Search

Disease incidence and disease severity of avocado fruit rot were assessed on cv. Hass and cv. Fuerte during 2019 and 2020 growing seasons. The highest percentages of disease incidence and disease severity were recorded in cv. fuerte in the market at El-Qanater El-Khayria, Qaliobia Governorate. On the other hand, the lowest percentages of disease incidence and disease severity were recorded in cv. Hass in the field at El- Rahawy, Giza Governorate during the two growing seasons. Four different fungi, i.e., Colletotrichum gloeosporioides, Lasiodiplodia theobromae, Fusarium moniliforme and Penicillium expansum were isolated from the naturally infected avocado fruits in the surveyed regions. Pathogenicity tests showed that the maximum percentage of disease severity on cv. Hass and cv. Fuerte resulted from infection by L. theobromae, followed by C. gloeosporioides, while the lowest percentage of disease severity was incited byP. expansum. The efficacy of alternative products namely essential oils of Lemongrass (Cymbopogon citratus L.), Rosemary (Rosmarinus officinalis L.) and Thyme (Thymus vulgaris L.) and Serenade ASO (Bacillus subtilis QST713) was evaluated in in vitro and in vivo as well as under field conditions for controlling fruit rot of avocado comparing with Imazalil, Copper oxide and Copper oxide nanoparticles. Complete inhibition of colony growth and protection from fruit rot was recorded with essential oils and Copper oxide at concentration of 3 ml or g/L of each. Meanwhile, the same effect was recorded at concentration of 1 ml/ L in case of Imazalil, Copper oxide nanoparticles and Serenade ASO. However, under field conditions, Copper oxide nanoparticles and Imazalil gave the highest efficacy for controlling avocado fruit rot disease, followed by Serenade ASO, Copper oxide and Thyme, while the lowest efficacy was recorded when trees sprayed with Lemongrass and Rosemary, respectively. The results indicated that avocado fruit rot disease could be controlled using suitable concentration of the tested treatments.

BACKGROUND: Postharvest diseases in fruits and vegetables are one of the major problems in storing them as a fresh agri-product. This study aimed to investigate the antifungal activity of licorice (Glycyrrhiza glabra) aqueous extract against the Penicillium expansum and the Penicillium digitatum in apple and tangerine fruits as well as their postharvest decay during storage time. METHODS: The minimum inhibitory concentration (MIC) of the molds, and the decay inhibition percentage (%DI) with the P.expansum for apple and P.digitatum for tangerine after treatment with licorice aqueous extract were measured. Additionally, the lesion diameter, titratable acidity (TA), total soluble solids (TSS), pH, and organoleptic properties were determined. RESULTS: The growth of molds was almost inhibited at the concentration of 62.5 mg/mL. The ability of licorice aqueous extract to significantly control and reduce the growth of P. expansum in apple by 60 and 20 % after 7 days and 21 days of storage time was proved, respectively. Furthermore, significant differences in pH and TSS (p

Mold growth is among the major causes of health impairment of cereals, in particular durum wheat (Triticum durum) for the synthesis of mycotoxins such as aflatoxins B1 and ochratoxin A (OTA), originally from poisoning in the consumer. In this context, the objectives of this work is the search and characterization of fungal strains Producers mycotoxins such as Aspergillus, Penicillium in semolina and their derivatives (traditional and industrial couscous) and detect and quantify total aflatoxins, aflatoxins B1 and ochratoxin mycotoxicologique to assess the risk associated with the consumption of these foods. In this regard, our work focuses on mycological and mycotoxicologique study of semolina and couscous deemed most commercialized in the town of Bechar-Algeria after a socio-economic survey. The mycological study testifies the high degree of pollution of our samples by Aspergillus, Penicillium. The expertise of genera reveals the high degree of invasion of our samples by Aspergillus, Penicillium. The examination of fungal procession characterizing our samples shows a very high index of distribution, or of fidelity of Penicillium 43.75% of our sample and 28.38% Aspergillus. The presence of these species is evidence that our samples have been abused, but especially poorly stored; should be noted the involvement of the genera Alternaria 7.10%, Fusarium 13.70%. Thin-layer chromatographic (TLC) analysis revealed that 50% of Aspergillus flavus-parasiticus strains were aflatoxin G-producing and aflatoxin B-free in our samples. Of the Aspergillus ochraceus strains 50% were OTA producers. The presumption of toxicity of the various samples appeared positive on TLC. The test of Elisa has confirmed the presence of the OTA in our samples, the analysis of its results shows that the majority of the rates of OTA taken on our analyzed samples follow the European standard, these rates are between 1.01 and 1.9, except for one sample (couscous) which has shown a rate much higher than the standard recommended by the regulation (> 100 ppb), the samples of semolina had a rate of OTA lower than the beginning of the detection (1 ppb). The results of the presence of AFB spread out between 4.93 ppb and > 40 ppb. The antifungal activity of the resin of Boswellia carterii was tested on the following strains: Aspergillus niger, Aspergillus flavus, Penicillium expansum. And kneaded according to the technique of diagonal growth on intermediate solid medium (PDA). The results showed that the yield of the aqueous extract varied between 96.2 and 99.8%. The results of the extracts also showed activity against the fungi studied 48.6% and 96.2%.

Penicillium expansum Link causes an economically important postharvest blue mold disease in a number of fruits and vegetables. In the present study, this fungus was isolated from rotted grapes and identified on morphological basis. Identification of the pathogen was further confirmed on molecular basis by using four different primer pairs namely ITS, β-tubulin, CMD and CF under accession numbers MN752155, MN787831, MN787832 and MN787833, respectively. Leaf extract of Chenopodium murale was assessed for its potential to control in vitro growth of P. expansum. For this purpose, leaves were extracted in methanol and after evaporation of the solvent, the resulting extract was successively partitioned with n- hexane, chloroform, ethyl acetate and n- butanol followed by antifungal bioassays with different concentrations (1.562 to 200 mg mL -1 ) each organic solvent fraction. Although all the fractions variably controlled the fungal pathogen, however, n- butanol fraction showed the highest antifungal activity causing 45–86% reduction in biomass of the pathogen. Ethyl acetate fraction was also highly antifungal and reduced fungal biomass by 44–81%. Chloroform and n- hexane fractions were comparatively less effective and reduced biomass of P. expansum by 30–72% and 11–44%, respectively. This study concludes that ethyl acetate and n- butanol fractions are highly antifungal in nature against P. expansum.

Blue mold decay is the one of most important postharvest disease of apples caused by the fungus, Penicillium expansum. This study aimed to investigate the biocontrol efficacy of the yeast, Wickerhamomyces anomalus, on postharvest blue mold decay of apples and the relative defense mechanisms. The results indicated that W. anomalus could significantly reduce the blue mold decay of apples, and the maximum inhibition was obtained when the concentration of W. anomalus was 1 × 108 cells ml−1. Furthermore, W. anomalus significantly reduced the fruit decay under ambient conditions, without generating any change in fruit quality. In vitro experiments showed that W. anomalus greatly inhibited the spore germination and germ tube elongation of P. expansum. Besides, its ease of adaptation, stable growth and potential colonization of in apple wounds or surfaces indicated that W. anomalus could compete with P. expansum for nutrients and space, leading to considerable inhibition blue mold decay. W. anomalus significantly induced the activities of polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT), phenylalanine ammonia-lyase (PAL), and ascorbate peroxidase (APX) in apples. Moreover, W. anomalus increased the contents of flavonoid and total phenols. All these results suggested that W. anomalus has potential biocontrol efficacy to control the postharvest blue mold decay of apples

Penicillium is one of the most important postharvest pathogens of citrus fruits worldwide. It induces blue or green mold disease, a decay that can lead to significant economic losses during storage. Based on internal transcribed spacer (ITS) sequences, seven Penicillium species and one closely related Talaromyces variabilis were identified from 30 rotten samples of citrus fruits marketed in Qena. Penicillium expansum was the most common species, recovered from 16.7% of the samples, followed by P. chrysogenum (10%) and P. polonicum (10%). Sixteen isolates were tested through inoculation on healthy citrus fruits; the data exhibited that 68.7% of isolates were highly virulent. A “Specific Gene Random Primer Polymerase Chain Reaction (SGRP-PCR)” marker technique indicated that the genetic similarity among P. expasum ranged from 49.4 to 85.7%, and a relatively correlation was found between SGRP band profile and species origin. Patulin was detected in 40% of P. expansum isolates. This study provided a useful molecular approach to identify different Penicillium species by sequencing ITS region, focus on the pathogenicity, compare between P. expansum isolates and their ability in patulin production.

Available online 13 October 2022, Bacteria and filamentous fungi (ff) are commonly encountered in biofilms developed in drinking water (DW) distribution systems (DWDS). Despite their intimate ecological relationships, researchers tend to study bacteria and ff separately. This work assesses the impact of bacteria-ff association in biofilm formation and tolerance to chlorination. One strain of Acinetobacter calcoaceticus isolated from DW was used as a model bacterium. Penicillium brevicompactum and P. expansum isolated from DW were the ff selected. Single species and inter-kingdom adhesion and biofilm formation occurred under two shear stress () conditions (0.05 and 1.6 Pa). The sessile structures were further characterized in terms of biomass production, respiratory activity and structure. The results showed that 1.6 Pa of shear stress and A. calcoaceticus-ff association favoured biofilm production. Inter-kingdom biofilms produced more biomass than A. calcoaceticus single species and reduced A. calcoaceticus susceptibility to disinfection, particularly to high sodium hypochlorite (SHC) concentrations. In addition, P. brevicompactum formed single species biofilms highly resistant to removal and inactivation by SHC. The presence of P. brevicompactum or P. expansum in inter-kingdom biofilms significantly decreased SHC removal and inactivation effects in comparison to the bacterial biofilms alone, proposing that using bacteria to form biofilms representative of DWDS can provide inaccurate conclusions, particularly in terms of biofilm production and susceptibility to disinfection., This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE) - funded by national funds through the FCT/MCTES (PIDDAC); Projects Germirrad - POCI-01-0247-FEDER-072237; PRESAGE - Aquatic/0007/2020, funded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalizaçao ˜ (POCI) and by national funds (PIDDAC) through FCT/MCTES; Project “HealthyWaters – Identification, Elimination, Social Awareness and Education of Water Chemical and Biological Micropollutants with Health and Environmental Implications”, with reference NORTE-01-0145-FEDER-000069, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This study was further supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020., info:eu-repo/semantics/publishedVersion

The widespread use of harmful fungicides in the agricultural sector has led to a demand for safer alternatives to protect against crop pathogens. The domestic apple is the second most highly consumed fruit in the world and encounters several pre- and post-harvest fungal and bacterial phytopathogens. The goal of this study was to explore the uncharacterized microbiome of a wild apple, Malus trilobata, as a potential source of novel biocontrol agents for two post-harvest fungi that affect commercial apples: Botrytis cinerea and Penicillium expansum. We sampled microflora associated with the leaves, bulk soil, and roots of Malus trilobata in two regions of Lebanon: Ehden reserve in the north and Dhour EL Choueir near Beirut. The two regions have different soil types Dhour EL Choueir and samples from the two regions showed very different microbial compositions, with greater microbial diversity among those from Ehden reserve. Molecular characterization revealed a wide variety of genera displaying activity against the two fungal pathogens, including several with previously unknown antifungal activity: Bosea, Microlunatus, Microbacterium, Mycetecola, Rhizobium and Paraphoma. In total, 92 strains inhibited Penicillium expansum (39%) and 87 strains inhibited Botrytis cinerea (38%) out of 237 screened. Further chemical and genetic characterization of one or more selected strains could pave the way for future development of new biocontrol agents for post-harvest applications.

Blue mold caused by Penicillium expansum is one of the most significant postharvest diseases of apples. Some microorganisms associated with the surface of ripening apples possess the ability to inhibit the growth of P. expansum. However, the existing literature about their colonization in the stages before ripening is not explored in depth. This study aims to characterize the antagonistic capacity of bacterial populations from five fruit development stages of ‘Royal Gala’ apples. The results have shown that the density of the bacterial populations decreases throughout the ripening stages of fruit (from 1.0 × 105 to 1.1 × 101 cfu/cm2). A total of 25 bacterial morphotypes (corresponding to five genera identified by 16S RNA) were differentiated in which Bacillus stood out as a predominant genus. In the in vitro antagonism tests, 10 Bacillus strains (40%) inhibited the mycelial growth of P. expansum from 30.1% to 60.1%, while in fruit bioassays, the same strains reduced the fruit rot ranging from 12% to 66%. Moreover, the bacterial strains with antagonistic activity increased in the ripening fruit stage. B. subtilis subsp. spiziennii M24 obtained the highest antagonistic activity (66.9% of rot reduction). The matrix-assisted laser desorption ionization- time of flight mass spectrometry analysis revealed that bacteria with antagonistic activity produce antifungal lipopeptides from iturin and fengycin families.

Background In the postharvest handling of horticultural commodities, plant extracts with fungicidal activity are a valid alternative to synthetic fungicides. The fungicidal activity of myrtle leaf extracts from eight cultivars was studied in vitro against Penicillium digitatum, Penicillium italicum, and Penicillium expansum and on artificially inoculated mandarins with green and blue molds during storage for 12 days at 20 °C and 90% RH. Results Hydroxybenzoic acids, hydrolysable tannins, and flavonols were identified by high-performance liquid chromatography (HPLC). Despite sharing the same phenolic profile, extracts of eight myrtle cultivars significantly differed in the concentration of phenolics. Hydrolysable tannins are the principal subclass representing nearly 44.9% of the total polyphenols, whereas myricitrin was the most abundant flavonol in all cultivars. Myrtle extracts strongly inhibited conidial germination of the pathogens tested, although the greatest efficacy was observed against P. digitatum. At a concentration of 20 g L-1 , all the extracts completely inhibited fungi growth; only 'Angela', 'Tonina' and 'Grazia' extracts were effective at lower concentrations (15 g L-1 ). On inoculated fruit, myrtle extracts significantly controlled rot development. As a preventive treatment, 'Ilaria' and 'Maria Rita' extracts significantly reduced the rate of fruit with green mold decay lesions. When applied as a curative treatment, all the exacts decreased the incidence of decay. Against P. italicum, all the extracts applied as preventive treatments controlled decay effectively, while as curative treatment some of the extracts were not effective. All the extracts reduced the size of the infected areas. Conclusion The results propose myrtle extracts as a possible natural alternative to synthetic fungicides. © 2021 Society of Chemical Industry.

In this study, green and eco-friendly biosynthesis of selenium nanoparticles (Se-NPs) were performed using Penicillium expansum ATTC 36200 for multiple biomedical applications. Mycosynthesized Se-NPs were completely characterized using UV, FT-IR, XRD, SEM, and TEM techniques. Se-NPs biosynthesized by P. expansum was characterized as a spherical shape with average size 4 to 12.7 nm. Moreover, Se-NPs were evaluated for multiple biomedical applications as antimicrobial, antioxidant, and anticancer activities and hemocompatibility. Results illustrated that Se-NPs have potential antimicrobial activity against Gram-positive (Bacillus subtilis ATCC6051 and Staphylococcus aureus ATCC23235), Gram-negative bacteria (Escherichia coli ATCC8739and Pseudomonas aeruginosa ATCC9027), fungi (Candida albicans ATCC90028, Aspergillus niger RCMB 02724 and Aspergillus fumigatus RCMB 02568), and antioxidant activity. Additionally, Se-NPs exhibited anticancer activity against PC3 cell line; IC50 was 99.25 μg/mL. Meanwhile, they showed non-hemolytic activity on human RBCs at concentration up to 250 μg/mL. In conclusion, biosynthetic Se-NPs by P. expansum are promising for many safe-use biomedical applications.

O controle de pragas agricolas e fundamental para elevar a producao das lavouras e reduzir as perdas no armazenamento. O foco na producao sustentavel de alimentos coloca os produtos naturais em destaque, sendo utilizados em formulacoes destinadas especialmente a agropecuaria orgânica. Oleos e extratos de plantas podem inibir crescimento de diversos organismos, incluindo fungos que atacam culturas de alto impacto economico. O oleo essencial de Thymus vulgaris foi estudado para verificar seu potencial emprego no controle dos fungos Aspergillus niger , Penicillium expansum , Sclerotinia sclerotiorum e Sclerotium rolfsii . A composicao quimica deste oleo foi determinada por cromatografia gasosa acoplada a espectrometria de massas e a atividade antifungica avaliada pela tecnica poison food . Foram encontradas 23 substâncias no oleo comercial de T. vulgaris , dentre elas: p-cimeno (23,75%), timol (21,78%) e carvacrol (26,14 %). O oleo essencial exibiu potente atividade antifungica frente aos quatro fungos, com inibicoes de 100% no crescimento micelial para as concentracoes de 0,1 % e 0,05 %.

Mandarin fruits are one of the most popular among the Citrus genus. They are consumed because of their nutritional and health benefits, as well as pleasant taste and smell. This paper describes the identification and characterization of Penicillium expansum, isolated from molded mandarin fruits. The obtained isolates were cultivated on five media [Czapek Yeast Autolysate agar (CYA), MEA (Malt extract agar), Creatine sucrose agar (CREA), Yeast extract sucrose agar (YES), and Oatmeal agar (OA)] and at five different incubation temperatures (5, 15, 25, 30, and 37 ?C). Isolates were sequenced for two molecular loci: internal transcribed spacer and beta-tubulin. Based on the results from morphological, physiological, molecular, and phylogenetic analyses, the recovered isolates were identified as P. expansum. The isolated species was confirmed as pathogenic to mandarin fruits in a pathogenicity test. To the best of our knowledge, this is the first report of P. expansum as a postharvest pathogen of mandarin fruit in Serbia.

The fruit of Carica papaya (pawpaw) is an important crop widely grown around the world. Isolation and control of fungi associated with spoiled pawpaw in the Mubi main market were carried out. A total of twenty (20) pawpaw fruits were collected from four locations, the isolation and characterization were done using standard procedure. The result revealed that four fungi cause pawpaw spoilage in the study area (Aspergillus niger, Penicillium expansum, Mucos spp and Rhizopus stolonifer) and were confirmed through a pathogenicity test. Location3 of the main market showed the highest disease incidence of 50%; location 2 the least with 20%. The efficacy of leaf extract of S. acuta was tested for antifungal activities against the four isolates and was positive as the zone of inhibition by the extract increases with an increase in concentration. It can be concluded that A. niger, P. expansum, Mucos spp and R. stolonifer were pathogens responsible for C. papaya fruit rot in Mubi main market. S. acuta leaf extract was able to restrain the growth of the pathogens. Further research should be carried out to determine the phytochemical present in the leaf extract of S. acuta and also to identify the active components in the plants.

Among the postharvest pathogens of apple fruit, Penicillium expansum (P.expansum) is considered to be one of the most common fungal pathogens worldwide. It is the causal agent of blue mold decay; the main serious economically disease of apple fruits, and the main producer of patulin (PAT). The principal objective of this work was to evaluate the aggressiveness and the PAT production of three isolated strains from apples produced in the East of Algeria. These strains were isolated then screened for their inhibitory activity against Escherichia coli and Bacillus subtilis (18 mm and 18 mm for S7; 10 mm and 11mm for S3), as well as their ability to cause blue rot (S4). The three strains S7, S3, and S4 (MN904448, MT023795 and MN904449, respectively) were identified as P. expansum by ITS1, ITS4, and β-tubulin gene sequences analysis. The in vitro ability to produce PAT was confirmed by Gas chromatography-mass spectrometry of strains’ crude extracts cul-tured on YES (Yeast-Extract-Sucrose) medium. Indeed, these strains exhibited a great capacity to cause blue mold decay for all tested apples (26 to 52 mm lesion diameter), after nine days of incubation at 25°C. Apples rotten area analysis that was performed by UPLC analysis revealed that these three strains were able to produce PAT at different concentrations ranging from 0.57 to 469 μg/mL. Thus, these strains constitute a risk to consumer health because these amounts exceed the permissive level of PAT.

Penicillium digitatum and Penicillium expansum are plant pathogenic fungi that cause the green and blue mold diseases, respectively, leading to serious postharvest economic losses worldwide. Moreover, P. expansum can produce mycotoxins, which are hazardous compounds to human and animal health. The development of tools that allow multiple and precise genetic manipulation of these species is crucial for the functional characterization of their genes. In this sense, CRISPR/Cas9 represents an excellent opportunity for genome editing due to its efficiency, accuracy and versatility. In this study, we developed protoplast generation and transformation protocols and applied them to implement the CRISPR/Cas9 technology in both species for the first time. For this, we used a self-replicative, recyclable AMA1-based plasmid which allows unlimited number of genomic modifications without the limitation of integrative selection markers. As test case, we successfully targeted the wetA gene, which encodes a regulator of conidiophore development. Finally, CRISPR/Cas9-derived ΔwetA strains were analyzed. Mutants showed reduced axenic growth, differential pathogenicity and altered conidiogenesis and germination. Additionally, P. digitatum and P. expansum ΔwetA mutants showed distinct sensitivity to fungal antifungal proteins (AFPs), which are small, cationic, cysteine-rich proteins that have become interesting antifungals to be applied in agriculture, medicine and in the food industry. With this work, we demonstrate the feasibility of the CRISPR/Cas9 system, expanding the repertoire of genetic engineering tools available for these two important postharvest pathogens and open up the possibility to adapt them to other economically relevant phytopathogenic fungi, for which toolkits for genetic modifications are often limited., This work was supported by PROMETEO/2018/066 from ‘Conselleria d’Educació’ (Generalitat Valenciana, Comunitat Valenciana, Spain). SG holds a ‘Juan de la Cierva Incorporación’ grant (IJC2020-042749-I) from the Spanish ‘Ministerio de Ciencia e Innovación’, funded by The European Union–NextGenerationEU.

Penicillium expansum, l’agent causal de la maladie de pourriture bleue dans les pommes, est l’un des champignons filamenteux les plus étudiés du genre Penicillium. Ce champignon phytopathogène peut infester de nombreux fruits pendant la récolte et tout au long de la période de stockage en produisant principalement la patuline. Cependant, la patuline n'est pas la seule mycotoxine produite par P. expansum, puisque ce dernier produit une grande variété de métabolites secondaires tels que la citrinine et la chaétoglobosine A. Chez les champignons filamenteux, les gènes codant pour les protéines impliquées dans le métabolisme secondaire sont organisés en clusters. Le métabolisme secondaire est régulé par des facteurs de transcription spécifiques ou globaux. Les facteurs de transcription spécifiques sont codés par des gènes qui sont situés dans le cluster de gènes biosynthétiques et qui agissent directement sur tous les autres gènes situés dans ce même cluster. Ces facteurs de transcription spécifiques sont contrôlés par des facteurs de transcription globaux, codés par des gènes situés en dehors du cluster biosynthétique et qui sont affectés par des stimuli environnementaux. Le complexe velvet, dépendant de la lumière, et impliquant trois facteurs de transcription globaux : VelB, LaeA et VeA, joue un rôle important dans la régulation du développement, de la sporulation, de la pathogénicité et du métabolisme secondaire chez de nombreuses espèces fongiques. La caractérisation du rôle de velB, laeA et veA dans la régulation du métabolisme secondaire ainsi que de plusieurs processus physiologiques est essentielle pour comprendre le comportement de ce champignon microscopique. Dans ce contexte, le premier objectif de cette thèse a consisté à investiguer l'implication de ces trois facteurs de transcription dans le développement fongique et le métabolisme secondaire chez P. expansum. Pour cela, nous avons réalisé une évaluation de la croissance in vivo et le comportement des trois souches mutantes, Pe∆velB, Pe∆laeA, et Pe∆veA, a été comparé à celui de la souche sauvage sur des pommes Golden Delicious. Les trois souches ont été capables de coloniser les pommes, mais à une vitesse inférieure à celle de la souche sauvage. Cependant, la souche Pe∆veA a été la seule souche incapable de percer la paroi des pommes et de sortir du fruit pour compléter son cycle de vie. Cela montre que VeA est le seul membre du complexe velvet qui régule la libération du champignon à travers la formation de corémies. Nous avons ensuite réalisé une analyse transcriptomique des trois souches mutantes. Indépendamment, chacun de ces facteurs de transcription globaux a montré son implication dans la régulation de l'expression de gènes impliqués dans la biosynthèse de métabolites secondaires, la conidiation, l'assimilation du nitrate, la biosynthèse de l'ergostérol et des sidérophores. Un second objectif de la thèse était de déterminer les interactions existantes entre ces trois membres du complexe velvet et quels étaient les gènes, les fonctions régulées directement ou indirectement par le complexe velvet. Afin de contrôler la production de métabolites secondaires par les champignons filamenteux, la compréhension des processus de régulation globale est essentielle. Les résultats indiquent que le complexe velvet est impliqué dans la régulation de la production de plusieurs métabolites secondaires tels que la patuline, la citrinine et la chaétoglobosine A, qui sont régulées positivement par VelB, LaeA et VeA ainsi que dans celle de divers processus de développement. Cependant, certains gènes impliqués dans la conidiation ou la biosynthèse de métabolites secondaires peuvent être régulés différemment par les membres de ce complexe.

Patulin is a toxic secondary metabolite of more than one fungal genera. It is biosynthesized by Penicillium spp., Byssochlamys spp., Aspergillus spp. and Paecilomyces spp. It also causes neurological, immunological, and gastrointestinal disorders in animals and humans. Patulin has been in the focus of the scientific community due to its occurrence in fruits, especially apples, as a result of infection by the necrotrophic plant pathogen Penicilium expansum. The European Commission has therefore set stricter limits for baby foods made from fruit (10 µg/kg) and for mild apple products (25 µg/kg). In addition to apples, patulin can also be found in other fruits such as pineapples, grapes, peaches and apricots. The patulin biosynthetic pathway involves more than ten steps, and the enzymes involved are regulated by 15 genes (from PePatA to PePatO), of which PePatL and PePatK are the most important. The main reactions that enable the formation of patulin are oxidation-reduction reaction. However, patulin production is not related to the virulence of P. expansum. Although the currently accepted scheme of patulin biosynthesis is described in the literature, this issue is still unresolved and important due to the complexity and interconnectedness of regulatory networks and other regulatory mechanisms. Therefore, the aim of this study is to provide a comprehensive and up- to-date overview of the patulin biosynthetic pathway to enable a better understanding of fungal pathogenicity and its implications for the development of food loss control strategies.

Um dos principais problemas no armazenamento de maçãs, se não o principal, é a ocorrência de podridões, tais como mofo azul (Penicillium expansum), mofo cinzento (Botrytis cinerea) e a podridão olho de boi (Neofabraea brasiliensis e N. actinideae). As perdas ocasionadas nesta fase, pelo aparecimento de doenças, resultam em grandes prejuízos econômicos. No Brasil, estima-se que estas perdas ocasionadas pelas podridões pós-colheita em maçãs, durante e após a armazenagem, totalizam 153,73 milhões de reais por ano (OGOSHI etal., 2019).

The effects of climate change, which play an important role in shaping environmental factors and intensifying the secondary metabolism of agriculturally important/foodborne fungal species, have led to an unexpected risk of contamination of food and feed with mycotoxins, which have enormous and complex implications for food safety and, consequently, for human health and the global economy. Several fundamental issues are at stake, but HRZZ-UIP-2020-02-8461 is attempting to come at least one step closer to solving the overall problem of avoiding modulation of fungicide efficacy due to changing climatic factors and stress the adaptation mechanisms of fungal cells, primarily for Penicillum expansum growth and the consequential patulin production. Apples are among the most popular fruits, but they are the most frequently infested by P. expansum and contaminated with its secondary metabolites. Despite this, there are currently no satisfactory strategies to reduce patulin concentrations in apples and apple products. However, there are traditional apple varieties that contain a higher number of polyphenolic compounds compared to commercial apple varieties. These compounds are an active component of plant defence against stress conditions. In addition, traditional varieties have higher antioxidant activity and a gene profile that makes them more resistant to climatic conditions, plant diseases, and other forms of abiotic stress. This has led to the idea of developing polyphenol-based strategies to reduce patulin content in apples and apple products, both for the ongoing HRZZ-UIP-2020-02-8461 and future projects. This presentation will provide an opportunity to discuss our idea, present initial published results, and identify potential new ways to achieve the overall goal of diminishing negative impact of mycotoxins from a food and feed safety perspective.

Jabuka je namirnica bogata dijetalnim vlaknima, fitokemikalijama, vitaminima, bioaktivnim spojevima i polifenolima. Ima utjecaj na smanjenje kroničnih bolesti, očuvanje zdravlja ploda i smanjenje nepoželjnih patogena zbog svojeg antioksidativnog djelovanja, prilikom snižavanja oksidativnog stresa. Cilj diplomskog rada je usporediti sorte 'Idared', 'Jonagold' i 'Golden Delicious' ubranih u sezoni 2021. godine s produkcijom mikotoksina patulin kojeg proizvodi plijesan Penicillium expansum, najčešći patogen u jabukama nakon berbe. Eksperimentalnim istraživanjem određen je udio ukupnih i pojedinačnih polifenola, prirodnih i ukupnih šećera, pH, udio flavonoida, topljiva suha tvar, udio ukupnih kiselina, antioksidacijska aktivnost te udio patulina u soku jabuke. Najviše polifenola određeno je u kaši, odnosno soku sorte 'Jonagold', a prema činjenici da je antioksidacijska aktivnost usko povezana sa sadržajem polifenola, komercijalna sorta 'Jonagold' pokazat će najveću otpornost na mikotoksin patulin. Patulin je identificiran u sorti 'Idared', dok u sortama 'Jonagold' i 'Golden Delicious' nema identificiranog patulina. Dobiveni rezultati doprinose boljem uvidu u otpornost komercijalnih sorti jabuka na zarazu s plijesni P. expansum.

Jabuka je voćna vrsta koja zauzima treće mjesto na ljestvici ukupne proizvodnje voća u svijetu budući da je važan izvor polifenolnih spojeva, minerala i vitamina tijekom cijele godine. Tradicionalne sorte jabuka predstavljaju sirovinu bogatu ukupnim polifenolnim spojevima i većom antioksidacijskom aktivnošću u odnosu na komercijalne sorte jabuka. Navedeni spojevi osim niza pozitivnih učinaka na ljudsko zdravlje, doprinose i očuvanju dugotrajnosti i stabilnosti ploda jabuke. Sok jabuke je dobiven prešanjem svježih jabuka i podvrgnut je postupku pasterizacije. Cilj diplomskog rada je ispitivanje skladišne otpornosti tradicionalnih sorti jabuka ´Ilzer Rosenapfel´, ´Winter Banane´ i ´Kraljevčica´ ubranih u sezoni 2021. godine na zarazu s plijesni Penicillium expansum i produkciju patulina. Također, određen je udio polifenola, antioksidacijska aktivnost te udio patulina u soku jabuke. Tradicionalna sorta jabuke ´Kraljevčica´ pokazala je najveći udio polifenola i u svježem uzorku i u soku jabuke. Patulin nije identificiran ni u jednom uzorku ispitivanih sorti jabuka. Dobiveni rezultati doprinose boljem uvidu u polifenolni profil ispitivanih tradicionalnih sorti, kao i uvid u otpornost tradicionalnih sorti jabuka na zarazu s plijesni P. expansum te posljedično produkciju patulina.