Biological activity of Streptomyces noursei against ochratoxin A producing Aspergillus niger

2012 ◽  
Vol 11 (3) ◽  
Author(s):  
Nanis G. Allam
Keyword(s):  
Biological Activity ◽  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Streptomyces Noursei

Effect of water activity on ochratoxin A production by Aspergillus niger aggregate species

2006 ◽  
Vol 108 (2) ◽  
pp. 188-195 ◽  
Author(s):  
A. Esteban ◽  
M.L. Abarca ◽  
M.R. Bragulat ◽  
F.J. Cabañes
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Water Activity ◽  
Effect Of Water

Influence of light on growth, conidiation and the mutual regulation of fumonisin B2 and ochratoxin A biosynthesis by Aspergillus niger

2012 ◽  
Vol 5 (2) ◽  
pp. 169-176 ◽  
Author(s):  
F. Fanelli ◽  
M. Schmidt-Heydt ◽  
M. Haidukowski ◽  
R. Geisen ◽  
A. Logrieco ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Blue Light ◽  
Short Wave ◽  
Light Conditions ◽  
Dark Incubation ◽  
Mutual Regulation ◽  
Blue Wavelength ◽  
Fumonisin B2 ◽  
Dark Production

Aspergillus niger is a fungus able to produce the carcinogenic mycotoxins ochratoxin A (OTA) and fumonisins. We analysed the influence of light of various wavelengths on growth, conidiation, fumonisin B2 (FB2) and OTA biosynthesis by A. niger ITEM 7097. Light from both sides of the spectrum, from long (627 nm) to short wavelengths (470-455 nm), had a stimulating effect on growth, with the highest stimulation under blue (455 nm, 1,700 Lux) and short-wave blue light (390 nm). Conidiation was reduced by 40% under a short blue wavelength (455 nm, 200 Lux), but strongly promoted under light at an even shorter wavelength (390 nm), with an increase of about 200 fold in comparison to the dark. Production of FB2 and OTA was mutually regulated by light. FB2 production was promoted under light conditions: red and blue light in particular increased FB2 biosynthesis by 40%. Conversely, OTA production was greatly inhibited under red and blue light in comparison to dark incubation, with a mean reduction of about 40 fold, indicating a reverse regulation of both biosynthetic pathways. Incubation under a 390 nm wavelength repressed the production of both toxins to non-detectable levels.

scholarly journals DETECTION AND INVESTIGATION OF ASPERGILLUS NIGER AND OCHRATOXIN A IN WALNUT AND PEANUT

2017 ◽  
Vol 48 (5) ◽  
Author(s):  
Khalifa & et al.
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Plant Protection ◽  
Uv Light ◽  
Wave Length ◽  
Artificial Medium ◽  
College Of Agriculture ◽  
Local Markets ◽  
Layer Chromatography ◽  
Isolation Test

This study was conducted at the Department of Plant Protection-College of Agriculture-University of Baghdad during 2015 -2016. The objective of the study is to investigate the contamination of the fungus Aspergillus niger in the seeds of peanuts and walnuts from the Iraqi local markets and the ability of these isolates to produce ochratoxin A in artificial medium. Forty samples of peanuts and walnuts were collected from local markets of the governorates of Baghdad, Erbil, Sulaymaniyah , Anbar and Dyiala for isolation test of  A. nigar. Results showed that A.niger was founded in the samples of walnuts from Erbil at percentage of 50% and 42.8% in the samples of peanuts from Baghdad ,and 40 % in peanuts from each Anbar and Dyiala, in addition to the fungus A.flavus at a rate of33.3 و 28.8 %  in the walnuts from Erbil and Baghdad respectively and 30% و28.8% in the peanuts from Anbar and Baghdad respectively. Eleven isolates of fungus A.niger was tested against its ability to produce Ochratoxin A after grown in yeast and sucrose extract media and analyzed using thin layer chromatography (TLC) under UV light wave length of 365 nanometer, two isolates were identified (K,E) out of the A.niger fungus isolated from peanuts found to be able to produce Ochratoxin A at different rates, depending on the degree of the brightness of the spots compared with standard Toxin. Then the eleven isolates were identified by morphology characters and confirm by using specific primer NIG1and NIG2, all the isolates showed to be A.niger.

Rubrofusarin from Aspergillus niger GTS01-4 and its biological activity

2017 ◽  
Author(s):  
Megawati ◽  
Rizna Triana Dewi ◽  
Hanny Mulyani ◽  
Faiza Maryani ◽  
Puspa Dewi N. Lotullung ◽  
...  
Keyword(s):  
Biological Activity ◽  
Aspergillus Niger

scholarly journals Aflatoxigenic and ochratoxigenic moulds and their toxins in tree nuts on Serbian market

2020 ◽  
pp. 9-18
Author(s):  
Irena Rakic ◽  
Gordana Dimic ◽  
Marija Skrinjar ◽  
Suncica Kocic-Tanackov
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Immunosorbent Assay ◽  
Alternaria Alternata ◽  
Rhizopus Oryzae ◽  
Limit Of Detection ◽  
Average Concentration ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mean Values ◽  
Tree Nuts

In this study, moulds and mycotoxins presence in different tree nuts were investigated. The results showed that all of the 25 samples were contaminated with moulds. Mean values of total mould count varied from 1-4.9 cfu per grain. The most frequent species in hazelnut samples were Rhizopus oryzae (32.2%) and Aspergillus niger (28.9%). In walnuts A. niger (75.6%), in cashews also A. niger (42.4%) while in pistachio samples Alternaria alternata (20.7%), and Cladosporium cladosporioides (20.7%) were the most dominant. Rhizopus oligosporus was the only identified species in all almond samples (100%). Using Enzyme Linked Immunosorbent Assay (ELISA), the presence of total aflatoxins and ochratoxin A was examinated. In all analyzed samples, levels of ochratoxin A were below the limit of detection. Total aflatoxins were detected only in walnut samples with average concentration of 7.1 ?g/kg.

scholarly journals BMS-192548, a Tetracyclic Binding Inhibitor of Neuropeptide Y Receptors, from Aspergillus niger WB2346. I. Taxonomy, Fermentation, Isolation and Biological Activity.

1995 ◽  
Vol 48 (10) ◽  
pp. 1055-1059 ◽  
Author(s):  
KRISHNA KODUKULA ◽  
MAREDITH ARCURI ◽  
JINGFANG QIAN CUTRONE ◽  
ROBERT M. HUGILL ◽  
SUSAN E. LOWE ◽  
...  
Keyword(s):  
Biological Activity ◽  
Aspergillus Niger ◽  
Neuropeptide Y ◽  
Y Receptors ◽  
Neuropeptide Y Receptors

scholarly journals Ochratoxigenic fungi and Ochratoxin A determination in dried grapes marketed in Tunisia

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Samir Chebil ◽  
Wafa Rjiba-Bahri ◽  
Souheib Oueslati ◽  
Hanen Ben Ismail ◽  
Anis Ben-Amar ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
High Performance ◽  
Its Region ◽  
Production Test ◽  
Potential Health ◽  
Dried Grapes ◽  
Pcr Product ◽  
Polymerase Chain

Abstract Purpose With the present work, we aimed to assess the occurrence of ochratoxigenic fungi and Ochratoxin A (OTA) in dried grapes from Tunisia. Methods Dried grapes samples (n = 90) were investigated for the presence of ochratoxigenic fungi, which were further characterized at the species level through amplification of the internal transcribed spacer (ITS) region and polymerase chain reaction (PCR) product sequencing. Fungal isolates were tested for their ochratoxigenic potential by high-performance liquid chromatography with fluorescence detection (HPLC-FLD), as well as dried grapes samples after an immunoaffinity column (IAC) clean-up procedure. Results Black Aspergilli isolates were the dominant genre among the filamentous fungi found in dried grapes samples and were the only OTA-producing fungi encountered. Aspergillus niger aggregate were the most frequently found isolates reaching 70%, 80%, and 85% in dried grapes samples from regions of Kelibia, Sfax, and Rafraf, respectively, while covered 100% of the relevant mycobiota found in imported samples. Aspergillus carbonarius isolates were found only in Sfax’s and Kelibia’s samples, while uniseriate Aspergilli were found between 7 and 20% in dried grapes from Kelibia, Sfax, and the imported samples. The in vitro OTA production test showed that 88.9% of OTA-producing isolates belonged to A. carbonarius with OTA levels varying from 0.06 to 1.32 μg/g of Czapek Yeast Agar (CYA). The remaining OTA-producing fungi (11.1 %) belonged to A. niger aggregate group having a maximum OTA potential of 2.88 μg/g CYA, and no uniseriate Aspergilli isolate was able to produce OTA. All dried grapes samples were free of OTA presence. Conclusion According to the present study’s findings, no OTA contamination was recorded in the investigated samples from Tunisian market. Nevertheless, the presence of strong OTA producers A. carbonarius in samples originated from the two out of three studied Tunisian regions, as well the high incidences of Aspergillus niger aggregate group with an attested potential for OTA production in all samples, necessitates further research on Tunisian dried grapes. Additionally, a continuous analysis of staple food of the Mediterranean diet is imperative to insure the best quality for the consumers and prevent potential health problems.

Distribution and Mycotoxigenic Potential of Aspergillus Section Nigri Species in Naturally Contaminated Almonds

2013 ◽  
Vol 76 (4) ◽  
pp. 702-706 ◽  
Author(s):  
JEFFREY D. PALUMBO ◽  
TERESA L. O'KEEFFE
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Aspergillus Species ◽  
Aspergillus Awamori ◽  
Aspergillus Tubingensis ◽  
Aspergillus Section Nigri ◽  
Total Potential ◽  
Fumonisin B2 ◽  
Low Levels ◽  
Aspergillus Section

In a previous study, inedible almond pick-out samples were assayed for aflatoxin and aflatoxigenic Aspergillus species. These samples contained high populations of black-spored Aspergillus section Nigri species. To investigate whether these species may contribute to the total potential mycotoxin content of almonds, Aspergillus section Nigri strains were isolated from these samples and assayed for ochratoxin A (OTA) and fumonisin B2 (FB2). The majority of isolates (117 strains, 68%) were identified as Aspergillus tubingensis, which do not produce either mycotoxin. Of the 47 Aspergillus niger and Aspergillus awamori isolates, 34 strains (72%) produced FB2 on CY20S agar, and representative strains produced lower but measurable amounts of FB2 on almond meal agar. No OTA-producing strains of Aspergillus section Nigri were detected. Almond pick-out samples contained no measurable FB2, suggesting that properly dried and stored almonds are not conducive for FB2 production by resident A. niger and A. awamori populations. However, 3 of 21 samples contained low levels (<1.5 ng/g) of OTA, indicating that sporadic OTA contamination may occur but may be caused by OTA-producing strains of other Aspergillus species.

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