scholarly journals Effect of a Debaryomyces hansenii and Lactobacillus buchneri Starter Culture on Aspergillus westerdijkiae Ochratoxin A Production and Growth during the Manufacture of Short Seasoned Dry-Cured Ham

2020 ◽  
Vol 8 (10) ◽  
pp. 1623
Author(s):  
Lucilla Iacumin ◽  
Martina Arnoldi ◽  
Giuseppe Comi
Keyword(s):  
Ochratoxin A ◽  
Starter Culture ◽  
Debaryomyces Hansenii ◽  
Aspergillus Ochraceus ◽  
In Situ Tests ◽  
Potential Health ◽  
Lactobacillus Buchneri ◽  
Dry Cured Ham ◽  
Aspergillus Westerdijkiae

Recently, specific dry-cured hams have started to be produced in San Daniele and Parma areas. The ingredients are similar to protected denomination of origin (PDO) produced in San Daniele or Parma areas, and include pork leg, coming from pigs bred in the Italian peninsula, salt and spices. However, these specific new products cannot be marked as a PDO, either San Daniele or Parma dry cured ham, because they are seasoned for 6 months, and the mark PDO is given only to products seasoned over 13 months. Consequently, these products are called short-seasoned dry-cured ham (SSDCH) and are not branded PDO. During their seasoning period, particularly from the first drying until the end of the seasoning period, many molds, including Eurotium spp. and Penicillium spp., can grow on the surface and work together with other molds and tissue enzymes to produce a unique aroma. Both of these strains typically predominate over other molds. However, molds producing ochratoxins, such as Aspergillus ochraceus and Penicillium nordicum, can simultaneously grow and produce ochratoxin A (OTA). Consequently, these dry-cured hams may represent a potential health risk for consumers. Recently, Aspergillus westerdijkiae has been isolated from SSDCHs, which could represent a potential problem for consumers. Therefore, the aim of this study was to inhibit A. westerdijkiae using Debaryomyces hansenii or Lactobacillus buchneri or a mix of both microorganisms. Six D. hansenii and six L. buchneri strains were tested in vitro for their ability to inhibit A. westerdijkiae. The strains D. hansenii (DIAL)1 and L. buchneri (Lb)4 demonstrated the highest inhibitory activity and were selected for in situ tests. The strains were inoculated or co-inoculated on fresh pork legs for SSDCH production with OTA-producing A. westerdijkiae prior to the first drying and seasoning. At the end of seasoning (six months), OTA was not detected in the SSDCH treated with both microorganisms and their combination. Because both strains did not adversely affect the SSDCH odor or flavor, the combination of these strains are proposed for use as starters to inhibit OTA-producing A. westerdijkiae.

Agrobacterium-mediated insertional mutagenesis of the ochratoxigenic fungus Aspergillus westerdijkiae

2007 ◽  
Vol 53 (1) ◽  
pp. 148-151 ◽  
Author(s):  
Marcia M Mata ◽  
Marta H Taniwaki ◽  
Beatriz T Iamanaka ◽  
Daniele Sartori ◽  
André L.M Oliveira ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Insertional Mutagenesis ◽  
Aspergillus Ochraceus ◽  
Agrobacterium Mediated Transformation ◽  
Morphological Variations ◽  
Carcinogenic Potential ◽  
Coffee Beans ◽  
Aspergillus Westerdijkiae ◽  
Polymerase Chain ◽  
First Time

Aspergillus westerdijkiae is a potent ochratoxin A (OTA) producer that has been found in coffee beans. OTA is known to have nephrotoxic effects and carcinogenic potential in animal species. Here we report for the first time the Agrobacterium-mediated transformation for Aspergillus westerdijkiae and the generation of ochratoxin-defective mutants. Conidia were transformed to hygromycin B resistance using strain AGL-1 of Agrobacterium tumefaciens. The obtained transformation frequency was up to 47 transformants per 106 target conidia. Among 600 transformants, approximately 5% showed morphological variations. Eight transformants with consistently reduced OTA production were obtained. Two of these transformants did not produce OTA (detection limit: 0.1 µg/kg); the other six mutants produced lower amounts of OTA (1%–32%) compared with the wild-type strain. By using thermal asymmetric interlaced polymerase chain reaction, we successfully identified a putative flavin adenine dinucleotide monooxygenase gene.Key words: Aspergillus ochraceus, Aspergillus westerdijkiae, Agrobacterium-mediated transformation, Agrobacterium-mediated insertional mutagenesis, ochratoxin A.

Penicillium Populations in Dry-Cured Ham Manufacturing Plants

2007 ◽  
Vol 70 (4) ◽  
pp. 975-980 ◽  
Author(s):  
PAOLA BATTILANI ◽  
AMEDEO PIETRI ◽  
PAOLA GIORNI ◽  
SILVIA FORMENTI ◽  
TERENZIO BERTUZZI ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Ochratoxin A ◽  
Potential Risk ◽  
Dominant Species ◽  
Surface Contamination ◽  
Curing Conditions ◽  
Manufacturing Plants ◽  
Dry Cured Ham ◽  
Penicillium Nordicum

Seven ham manufacturing plants were sampled for 1 year to assess the mycoflora present in the air and on hams, with special attention given to potential mycotoxin producers. Temperature and relative humidity were recorded in the ripening rooms. Maturing rooms held hams from 2 to 3 through 6 to 7 ripening months, and aging rooms held hams for the following 6 to 7 months, until the 14-month ripening point, when they were ready for the market. Mean temperatures and relative humidities registered during the study were 14.9°C and 62.4%, respectively, in maturing rooms and 16.3°C and 57.6% in aging rooms. Aspergilli and penicillia, potential mycotoxin producers, were isolated in all the plants from the air and the ham. Aspergilli represented 5% of the isolates, while penicillia were largely dominant, with Penicillium nalgiovense being the most represented species (around 60% of the penicillia), followed by Penicillium nordicum, with 10 and 26% of the penicillia isolated, respectively, from the air or the ham. Ochratoxin A production ability, checked in vitro at 25°C, was observed in 50% of the P. nordicum isolates obtained both from the air and the ham. Air and ham surface contamination by penicillia was greater in the ripening rooms, where higher temperatures were registered. A certain correlation was also observed between air and ham surface contamination. On the basis of this study, P. nordicum, the ochratoxin A producer that is notable on proteinaceous substrates, is normally present in ham manufacturing plants in Italy, even though not a dominant species. Further studies are necessary to clarify and ensure if dry-curing conditions minimize the potential risk of ochratoxin A formation in the product.

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.

Mechanisms involved in reduction of ochratoxin A produced by Aspergillus westerdijkiae using Debaryomyces hansenii CYC 1244

2011 ◽  
Vol 151 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Jéssica Gil-Serna ◽  
Belén Patiño ◽  
Laura Cortés ◽  
María Teresa González-Jaén ◽  
Covadonga Vázquez
Keyword(s):  
Ochratoxin A ◽  
Debaryomyces Hansenii ◽  
Aspergillus Westerdijkiae

In vitro effect of some fungicides used in cultivation of Capsicum spp. on growth and ochratoxin A production by Aspergillus species

2013 ◽  
Vol 6 (2) ◽  
pp. 159-165
Author(s):  
L. Santos ◽  
S. Marín ◽  
V. Sanchis ◽  
A.J. Ramos
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Fruit Production ◽  
Aspergillus Species ◽  
Aspergillus Ochraceus ◽  
Fungal Load ◽  
Capsicum Spp ◽  
Vitro Effect ◽  
Yeast Extract Sucrose

The present study aimed to assess the effect of some pre-harvest fungicides commonly used in Capsicum fruit production on growth and ochratoxin A production of three Aspergillus species found in Capsicum powder. Aspergillus tubingensis, Aspergillus ochraceus and Aspergillus westerdijkiae, previously isolated from paprika and chilli, were inoculated on yeast extract sucrose agar and paprika extract agar supplemented with different fungicides at their recommended dosage rates, and incubated at 20 and 30 °C during 7 days. Radial growth was measured after 3, 5 and 7 days and ochratoxin A production was determined by high-performance liquid chromatography with fluorescence detection on day 7. Dodine 40% and mancozeb 80% were the most effective fungicides in inhibiting growth and ochratoxin A production, regardless of the fungal strain tested or temperature conditions. Whereas the application of fungicides could be very attractive in reducing the mycotoxigenic fungal load, it can also stimulate ochratoxin A production in some cases.

A new preparative method for simultaneous purification of ochratoxin A and ochratoxin B from wheat culture inoculated with Aspergillus ochraceus

2016 ◽  
Vol 9 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Z.Y. Zhao ◽  
N. Liu ◽  
L.C. Yang ◽  
A.B. Wu ◽  
Z.L. Zhou ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Ochratoxin A ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Preparative Method ◽  
Aspergillus Ochraceus ◽  
Potential Health ◽  
Ochratoxin B ◽  
Purity Analysis

Ochratoxins are a mycotoxin family frequently found in agricultural commodities worldwide and pose a potential health risk to humans and animals. To obtain large amounts of high-purity ochratoxins for food safety monitoring and toxicological research, a novel and effective method was established for simultaneous purification of ochratoxin A (OTA) and ochratoxin B (OTB) from a wheat culture inoculated with an ochratoxin-producing Aspergillus strain. The inoculated wheat culture was first extracted with methanol:water (80:20, v/v), followed by one or two cleanup procedures involving acid-assisted liquid-liquid extraction and gel permeation chromatography. Subsequently, target analytes were separated and collected using preparative high performance liquid chromatography. Finally, a combined approach of ultra-high performance liquid chromatography, ultraviolet spectrophotometry and mass spectrometry was applied for purity analysis and structural identification of the obtained toxins. As a result, 100 g of an inoculated wheat culture yielded 69 mg of OTA and 6 mg of OTB with purities greater than 98%. This proposed method might serve as a valuable reference to obtain expensive ochratoxin standards. To the best of our knowledge, this is the first report on simultaneous preparation of OTA and OTB from artificially inoculated wheat culture.

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

2009 ◽  
pp. 69-77 ◽  
Author(s):  
Aleksandra Bocarov-Stancic ◽  
Aleksandra Miljkovic ◽  
Radmila Resanovic ◽  
Ksenija Nesic ◽  
Vesna Jacevic ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Yeast Extract ◽  
Toxin Production ◽  
Aspergillus Ochraceus ◽  
Submerged Cultivation ◽  
Wheat Grain ◽  
Liquid Media ◽  
Potato Dextrose Broth ◽  
Solid Substrates

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 Bocarov-Stancic 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.

scholarly journals Efficacy of the Combined Protective Cultures of Penicillium chrysogenum and Debaryomyces hansenii for the Control of Ochratoxin A Hazard in Dry-Cured Ham

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 710 ◽  
Author(s):  
Eva Cebrián ◽  
Mar Rodríguez ◽  
Belén Peromingo ◽  
Elena Bermúdez ◽  
Félix Núñez
Keyword(s):  
Ochratoxin A ◽  
Penicillium Chrysogenum ◽  
Debaryomyces Hansenii ◽  
Relative Expression ◽  
Expression Of Genes ◽  
Dry Cured Ham ◽  
Penicillium Nordicum ◽  
Individual Use ◽  
Protective Culture ◽  
Protective Cultures

The ecological conditions during the ripening of dry-cured ham favour the development of moulds on its surface, being frequently the presence of Penicillium nordicum, a producer of ochratoxin A (OTA). Biocontrol using moulds and yeasts usually found in dry-cured ham is a promising strategy to minimize this hazard. The aim of this work is to evaluate the effect of previously selected Debaryomyces hansenii and Penicillium chrysogenum strains on growth, OTA production, and relative expression of genes involved in the OTA biosynthesis by P. nordicum. P. nordicum was inoculated against the protective cultures individually and combined on dry-cured ham for 21 days at 20 °C. None of the treatments reduced the growth of P. nordicum, but all of them decreased OTA concentration. The lower production of OTA could be related to significant repression of the relative expression of otapksPN and otanpsPN genes of P. nordicum. The efficacy of the combined protective cultures was tested in 24 dry-cured hams in industrial ripening (an 8 month-long production). OTA was detected in nine of the 12 dry-cured hams in the batch inoculated only with P. nordicum. However, in the batch inoculated with both P. nordicum and the combined protective culture, a considerable reduction of OTA contamination was observed. In conclusion, although the efficacy of individual use P. chrysogenum is great, the combination with D. hansenii enhances its antifungal activity and could be proposed as a mixed protective culture to control the hazard of the presence of OTA in dry-cured ham.

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