Publications by authors named "Martinez-Culebras P"

Edible Insects (EIs) are an alternative source of bioactive compounds such as proteins or fatty acids and micronutrients as vitamins or minerals, thus showing potential to replace traditional foodstuffs in an economical and environmentally friendly way. Nonetheless, EIs can accumulate hazardous chemicals such as mycotoxins and heavy metals. The aim of the present study is to determine mycotoxins and heavy metal content in raw insect samples and those resulting products obtained after supercritical fluid extraction (SFE).

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The control of heat-resistant fungi (HRFs), which cause spoilage of heat-treated fruit products, is considered a challenge for the fruit juice and beverage industry and requires new strategies for the development of antifungal compounds. In this study, four antifungal proteins (AFPs) from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC), were evaluated against conidia from a representative collection of HRFs. A total of 19 strains from 16 different species belonging to the genera Aspergillus, Hamigera, Paecilomyces, Rasamsonia, Sarocladium, Talaromyces and Thermoascus were included in the study.

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Article Synopsis
  • The study focused on identifying fungal species responsible for spoilage in sliced bread and assessing the effectiveness of antifungal proteins (AFPs) derived from fungi against these species.
  • The main fungal culprits identified were various Penicillium species, including P. roqueforti and P. chrysogenum, as well as some Aspergillus species.
  • Among the AFPs tested, PdAfpB and PeAfpA exhibited strong antifungal properties, with PdAfpB showing notable efficacy in reducing spoilage fungal growth in bread, indicating its potential as a natural preservative to extend shelf life.
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Fungal antifungal proteins (AFPs) have attracted attention as novel biofungicides. Their exploitation requires safe and cost-effective producing biofactories. Previously, Penicillium chrysogenum and Penicillium digitatum produced recombinant AFPs with the use of a P.

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The global challenge to prevent fungal spoilage and mycotoxin contamination on food and feed requires the development of new antifungal strategies. Antimicrobial peptides and proteins (AMPs) with antifungal activity are gaining much interest as natural antifungal compounds due to their properties such as structure diversity and function, antifungal spectrum, mechanism of action, high stability and the availability of biotechnological production methods. Given their multistep mode of action, the development of fungal resistance to AMPs is presumed to be slow or delayed compared to conventional fungicides.

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phytopathogenic species provoke severe postharvest disease and economic losses. is the main pome fruit phytopathogen while and cause citrus green and blue mold, respectively. Control strategies rely on the use of synthetic fungicides, but the appearance of resistant strains and safety concerns have led to the search for new antifungals.

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Article Synopsis
  • The study addresses the need for new antifungal strategies to combat fungal spoilage and mycotoxin contamination in food and feed.
  • Researchers tested four antifungal proteins (AFPs) from two types of Penicillium fungi against a wide range of harmful mycotoxin-producing fungi.
  • Results showed that one protein, PeAfpA, effectively inhibited the growth of all tested fungi, while other proteins also displayed significant antifungal activity, highlighting their potential for future applications in food preservation and crop protection.
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The present study addressed the protective effects against oxidative stress (OS) of a cocoa powder extract (CPEX) on the protein expression profile of . A proteomic analysis was performed after culture preincubation with CPEX either without stress (-OS) or under stress conditions (+OS) (5 mM of HO). LC-MS/MS identified 33 differentially expressed proteins (-OS: 14, +OS: 19) that were included By Gene Ontology analysis in biological processes: biosynthesis of amino acids, carbohydrate metabolism and reactive oxygen species metabolic process.

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Multiplex real-time polymerase chain reaction (PCR) provides a fast and accurate DNA-based tool for the simultaneous amplification of more than one target sequence in a single reaction. Here a duplex real-time PCR assay is described for the simultaneous detection of Aspergillus carbonarius and members of the Aspergillus niger aggregate, which are the main responsible species for ochratoxin A (OTA) contamination in grapes. This single tube reaction targets the beta-ketosynthase and the acyl transferase domains of the polyketide synthase of A.

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Fungi play a key role in dry-cured ham production because of their lipolytic and proteolytic activities. In the present study, 74 fungal strains from dry-cured Teruel hams and air chambers were tested for proteolytic and lipolytic activities, with a view to their possible use as starter cultures. Lipolytic activity of fungi was studied against lauric, palmitic, stearic and oleic acids, whereas proteolytic activity was studied against casein and myosin.

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Article Synopsis
  • - The study investigates how oxidative stress affects the production of ochratoxin A (OTA) in the fungus Aspergillus carbonarius, using the oxidant menadione and various antioxidants like BHT, catechin, and resveratrol.
  • - Results showed that menadione increases both reactive oxygen species (ROS) and OTA levels while negatively impacting fungal growth, and that certain antioxidants can also lead to higher OTA levels despite minimal impact on growth at low concentrations.
  • - Ultimately, the findings suggest that oxidative stress enhances OTA production in the fungus, and relying solely on natural antioxidants to control OTA contamination in grapes is ineffective.
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Ochratoxin A (OTA), a nephrotoxic compound produced by certain Aspergillus and Penicillium species, is one of the most abundant mycotoxins in food commodities. Aspergillus carbonarius is the main source of OTA in wine, grape juice and dried vine fruits. Although many studies have focused on OTA production by A.

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The present study reports the natural mycobiota occurring in dry-cured hams, and in particular on the incidence of mycotoxin-producing fungi. A total of 338 fungal colonies were isolated from three stages of production, these being the post-salting, ripening and aging stages in two manufacturing plants. The results show that fungi were more frequently isolated from the aging stage and that the predominant filamentous fungal genus isolated was Penicillium.

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An enhanced green fluorescent protein has been used to tag an OTA-producing strain of Aspergillus carbonarius (W04-40) isolated from naturally infected grape berries. Transformation of the fungus was mediated by Agrobacterium tumefaciens. The most efficient transformation occurred when the co-cultivation was done with 10(4) conidia due to higher frequency of resistance colonies (894 per 10(4) conidia) and lower background obtained.

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Aspergillus carbonarius is an important ochratoxin A producing fungus that is responsible for mycotoxin contamination of grapes and wine. In this study, the proteomes of highly (W04-40) and weakly (W04-46) OTA-producing A. carbonarius strains were compared to identify proteins that may be involved in OTA biosynthesis.

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Aspergillus carbonarius is an important ochratoxin A (OTA)-producing fungus that is responsible for toxin contamination of grapes and wine, coffee and cocoa. A suppression subtractive hybridization (SSH) approach was performed with two strains of A. carbonarius, antagonistic in their OTA-production ability, to identify genes whose expression is linked with the ability to produce OTA.

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This paper reports a duplex real-time polymerase chain reaction (PCR) assay for the simultaneous detection of members of the Aspergillus niger aggregate and A. carbonarius, which are the main responsible species for ochratoxin A (OTA) contamination in grapes. This single tube reaction targets the beta-ketosynthase and the acyl transferase domains of the poliketide synthase of A.

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This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A.

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The present study reports on the natural mycobiota occurring in cocoa beans, paying special attention to the incidence of fungal species that are potential producers of mycotoxins. The results show that predominant fungi were different species of the genus Aspergillus belonging to section Flavi and Nigri. Of the 214 strains of Aspergillus section Flavi collected from cocoa beans, 120 were identified as A.

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Aspergillus carbonarius is the main species responsible for ochratoxin A accumulation in wine grapes and consequently, its rapid and sensitive detection is increasingly investigated. A new real-time PCR (RTi-PCR) based procedure was developed for the rapid and specific detection and quantification of A. carbonarius in wine grapes.

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The population structure and genetic variation of two begomoviruses: tomato yellow leaf curl Sardinia virus (TYLCSV) and tomato yellow leaf curl virus (TYLCV) in tomato crops of Spain were studied from 1997 until 2001. Restriction digestion of a genomic region comprised of the CP coat protein gene (CPR) of 358 TYLC virus isolates enabled us to classify them into 14 haplotypes. Nucleotide sequences of two genomic regions: CPR, and the surrounding intergenic region (SIR) were determined for at least two isolates per haplotype.

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Ochratoxigenic mycobiota in grapes from representative wine regions in Valencia was identified. Black aspergilli were predominant among the different Aspergillus spp. isolated.

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During the summer and autumn of 2001, symptoms of interveinal yellowing, bronzing, brittleness, and rolling of lower leaves were observed in greenhouse- and field-grown tomato (Lycopersicon esculentum) plants in Castellon Province in eastern Spain. Symptoms resembled those caused by the whitefly-transmitted criniviruses (1,2). Total RNA was extracted from 28 samples of symptomatic leaves collected in three greenhouses and one field and analyzed by reverse transcription-polymerase chain reaction using primers specific for Tomato chlorosis virus (ToCV) (1) and Tomato infectious chlorosis virus (TICV) (2).

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Pepino mosaic virus (PepMV) is a potexvirus recently identified as the causal agent of a new disease occurring in protected tomato (Lycopersicon esculentum Mill.) crops in the Netherlands (2). PepMV has been subsequently identified in England, Germany, Italy, Morocco, Portugal, and Spain.

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At the beginning of 2000, a damaging disease developed on protected tomato (Lycopersicon esculentum) crops grown in polyethylene greenhouses in different regions of Spain. Production losses were estimated at 15 to 80%. The tomato plants showed a variety of symptoms.

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