Silver coated porous silicon microarray SERS platform for detecting aflatoxin B1 fumonisin B1 and ochratoxin A.

Toxigenic mold contamination in food and agricultural commodities affects a quarter of the world's crops with massive economic losses and consequential health risks. Herein, we present a newly developed nanostructured microarray based on silver-coated porous silicon (Ag-pSi) used as a surface-enhanced Raman scattering (SERS) transducer. The internal porous void and pore morphology were optimized to amplify the SERS effect while achieving an enhancement factor of 1.

Sweet Pepper cv. Lai Lai Ripeness Stage Influences Susceptibility to Mycotoxinogenic Alternaria alternata Causing Black Mold.

Sweet pepper (Capsicum annuum) is a highly nutritious and economically important vegetable grown worldwide. Black mold, caused by mycotoxin-producing Alternaria spp., is a common postharvest disease during cold storage and transport, leading to significant produce losses.

Antifungal effect and mode of activity of zinc chloride against toxigenic fungus Aspergillus flavus.

Fungal plant pathogens cause considerable losses in yield and quality of field crops worldwide. Under specific environmental conditions, many fungi, such as Aspergillus spp., produce mycotoxins while colonizing their host, which accumulate in human and animal tissues, posing a serious threat to consumer health.

Sensitive ratiometric detection of Fumonisin B using a reusable Ag-pSi SERS platform.

Food and agricultural commodities endure consistent contamination by mycotoxins, low molecular weight fungal metabolites, which pose severe health implications to humans together with staggering economic losses. Herein, a ratiometric aptasensor was constructed using silver-coated porous silicon (Ag-pSi) used as an efficient surface-enhanced Raman scattering (SERS) substrate. The bioassay included direct detection of fumonisin B (FB), an abundant and widespread contaminant, by a specific aptamer sequence immobilized on the porous transducer.

A comparative study of aptasensor vs. immunosensor for ultrasensitive detection of aflatoxin B1 using Ag-pSi SERS substrate.

Numerous SERS based platforms have been designed to address the emerging need for detecting fungal metabolite contamination in foodstuffs, and specifically the Group 1 carcinogen aflatoxin B1. Herein, 4-aminothiophenol modified silver-coated porous silicon was used as the SERS substrate. Two ratiometric responses were individually assessed upon direct target capture using specific aptamers or antibodies.

Nanogel Particles Based on Modified Nucleosides and Oligosaccharides as Advanced Delivery System.

This work addresses the challenge of delivering bioactive molecules by designing biocompatible nanogel particles (NGPs) utilizing rationally modified nature-sourced building blocks: capryl-oligochitosan and oxidized inosine. Capryl substituents endowed the resultant NGPs with membrane-penetration capabilities, while purine-containing inosine allowed H-bond/π-π/π-cation interactions. The prepared NGPs were complexed with carboxyfluorescein-labeled single-stranded oligonucleotide (FAM-oligo) and DsRed-encoding plasmid DNA.

Aneuploidy Formation in the Filamentous Fungus Aspergillus flavus in Response to Azole Stress.

Aspergillus flavus is a mycotoxigenic fungus that contaminates many important agricultural crops with aflatoxin B1, the most toxic and carcinogenic natural compound. This fungus is also the second leading cause of human invasive aspergillosis, after Aspergillus fumigatus, a disease that is particularly prevalent in immunocompromised individuals. Azole drugs are considered the most effective compounds in controlling Aspergillus infections both in clinical and agricultural settings.

Ensiling process and pomegranate peel extract as a natural additive in potential prevention of fungal and mycotoxin contamination in silage.

A study was conducted on six animal feed centers in Israel where fungal and mycotoxin presence was examined in maize and wheat silages. Fumonisin mycotoxins FB and FB were present in every maize silage sample analyzed. Interestingly, no correlation was found between the occurrence of specific mycotoxins and the presence of the fungal species that might produce them in maize and wheat silages.

Analysis of Stored Wheat Grain-Associated Microbiota Reveals Biocontrol Activity among Microorganisms against Mycotoxigenic Fungi.

Wheat grains are colonized by complex microbial communities that have the potential to affect seed quality and susceptibility to disease. Some of the beneficial microbes in these communities have been shown to protect plants against pathogens through antagonism. We evaluated the role of the microbiome in seed health: in particular, against mycotoxin-producing fungi.

Rapid Detection and Quantification of Patulin and Citrinin Contamination in Fruits.

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by and species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps.

Host Factors Modulating Ochratoxin A Biosynthesis during Fruit Colonization by .

is a strong and consistent ochratoxin A (OTA) producer and considered to be the main source of this toxic metabolite in grapes and grape products such as wine, grape juice and dried vine fruit. OTA is produced under certain growth conditions and its accumulation is affected by several environmental factors, such as growth phase, substrate, temperature, water activity and pH. In this study, we examined the impact of fruit host factors on regulation and accumulation of OTA in colonized grape berries, and assessed in vitro the impact of those factors on the transcriptional levels of the key genes and global regulators contributing to fungal colonization and mycotoxin synthesis.

Functional roles of LaeA, polyketide synthase, and glucose oxidase in the regulation of ochratoxin A biosynthesis and virulence in Aspergillus carbonarius.

Aspergillus carbonarius is the major producer of ochratoxin A (OTA) among Aspergillus species, but the contribution of this secondary metabolite to fungal virulence has not been assessed. We characterized the functions and addressed the roles of three factors in the regulation of OTA synthesis and pathogenicity in A. carbonarius: LaeA, a transcriptional factor regulating the production of secondary metabolites; polyketide synthase, required for OTA biosynthesis; and glucose oxidase (GOX), regulating gluconic acid (GLA) accumulation and acidification of the host tissue during fungal growth.

The pH-Responsive Transcription Factor PacC Governs Pathogenicity and Ochratoxin A Biosynthesis in .

Pathogenic fungi must respond effectively to changes in environmental pH for successful host colonization, virulence and toxin production. is a mycotoxigenic pathogen with the ability to colonize many plant hosts and secrete ochratoxin A (OTA). In this study, we characterized the functions and addressed the role of PacC-mediated pH signaling in pathogenicity using designed gene knockout mutant.

Synergistic Inhibition of Mycotoxigenic Fungi and Mycotoxin Production by Combination of Pomegranate Peel Extract and Azole Fungicide.

Fungal plant pathogens cause considerable losses in yield and quality of field crops worldwide. In addition, under specific environmental conditions, many fungi, including such as some and spp., are further able to produce mycotoxins while colonizing their host, which accumulate in human and animal tissues, posing a serious threat to consumer health.

Identification and Toxigenic Potential of Fungi Isolated from Peppers.

peppers are among the most popular horticultural crops produced and consumed worldwide. This study aimed to assess the occurrence of spoilage fungi responsible for post-harvest losses in the most common varieties of peppers collected from retail markets in Nigeria and Ghana. Forty fungal isolates belonging to 7 families, 8 genera, and 17 species were identified on the basis of morphology, culture characteristics, and DNA sequencing of the internal transcribed spacer (ITS) region.

Isolation and chemical characteristics of rhamnose enriched polysaccharide from Grateloupia lithophila.

The crude polysaccharide was extracted from Grateloupia lithophila through hot-water extraction and deproteinization. Further, fractionated by anion-exchange column using Q-Sepharose and purified by gel-permeation chromatography using Sepharose 4-LB column. The crude and purified polysaccharide contains high carbohydrate (75.

Rapid Detection and Identification of Mycotoxigenic Fungi and Mycotoxins in Stored Wheat Grain.

This study aimed to assess the occurrence of toxigenic fungi and mycotoxin contamination in stored wheat grains by using advanced molecular and analytical techniques. A multiplex polymerase chain reaction (PCR) strategy was established for rapid identification of mycotoxigenic fungi, and an improved analytical method was developed for simultaneous multi-mycotoxin determination in wheat grains by liquid chromatography-tandem mass spectrometry (LC/MS/MS) without the need for any clean-up. The optimized multiplex PCR method was highly specific in detecting fungal species containing species-specific and mycotoxin metabolic pathway genes.

Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis (Forsskal).

Sulfated polysaccharide was isolated from Gracilaria debilis and purified through gel chromatography and their molecular weight was determined through AGE and PAGE. The total sugars in the crude, fractionated and purified polysaccharide were estimated as 52.65%, 59.

Structural characterization and bioactivities of sulfated polysaccharide from Monostroma oxyspermum.

Sulfated polysaccharide was isolated from Monostroma oxyspermum through hot water extraction, anion-exchange and gel permeation column chromatography. The sulfated polysaccharide contained 92% of carbohydrate, 0% of protein, 7.8% of uronic acid, 22% of ash and 33% of moisture respectively.