In vitro biosinteza ohratoksina A kod izolata Aspergillus ochraceus E'G

This paper deals with the biosynthetic capacity for ochratoxin A (OTA) production by Aspergillus ochraceus E'G isolate derived from A. ochraceus CBS 108.08 strain, during 2007. Preliminary analysis of fungal potential for the production of OTA were performed according to the modified method of Filtenborg et al. (1983). Toxin production was tested in the following liquid media: (i) glucose-peptone-yeast extract broth (GPY - pH 5.6), (ii) potato-dextrose broth (PDB - pH 6.9), (iii) yeast extract-sucrose broth (YES - pH 6.5), and (iv) YES broth supplemented with 0.23 mg/l ZnSO4 x 5 H2O (YESZn - pH 6.5) after stationary and submerged cultivation. Dynamics of OTA biosynthesis was tested after the cultivation of A. ochraceus E'G on natural solid substrates, such as wet sterilized rice, corn and wheat grain. Cultivations were performed during different time periods (ranging from four days to few weeks) at different temperatures (ranging from 21°C to 30°C). The presence of OTA was determined as follows: (i) in liquid media according to the method of Balzer et al. (1978) modified by Bočarov-Stančić et al. (2003), and (ii) in the solid substrates according to the Serbian official methods for sampling and analyzing of fodder (Official Gazette of SFRY, No. 15/87). After the cultivation of A. ochraceus E'G isolate in liquid media, the highest yield of OTA (6.4 mg/l) was obtained after submerged cultivation in PDB (4 days, 128 rpm, 21-23°C). In the case of cultivation on solid substrates, the highest amount of OTA (800.0 mg/kg of dry matter) was recorded after several week long cultivation on wheat grain at 30±1°C.Ispitivanjem je bio obuhvaćen izolat Aspergillus ochraceus E'G izveden iz soja A. ochraceus CBS 108.08. Preliminarne analize prisustva ohratoksina A (OTA) su izvršene prema modifikovanoj metodi Filtenborg -a i sar. (1983) na agarizobanim podlogama. Proizvodnja toksina je testirana u sledećim tečnim podlogama: 1) glukoza-pepton-ekstrakt kvasca u bujonu (GPY - pH 5,6), 2) krompir - dekstroznom bujonu (PDB - pH 6,9), 3) ekstrakt kvasca - saharoznom bujonu (YES - pH 6,5) i 4) ekstrakt kvasca-saharoznom bujonu sa dodatkom 0,23 mg/l ZnSO4 x 5 H2O (YESZn - pH 6,5) u uslovima stacionarne i submerzne kultivacije. Dinamika biosinteze ohratoksina A praćena je nakon gajenja na prirodnim čvrstim supstratima (zrno pirinča, kukuruza i pšenice) tokom višenedeljne kultivacije. Ohratoksin A je izolovan iz tečnih podloga za kultivaciju i produkciju primenom metode Balzera i sar. (1978) modifikovane prema Bočarov-Stančić i sar. (2003), dok je kvantitacija OTA u prirodnim čvrstim supstratima izvršena prema Pravilniku o metodama uzimanja uzoraka i metodama fizičkih, hemijskih i mikrobioloških analiza stočne hrane ('Sl. list SFRJ', br. 15/87). Pri gajenju izolata A. ochraceus E'G u tečnim podlogama najveći prinos OTA je dobijen pri korišćenju PDB (6,4 mg/l) i to u uslovima submerzne kultivacije (4 dana, 128 o/min, 21-23°C). U slučaju kultivacije na zrnu žitarica najveću količinu OTA je izolat A. ochraceus E'G biosintetisao posle višenedeljne kultivacije na zrnu pšenice i 30±1°C (800,0 mg/kg)

Meat quality characteristics of DurocxYorkshire, DurocxYorkshirexwild boar and wild boar

Chemical composition, pH value, fatty acids profile, cholesterol content, color and sensory analysis of pork meat from Duroc x Yorkshire (D x Y), Duroc x Yorkshire x wild boar (D x Y x WB) crossbreeds and wild boars (WB) was investigated. Samples for all tests were taken from m. longissimus dorsi. Chemical composition and pH value were tested by ISO methods. Fatty acid and cholesterol determination was performed by gas chromatography technique with external standard method. Color was determined instrumentally using the thristimulus colourimeter. The overall sensoric quality (appearance, texture and smell) of samples of raw meat was evaluated. In evaluation of results the scoring system was used. In chemical composition (moisture, fat, protein, ash) and pH values statistically significant difference was noted (p<0,05) between each of the examined groups. Also, among all the examined groups statistically significant difference (p<0,05) was found for fatty acids and cholesterol content. Measurment of the color of meat from all three groups showed that the L*, a * b *, Chroma and Hue angle were also statistically significantly different (p<0,01)

ПОРЕЂЕЊЕ ELISA И HPLC МЕТОДЕ ЗА ДЕТЕКЦИЈУ МИКОТОКСИНА АНАЛИЗОМ РЕЗУЛТАТА PROFICIENCY ТЕСТОВА

Different analytical techniques for the detection of mycotoxins have been developed in order to control the levels of mycotoxins in food and feed. Conventional analytical methods for mycotoxin determination are involving techniques such as thinlayer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Also, rapid methods for mycotoxin analysis have become increasingly important. Enzyme-linked immuno-sorbent assay (ELISA) is one of the most common rapid methods for determination of these natural contaminants. The aim of this study was to provide a comparison between two different methods of analysis (HPLC and ELISA) for the detection of different mycotoxins using data that originate from commercial proficiency tests. Based on the statistical evaluation of the results for both methods, in three proficiency tests for various mycotoxins (aflatoxins, ochratoxin and zearalenone), it could be concluded that both techniques can equally be used, although ELISA is considered to be the screening one.У циљу контроле присуства микотоксина и нивоа контаминације хране и хране за животиње развијене су различите аналитичке технике за детекцију ових природних контаминената. Конвенционалне аналитичке методе за утврђивање микотоксина су танкослојна хроматографија (ТЛЦ), течна хроматографија високих перформанси (ХПЛЦ) и гасна хроматографија (ГЦ). Такође, брзе методе за микотоксиколошке анализе постају све важније, међу којима је ЕЛИСА (Enzyme linked immuno-sorbent assay) једна од најприменљивијих. Циљ овог рада био је да се две различите и најчешће коришћене лабораторијске методе за утврђивање различитих микотоксина (ХПЛЦ и ЕЛИСА) упореде анализом података који потичу из комерцијалних тестова оспособљености (proficiency тестова). На основу детаљне статистичке процене резултата добијених применом ових метода за квантификацију афлатоксина, охратоксина и зеараленона, у три комерцијална proficiency теста, може се закључити да обе технике могу равноправно да се користе с великом поузданошћу, иако се често наводи да је ЕЛИСА погодна само за почетну тријажу узорака

Examination of the efficacy of various feed additives on the pathomorphological changes in broilers treated with T-2 toxin

A 21-day-long experiment was performed on 160 one-day-old 'Ross' broiler chicks. This research was done with the aim of investigating pathomorphological changes in broilers exposed to a relatively small amount of T-2 toxin (2 ppm) and the possibility of prevention and/or alleviating adverse effects of T-2 toxin using various feed additives. Pathohistological examination showed negative consequences of T-2 toxin in all examined organs as degenerative changes developed in small intestine mucosa, enterocites and hepatocites necroses, as well as lymphocites depletion in bursa of Fabricius. Disparately from inorganic (Minazel-plus, Mz) and organic (Mycosorb, Ms) adsorbents, which did not provoke protective effects, in liver, small intestine and bursa of Fabricius of broilers who were given feed with T-2 toxin and mixed adsorbent (Mycofix-plus, Mf), mostly preserved structure of these organs could be noted

Efficacy of T-2 toxin detoxifying agent in broiler chickens

This investigation was conducted in order to investigate the efficacy of the detoxifying agent Mycofix® Plus (MP) in the prevention and/or alleviation in vivo adverse effects of T-2 toxin in broilers. In addition, the adsorbing potential of MP was estimated in vitro. Mean degradation levels of T-2 toxin with MP in vitro, as measured by HPTLC, varied from 26.06 to 31.02 % and the adsorption ability was elevated in acidic environment (pH 3). In vivo trial was performed on 160 one day old "Ross" broiler chicks and lasted for 21 days. Birds were divided into 4 equal groups as follows: Group 1 - negative control; Group 2 - positive control - 2 ppm T-2 toxin; Group 3 - 2 ppm T-2 toxin+2 kg/t MP; Group 4 - 2 kg/t MP. Broilers fed the diet containing 2 mg/kg of T-2 toxin without MP developed typical T-2 toxicosis. Birds that were fed the diet containing both T-2 and MP had better performances and no oral ulcerations as the dominant sign of T-2 toxicosis were observed. Histopathological examination of tissues originating from birds fed the diet containing T-2 toxin revealed degenerative changes in the oral and small intestine mucosa, necroses of enterocytes and hepatocytes, as well as depletion of lymphocytes in the bursa Fabricii. Immunohistochemical examination also revealed negative effects of T-2 toxin on cells proliferation in intestineal and bile duct mucosa, as well as on lymphocytes from bursa Fabricii. The macroscopic and microscopic structure of the liver, intestine and bursa Fabricii of broilers fed a diet containing T-2 toxin and MP was mostly preserved. Cutaneous basophile hypersensitivity reaction was weaker in broilers fed mixtures containing 2 mg/kg T-2 toxin

Diagnosis of mycotoxicoses in veterinary medicine

The problem of mycotoxin presence in animal feed and the consequences that arise due to this, represent a great challenge for anyone encountering them. In the chain which includes studies from prevention to treatment, a very important place and a frequent source of confusion is the process of diagnosing diseases caused by mycotoxins. The aim of this paper is to present a long experience of the team of experts at the Institute of Veterinary Medicine of Serbia in Belgrade, who follows this issue in terms of clinical manifestations of mycotoxicoses in different animal species, pathomorphological and pathohistological changes that characterize them, and laboratory analysis of feed which is the source of those biological hazards and natural contaminants. Based on the findings it could be concluded that mycotoxin contamination is common. Although these levels usually do not exceed the limits laid by the legislation, considering the cumulative effects and possible chronic exposure of animals to their harmful influence, appropriate and competent approach is necessary. Namely, even when direct losses, such as animals’ mortality, are not present, indirect losses, due to a drop of animal performances and production, as well as the occurrence of secondary infections, should not be neglected

Ochratoxin A 'in vitro' biosynthesis by the Aspergillus ochraceus E'G isolate

This paper deals with the biosynthetic capacity for ochratoxin A (OTA) production by Aspergillus ochraceus E'G isolate derived from A. ochraceus CBS 108.08 strain, during 2007. Preliminary analysis of fungal potential for the production of OTA were performed according to the modified method of Filtenborg et al. (1983). Toxin production was tested in the following liquid media: (i) glucose-peptone-yeast extract broth (GPY - pH 5.6), (ii) potato-dextrose broth (PDB - pH 6.9), (iii) yeast extract-sucrose broth (YES - pH 6.5), and (iv) YES broth supplemented with 0.23 mg/l ZnSO4 x 5 H2O (YESZn - pH 6.5) after stationary and submerged cultivation. Dynamics of OTA biosynthesis was tested after the cultivation of A. ochraceus E'G on natural solid substrates, such as wet sterilized rice, corn and wheat grain. Cultivations were performed during different time periods (ranging from four days to few weeks) at different temperatures (ranging from 21°C to 30°C). The presence of OTA was determined as follows: (i) in liquid media according to the method of Balzer et al. (1978) modified by Bočarov-Stančić et al. (2003), and (ii) in the solid substrates according to the Serbian official methods for sampling and analyzing of fodder (Official Gazette of SFRY, No. 15/87). After the cultivation of A. ochraceus E'G isolate in liquid media, the highest yield of OTA (6.4 mg/l) was obtained after submerged cultivation in PDB (4 days, 128 rpm, 21-23°C). In the case of cultivation on solid substrates, the highest amount of OTA (800.0 mg/kg of dry matter) was recorded after several week long cultivation on wheat grain at 30±1°C

Effect of goat breed on the meat quality

The quality of goat meat has recently become an important aspect in the marketing of goats in Serbia. The aim of this study was to compare some goat meat quality parameters of various races and to determine the differences between them. Goat breeds were Balkan goat and Serbian White goat, both female in the age of four years. Analysis of quality parameters: chemical composition (moisture, protein, total fat, ash,), pH value, fatty acids, amino acids, microelements content, tenderness, cooking loss and colour measurements were done. Statistically significant difference was found between the samples of two groups of goat meat (P <0.05) in relation to: live weight (kg), water (%), fat (%), protein (%), ash (%), among 11 of 15 tested fatty acids, amino acid leucin, sensory examination of fresh meat for the palpatory evaluated firmness and in the content of copper and zinc. Statistically significant differences between the groups did not existed regarding the pH value, fatty acids eicosenoic, cis-heptadecenoic, t-elaidic, t-linolelaidic and amino acids alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine. Also there was no statistically significant difference in instrumental testing of the meat color, sensory evaluation of surface color, visual evaluated structure, olfactory evaluated odor and iron and manganese. These results suggest that the race of animal has an impact on meat quality. [Projekat Ministarstva nauke Republike Srbije, br. TR 31053: Implementation of new biotechnological solutions in breeding of cattle, sheep and goats for the purpose of obtaining biologically valuable and safe food