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A chemical investigation on an endophytic fungus Penicillium expansum isolated from the medicinal plant Plantago depressa Willd. (Plantaginaceae) afforded one new diketopiperazine-type alkaloid, namely penicimine A (1), as well as two known congeners (2 and 3). Their structures were elucidated by widespread spectroscopic data, and the absolute configurations of 1 and 2 were further confirmed by single-crystal X-ray diffraction analyses. Compound 1 represented the first example of benzyl-containing diketopiperazine-type alkaloid bearing a methyl group attached at C-15 position. Compound 1 showed anti-inflammatory activity against LPS-induced nitric oxide (NO) production in RAW264.7 mouse macrophages with an IC50 value of 25.65 μM. [ABSTRACT FROM AUTHOR]

One of the most significant challenges associated with postharvest apple deterioration is the blue mold caused by Penicillium expansum, which leads to considerable economic losses to apple production industries. Apple fruits are susceptible to mold infection owing to their high nutrient and water content, and current physical control methods can delay but cannot completely inhibit P. expansum growth. Biological control methods present promising alternatives; however, they are not always cost effective and have application restrictions. P. expansum infection not only enhances disease pathogenicity, but also inhibits the expression of host-related defense genes. The implementation of new ways to investigate and control P. expansum are expected with the advent of omics technology. Advances in these techniques, together with molecular biology approaches such as targeted gene deletion and whole genome sequencing, will lead to a better understanding of the P. expansum infectious machinery. Here, we review the progress of research on the blue mold disease caused by P. expansum in apples, including physiological and molecular infection mechanisms, as well as various methods to control this common plant pathogen. [ABSTRACT FROM AUTHOR]

The present work aimed to study the essential oil (EO) variation of Dracocephalum moldavica L. under different phenological stages. The EO yield was highest in the flowering stage, followed by floral budding, fruit set, and vegetative stages. Twenty-three components in EOs were identified by GC-MS and quantified using GC-FID. Geranyl acetate (31–50 %), geranial (16–27 %), geraniol (12–13.4 %) and neral (10.67–17.30 %) were four main constituents. Antifungal assays of EO through mycelial growth inhibition percentages (MGI %) with four concentrations (0, 250, 500, and 750 µl/l) showed concentration-dependent responses. EOs showed the high potential of antifungal activity with ID50 values of (89–145), (27–88) and (183–339) µl/l and ID90 values of (667–1293), (509–1296), and (389–866) µl/l for Aspergillus niger, Penicillium expansum, and Trichoderma harzianum respectively. EO of D. moldavica showed considerable promise as a natural bio-preservative and bio-antifungal agent. [ABSTRACT FROM AUTHOR]

The plant pathogenic fungus Penicillium expansum is a major concern of the global food industry due to its wide occurrence and ability to produce various mycotoxins, of which the most significant is patulin. Relatively less highlighted in the literature, in comparison with the other food-borne mycotoxins, patulin is one of the main factors in economic losses of vegetables and fruits. Otherwise, patulin is a health hazard which results in both short-term and long-term risks. This review includes knowledge on the biosynthetic mechanisms used for secondary metabolite production in P. expansum, with special emphasis on patulin biosynthesis. The abiotic factors triggering the production of patulin and the strategies developed to reduce or prevent the contamination by this mycotoxin are comprehensively discussed. The database presented in this review would be useful for the prioritization and development of future research. [ABSTRACT FROM AUTHOR]

Total extracts and kuwanon G fromMorus nigraroot bark showed antifungal activity against several phytopathogenic fungi, with minimal inhibitory concentration (MIC50) ranging from 32 to 128 μg/ml and from 16 to 64 μg/ml, respectively. Acetonic extracts inhibited 60%B. cinereabiofilm formation at concentration of 128 μg/ml. [ABSTRACT FROM PUBLISHER]

The sessile drop technique was used to investigate the evolution of the physicochemical properties of cedar wood as a function of contact time with thePenicillium expansumspores. The most important finding showed that the impact of different contact periods (2, 4, 6, 8, 10, and 24 hr) on the wood surface were very indicative. In fact, after 2 hr of contact, the results have shown a significant impact of the bioadhesion of spores to the substrate on both the hydrophobic character (θW = 108.5°; ΔGiwi = −28.25 mJ/m2), the electron donor (γ− = 13.63 mJ/m2), and the electron acceptor (γ+ = 4.35 mJ/m2) parameters that were significantly reduced compared to the initial wood (θW = 118.5°; ΔGiwi = −6.29 mJ/m2; γ− = 32.1 mJ/m2; and γ+ = 9.1 mJ/m2). In addition, this decrease of parameters continued over time to stabilize after 10 hr of contact. Indeed, after 24 hr, the acid/base properties were almost zero and the contact angle with water decreased to 30°. Moreover, it was found that the coefficient of correlation (r2) was strong between the contact angle with water, the surface energy, and the electron acceptor character with the contact time parameter with values (r2 = 0.65), (r2 = 0.79), and (r2 = 0.68), respectively. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles production was performed by the green chemistry the Zanjan gold mine. The formation of nanosilvers was primarily confirmed by observation of color changing from colorless to brownish and UV-visible spectroscopy after 72 h of the reaction. The XRD spectrum exhibited 2θ values corresponding to silver nanocrystals. TEM and SEM micrographs showed the extracellular formation of spherical silver nanoparticles in the size range of 30–150 nm byPenicillium chrysogenumand extracellular formation of cubical silver nanoparticles in the size range of 50–200 nm byPenicillium expansum. [ABSTRACT FROM AUTHOR]

The inhibitory activity of five plant extracts viz.Artemisia absinthiumL., Rumex obtusifoliusL., Taraxacum officinaleWeber ex Wiggers, Plantago lanceolataL. andMalva sylvestrisL. were evaluated against the mycelial growth of three fungiAlternaria alternata(Fr.) Keissler, Penicillium expansumLink ex Thom. andMucor piriformisFisher that cause rot diseases in fruits and vegetables resulting in low yield and quality of fruits and vegetables. Results revealed that all the concentrations of plant extracts brought about significant inhibition in the mycelial growth of these pathogenic fungi. However, the highest concentration caused maximum inhibition in the mycelial growth followed by lower concentrations of plant extracts. The extract ofA. absinthiumleaves at highest concentration (S) proved highly effective in inhibiting the mycelial growth of all these pathogenic fungi followed by other plant extracts. These plants thus may have potential as the new natural fungicide for management of fungal rot diseases. [ABSTRACT FROM AUTHOR]

A specific symbioticBacillusspecies isolated from a rhabditid entomopathogenic nematode,Rhabditis (Oscheius)sp. was found to produce a number of bioactive compounds. The present study was conducted to determine the effect of six different nitrogen sources in combination with fructose on the production of antifungal crude extract byBacillussp. againstPenicillium expansum. The yield of crude extract and antifungal activity against the test fungi differed significantly when the nitrogen sources in the fermentation media were changed. The highest yield was recorded for beef extract plus fructose (921 mg/L). The antifungal activity was higher in yeast extract plus fructose [P. expansum(46.5 ± 2.12 mm)], followed by beef extract. High performance liquid chromatography analysis of the crude antimicrobial substances revealed different peaks with different retention times indicating that they produced different compounds. When a carbon source was not included in the fermentation medium, the antimicrobial production was substantially reduced almost eight times. Carbon source in the fermentation medium plays a vital role in the production of antimicrobial substances. Yeast extract and fructose as nitrogen and carbon sources in the fermentation medium produced maximum antimicrobial activity. [ABSTRACT FROM AUTHOR]

A specific symbioticBacillussp. isolated from a rhabditid entomopathogenic nematode,Rhabditis(Oscheius) sp. was found to produce large number of bioactive compounds. The present study was conducted to determine the effect of carbon and nitrogen sources for the production of antimicrobial substances byBacillussp. The yield of the crude antimicrobial substances and antimicrobial activity against the test micro-organism also differed significantly when carbon and nitrogen sources in the fermentation media were changed. The antifungal activity was significantly high in yeast extract plus fructose (46.5 ± 2.12 mm) followed by yeast extract plus maltose, beef extract plus fructose and meat infusion plus glucose. High pressure liquid chromatography analysis of the crude antimicrobial substances revealed different peaks with different retention time indicating that they produced different compounds. When the carbon source was not included in the fermentation media, the antimicrobial production was substantially reduced. The results indicate that carbon source in the fermentation media plays a vital role in the production of antifungal substances. It is concluded that yeast extract and fructose as nitrogen and carbon sources produced maximum activity, which can effectively control the blue mould caused byPenicillium expansumin apples and pears. [ABSTRACT FROM PUBLISHER]

Apple cultivars are attacked by many fungal diseases, both on the tree and during storage. One of the most serious is blue mould, caused byPenicillium expansum.In this study, 5-(n)-alkylresorcinols (AR) were isolated from rye bran by the supercritical fluid of carbon dioxide and were used for the preparation of bioactive emulsions. These emulsions were applied to harvested fruit of five apple varieties to determine the levels of antifungal activity.A significant inhibition of disease symptoms was obtained after spraying some of the prepared AR emulsions on fruits that had been experimentally infected withPenicillium expansum. The most effective emulsions consisted of 0.025% (m/v) ARs, 0.1% (m/v) xanthan gum, 0.5% (m/v) Synperonic 91/6 or PDMs-copolymer, 0.2% (m/v) Tween 20, 1% (m/v) Trioleate, 2% (m/v) oleylalcohol, 2% (m/v) PEG 400, 5% (m/v) CaCl2or NaCl suspended in water. [ABSTRACT FROM AUTHOR]

Torulaspora delbrueckii alone and in combination with methyl jasmonate was applied to the control of Penicillium expansum. For evaluation of direct effect of Methyl jasmonate on mycelial growth of pathogen, it was added to potato dextrose agar culture at different concentrations. Effect of methyl jasmonate on population of yeast in nutrient yeast dextrose broth media was determined after 24 and 48 h. Results showed that methyl jasmonate had no significant direct effect on pathogen and yeast. Also, evaluation of methyl jasmonate effect on the population of yeast in apple wounds indicated that methyl jasmonate at different concentrations increased population growth of yeast at 20°C, 8 and 15 days after inoculation in toward the control and it had no significant effect on population dynamics of yeast at 4°C. In vivo, the results indicated that combination of methyl jasmonate with antagonistic yeast reduced the blue mould of apples better than methyl jasmonate and yeast alone. [ABSTRACT FROM AUTHOR]

In this study, antagonistic yeast Candida membranifaciens was combined with different concentrations of silicon (Si; 0, 0.1, 0.3 and 0.5% wt/vol) to evaluate the control of blue mold of apple in storage at 20°C and 5°C. Preliminary studies showed that Si at 0.6% or above inhibited mycelial growth of pathogens significantly in vitro. In vitro studies showed that Si at 0.1% had lower effect on yeast growth. In vivo studies showed that combination of different concentrations of Si with C. membranifaciens improved the efficacy of yeast in control of disease better than Si and yeast alone (P < 0.05). Our result showed that the effective concentration of Si is varied based on pathogen isolates and temperature, so that the most effective concentration of Si was 0.5% for isolate P2 at 20°C and 0.5% and 0.1% for isolates P1 and P2 at 5°C. [ABSTRACT FROM PUBLISHER]

In “Rocha” pear, postharvest diseases, blue and grey moulds caused by Penicillium expansum and Botrytis cinerea, respectively, are particularly important. The control of postharvest decay has been based on the use of synthetic fungicides. However, there are risks to consumer health and the environment. In previous work, the antagonistic activity of the yeast-like fungus Aureobasidium pullulans (isolated from the surfaces of fruit, leaves and branches of “Rocha” pear trees), when applied as a wound treatment, was able to significantly reduce postharvest decay caused by P. expansum under storage conditions, and during simulated shelf-life. For more effective prevention and reduction of postharvest diseases in fruits it is necessary to understand the complex interactions in biological control between host, pathogen and antagonist, for which information is currently lacking. Thus, the aims of this study were to evaluate the biocontrol activity of the yeast-like fungus A. pullulans against P. expansum and to elucidate the resistance mechanism involved in the antagonistic activity of A. pullulans to oxidative stress. Fruits of Pyrus communis L. cv. Rocha were stored at −0.5°C, 95% relative humidity for 5.5 months. Fruit maturity was measured in terms of pericarp colour, sugar analysis, Streif index and flesh firmness. Assays of carbon dioxide and ethylene, electrolyte leakage, ascorbate, glutathione and antioxidant enzymes were used to evaluate oxidative stress. Furthermore, malondialdehyde, considered as a final product of lipid peroxidation, and the levels of hydrogen peroxide and methanesulfonic acid were determined and linked to oxidative stress impact on the lipid phase of cell membranes. During a 5-month period, fruit firmness, value of hue angle and colour, and Streif index changed significantly. Sucrose content decreased whereas fructose, glucose and sorbitol levels increased. After inoculation with A. pullulans and infection with P. expansum, a fungistatic, rather than fungicidal, effect was detected from 2.5 months onwards. Three months after storage, the higher superoxide dismutase activity and hydrogen peroxide levels caused by A. pullulans plus P. expansum were possibly associated with additional unsaturated fatty acids, as reflected by increased acyl lipid peroxidation. After five months of storage, in tissues inoculated with A. pullulans followed by infection with P. expansum, oxidative stress was linked to a general increase in the antioxidant peroxidase system activity. Glutathione and ascorbate content also increased along with the loss of cellular membrane selectivity. The results revealed a fungistatic effect of A pullulans on P. expansum. The prevalence of oxidative stress on “Rocha” pear wounds during the storage period was characterized, taking into account the interactions between A. pullulans and P. expansum. The information gained forms the basis for a biocontrol strategy, and the development of successful formulations for application in the orchard and after harvest. This strategy could eradicate and protect fruit against postharvest diseases, and is thus a promising alternative to the use of synthetic pesticides, being safe for the environment and for human health. [ABSTRACT FROM PUBLISHER]

Post-harvest pathogens cause major losses in apple production. Biological control by using epiphytic yeasts against Penicillium expansum has been considered as an alternative method for controlling the post-harvest decays. The yeast isolates Rhodotorula mucilaginosa, Pichia guilliermondii, which showed high biocontrol efficacy against P. expansum, were selected for formulation tests. Formulation is an important step in developing a biocontrol product. The successful delivery of biocontrol agents, shelf life, stability and effectiveness in commercial conditions depend on the formulation. In the formulation, the carrier is the primary material used to allow a bioproduct to be dispersed effectively. Yeast isolates were grown in a cane molasses-based medium. Harvested yeast cells were combined with inorganic (talk, kaolin) and organic (Rice bran, wheat bran) carriers. Viability of the yeast cells in formulations stored at 4°C and 24°C was determined each month during 6 months storage. After 6 months storage to evaluate efficacy of formulations, all formulations were tested on apple to control blue mold in storage condition. High stability of antagonistic yeasts was achieved by using organic and inorganic carriers. Rice bran and wheat bran stimulated the germination of the yeasts cells during storage period. Both of the yeasts had significantly highest viable yeast cell content over 6 months in formulation containing wheat bran as a carrier. P.guillermondii in all formulations had significantly higher shelf life and was effective than R. mucilaginosa. [ABSTRACT FROM AUTHOR]

A method for the simultaneous determination of 33 pesticides or degradation products together with patulin in apples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The method involved homogenization of the apples, extraction with ammonium acetate-acetic acid solution in methanol-water by ultrasonication, filtration, and determination by LC-MS/MS. The repeatability and within-laboratory reproducibility for the three spiking levels 0.02, 0.04 and 0.2 mg kg-1 were between 4% and 35%. In general, the repeatability and reproducibility were about 10-20%. The limits of quantification (LOQs) were between 0.01 and 0.14 mg kg-1. The method was used on incurred samples from parts of the ISAFRUIT project financed by the European Commission under the 6th Framework Programme. Samples were analysed at four different stages: after harvest, after storage (controlled), after a water bath, and after 28 days at room temperature. Pesticide residues were found at all stages, but no significant differences in the concentration were seen between the stages analysed. The concentration decreased significantly only for tolylfluanid after storage at room temperature for 28 days when only 0-6% of the original amount of tolylfluanid remained in the apples. No patulin was found in the apples stored for 28 days at room temperature and no growth of Penicillium expansum was observed on these apples. However, when the apples were inoculated with a spore suspension of P. expansum, high concentrations of patulin were found. [ABSTRACT FROM AUTHOR]

An antifungal assay with cell-free culture supernatant of Pichia ohmeri 158 and Candida guilliermondii P3 was tested against Penicillium expansum strain #2 at 25°C by measuring hyphal length and percentage conidia germination. C. guilliermondii was more effective against P. expansum conidia germination (58.15% inhibition), while P. ohmeri showed higher inhibition of mycelial growth (66.17%), indicating a probable mechanism associated with killer activity. This killer toxin (molecular mass <3 kDa) was partially purified by normal phase HPLC, using TSKgel Amide-80 analytical and preparative columns. Compared with crude extract, the killer toxin eluted from the post analytical column significantly inhibited P. expansum:% inhibition rose from 42.16 to 90.93% (C. guilliermondii) and 39.32 to 91.12% (P. ohmeri) (p < 0.05). The one-step purification process was adequate in isolating killer toxin from culture supernatant and also increased anti-Penicillium activity. [ABSTRACT FROM AUTHOR]

Patulin is a mycotoxin produced by species of Penicillium and Aspergillus and is toxic to a wide range of organisms, including humans and livestock. To produce large amount of pure patulin for research purposes, high-speed counter-current chromatography (HSCCC) and preparative high-performance liquid chromatography (prep-HPLC) were applied to the purification of patulin. Apple juice was inoculated with P. expansum and containing 0.5 mg patulin per ml was used as a starting material for separation. For HSCCC, a biphasic solvent system consisted of ethyl acetate-hexane-pH 4 acetic acid (7.5:2.5:10, v/v/v) was used. For prep-HPLC, the separation was carried out in a C18 reversed-phase preparative column with a mobile phase containing acetonitrile-pH 4 acetic acid (5:95, v/v). Fractions containing patulin were collected and analysed by analytical HPLC and identified by congruent retention time and ultraviolet/visible (UV-VIS) spectrum of the standard. The structure of the purified patulin was confirmed by mass spectrometry and nuclear magnetic resonance. HSCCC produced 21.9 mg of patulin from 50 ml apple juice culture whereas the prep-HPLC yielded 18.1 mg. HSCCC also produced purer patulin than the prep-HPLC (98.6 versus 96.3%) and higher recovery (86.2 versus 71.3%). In addition, the HSCCC method is advantageous for its lower cost and a simpler procedure compared with the prep-HPLC. This one-step HSCCC method can potentially provide a simple, effective and environmentally friendly tool for obtaining gram-level pure patulin for toxicology, detoxification and many other patulin-related studies. [ABSTRACT FROM AUTHOR]

Fifty samples of apple juices were investigated for patulin levels using HPLC with UV detection. It was found that 38 (76? samples contained no detectable patulin (LOD = 7.5 µg l-1), but some samples had high patulin levels (845 µg l-1) compared to other branded mixed juices (21-70 µg l-1) and apple juices procured from local vendors (191 µg l-1). The survey provides evidence of a need to educate the apple-juice industry in the use of good quality apples for juice production. In addition, the levels of patulin found showed a saturation of the provisional maximum tolerable daily intake (PMTDI) based on intake figures in terms of an average and 90th percentile of 27-60% and 107-190%, respectively, in different age groups. This monitoring study may help in formulating guidelines for patulin levels, which are not yet implemented by Prevention of Food Adulteration (PFA) Act of India. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This work assesses the extent of patulin contamination in Penicillium expansum-infected apples stored at room temperature for short periods of time and its relationship with apple variety (Golden or Fuji), degree of ripeness and size of lesions. Inoculated apples were incubated at 20°C. Patulin was determined in both sound and decayed tissue from cylindrical samples taken around the lesions and cut into 0.5-cm thick sections. Higher accumulation of patulin occurred in Golden apples, with less ripened apples showing higher concentrations. Total accumulated patulin was similar or higher in 4-cm compared to 2-cm lesioned apples, although a decrease in patulin concentration was observed in older lesion sections. Patulin accumulation occurred over a short period of time at room temperature, thus the stand-by period before processing should be minimised. Of total patulin, 2–6% migrated to the surrounding sound tissue, thus trimming tissue around the rotten part may be a good preventive practice for apple derivative production. [ABSTRACT FROM AUTHOR]

The article develops a technique to evaluate the population levels of strain 1100-6, an effective biocontrol agent identified Pseudomonas fluorescens for apple blue mold, on wounded apples, in the presence and absence of Penicillium expansum or Penicillium solitum using green fluorescent protein as a marker. Strain 1100-6 cells were examined using fluorescence microscopy and direct fluorescence scanning with a digital imaging software for quantifying fluorescence produced by either technique.

Evaluates the protective effects of three fungicides for their efficacy against blue mold caused by thiabendazole-sensitive and -resistant isolates of Penicillium expansum to develop alternate fungicides to thiabendazole. Fludioxonil; Cyprodinil; Mixture of fludioxonil and cyprodinil.

The production of mycotoxins and other secondary metabolites by Penicillium expansum on blackcurrant and cherry juice has been studied at10 deg.C and 25 deg.C under storage imitated conditions. P. expansumwas able to synthesize extracellular patulin under all conditions, and together with extracellular chaetoglobosin A when unlimited oxygenwas available. Patulin, the chaetoglobosins A and C, the communesinsA and B and the expansolides A and B could be detected intracellularly depending on the conditions. The metabolites were detected using thin-layer chromatography and high-performance liquid chromatography with diode array detection by comparison to standards. A method to detect the expansolides A and B by TLC was developed. [ABSTRACT FROM AUTHOR]