scholarly journals Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables

2010 ◽  
pp. 33-45 ◽  
Author(s):  
Suncica Kocic-Tanackov ◽  
Gordana Dimic ◽  
Jelena Levic ◽  
Dusanka Pejin ◽  
Jelena Pejin ◽  
...  

In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found in fresh salads were Cladosporium (42.89%), Penicillium (25.78%), Aspergillus (14.67%) and Alternaria (6.89%). C. cladosporioides (40.44%), followed by A. niger (10.22%), P. aurantiogriseum (7.55%), A. alternata (6.89%) and Fusarium spp. (3.11%) were the most dominating species. Other species were represented with 2.22% (Eurotium spp.), 1.56% (Botrytis spp.), 0.67% (Phoma spp.), 0.44% (Geotrichum spp., Mucor spp., Phialophora spp.) and 0.22% (Emericella spp., Paecilomyces spp., Trichoderma spp., Xeromyces spp.). Twenty-two of 41 identified mould species were potentially toxigenic, which accounted for 46.18% of the total isolated population. The most frequent were the potential producers of ochratoxin A (17.77%). Potential producers of moniliformin were isolated in 3.11% of samples, while producers of fumonisin and STC were found in 2.67% and 2.44% of samples, respectively. The tested isolates of OA producers did not demonstrate the ability to biosynthetise this mycotoxins, but two out of five isolates of A. versicolor were found to biosynthesise STC in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate that such products may threaten human health, considering that isolated species were potentially toxigenic, while isolates of A. versicolor also biosynthesised STS.

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 574
Author(s):  
Wasiatus Sa’diyah ◽  
Akira Hashimoto ◽  
Gen Okada ◽  
Moriya Ohkuma

The diversity of sporocarp-inhabiting fungi (SCIF) was examined using six samples of xylarialean fungi from two different forests in Ibaraki Prefecture, Japan: a moist forest in the Sakuragawa area and an urban dry forest in the Tsukuba area. These fungi were enumerated using direct observation and dilution plate methods. We obtained 44 isolates, and careful morphological and molecular phylogenetic studies of these isolates revealed that approximately 30% of the operating taxonomic units were undescribed or cryptic species related to known fungi. Although typical mycoparasitic fungi, such as helotialean fungi and Trichoderma spp., were not isolated, the genera Acremonium, Acrodontium, and Simplicillium were detected. Comparisons of SCIF communities between the two forests suggested that the number of isolated species in the Sakuragawa area was lower than that in the Tsukuba area. Soil-borne fungi, such as Aspergillus, Beauveria, Penicillium, and Talaromyces, or polypores/corticioid mushrooms, are frequently detected in the Tsukuba area. Factors affecting SCIF communities in the two forests are discussed. Some noteworthy fungi are briefly described with notes on taxonomy, ecology, and molecular phylogeny.


2018 ◽  
Vol 3 (3) ◽  
pp. 553-564
Author(s):  
Felipe De Jesús Osuna-Canizalez ◽  
María Félix Moreno-López ◽  
Faustino García-Pérez ◽  
Sergio Ramírez-Rojas ◽  
Jaime Canul-Ku
Keyword(s):  

En Morelos, la pudrición de la raíz causada por Fusarium spp., es una de las principales enfermedades de la nochebuena de interior. Por su efecto devastador, en su prevención o control se realizan aplicaciones frecuentes de productos químicos, con los riesgos inherentes a la salud humana y al ambiente. En la búsqueda de alternativas bioracionales al manejo de esta enfermedad, se realizó un ensayo en el que se evaluaron tres cepas comerciales de Trichoderma spp., en tres diferentes sustratos: S1= “tierra de hoja” (70% v/v)+tezontle grueso (15% v/v)+tezontle fino (10% v/v)+agrolita (5% v/v); S2= turba (80% v/v)+ fibra de coco (20% v/v); S3= “tierra de hoja” (70%) + “tepojal” (30%), en las variedades comerciales más comunes, Freedom Red y Prestige Red. Se utilizó un diseño factorial de tratamientos 4 x 3 x 2 y los tratamientos resultantes se evaluaron en un diseño completamente al azar con seis repeticiones. Respecto a la incidencia de pudrición de la raíz, las cepas comerciales de Trichoderma spp., no mostraron diferencias entre sí ni con el testigo químico. La pudrición de la raíz estuvo asociada con S2, debido a una baja capacidad de aireación, y sólo se presentó en Prestige Red. La población (UFC g-1) de Trichoderma spp., en el sustrato al término del ciclo, fue igual (p≤ 0.05) entre cepas comerciales y entre estas y el testigo químico (sin inoculación), debido a la presencia de cepas nativas de Trichoderma en los componentes orgánicos de los sustratos (“tierra de hoja”, turba y fibra de coco).


2009 ◽  
Vol 15 (1) ◽  
pp. 97-105 ◽  
Author(s):  
P.V. Martínez Culebras ◽  
A. Crespo-Sempere ◽  
J.V. Gil ◽  
D. Ramón

Fungal polyketide synthases (PKS) are responsible for the biosynthesis of several mycotoxins and other secondary metabolites. PKS genes in ochratoxin producing species from Aspergillus and Penicillum genera have been identified using a degenerate primer pair developed for the acyl transferase (AT) domain of fungal PKSs. Sequences of AT domains were aligned and analyzed using phylogenetic methods. The AT domain sequences appeared to be specific for a particular type of fungal PKSs and were related to PKSs involved in different mycotoxin biosynthesis pathways, including ochratoxin A. We have also developed primers suitable for amplifying AT domain sequences in strains belonging to the A. niger aggregate. DNA from most of the black Aspergillus species currently recognized was tested. Primers showed general applicability and other Aspergillus species belonging to section Nigri were successfully amplified.


1986 ◽  
Vol 26 (4) ◽  
pp. 431 ◽  
Author(s):  
MJ Barbetti

In field studies we monitored the effects of time of season, trash and fungicides on the populations of fungi associated with leaves and petioles of newly sown subterranean clover, particularly in relation to the development of disease symptoms. These effects were compared with the fungal population changes occurring in a nearby established subterranean clover pasture. A range of fungi, notably Leptosphaerulina trifolii, Phoma medicaginis and Stemphylium globuliferum, were found to colonise subterranean clover cotyledons, leaves and petioles readily throughout the growing season from as early as 1 week after emergence. The incidence of L. trifolii and S. globuliferum was reasonably consistent throughout the growing season. Alternaria spp., Cladosporium spp., Myrothecium verrucaria, P. medicaginis and Trichoderma spp. were more prevalent later in the season. Fusarium avenaceum and other Fusarium spp. were more prevalent early in the season, while Pithomyces chatarum and S. botryosum were more prevalent midseason. The fungi isolated showed no ability, under the conditions of this investigation, to cause disease, and there was no correlation between fungi isolated and disease symptoms observed. The incidence of several fungi, especially L. trifolii and P. medicaginis, was greatly increased by the presence of trash from the previous season but was greatly decreased by regular applications of fungicide.


Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1767-1774 ◽  
Author(s):  
E. Gachango ◽  
L. E. Hanson ◽  
A. Rojas ◽  
J. J. Hao ◽  
W. W. Kirk

A survey of seed potato tubers in Michigan seed production storage facilities was carried out during 2009 and 2010. Fusarium spp. associated with tuber dry rot symptoms were identified to species and tested for sensitivity to difenoconazole, fludioxonil, and thiabendazole. Symptomatic tubers (n = 370) were collected from a total of 51 seed lots, from which 228 isolates of Fusarium were recovered and identified to 11 species. Fusarium oxysporum was the most commonly isolated species (30.3%), followed by F. equiseti (19.3%). F. sambucinum and F. avenaceum were third most prevalent (each at 13.6%). Less prevalent species (each at 4 to 10%) included F. cerealis, F. solani, and F. acuminatum; and species present at ≤3% included F. sporotrichioides, F. torulosum, F. tricinctum, and F. graminearum. Representative isolates of all species were pathogenic when inoculated onto seed tubers (‘Dark Red Norland’). Isolates of F. sambucinum were the most virulent. All 228 isolates of Fusarium were sensitive to difenoconazole (effective fungicide concentration that caused 50% inhibition of mycelial growth [EC50] < 5 mg/liter). Insensitivity to fludioxonil (EC50 > 100 mg/liter) was detected only for F. sambucinum and F. oxysporum isolates at 8.9 and 20.4%, respectively. All isolates were sensitive to thiabendazole (EC50 < 5 mg/liter), except for those of F. sambucinum (EC50 > 100 mg/liter). Therefore, knowledge of what Fusarium spp. are present in seed potato storage facilities in Michigan may be important if using fludioxonil or thiabendazole for seed piece treatment but not when using difenoconazole.


2003 ◽  
Vol 69 (4) ◽  
pp. 384-392 ◽  
Author(s):  
K. KUMAKURA ◽  
S. WATANABE ◽  
J. TOYOSHIMA ◽  
T. MAKINO ◽  
T. ICHIKAWA ◽  
...  

Author(s):  
Jaygendra Kumar ◽  
Mukesh Kumar ◽  
Akash Tomar ◽  
. Vaishali ◽  
Pushpendra Kumar ◽  
...  

Trichoderma species are well known for their biocontrol activity which colonize many soil and tuber-borne and foliage plant pathogens. In this study, 12 native isolates of Trichiderma spp were collected from various crop rhizosphere soil samples and characterized them phenotypically based on morphological and cultural features and genotypically based on sequence analysis of internal transcribed spacer (ITS) region-PCR amplification. The results obtained from phenotypic and genotypic observation revealed that isolates were belonged to five different species namely T. asperellum, T. harzianum, T. longibrachiatum, T. koningii and T. koningiopsis. All Trichoderma isolates produced ~600 bp amplicon and phylogenetic analysis revealed that all isolates were grouped with respective species. Further, the antagonistic potential of all the isolates was evaluated against Fusarium spp. following in vitro dual culture method. The results showed that isolates of T. harzianum exhibited maximum growth inhibition activity. The highest rate of inhibition was recorded with T. harzianum isolate TBT6 (87.1%) followed by TBT7 (82.2%), while the least inhibition was observed in T. longibrachiatum isolate TBT10 (59.7%) after 7 days of incubation. The antagonistic T. harzianum isolate TBT6 can be used for development of Trichoderma based bio-formulation and served as bio-control agent against Fusaium spp. under field conditions.


2021 ◽  
Vol 19 (2) ◽  
pp. 158-169
Author(s):  
María del Valle Rodríguez Pinto ◽  
Rodrigo Orlando Campo Arana ◽  
Carlos Enrique Cardona Ayala ◽  
Eduardo Emilio Manjarres Cogolllo ◽  
Billy Jose Rossi Torecilla

La berenjena es una solanacea afectada por la Marchitez Vascular (MV) asociada a Fusarium oxysporum f. sp. melongena que destruye el tejido vascular, causando clorosis y finalmente muerte de la planta, generando pérdidas entre 70 y 90 % de la producción en cultivos establecidos del departamento de Córdoba, Colombia. El objetivo fue identificar cepas nativas de Trichoderma spp. para el biocontrol de Fusarium spp., en berenjena. Fueron aisladas de campo cinco cepas de Trichoderma spp: TC05, TM04, TS03, TC02, TM01 y cinco cepas de Fusarium spp: FM01, FS02, FC03, FC04, FS05, en laboratorio mediante cultivos duales bajo un diseño completamente al azar (DCA) con cinco repeticiones en arreglo factorial 5x6, donde el primer factor correspondió a las cepas de Fusarium spp., y el segundo a las cepas de Trichoderma spp. y un testigo, fue medido  a las cepas de Fusarium spp. el diámetro de la colonia para determinar el porcentaje de inhibición y la eficiencia de biocontrol de Trichoderma spp. siendo la cepa TC05 la mejor al inhibir entre 73 y 91,2 % las cinco cepas de Fusarium spp; posteriormente en casa malla fue evaluado el biocontrol de la MV bajo un diseño completamente al azar con cinco tratamientos y nueve repeticiones, preinoculando plántulas de berenjena con la cepa TC05 en dosis 1x108, 1x107, 1x106 UFC mL-1, una cepa comercial de Trichoderma spp dosis 1x108 UFC mL-1 y un testigo (control con agua), y 10 días después de inoculadas (DDI) con la cepa FS02. Los resultados a los 45 DDI los índices de la enfermedad foliar e índice de decoloración vascular fueron menores con Trichoderma spp, respecto al testigo con incidencia de 45 % con MV. Se concluye que la cepa nativa TC05, tiene potencial para ser utilizada en el manejo integrado de la MV de la berenjena en Córdoba, Colombia.  


2016 ◽  
Vol 25 (4) ◽  
pp. 331 ◽  
Author(s):  
Mutia Erti Dwiastuti ◽  
Melisa N Fajri ◽  
Yunimar Yunimar

<p>Layu yang disebabkan oleh Fusarium spp. merupakan salah satu penyakit penting tanaman stroberi (Fragaria x ananassa<br />Dutch.) di daerah subtropika, yang dapat menggagalkan panen. Penelitian bertujuan untuk mempelajari potensi Trichoderma spp.<br />dalam mengendalikan Fusarium spp. Isolat Trichoderma spp. diisolasi dari rizosfer tanaman stroberi dan Fusarium spp. diisolasi<br />dari tanaman stroberi yang mengalami layu fusarium. Isolat cendawan dimurnikan, dikarakterisasi, dan dibandingkan dengan isolat<br />cendawan acuan. Uji antagonis dilakukan secara in vitro dan in vivo. Uji in vitro dilakukan dengan metode dual culture dan slide<br />culture. Uji in vivo dilakukan di rumah kasa menggunakan dua varietas stroberi, yaitu Santung serta California. Hasil penelitian <br />in vitro memperoleh dua jenis isolat cendawan antagonis, yaitu Trichoderma sp.1 dan Trichoderma sp.2, dan dua jenis cendawan <br />patogen Fusarium, yaitu Fusarium sp.1 dan Fusarium sp.2. Isolat Trichoderma sp.1 memiliki kemampuan antagonisme lebih tinggi<br />dibandingkan dengan isolat Trichoderma sp.2. Isolat Trichoderma sp.1 mampu menghambat pertumbuhan Fusarium sp.1 dan<br />Fusarium sp.2 secara berturut- turut, yaitu 49,7% dan 49,6%. Isolat Trichoderma sp.2 mampu menghambat pertumbuhan Fusarium<br />sp.1 dan Fusarium sp.2 lebih rendah, yaitu sebesar 45,8% dan 43,4%. Mekanisme antagonis yang terjadi antara cendawan antagonis<br />dan patogen pada uji in vitro, yaitu pembelitan dan intervensi hifa. Hasil pada uji in vivo pada perlakuan Trichoderma sebelum<br />Fusarium menunjukkan keefektifan pengendalian paling baik (41,72%) dibanding perlakuan lain. Varietas Santung lebih tahan<br />terhadap serangan patogen dibandingkan varietas California. Implikasi dari hasil penelitian ini adalah, agens hayati Trichoderma<br />spp. lebih optimal digunakan sebagai pencegahan (preventif) tanpa menunggu tanaman terinfeksi penyakit layu fusarium.</p>


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