Search results for " biotechnology"
showing 10 items of 3723 documents
Evaluation of Mycotoxin Residues on Ready-to-Eat Food by Chromatographic Methods Coupled to Mass Spectrometry in Tandem
2018
Simultaneous determination of twenty-seven mycotoxins in ready-to-eat food samples using &ldquo
Sterigmatocystin-induced cytotoxicity via oxidative stress induction in human neuroblastoma cells.
2020
Abstract Sterigmatocystin (STE) is a mycotoxin produced by fungi of the genus Aspergillus. Considering that the effect of STE on neuronal system has not been well studied, the aim of the present study consists to investigate the cytotoxic effects of STE in human neuroblastoma (SH-SY5Y) cells. Moreover, the role of oxidative stress and intracellular defense systems was assessed by evaluating reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and antioxidant no-enzymatic (GSH) levels and enzymatic (GPx, GST, CAT and SOD) activity. Our results revealed that STE decreased cell viability in a dose and time-dependent manner. Furthermore, after 24 h of exposure, STE induced an incr…
Extent of variation of the Bacillus thuringiensis toxin reservoir: the case of the geranium bronze, Cacyreus marshalli butler (Lepidoptera: Lycaenida…
2002
ABSTRACT Despite the fact that around 200 cry genes from Bacillus thuringiensis have already been cloned, only a few Cry proteins are toxic towards a given pest. A crucial step in the mode of action of Cry proteins is binding to specific sites in the midgut of susceptible insects. Binding studies in insects that have developed cross-resistance discourage the combined use of Cry proteins sharing the same binding site. If resistance management strategies are to be implemented, the arsenal of Cry proteins suitable to control a given pest may be not so vast as it might seem at first. The present study evaluates the potential of B. thuringiensis for the control of a new pest, the geranium bronze…
Cytotoxic effects of individual and combined sterigmatocystin and nivalenol on liver hepatocellular carcinoma cells
2020
Abstract Since humans are exposed to different mycotoxins through daily intake, there is increasing concern about the adverse effects of the interactions between them. Cytotoxicity of sterigmatocystin (STE) and nivalenol (NIV) alone and in combination in human hepatocarcinoma (HepG2) cells was evaluated by MTT assay. Furthermore, ROS production and alteration of ΔΨm as mechanisms of action were assessed. Cells were treated with concentrations ranging from 0.15 to 5 μM for NIV and from 0.78 to 50 μM for STE individually and in binary combinations. The combination ratio between the mixture STE + NIV was 10:1. The IC50 values of NIV ranged from 0.96 to 0.66 μM, whereas no IC50 values were obta…
Sterigmatocystin: Occurrence, toxicity and molecular mechanisms of action – A review
2020
The mycotoxin sterigmatocystin (STE) is produced mainly by Aspergillus fungi. It has been reported to occur in grains and grain-based products, cheese, coffee, spices and beer. The STE is a known biogenic precursor of aflatoxin B1, sharing with it several structural and biological similarities. The STE has been shown to be hepatotoxic and nephrotoxic in animals and it has been classified as possible human carcinogen (group 2B) by IARC. The STE has been reported to cause a marked decrease in cell proliferation in different mammalian cells. Data available on literature suggest that the cellular mechanisms underlying STE-induced toxicity include the induction of oxidative stress, mitochondrial…
Evidence that water transmits Vibrio vulnificus biotype 2 infections to eels
1995
Vibrio vulnificus biotype 2 is classically considered an obligate eel pathogen. However, it has recently been associated with one human septicemic case. In this paper, the opportunistic behavior of this pathogen is discussed. The bacterium can survive alone in brackish water or attached to eel surfaces for at least 14 days. It is able to spread through water and infect healthy eels by using skin as a portal of entry. These results suggest that water and infected eels may act as reservoirs of infection. A capsule seems to be essential for waterborne infectivity, which would explain why cells recovered from naturally diseased eels give rise to pure cultures of opaque colonies. The spread of t…
The role of mitochondria in sterigmatocystin-induced apoptosis on SH-SY5Y cells
2020
Mitochondria are cellular organelles involved in many crucial functions, such as generation of energy (ATP) and initiation of apoptosis. The aim of the present study was to evaluate the role of mitochondria in the toxicity induced by sterigmatocystin (STE), a mycotoxin produced by fungi of the genus Aspergillus, on SH-SY5Y cells. Our results showed that STE exposure decreased cell viability in a time- and concentration-dependent manner by MTT assay and caused mitochondrial dysfunction, as highlighted by the increase of STE cytotoxicity in cells forced to rely on mitochondrial oxidative phosphorylation. Furthermore, intracellular ATP depletion and increased mitochondrial reactive oxygen spec…
In situ analysis of the bacterial communities associated to farmed eel by whole-cell hybridization.
1999
Bacterial communities in water samples and eel slime were investigated by fluorescence in situ hybridization of whole bacterial cells in an eel intensive culture system over 1 year. A newly developed probe, matching 27 Vibrio spp., and a specific probe for Vibrio vulnificus were used. Phylogenetic probes complementary to selected regions of the 16S and 23S ribosomal RNA revealed that Proteobacteria of the alpha and beta subclass were predominant in water and eel slime. Members of the gamma subclass (e.g. vibrios and aeromonads) were more abundant in eel slime, although no V. vulnificus was detected.
Glyphosate-based herbicide use affects individual microbial taxa in strawberry endosphere but not the microbial community composition
2023
AbstractAimsIn a field study, the effects of treatments of glyphosate-based herbicides (GBHs) in soil, alone and in combination with phosphate fertilizer, were examined on the performance and endophytic microbiota of garden strawberry.Methods and resultsThe root and leaf endophytic microbiota of garden strawberries grown in GBH-treated and untreated soil, with and without phosphate fertilizer, were analyzed. Next, bioinformatics analysis on the type of 5-enolpyruvylshikimate-3-phosphate synthase enzyme was conducted to assess the potential sensitivity of strawberry-associated bacteria and fungi to glyphosate, and to compare the results with field observations. GBH treatments altered the abu…
Classification of olive leaves and pulp extracts by comprehensive two-dimensional liquid chromatography of polyphenolic fingerprints.
2019
Abstract The development of a new comprehensive two-dimensional liquid chromatographic method is described, to obtain the profiles of polyphenolic compounds present in olive (Olea europaea L.) leaves and pulps from different genetic origin. Optimisation of the stationary phase nature, particle size, column length and internal diameter, as well as other separation conditions, was performed. Along the study, three stationary phases (C18, PFP and phenyl) in the first dimension (1D), and five (C18, amide, cyano, phenyl and PFP) in the second dimension (2D) were combined to obtain the maximal number of resolved peaks. The optimised method successfully characterised the presence of 26 and 29 comm…