scholarly journals Effects of temperature and incubation period on production of toxic metabolites by Alternaria radicina and A. alternata

2012 ◽  
Vol 58 (2) ◽  
pp. 7-18
Author(s):  
Krystyna Tylkowska ◽  
Jadwiga Grabarkiewicz-Szczęsna ◽  
Dorota Szopińska ◽  
Hanna Dorna ◽  
Michele Solfrizzo ◽  
...  
Keyword(s):  
Incubation Period ◽  
Methyl Ether ◽  
Tenuazonic Acid ◽  
Alternariol Methyl Ether ◽  
Rice Grains ◽  
Toxic Metabolites ◽  
Effects Of Temperature

The production of toxic metabolites by four isolates of <i>Alternaria radicina</i> and two isolates of <i>A. alternata</i> in rice grains and carrot discs at 1, 10 and 20<sup>°</sup>C was investigated. Incubation lasted 21 and 35 days or 14 and 28 days for rice grains and carrot discs, respectively. Accumulation of toxins in inoculated carrot roots stored for 24 weeks and in inoculated dried carrots stored for 48 weeks was also determined. It was found that <i>A. radicina</i> produced radicinin (RAD) and <i>epi</i>-radicinol (<i>epi</i>-ROH), whereas tenuazonic acid (TeA), altertoxin I (ATX I), alternariol (AOH) and alternariol methyl ether (AME) were produced by <i>A. alternata</i>. Although the isolates tested were capable of producing toxins in rice grains at 1<sup>°</sup>C, none of them was detected in carrot discs. Accumulation of <i>epi</i>-ROH was observed in carrot roots stored for 24 weeks, whereas decreased amounts of RAD and <i>epi</i>-ROH were observed in dried carrots stored for 48 weeks. No <i>A. alternata</i> toxins were detected in stored carrot roots, whereas trace amounts of AOH were recorded in dried carrots after 32 and 48 weeks of storage.

Mycotoxins - Their Biosynthesis in Alternaria

1985 ◽  
Vol 48 (1) ◽  
pp. 80-91 ◽  
Author(s):  
E. E. STINSON
Keyword(s):  
Secondary Metabolites ◽  
Methyl Ether ◽  
Current View ◽  
Tenuazonic Acid ◽  
Alternariol Methyl Ether ◽  
Wide Assortment

Alternaria produce a wide assortment of toxic and nontoxic secondary metabolites. A brief summary of the numerous secondary metabolites of Alternaria and their toxicity is followed by a presentation of the current view of the polyketide biosynthetic mechanism and its application to the biosynthesis of these compounds. Possible mechanisms for the biosynthesis of alternariol, alternariol methyl ether, and other dibenzo-α-pyrones are presented, as well as mechanisms for the biosynthesis of tenuazonic acid and altertoxin I. Bioregulation of the production of these materials by light, heat, nutrients and NADPH production, and the role of mannitol in NADPH formation are also discussed.

scholarly journals AlternariaMycotoxins in Food and Feed: An Overview

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Laura Escrivá ◽  
Souheib Oueslati ◽  
Guillermina Font ◽  
Lara Manyes
Keyword(s):  
Methyl Ether ◽  
Direct Injection ◽  
Strand Break ◽  
Sphingolipid Metabolism ◽  
Tenuazonic Acid ◽  
Alternariol Methyl Ether ◽  
Food And Feed ◽  
Dna Strand ◽  
Review Reports ◽  
Solid Liquid

Alternariais one of the major mycotoxigenic fungal genera with more than 70 reported metabolites.Alternariamycotoxins showed notably toxicity, such as mutagenicity, carcinogenicity, induction of DNA strand break, sphingolipid metabolism disruption, or inhibition of enzymes activity and photophosphorylation. This review reports on the toxicity, stability, metabolism, current analytical methods, and prevalence ofAlternariamycotoxins in food and feed through the most recent published research. Half of the publications were focused on fruits, vegetables, and derived products—mainly tomato and apples—while cereals and cereal by-products represented 38%. The most studied compounds were alternariol, alternariol methyl ether, tentoxin, and tenuazonic acid, but altenuene, altertoxins (I, II, and III), and macrosporin have been gaining importance in recent years. Solid-liquid extraction (50%) with acetonitrile or ethyl acetate was the most common extraction methodology, followed by QuEChERS and dilution-direct injection (both 14%). High- and ultraperformance liquid chromatography coupled with tandem mass spectrometry was the predominant determination technique (80%). The highest levels of alternariol and alternariol methyl ether were found in lentils, oilseeds, tomatoes, carrots, juices, wines, and cereals. Tenuazonic acid highest levels were detected in cereals followed by beer, while alternariol, alternariol methyl ether, tenuazonic acid, and tentoxin were found in legumes, nuts, and oilseeds.

Alternaria Toxins and Their Importance in Food

1984 ◽  
Vol 47 (11) ◽  
pp. 886-901 ◽  
Author(s):  
A. DOUGLAS KING ◽  
JOHN E. SCHADE
Keyword(s):  
Methyl Ether ◽  
Plant Tissue ◽  
Growth Conditions ◽  
Diseased Plant ◽  
Optimum Temperature ◽  
Tenuazonic Acid ◽  
Toxic Compounds ◽  
Alternariol Methyl Ether ◽  
Alternaria Toxins ◽  
Test Organisms

Members of the genus Alternaria are known to produce compounds that are pathogenic to plants and other test organisms, including animals. Of the more than 30 compounds produced, tenuazonic acid, alternariol, alternariol methyl ether and altertoxin I are the most toxic to animals. These toxic compounds have been isolated from diseased plant tissue and could be a problem with foods, although only tenuazonic acid has been isolated in small amounts from wholesome foods. A number of Alternaria spp. can produce these compounds and some species produce many of the compounds. Growth conditions under which the compounds are produced are not well-defined; generally the optimum temperature for their production is near 20°C.

Liquid Chromatographic Determination of Tenuazonic Acid and Alternariol Methyl Ether in Tomatoes and Tomato Products

1985 ◽  
Vol 68 (4) ◽  
pp. 640-642 ◽  
Author(s):  
Michael E Stack ◽  
Philip B Mislivec ◽  
John A G Roach ◽  
Albert E Pohland
Keyword(s):  
Methyl Ether ◽  
Chromatographic Determination ◽  
Ionization Mass ◽  
Tenuazonic Acid ◽  
Fluorescence Detector ◽  
Alternariol Methyl Ether ◽  
Ultraviolet Detector ◽  
In Series ◽  
Tomato Products ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for determining tenuazonic acid (TA) and alternariol methyl ether (AME) in tomatoes and tomato products is described. The Alternaria metabolites are extracted from a water slurry of the sample with CHCL3, the mixture is centrifuged, and the extract is fractionated on a silica gel column. Reverse phase LC with an ultraviolet detector (for TA) and a fluorescence detector (for AME) connected in series is used for final separation and determination. The limit of determination for TA and AME is 25 and 3 ng/g, respectively, with average recoveries from catsup of 83 and 68%, respectively. The LC method also detects alternariol, but interfering peaks in some samples prevent accurate quantitation. Chemical ionization mass spectrometry (CI MS) is used to confirm TA. Samples (142) of tomatoes collected from commercial processing lines were analyzed; TA was found in 73 samples (0.4-70 μg/g).

The Effects of Temperature and Incubation Period on Resveratrol Production and Antioxidant Activity on Iksan 526

2014 ◽  
Vol 26 (4) ◽  
pp. 468-473
Author(s):  
Eunmi Lee ◽  
◽  
Chun-Sun Seo ◽  
Woo-Jae kim ◽  
Jong-Ho Park ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Incubation Period ◽  
Effects Of Temperature

scholarly journals Temperature and incubation period affect Septoria pistaciarum conidium germination: disease forecasting and validation

2021 ◽  
Vol 60 (1) ◽  
pp. 113-117
Author(s):  
Thomas THOMIDIS ◽  
Konstantinos MICHOS ◽  
Fotis CHATZIPAPADOPOULOS ◽  
Amalia TAMPAKI
Keyword(s):  
Incubation Period ◽  
Disease Severity ◽  
Leaf Spot ◽  
Disease Risk ◽  
Generic Model ◽  
High Disease Severity ◽  
Conidium Germination ◽  
Effects Of Temperature ◽  
Important Disease ◽  
Septoria Leaf Spot

Septoria leaf spot is an important disease of pistachio trees in Greece. This study aimed to determine effects of temperature and the incubation period on germination of conidia of Septoria pistaciarum, and to evaluate a generic model to forecast pistachio leaf spot under the field conditions of Aegina Island, Greece. The optimum temperature for conidium germination was 23°C, and germination was inhibited at 35 and 4°C. At constant temperature of 23°C, conidia commenced germination after 9 h. The predictive model indexed disease risk close to 100 at 10 May at two locations (Rachi Moschona and Vigla) in 2017, and first leaf spot symptoms were observed on 17 May. Moderate to high disease severity (>25% leaves infected) were observed in unsprayed trees at the end of May. In 2018, the model indexed risk close to 100 on 9 May at Rachi Moschona, and first symptoms were observed on 18 May. Moderate to high disease severity (>25% leaves infected) were observed in unsprayed trees on 25th of May. This study has shown that the forecasting model can be used in Aegina Island, Greece, to predict the severity of Septoria leaf spot of pistachio.

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