Reactive oxygen intermediates (ROIs) and reactive nitrogen intermediates (RNIs) have now become w... more Reactive oxygen intermediates (ROIs) and reactive nitrogen intermediates (RNIs) have now become well established as important signalling molecules in physiological settings within microorganisms, mammals and plants. These intermediates are routinely synthesised in a highly controlled and transient fashion by NADPH-dependent enzymes, which constitute key regulators of redox signalling. Mild oxidants such as hydrogen peroxide (H2O2) and especially nitric oxide (NO) signal through chemical reactions with specific atoms of target proteins that result in covalent protein modifications. Specifically, highly reactive cysteine (Cys) residues of low pKa are a major site of action for these intermediates. The oxidation of target Cys residues can result in a number of distinct redox-based, post-translational modifications including S-nitrosylation, S-glutathionylation; and sulphenic acid, sulphinic acid and disulphide formation. Importantly, such modifications precisely regulate protein structure and function. Cys-based redox switches are now increasingly being found to underpin many different signalling systems and regulate physiological outputs across kingdoms.
Archives of Phytopathology and Plant Protection, 2011
The phylogenecity of the four Fusarium mycotoxin gene (Fum 5) that has already been deposited in ... more The phylogenecity of the four Fusarium mycotoxin gene (Fum 5) that has already been deposited in National Center for Biotechnology Information (NCBI) gene bank was studied with a comparative sequence alignment with other fungi like Aspergillus sps. Cochiliobolus sps. These results clearly indicated that the Fum 5 genes of Fusarium species were originated from Aspergillues fumigates and Cochliobolus heterostrophus. Fum 5 gene closer identity was also observed clearly with other fungal Fusarium species of Aspergillus and Gibberella species.
In this study, we investigated the pathogenicity and patulin production by ten strains of Penicil... more In this study, we investigated the pathogenicity and patulin production by ten strains of Penicillium expansum on various fruits (apples, apricots, kiwis, plums and peaches) at two (4°C and 25°C) different temperature regimes. All strains caused the infectious rots on all fruits at 4 and 25°C except one strain (PEX 09) at 4°C. Two strains (PEX 20 and PEX 12) out of ten produced the highest amounts of patulin on all fruits tested. The patulin production by P. expansum is high at 25°C compared to 4°C. All strains of P. expansum accumulated patulin ranging from 100–13,200 μg/kg and nine strains ranging from 100–12,100 μg/kg in all fruits at 25°C and 4°C, respectively. Among ten strains of P. expansum, strain PEX 20 produced the greatest amount of patulin on apricots (13,200 μg/kg of rotten fruit) and on apples (12,500 μg/kg) at 25°C after 9 days of incubation. At 4°C, this strain produced 12,100, 12,000, 2,100 and 1,200 μg/kg of patulin on apricots, apples, plums and peaches, respectively, after 45 days of incubation. Strain PEX 12 produced the highest amount of patulin on kiwis (10,700 μg/kg) at 25°C and 10,300 μg/kg at 4°C. Patulin production by P. expansum on peaches and plums at both temperatures were lower than other fruits. The results of this study showed that careful removal of rotten fruits is essential to produce patulin-free fruit juice, since high patulin levels in apricots, apples and kiwis could result in a level greater than 50 μg/kg of this mycotoxin in finished fruit juices, when one contaminated fruit occurs in 264, 250 and 214 fruits, respectively. So, the fruit processors should take care in not using rotten fruits for juice production to avoid the patulin problem worldwide, since this study proved that most important fruits being used for juice production and direct human consumption are susceptible to P. expansum and subsequent patulin production even at low temperatures. This is the first comprehensive report regarding patulin production by different strains of P. expansum on various fruits from Italy at different temperature regimes.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 2009
This investigation was undertaken to test different control strategies against Botrytis cinerea v... more This investigation was undertaken to test different control strategies against Botrytis cinerea vineyards. Two commercial vineyards, “Barbera” and “Moscato,” located in Piedmont (Northern Italy) were divided into seven plots and treated with different combinations of fungicides including fenhexamid, pyrimethanil, fludioxonil + cyprodinil, iprodione, and boscalid, a new carboxamide compound. An integrated strategy including a chemical (pyrimethanil) and a biocontrol agent (Trichoderma spp. t2/4ph1) was also included. At harvest, the percentage of bunches and berries attacked by B. cinerea and the concentration of the chemical fungicides were determined. All the pesticide residues at harvest were below the maximum residue level (MRL), except when two applications of pyrimethanil per season were applied. Boscalid was the most effective active ingredient against B. cinerea among the tested chemicals. When boscalid application was followed by a treatment with pyrimethanil, its efficacy was similar to that shown by two treatments of pyrimethanil. However, this second strategy was not feasible due to the risks of resistance development in the pathogen and to the residue accumulation as indicated by the analysis.
Few strains of Metschnikowia pulcherrima (Pitt) M.W. Miller are under development for control of ... more Few strains of Metschnikowia pulcherrima (Pitt) M.W. Miller are under development for control of postharvest pathogens on fruit. A substrate was developed to optimize the biomass production of M. pulcherrima strain BIO126. Different complex nutrient sources, with or without pH control, were tested. Growth in yeast extract provided at concentrations > or =30 g*L-1 yielded the highest biomass. The addition of two carbon sources, D-mannitol and L-sorbose, at 5 g*L-1 each, significantly improved yeast growth. The greatest amount of yeast growth occurred when pH values of the medium ranged from 5.0 to 7.5. A combination of yeast extract, D-mannitol, and L-sorbose (YEMS), probably with diauxic utilization, showed a synergistic effect, widening the exponential phase (maximum specific growth rate of 0.45 h-1) and increasing the final cell number (1.5 x 109 cells*mL-1) and dry biomass (6.0 g*L-1) in well-controlled batch fermentation. In efficacy trials on 'Golden Delicious' apples, M. pulcherrima grown in YEMS effectively reduced incidence and severity of Botrytis cinerea (51.1% and 70.8%, respectively) and Penicillium expansum (41.7% and 14.0%, respectively). Also on 'Gala' apples, the best reduction of grey and blue mould incidence was obtained with cells grown in YEMS (58.1% and 50.5%, respectively).
Food Additives & Contaminants Part B-surveillance, 2008
Pear, peach, apricot, and mixed juices (125 samples) were purchased in Italian supermarkets and o... more Pear, peach, apricot, and mixed juices (125 samples) were purchased in Italian supermarkets and organic food shops and analysed for patulin content. An overall incidence of 34.4? was observed in the fruit juices, with a mean contamination level of 3.6 µg kg–1. No one sample exceeded 50 µg kg–1, the maximum permitted limit according to European legislation. However, 19 positive samples contained more than 10 µg kg–1 of patulin, which is the maximum level permitted for baby food. The incidence of patulin contamination was significantly higher in pear juices (64.1?) than in apricot, peach, or mixed juices. Statistical analysis (p = 0.002; Kruskal–Wallis test) showed a significantly higher level of patulin in pear (5.1 µg kg–1) and mixed juices (4.9 µg kg–1) than in the other juices. A slightly higher incidence of positive samples was found in conventional juices (35.7?) compared with the organic ones (29.6?). The magnitude between the mean contamination levels was similar in conventional (3.6 µg kg–1) and organic (3.3 µg kg–1) juices (p = 0.474; Mann–Whitney U-test). Samples were further divided based on the fruit content in fruit juices, fruit nectars, and fruit drinks. In fruit nectars the incidence of positive samples (37.8?) was slightly higher than in fruit drinks (27.2?), but the mean patulin contamination was higher in fruit drinks (5.2 µg kg–1) than in fruit nectars (3.4 µg kg–1). However, the magnitude between the two means was not statistically different (p = 0.734; Mann–Whitney U-test). Italian juices had a higher incidence of patulin (35.3?), with a lower mean content (3.5 µg kg–1), compared with the incidence (22.2?) and level (4.1 µg kg–1) foreign juices commercially available in Italy. The magnitude of the means between Italian and foreign juices was not statistically different, according to the Mann–Whitney U-test (p = 0.616). The estimated intake of patulin ranged from 0.1 to 1.5 ng kg–1 body weight for the whole population and from 0.3 to 5.1 ng kg–1 body weight for the consumers only. The highest patulin intake was estimated for consumers of pear juices, followed by consumers of mixed juices. The daily intake of patulin derived from the consumption of pear juice suggests that also pear juices, though a minor patulin source, could be monitored for their patulin content in order to control the mycotoxin contamination, especially in countries, such as Italy, where pear nectars are preferred as fruit drinks.
Reactive oxygen intermediates (ROIs) and reactive nitrogen intermediates (RNIs) have now become w... more Reactive oxygen intermediates (ROIs) and reactive nitrogen intermediates (RNIs) have now become well established as important signalling molecules in physiological settings within microorganisms, mammals and plants. These intermediates are routinely synthesised in a highly controlled and transient fashion by NADPH-dependent enzymes, which constitute key regulators of redox signalling. Mild oxidants such as hydrogen peroxide (H2O2) and especially nitric oxide (NO) signal through chemical reactions with specific atoms of target proteins that result in covalent protein modifications. Specifically, highly reactive cysteine (Cys) residues of low pKa are a major site of action for these intermediates. The oxidation of target Cys residues can result in a number of distinct redox-based, post-translational modifications including S-nitrosylation, S-glutathionylation; and sulphenic acid, sulphinic acid and disulphide formation. Importantly, such modifications precisely regulate protein structure and function. Cys-based redox switches are now increasingly being found to underpin many different signalling systems and regulate physiological outputs across kingdoms.
Archives of Phytopathology and Plant Protection, 2011
The phylogenecity of the four Fusarium mycotoxin gene (Fum 5) that has already been deposited in ... more The phylogenecity of the four Fusarium mycotoxin gene (Fum 5) that has already been deposited in National Center for Biotechnology Information (NCBI) gene bank was studied with a comparative sequence alignment with other fungi like Aspergillus sps. Cochiliobolus sps. These results clearly indicated that the Fum 5 genes of Fusarium species were originated from Aspergillues fumigates and Cochliobolus heterostrophus. Fum 5 gene closer identity was also observed clearly with other fungal Fusarium species of Aspergillus and Gibberella species.
In this study, we investigated the pathogenicity and patulin production by ten strains of Penicil... more In this study, we investigated the pathogenicity and patulin production by ten strains of Penicillium expansum on various fruits (apples, apricots, kiwis, plums and peaches) at two (4°C and 25°C) different temperature regimes. All strains caused the infectious rots on all fruits at 4 and 25°C except one strain (PEX 09) at 4°C. Two strains (PEX 20 and PEX 12) out of ten produced the highest amounts of patulin on all fruits tested. The patulin production by P. expansum is high at 25°C compared to 4°C. All strains of P. expansum accumulated patulin ranging from 100–13,200 μg/kg and nine strains ranging from 100–12,100 μg/kg in all fruits at 25°C and 4°C, respectively. Among ten strains of P. expansum, strain PEX 20 produced the greatest amount of patulin on apricots (13,200 μg/kg of rotten fruit) and on apples (12,500 μg/kg) at 25°C after 9 days of incubation. At 4°C, this strain produced 12,100, 12,000, 2,100 and 1,200 μg/kg of patulin on apricots, apples, plums and peaches, respectively, after 45 days of incubation. Strain PEX 12 produced the highest amount of patulin on kiwis (10,700 μg/kg) at 25°C and 10,300 μg/kg at 4°C. Patulin production by P. expansum on peaches and plums at both temperatures were lower than other fruits. The results of this study showed that careful removal of rotten fruits is essential to produce patulin-free fruit juice, since high patulin levels in apricots, apples and kiwis could result in a level greater than 50 μg/kg of this mycotoxin in finished fruit juices, when one contaminated fruit occurs in 264, 250 and 214 fruits, respectively. So, the fruit processors should take care in not using rotten fruits for juice production to avoid the patulin problem worldwide, since this study proved that most important fruits being used for juice production and direct human consumption are susceptible to P. expansum and subsequent patulin production even at low temperatures. This is the first comprehensive report regarding patulin production by different strains of P. expansum on various fruits from Italy at different temperature regimes.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 2009
This investigation was undertaken to test different control strategies against Botrytis cinerea v... more This investigation was undertaken to test different control strategies against Botrytis cinerea vineyards. Two commercial vineyards, “Barbera” and “Moscato,” located in Piedmont (Northern Italy) were divided into seven plots and treated with different combinations of fungicides including fenhexamid, pyrimethanil, fludioxonil + cyprodinil, iprodione, and boscalid, a new carboxamide compound. An integrated strategy including a chemical (pyrimethanil) and a biocontrol agent (Trichoderma spp. t2/4ph1) was also included. At harvest, the percentage of bunches and berries attacked by B. cinerea and the concentration of the chemical fungicides were determined. All the pesticide residues at harvest were below the maximum residue level (MRL), except when two applications of pyrimethanil per season were applied. Boscalid was the most effective active ingredient against B. cinerea among the tested chemicals. When boscalid application was followed by a treatment with pyrimethanil, its efficacy was similar to that shown by two treatments of pyrimethanil. However, this second strategy was not feasible due to the risks of resistance development in the pathogen and to the residue accumulation as indicated by the analysis.
Few strains of Metschnikowia pulcherrima (Pitt) M.W. Miller are under development for control of ... more Few strains of Metschnikowia pulcherrima (Pitt) M.W. Miller are under development for control of postharvest pathogens on fruit. A substrate was developed to optimize the biomass production of M. pulcherrima strain BIO126. Different complex nutrient sources, with or without pH control, were tested. Growth in yeast extract provided at concentrations > or =30 g*L-1 yielded the highest biomass. The addition of two carbon sources, D-mannitol and L-sorbose, at 5 g*L-1 each, significantly improved yeast growth. The greatest amount of yeast growth occurred when pH values of the medium ranged from 5.0 to 7.5. A combination of yeast extract, D-mannitol, and L-sorbose (YEMS), probably with diauxic utilization, showed a synergistic effect, widening the exponential phase (maximum specific growth rate of 0.45 h-1) and increasing the final cell number (1.5 x 109 cells*mL-1) and dry biomass (6.0 g*L-1) in well-controlled batch fermentation. In efficacy trials on 'Golden Delicious' apples, M. pulcherrima grown in YEMS effectively reduced incidence and severity of Botrytis cinerea (51.1% and 70.8%, respectively) and Penicillium expansum (41.7% and 14.0%, respectively). Also on 'Gala' apples, the best reduction of grey and blue mould incidence was obtained with cells grown in YEMS (58.1% and 50.5%, respectively).
Food Additives & Contaminants Part B-surveillance, 2008
Pear, peach, apricot, and mixed juices (125 samples) were purchased in Italian supermarkets and o... more Pear, peach, apricot, and mixed juices (125 samples) were purchased in Italian supermarkets and organic food shops and analysed for patulin content. An overall incidence of 34.4? was observed in the fruit juices, with a mean contamination level of 3.6 µg kg–1. No one sample exceeded 50 µg kg–1, the maximum permitted limit according to European legislation. However, 19 positive samples contained more than 10 µg kg–1 of patulin, which is the maximum level permitted for baby food. The incidence of patulin contamination was significantly higher in pear juices (64.1?) than in apricot, peach, or mixed juices. Statistical analysis (p = 0.002; Kruskal–Wallis test) showed a significantly higher level of patulin in pear (5.1 µg kg–1) and mixed juices (4.9 µg kg–1) than in the other juices. A slightly higher incidence of positive samples was found in conventional juices (35.7?) compared with the organic ones (29.6?). The magnitude between the mean contamination levels was similar in conventional (3.6 µg kg–1) and organic (3.3 µg kg–1) juices (p = 0.474; Mann–Whitney U-test). Samples were further divided based on the fruit content in fruit juices, fruit nectars, and fruit drinks. In fruit nectars the incidence of positive samples (37.8?) was slightly higher than in fruit drinks (27.2?), but the mean patulin contamination was higher in fruit drinks (5.2 µg kg–1) than in fruit nectars (3.4 µg kg–1). However, the magnitude between the two means was not statistically different (p = 0.734; Mann–Whitney U-test). Italian juices had a higher incidence of patulin (35.3?), with a lower mean content (3.5 µg kg–1), compared with the incidence (22.2?) and level (4.1 µg kg–1) foreign juices commercially available in Italy. The magnitude of the means between Italian and foreign juices was not statistically different, according to the Mann–Whitney U-test (p = 0.616). The estimated intake of patulin ranged from 0.1 to 1.5 ng kg–1 body weight for the whole population and from 0.3 to 5.1 ng kg–1 body weight for the consumers only. The highest patulin intake was estimated for consumers of pear juices, followed by consumers of mixed juices. The daily intake of patulin derived from the consumption of pear juice suggests that also pear juices, though a minor patulin source, could be monitored for their patulin content in order to control the mycotoxin contamination, especially in countries, such as Italy, where pear nectars are preferred as fruit drinks.
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