ethyl acetate:acetone=4:1, while the third was based on a combination of the former two methods, i.e. clean-up through columns filled with a mixture of aluminum oxide and activated charcoal slurry-packed and eluted with ethyl acetate:acetone=4:1. The second method was found the most effective for obtaining satisfactory recoveries at four fortification levels. For pirimiphos-methyl, recoveries were in the range of 91.3-96.0% and had good reproducibility, i.e. RSD ranging from 2.2-4.1%, while the corresponding range for chlorpyrifos-methyl was 81.6-88.2%, and the RSD range 2.5-5.4%. The chosen method was further optimized in order to establish the optimum volume of elution solvent used during the clean-up procedures. The highest recoveries of 93.7±3.5% for pirimiphos- methyl and 85.3±2.5% for chlorpyrifos-methyl were obtained after elution with 25 ml volume of solvent. Considering all, simple, efficient and reliable GC/MS detection of pirimiphosmethyl and chlorpyrifos-methyl residues in wheat grain substrate altered by fermentation with L. plantarum was achieved by the two-steps extraction with 25 ml of methanol:acetone=1:1 solvent mix for 30 min, followed by a clean-up procedure through a glass column with florisil coupled with elution by 25 ml of ethyl acetate:acetone=4:1.Poređene su efikasnosti tri različite metode pripreme uzoraka za određivanje ostataka pirimifos-metila i hlorpirifos-metila u uzorcima pšenice (Triticum spelta) fermentisane sa Lactobacillus plantarum. Sve tri metode zasnivale su se na metanolsko-acetonskoj (1:1) ekstrakciji dok su se procedure prečišćavanja dobijenih ekstrakata razlikovale. Prva metoda bila je prečišćavanje kroz kolonu punjenu smešom aluminijum-oksida i aktivnog uglja u kombinaciji sa dihlormetanom kao eluentom, druga prečišćavanje kroz kolonu punjenu florisilom u kombinaciji sa smešom etil-acetata i acetona (4:1) kao eluentom, dok se treća zasnivala na kombinaciji prve dve, tj. prečišćavanju kroz kolonu punjenu smešom aluminijum-oksida i aktivnog uglja u kombinaciji sa smešom etil-acetata i acetona (4:1) kao eluentom. Druga testirana metoda pokazala se kao najefikasnija, pri čemu su dobijeni prinosi pirimifos-metila u opsegu 91,3-96,0% za četiri koncentraciona nivoa obogaćivanja, sa RSD% u opsegu 2,2-4,1%, dok su za hlorpirifos-metil ovi prinosi bili u opsegu 81,6-88,2% sa RSD% u opsegu 2,5-5,4%. Odabrana metoda je dodatno optimizovana variranjem različitih zapremina korišćenog eluenta. Najveći prinos metode za oba ispitivana pesticida postignut je pri zapremini eluenta od 25 ml (93,7±3.5% za pirimifos-metil i 85,3±2,5% za hlorpirifos-metil). Predložena metoda, bazirana na 30-minutnoj ekstrakciji sa 25 ml smeše metanol:aceton=1:1, prečišćavanju na florisilskoj koloni i eluiranju sa 25 ml smeše etilacetat: aceton=4:1, pokazala se kao efikasna, jednostavna i pouzdana metoda za određivanje ostataka ispitivanih organofosfata u fermentisanom žitnom supstratu

Antifungalna aktivnost šest etarskih ulja poreklom iz Srbije na Trichoderma aggressivum f. europaeum

Six essential oils (EOs) extracted from plants originating in Serbia were assayed for inhibitory and fungicidal activity against a major fungal pathogen of button mushroom causing green mould disease, Trichoderma agressivum f. europaeum. The strongest activity was demonstrated by the oils of basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.). Medium antifungal activity of St. John's wort (Hypericum perforatum L.) and walnut [Juglans regia (F)] oils was also recorded. Oils extracted from yarrow (Achillea millepholium L.) and juniper (Juniperus communis L.) exhibited the lowest activity. Peppermint oil showed fungicidal effect on the pathogen, having a minimum fungicidal concentration of 0.64 μl ml-1. The main components of peppermint essential oil were menthone (37.02%), menthol (29.57%) and isomenthone (9.06%).Ispitana je inhibitorna i fungicidna aktivnost šest etarskih ulja ekstrahovanih iz biljaka poreklom iz Srbije na Trichoderma agressivum f. europaeum. Patogen je prouzrokovač zelene plesni šampinjona, bolesti koja nanosi najviše štete u prinosu. Najveću aktivnost je ispoljilo ulje bosiljka (Ocimum basilicum L.) i pitome nane (Mentha piperita L.). Niža aktivnost je uočena kod ulja kantariona (Hypericum perforatum L.) i oraha [Juglans regia (F)]. Ulja ekstrahovana iz hajdučke trave (Achillea millepholium L.) i kleke (Juniperus communis L.) ispoljila su najmanju aktivnost. Ulje pitome nane je ispoljilo fungicidni efekat na patogena, sa minimalnom fungicidnom koncentracijom od 0.64 μl ml-1. Najzastupljenije komponente etarskog ulja nane su bile menton (37.02%), mentol (29.57%) i izomenton (9.06%)

Antifungal activity of six plant essential oils from Serbia against Trichoderma aggressivum f. europaeum

Six essential oils (EOs) extracted from plants originating in Serbia were assayed for inhibitory and fungicidal activity against a major fungal pathogen of button mushroom causing green mould disease, Trichoderma agressivum f. europaeum. The strongest activity was demonstrated by the oils of basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.). Medium antifungal activity of St. John's wort (Hypericum perforatum L.) and walnut [Juglans regia (F)] oils was also recorded. Oils extracted from yarrow (Achillea millepholium L.) and juniper (Juniperus communis L.) exhibited the lowest activity. Peppermint oil showed fungicidal effect on the pathogen, having a minimum fungicidal concentration of 0.64 μl ml-1. The main components of peppermint essential oil were menthone (37.02%), menthol (29.57%) and isomenthone (9.06%)

Efficiencies of different methods for determination of organophosphate pesticide residues in fermented wheat substrate

In the present work, the efficiencies of three different sample preparation methods for GC/MS determination of pirimiphos-methyl and chlorpyrifos-methyl residues in wheat (Triticumspelta) samples fermented by Lactobacillus plantarum were compared. All three methods werebased on methanol:acetone=1:1 extraction, while further purification of the obtained sampleswas altered. First purification was through a column containing a mixture of aluminiumoxide and activated charcoal slurry-packed and eluted with dichlormethane, the second waspurification on a florisil column slurry-packed and eluted with ethyl acetate:acetone=4:1, whilethe third was based on a combination of the former two methods, i.e. clean-up through columnsfilled with a mixture of aluminum oxide and activated charcoal slurry-packed and elutedwith ethyl acetate:acetone=4:1. The second method was found the most effective for obtainingsatisfactory recoveries at four fortification levels. For pirimiphos-methyl, recoveries werein the range of 91.3-96.0% and had good reproducibility, i.e. RSD ranging from 2.2-4.1%, whilethe corresponding range for chlorpyrifos-methyl was 81.6-88.2%, and the RSD range 2.5-5.4%.The chosen method was further optimized in order to establish the optimum volume of elutionsolvent used during the clean-up procedures. The highest recoveries of 93.7±3.5% for pirimiphos-methyl and 85.3±2.5% for chlorpyrifos-methyl were obtained after elution with 25 mlvolume of solvent. Considering all, simple, efficient and reliable GC/MS detection of pirimiphosmethyland chlorpyrifos-methyl residues in wheat grain substrate altered by fermentation withL. plantarum was achieved by the two-steps extraction with 25 ml of methanol:acetone=1:1solvent mix for 30 min, followed by a clean-up procedure through a glass column with florisilcoupled with elution by 25 ml of ethyl acetate:acetone=4:1

Mogućnosti korišćenja biotesta za praćenje ostataka klomazona u zemljištu tipa peskuša

A bioassay test was conducted to evaluate the sensitivity of maize, sunflower and barley to clomazone residues in sandy loam soil. Clomazone was applied at different rates from 0.12 to 12 mg a.i./kg of soil. The parameters measured 14 days after treatment were: shoot height, fresh and dry weight, and content of pigments (carotenoids, chlorophyll a and chlorophyll b). The results showed that the lowest clomazone concentration caused a significant reduction in all measured parameters for barley and sunflower shoots. Fresh weight of maize shoots was not sensitive to clomazone residual activity in soil while the other parameters were highly inhibited. Nomenclature: clomazone (2-(2-chlorbenzyl)-4,4-dimethyl-1,2-oxazolidin-3-one), maize (Zea mays L.), sunflower (Helianthus annuus L.), barley (Hordeum vulgare L.)U radu je ispitivana osetljivost kukuruza, suncokreta i ječma na rezidualno delovanje klomazona u zemljištu tipa peskuša, metodom biotesta. Klomazon je primenjen u seriji koncentracija 0.12-12 mg a.s./kg zemljišta. Nakon 14 dana rasta biljaka mereni su vegetativni (visina, sveža i suva masa izdanka) i fiziološki parametri (sadržaj karotenoida hlorofila a i hlorofila b). Dobijeni rezultati pokazuju da su i najmanje koncentracije klomazona izazvale značajno smanjenje merenih vegetativnih i fizioloških parametara kod ječma i suncokreta. Izdanci kukuruza nisu pokazali istu osetljivost prema ostacima klomazona u zemljištu tipa peskuša pa je sveža masa izdanka ostala nepromenjena u varijantama sa različitim koncentracijama herbicida, a ostali mereni parametri su bili značajno inhibirani