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1.
Curr Microbiol ; 81(7): 180, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38761223

RESUMO

Postharvest fungal diseases cause serious fruit losses and food safety issues worldwide. The trend in preventing food loss and waste has shifted to environmentally friendly and sustainable methods, such as biological control. Penicillium expansum is a common postharvest contaminant fungus that causes blue mould disease and patulin formation on apples. This study aimed to provide biocontrol using Metschnikowia pulcherrima isolates against P. expansum, and to understand their antagonistic action mechanisms. In vitro, 38.77-51.69% of mycelial growth inhibition of P. expansum was achieved by M. pulcherrima isolates with the dual culture assay, while this rate was 69.45-84.89% in the disc diffusion assay. The disease symptoms of P. expansum on wounds were reduced by M. pulcherrima, on Amasya apples. The lesion diameter, 41.84 mm after 12 d of incubation in control, was measured as 24.14 mm when treated with the most effective M. pulcherrima DN-MP in vivo. Although the antagonistic mechanisms of M. pulcherrima isolates were similar, there was a difference between their activities. In general, DN-HS and DN-MP isolates were found to be more effective. In light of all these results, it can be said that M. pulcherrima isolates used in the study have an antagonistic effect against the growth of P. expansum both in vitro and in vivo in Amasya apples, therefore, when the appropriate formulation is provided, they can be used as an alternative biocontrol agent to chemical fungicides in the prevention of postharvest diseases.


Assuntos
Antibiose , Malus , Metschnikowia , Penicillium , Doenças das Plantas , Penicillium/crescimento & desenvolvimento , Penicillium/isolamento & purificação , Penicillium/efeitos dos fármacos , Penicillium/fisiologia , Malus/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Metschnikowia/crescimento & desenvolvimento , Metschnikowia/fisiologia , Frutas/microbiologia , Agentes de Controle Biológico/farmacologia
2.
World J Microbiol Biotechnol ; 40(6): 179, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668807

RESUMO

Core histones in the nucleosome are subject to a wide variety of posttranslational modifications (PTMs), such as methylation, phosphorylation, ubiquitylation, and acetylation, all of which are crucial in shaping the structure of the chromatin and the expression of the target genes. A putative histone methyltransferase LaeA/Lae1, which is conserved in numerous filamentous fungi, functions as a global regulator of fungal growth, virulence, secondary metabolite formation, and the production of extracellular glycoside hydrolases (GHs). LaeA's direct histone targets, however, were not yet recognized. Previous research has shown that LaeA interacts with core histone H2B. Using S-adenosyl-L-methionine (SAM) as a methyl group donor and recombinant human histone H2B as the substrate, it was found that Penicillium oxalicum LaeA can transfer the methyl groups to the C-terminal lysine (K) 108 and K116 residues in vitro. The H2BK108 and H2BK116 sites on recombinant histone correspond to P. oxalicum H2BK122 and H2BK130, respectively. H2BK122A and H2BK130A, two mutants with histone H2B K122 or K130 mutation to alanine (A), were constructed in P. oxalicum. The mutants H2BK122A and H2BK130A demonstrated altered asexual development and decreased extracellular GH production, consistent with the findings of the laeA gene deletion strain (ΔlaeA). The transcriptome data showed that when compared to wild-type (WT) of P. oxalicum, 38 of the 47 differentially expressed (fold change ≥ 2, FDR ≤ 0.05) genes that encode extracellular GHs showed the same expression pattern in the three mutants ΔlaeA, H2BK122A, and H2BK130A. The four secondary metabolic gene clusters that considerably decreased expression in ΔlaeA also significantly decreased in H2BK122A or H2BK130A. The chromatin of promotor regions of the key cellulolytic genes cel7A/cbh1 and cel7B/eg1 compacted in the ΔlaeA, H2BK122A, and H2BK130A mutants, according to the results of chromatin accessibility real-time PCR (CHART-PCR). The chromatin accessibility index dropped. The histone binding pocket of the LaeA-methyltransf_23 domain is compatible with particular histone H2B peptides, providing appropriate electrostatic and steric compatibility to stabilize these peptides, according to molecular docking. The findings of the study demonstrate that H2BK122 and H2BK130, which are histone targets of P. oxalicum LaeA in vitro, are crucial for fungal conidiation, the expression of gene clusters encoding secondary metabolites, and the production of extracellular GHs.


Assuntos
Proteínas Fúngicas , Regulação Fúngica da Expressão Gênica , Glicosídeo Hidrolases , Histonas , Lisina , Família Multigênica , Penicillium , Metabolismo Secundário , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Histonas/genética , Lisina/metabolismo , Lisina/biossíntese , Metilação , Penicillium/genética , Penicillium/enzimologia , Penicillium/metabolismo , Penicillium/crescimento & desenvolvimento , Processamento de Proteína Pós-Traducional , Reprodução Assexuada/genética , Metabolismo Secundário/genética
3.
Int J Mol Sci ; 23(2)2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35054864

RESUMO

Penicillium digitatum is a widespread pathogen responsible for the postharvest decay of citrus, one of the most economically important crops worldwide. Currently, chemical fungicides are still the main strategy to control the green mould disease caused by the fungus. However, the increasing selection and proliferation of fungicide-resistant strains require more efforts to explore new alternatives acting via new or unexplored mechanisms for postharvest disease management. To date, several non-chemical compounds have been investigated for the control of fungal pathogens. In this scenario, understanding the molecular determinants underlying P. digitatum's response to biological and chemical antifungals may help in the development of safer and more effective non-chemical control methods. In this work, a proteomic approach based on isobaric labelling and a nanoLC tandem mass spectrometry approach was used to investigate molecular changes associated with P. digitatum's response to treatments with α-sarcin and beetin 27 (BE27), two proteins endowed with antifungal activity. The outcomes of treatments with these biological agents were then compared with those triggered by the commonly used chemical fungicide thiabendazole (TBZ). Our results showed that differentially expressed proteins mainly include cell wall-degrading enzymes, proteins involved in stress response, antioxidant and detoxification mechanisms and metabolic processes such as thiamine biosynthesis. Interestingly, specific modulations in response to protein toxins treatments were observed for a subset of proteins. Deciphering the inhibitory mechanisms of biofungicides and chemical compounds, together with understanding their effects on the fungal physiology, will provide a new direction for improving the efficacy of novel antifungal formulations and developing new control strategies.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Penicillium/efeitos dos fármacos , Espectrometria de Massas em Tandem , Antioxidantes/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Cromatografia Líquida , Endorribonucleases/farmacologia , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/farmacologia , Testes de Sensibilidade Microbiana , Penicillium/crescimento & desenvolvimento , Proteômica , Tiabendazol/farmacologia
4.
Molecules ; 26(23)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34885725

RESUMO

The ethyl acetate extract of an ISP-2 agar cultivation of the wasp nest-associated fungus Penicillium sp. CMB-MD14 exhibited promising antibacterial activity against vancomycin-resistant enterococci (VRE), with a bioassay guided chemical investigation yielding the new meroterpene, oxandrastin A (1), the first andrastin-like metabolite with an extra oxygenation at C-2. A culture media optimisation strategy informed a scaled-up rice cultivation that yielded 1, together with three new oxandrastins B-D (2-4), two known andrastins C (5) and F (6), and a new meroterpene of the austalide family, isoaustalide F (7). Structures of 1-7 were assigned based on detailed spectroscopic analysis and chemical interconversion. A GNPS molecular networking analysis of the rice cultivation extract detected the known austalides B (8), H (9), and H acid (10), tentatively identified based on molecular formulae and co-clustering with 7. That the anti-VRE properties of the CMB-MD14 extract were exclusively attributed to 1 (IC50 6.0 µM, MIC99 13.9 µM), highlights the importance of the 2-OAc and 3-OAc moieties to the oxandrastin anti-VRE pharmacophore.


Assuntos
Antibacterianos/química , Oryza/efeitos dos fármacos , Penicillium/química , Terpenos/química , Animais , Antibacterianos/farmacologia , Austrália , Enterococcus/efeitos dos fármacos , Enterococcus/patogenicidade , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oryza/microbiologia , Penicillium/crescimento & desenvolvimento , Terpenos/farmacologia , Vespas/química , Vespas/microbiologia
5.
World J Microbiol Biotechnol ; 38(1): 10, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34866162

RESUMO

In recent years, the utilisation of endophytes has emerged as a promising biological treatment technology for the degradation of plastic wastes such as biodegradation of synthetic plastics. This study, therefore, aimed to explore and extensively screen endophytic fungi (from selected plants) for efficient in vitro polyvinyl alcohol (PVA) biodegradation. In total, 76 endophytic fungi were isolated and cultivated on a PVA screening agar medium. Among these fungi, 10 isolates showed potential and were subsequently identified based on phenotypical characteristics, ITS ribosomal gene sequences, and phylogenetic analyses. Four strains exhibited a maximum level of PVA-degradation in the liquid medium when cultivated for 10 days at 28 °C and 150 rpm. These strains showed varied PVA removal rates of 81% (Penicillium brevicompactum OVR-5), 67% (Talaromyces verruculosus PRL-2), 52% (P. polonicum BJL-9), and 41% (Aspergillus tubingensis BJR-6) respectively. The most promising PVA biodegradation isolate 'OVR-5', with an optimal pH at 7.0 and optimal temperature at 30 °C, produced lipase, manganese peroxidase, and laccase enzymes. Based on analyses of its metabolic intermediates, as identified with GC-MS, we proposed the potential PVA degradation pathway of OVR-5. Biodegradation results were confirmed through scanning electron microscopy and Fourier transform infrared spectroscopy. This study provides the first report on an endophytic P. brevicompactum strain (associated with Orychophragmus violaceus) that has a great ability for PVA degradation providing more insight on potential fungus-based applications in plastic waste degradation.


Assuntos
Penicillium/crescimento & desenvolvimento , Plásticos/análise , Álcool de Polivinil/análise , Biodegradação Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Redes e Vias Metabólicas , Rizosfera , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Mol Microbiol ; 116(6): 1512-1532, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34797006

RESUMO

Numerous transcription factors (TFs) in ascomycete fungi play crucial roles in cellular processes; however, how most of them function is poorly understood. Here, we identified and characterized a novel TF, CxrC (POX01387), acting downstream of the key TF CxrA, which is essential for plant-biomass-degrading-enzyme (PBDE) production in Penicillium oxalicum. Deletion of cxrC in P. oxalicum significantly affected the production of PBDEs, as well as mycelial growth and conidiospore production. CxrA directly repressed the expression of cxrC after about 12 hr following switch to Avicel culture. CxrC bound the promoters of major PBDE genes and genes involved in conidiospore development. CxrC was found to bind the TSSGTYR core sequence (S: C and G; Y: T and C; R: G and A) of the important cellulase genes cbh1 and eg1. Both N- and C-terminal peptides of CxrC and the CxrC phosphorylation were found to mediate its homodimerization. The conserved motif LPSVRSLLTP (65-74) in CxrC was found to be required for regulating cellulase production. This study reveals novel mechanisms of TF-mediated regulation of the expression of PBDE genes and genes involved in cellular processes in an ascomycete fungus.


Assuntos
Proteínas Fúngicas/metabolismo , Penicillium/metabolismo , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Celulase/antagonistas & inibidores , Celulase/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Penicillium/química , Penicillium/genética , Penicillium/crescimento & desenvolvimento , Regiões Promotoras Genéticas , Esporos Fúngicos/química , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética
7.
Toxins (Basel) ; 13(8)2021 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-34437421

RESUMO

Penicillium expansum is an important postharvest pathogen of pomaceous fruit and a causal agent of blue mold or soft rot. In this study, we investigated the effect of ambient pH on growth, ultrastructure alteration, and pathogenicity of P. expansum, as well as accumulation of patulin and expression of genes involved in patulin biosynthesis. Under different pH, the fungus was routinely cultured and collected for growth, pathogenicity, patulin production, and gene expression studies using transmission electron microscopy, apple inoculation, HPLC, and RT-qPCR methods. Different ambient pH had significant impact on expression of genes and growth factors involved in patulin biosynthesis. Under same range of pH, gene expression profile, growth factors, and patulin accumulation (in vivo and in vitro) all showed similar changing trends. A well-developed cell was observed in addition to upregulation of genes at pH between pH 5.0 and 7.0, while the opposite was observed when pH was too basic (8.5) or too acid (2.5). Additionally, ambient pH had direct or indirect influence on expression of PecreaA, PelaeA, and PepacC. These findings will help in understanding the effect of ambient pH on growth, pathogenicity, and patulin production and support the development of successful methods for combating P. expansum infection on apple fruits.


Assuntos
Frutas/microbiologia , Malus/microbiologia , Penicillium , Biomassa , Regulação Fúngica da Expressão Gênica , Germinação , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Patulina/biossíntese , Penicillium/genética , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Penicillium/patogenicidade
8.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202776

RESUMO

The chemical composition, antioxidant activity, and antimicrobial properties of three commercially available essential oils: rosemary (REO), lavender (LEO), and mint (MEO), were determined in the current study. Our data revealed that the major components of REO, MEO, and LEO were 1,8-cineole (40.4%), menthol (40.1%), and linalool acetate (35.0%), respectively. The highest DPPH radical-scavenging activity was identified in MEO (36.85 ± 0.49%) among the investigated EOs. Regarding antimicrobial activities, we found that LEO had the strongest inhibitory efficiencies against the growth of Pseudomonas aeruginosa and Candida (C.) tropicalis, MEO against Salmonella (S.) enterica, and REO against Staphylococcus (S.) aureus. The strongest antifungal activity was displayed by mint EO, which totally inhibited the growth of Penicillium (P.) expansum and P. crustosum in all concentrations; the growth of P. citrinum was completely suppressed only by the lowest MEO concentration. The lowest minimal inhibitory concentrations (MICs) against S. enterica, S. aureus, and C. krusei were assessed for MEO. In situ analysis on the bread model showed that 125 µL/L of REO exhibited the lowest mycelial growth inhibition (MGI) of P. citrinum, and 500 µL/L of MEO caused the highest MGI of P. crustosum. Our results allow us to make conclusion that the analysed EOs have promising potential for use as innovative agents in the storage of bakery products in order to extend their shelf-life.


Assuntos
Anti-Infecciosos/farmacologia , Pão/microbiologia , Lavandula/química , Mentha/química , Óleos Voláteis/farmacologia , Penicillium/crescimento & desenvolvimento , Rosmarinus/química , Anti-Infecciosos/química , Bactérias/crescimento & desenvolvimento , Candida tropicalis/crescimento & desenvolvimento , Óleos Voláteis/química
9.
Toxins (Basel) ; 13(6)2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199507

RESUMO

Wild yeasts isolated from the surface of apples were screened for antagonistic activity against Penicillium expansum, the main producer of the mycotoxin patulin. Three antagonistic yeasts (Y33, Y29 and Y24) from a total of 90 were found to inhibit P. expansum growth. Identification by ITS region sequence and characterization showed that three selected isolates of yeast should be different strains of Metschnikowia pulcherrima. Several concentrations of the selected yeasts were used to study their in vitro antifungal effectivity against P. expansum on Petri dishes (plates with 63.6 cm2 surface) whereas their potential activity on patulin reduction was studied in liquid medium. Finally, the BCA that had the best in vitro antifungal capacity against P. and the best patulin degradation capacity was selected to be assessed directly on apples. All the selected strains demonstrated antifungal activity in vitro but the most efficient was the strain Y29. Isolated strains were able to reduce patulin content in liquid medium, Y29 being the only strain that completely reduced patulin levels within 120 h. The application of Y29 as biocontrol agent on the surface of apples inoculated with P. expansum, inhibited fungal growth and patulin production during storage. Therefore, the results shown that this yeast strain could be used for the reduction of P. expansum and its mycotoxin in apples or apple-based products by adapting the procedure application.


Assuntos
Agentes de Controle Biológico , Frutas/microbiologia , Malus/microbiologia , Metschnikowia/isolamento & purificação , Patulina/metabolismo , Penicillium/crescimento & desenvolvimento , Frutas/química , Malus/química , Metschnikowia/metabolismo , Patulina/análise , Doenças das Plantas/prevenção & controle
10.
J Basic Microbiol ; 61(9): 782-794, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34309887

RESUMO

Cold-active catalase (CAT) elicits great interest because of its vast prospective at the medical, commercial, and biotechnological levels. The study paper reports the production of cold-active CAT by the strain Penicillium griseofulvum P29 isolated from Antarctic soil. Improved enzyme production was achieved by optimization of medium and culture conditions. Maximum CAT was demonstrated under low glucose content (2%), 10% inoculum size, temperature 20°C, and dissolved oxygen concentration (DO) 40%. An effective laboratory technology based on changing the oxidative stress level through an increase of DO in the bioreactor was developed. The used strategy resulted in a 1.7- and 1.4-fold enhanced total enzyme activity and maximum enzyme productivity. The enzyme was purified and characterized. P. griseofulvum P29 CAT was most active at approximately 20°C and pH 6.0. Its thermostability was in the range between 5°C and 40°C.


Assuntos
Biotecnologia/métodos , Catalase/genética , Catalase/metabolismo , Temperatura Baixa , Penicillium/genética , Regiões Antárticas , Catalase/análise , Concentração de Íons de Hidrogênio , Estresse Oxidativo , Penicillium/enzimologia , Penicillium/crescimento & desenvolvimento , Penicillium/isolamento & purificação , Temperatura
11.
Int J Food Microbiol ; 344: 109111, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33676331

RESUMO

Currants are prone to contamination by ochratoxin during cultivation, processing and storage conditions. Saccharomyces cerevisiae is considered to be among the main species of grape yeast flora able to control antagonistic fungi. In this study, the potential of S. cerevisiae Y33 was investigated to inhibit the growth of several fungal species indigenous to the microbiota of grapes. Moreover, the efficacy of this yeast species was investigated to inhibit OTA by toxin producing fungi both in vitro and in situ. For this purpose thirty-five different fungal species, belonging to the genera Aspergillus, Penicillium, Cladosporium, Fusarium and Alternaria interacted in vitro with S. cerevisiae on Malt Extract agar plates, stored at 25 °C for 14 days. Results showed that the highest OTA producer A. carbonarius F71 was inhibited more than 99% from day 7, in contrast to A. niger strains that presented enhanced OTA production at day 14 due to interaction with S. cerevisiae Y33. Additionally, the antifungal potential of the selected yeast was also studied in situ on currants subjected to different treatments and stored at 25 °C for 28 days. Microbiological analysis was undertaken for the enumeration of the bacterial and fungal flora, together with OTA determination at 7 and 21 days. To quantify A. carbonarius on all treated currant samples, molecular analysis with Real Time PCR was employed. A standard curve was prepared with A. carbonarius DNA. The efficiency of the curve was estimated to 10.416, the slope to -3.312 and the range of haploid genome that could be estimated was from 1.05 to 105∙105. The amount of A. carbonarius DNA in all treated currants samples, where the fungus was positively detected, ranged from as low as 0.08 to 562 ng DNA/g currants. The antifungal activity of S. cerevisiae Y33 was observed in all studied cases, causing inhibition of fungal growth and OTA production.


Assuntos
Antibiose/fisiologia , Ocratoxinas/biossíntese , Ribes/microbiologia , Saccharomyces cerevisiae/patogenicidade , Alternaria/crescimento & desenvolvimento , Alternaria/metabolismo , Antifúngicos/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Cladosporium/crescimento & desenvolvimento , Cladosporium/metabolismo , Frutas/microbiologia , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces cerevisiae/genética , Fermento Seco
12.
J Sci Food Agric ; 101(10): 4229-4240, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33426638

RESUMO

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.


Assuntos
Citrus/microbiologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Fungicidas Industriais/farmacologia , Myrtus/química , Penicillium/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Extratos Vegetais/farmacologia , Conservação de Alimentos/instrumentação , Conservantes de Alimentos/química , Armazenamento de Alimentos , Frutas/microbiologia , Penicillium/classificação , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Folhas de Planta/química
13.
J Agric Food Chem ; 69(3): 945-954, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33438400

RESUMO

A novel chemical conjugate between chitosan (CH) and riboflavin (RF) has been synthesized and characterized via Fourier transform infrared, NMR, and other spectroscopic methods. Photophysical and photochemical properties such as absorption spectra, fluorescence emission, fluorescence anisotropy, and singlet oxygen generation were characterized as well. This new biopolymer-based conjugate was designed to have an antifungal effect enhanced through antimicrobial photodynamic therapy. The antifungal effect of this conjugate (CH-RF) was compared with CH and RF against Penicillium digitatum in vitro. The conjugate showed the highest fungal growth inhibition of all systems tested at a dose of 0.5% w/v. This new biopolymer-based compound could be a promising alternative to fungicides used in citrus fruits postharvest.


Assuntos
Quitosana/química , Quitosana/farmacologia , Fungicidas Industriais/farmacologia , Penicillium/efeitos dos fármacos , Riboflavina/química , Riboflavina/farmacologia , Citrus/microbiologia , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Luz , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia
14.
Food Chem ; 335: 127646, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32731123

RESUMO

Carbon/ZnO coaxial microfibers were synthesized with the hypha of Penicillium expansum as low-cost and green template. The SEM images, XRD and Raman spectra were used to characterize the morphology and chemical components of the prepared microfibers. The formation of the coaxial structure could be attributed to the attachment of Zn2+ onto the hypha surface through coordination and electrostatic interactions. Sensing performance of the carbon/ZnO microfibers toward Dopamine (DA) were evaluated by dropping method. Results showed that the proposed sensor exhibited good selectivity, reproducibility, and stability with a detection limit of 0.106 µM. Two linear ranges were obtained from 0 to 50 and 50 to 300 µM. The practicality of the carbon/ZnO microfibers was supported by the successful detection of DA in pork with recovery ranging from 96.85% to 104.51%. Based on the excellent electrochemical performance and easy preparation, the proposed sensor provides a promising method for determination of DA.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Carbono/metabolismo , Dopamina/análise , Hifas/metabolismo , Carne/análise , Penicillium/metabolismo , Óxido de Zinco/química , Óxido de Zinco/metabolismo , Animais , Técnicas Biossensoriais/instrumentação , Hifas/crescimento & desenvolvimento , Penicillium/crescimento & desenvolvimento , Suínos
15.
J Appl Microbiol ; 131(2): 743-755, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33251646

RESUMO

AIMS: This paper aims to quantify the growth and organic acid production of Aspergillus niger, Penicillium chrysogenum and Penicillium simplicissimum when these fungi are exposed to varying levels of lithium (Li) and cobalt (Co). The study also tests whether pre-exposing the fungi to these metals enables the fungi to develop tolerance to Li or Co. METHODS AND RESULTS: When cultures of A. niger, P. chrysogenum or P. simplicissimum were exposed to 250 mg l-1 of Li or Co, biomass production and excretion of organic acids were significantly inhibited after 5 days of growth compared to cultures grown in the absence of these metals. Pre-exposing cultures of A. niger to 250 mg l-1 of Li or Co for 20 days significantly increased biomass production when the fungus was subsequently sub-cultured into 250 or 500 mg l-1 of Li or Co. However, pre-exposure of P. chrysogenum or P. simplicissimum to 250 mg l-1 of Li or Co for 20 days did not increase biomass production. CONCLUSIONS: Aspergillus niger, but not the Penicillium species, developed tolerance to Li and to Co during the 20-day pre-exposure period. Therefore, processes that utilize fungal bioleaching with A. niger to mobilize and recover valuable metals such as Li or Co should consider a pre-exposure step for fungi to improve their tolerance to metal toxicity. SIGNIFICANCE AND IMPACT OF THE STUDY: Fungi may have the ability to extract valuable metals such as Li and Co from spent rechargeable batteries. However, the toxicity of the extracted metals can inhibit fungal growth and organic acid production. Pre-exposure to metals may alleviate toxicity for some fungal species. This knowledge can be used to improve the design of bioleaching protocols, increasing the potential for fungal bioleaching to become an economical and environmentally friendly method of recovering Li and Co from spent batteries.


Assuntos
Cobalto/toxicidade , Fungos/efeitos dos fármacos , Lítio/toxicidade , Ácidos , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Aspergillus niger/metabolismo , Biomassa , Fontes de Energia Elétrica , Íons , Compostos Orgânicos/metabolismo , Penicillium/efeitos dos fármacos , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Penicillium chrysogenum/efeitos dos fármacos , Penicillium chrysogenum/crescimento & desenvolvimento , Penicillium chrysogenum/metabolismo
16.
Bioprocess Biosyst Eng ; 44(3): 549-561, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33200291

RESUMO

An endo-1,4-ß-mannanase gene (manB) from a Bacillus pumilus Nsic-2 grown in a stinky tofu emulsion was cloned and expressed in Pichia pastoris GS115. After characterized, the endo-1,4-ß-mannanase (manB) show maximum activity at pH 6.0 and 50 °C with LBG as substrate and perform high stability at a range of pH 6-8. After applying for a shake flask fermentation, the specific activity of manB reached 3462 U/mg. To produce mannose, the soybean meal (SBM) was pretreated by biological fermentation for 11 days with Penicillium brevicompactum, and then hydrolyzed by manB. As a result, mannose yield reached 3.58 g per 1 kg SBM which indicated that 0.358% SBM was converted into mannose after hydrolyzation, and mean a total 20% mannan of SBM converting into mannose, while the control group demonstrated only 1.78% conversion. An effective ß-mannanase for the bioconversion of mannan-rich biomasses and an efficient method to produce mannose with soybean meal were introduced.


Assuntos
Bacillus pumilus/genética , Proteínas de Bactérias/biossíntese , Expressão Gênica , Glycine max/química , Penicillium/crescimento & desenvolvimento , Saccharomycetales , beta-Manosidase/biossíntese , Bacillus pumilus/enzimologia , Proteínas de Bactérias/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Saccharomycetales/genética , Saccharomycetales/crescimento & desenvolvimento , beta-Manosidase/genética
17.
Fungal Biol ; 125(1): 62-68, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33317777

RESUMO

Penicillium verrucosum contaminates temperate cereals with ochratoxin A (OTA) during harvesting and storage. We examined the effect of temperature (25 vs 30 oC), CO2 (400 vs 1000 ppm) and matric/solute stress (-2.8 vs -7.0 MPa) on (i) growth, (ii) key OTA biosynthetic genes and (iii) OTA production on a milled wheat substrate. Growth was generally faster under matric than solute stress at 25 oC, regardless of CO2 concentrations. At 30 oC, growth of P. verrucosum was significantly reduced under solute stress in both CO2 treatments, with no growth observed at -2.8 MPa (=0.98 water activity, aw) and 1000 ppm CO2. Overall, growth patterns under solute stress was slower in elevated CO2 than under matric stress when compared with existing conditions. The otapksPV gene expression was increased under elevated CO2 levels in matric stress treatments. There was fewer effects on the otanrpsPV biosynthetic gene. This pattern was paralleled with the production of OTA under these conditions. This suggest that P. verrucosum is able to actively grow and survive in both soil and on crop debris under three way interacting climate-related abiotic factors. This resilience suggests that they would still be able to pose an OTA contamination risk in temperate cereals post-harvest.


Assuntos
Regulação Fúngica da Expressão Gênica , Ocratoxinas , Penicillium , Mudança Climática , Regulação Fúngica da Expressão Gênica/fisiologia , Ocratoxinas/análise , Ocratoxinas/biossíntese , Penicillium/química , Penicillium/genética , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Triticum/metabolismo
18.
Compr Rev Food Sci Food Saf ; 19(6): 3416-3438, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33337032

RESUMO

Penicillium expansum is a necrotrophic plant pathogen with a wide range of fruit hosts. It causes blue mold rot during fruit storage, transport, and sale, resulting in huge economic losses to the fruit industry. Moreover, this pathogen is also the main producer of patulin, a toxic secondary metabolite that contaminates fruit and fruit-derived products and impairs human health. Therefore, understanding molecular basis of the pathogenicity and patulin biosynthesis of the fungal pathogen has important scientific significance and also plays an important guiding role in the research and development of new control technologies. Here, we comprehensively summarize the recent research progress, particularly regarding the molecular aspects of pathogenicity, patulin biosynthesis, and the related regulatory mechanisms, as well as control technologies for blue mold rot in the fruit industry.


Assuntos
Frutas/microbiologia , Patulina/biossíntese , Penicillium/patogenicidade , Microbiologia de Alimentos , Armazenamento de Alimentos , Penicillium/química , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
19.
Compr Rev Food Sci Food Saf ; 19(2): 643-669, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33325175

RESUMO

In this review, we present the current information on development and applications of biological control against phytopathogenic organisms as well as mycotoxigenic fungi in Malaysia as part of the integrated pest management (IPM) programs in a collective effort to achieve food security. Although the biological control of phytopathogenic organisms of economically important crops is well established and widely practiced in Malaysia with considerable success, the same cannot be said for mycotoxigenic fungi. This is surprising because the year round hot and humid Malaysian tropical climate is very conducive for the colonization of mycotoxigenic fungi and the potential contamination with mycotoxins. This suggests that less focus has been made on the control of mycotoxigenic species in the genera Aspergillus, Fusarium, and Penicillium in Malaysia, despite the food security and health implications of exposure to the mycotoxins produced by these species. At present, there is limited research in Malaysia related to biological control of the key mycotoxins, especially aflatoxins, Fusarium-related mycotoxins, and ochratoxin A, in key food and feed chains. The expected threats of climate change, its impacts on both plant physiology and the proliferation of mycotoxigenic fungi, and the contamination of food and feed commodities with mycotoxins, including the discovery of masked mycotoxins, will pose significant new global challenges that will impact on mycotoxin management strategies in food and feed crops worldwide. Future research, especially in Malaysia, should urgently focus on these challenges to develop IPM strategies that include biological control for minimizing mycotoxins in economically important food and feed chains for the benefit of ensuring food safety and food security under climate change scenarios.


Assuntos
Contaminação de Alimentos/prevenção & controle , Fungos/crescimento & desenvolvimento , Micotoxinas , Doenças das Plantas/microbiologia , Aspergillus/crescimento & desenvolvimento , Agentes de Controle Biológico , Produtos Agrícolas/microbiologia , Inocuidade dos Alimentos , Fusarium/crescimento & desenvolvimento , Malásia , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle
20.
J Evid Based Integr Med ; 25: 2515690X20971578, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33241708

RESUMO

This study examined the toxicity and antimicrobial effects of ethanol and aqueous extracts from Amaranthus caudatus grown on soils formulated from parent particles of silt, sand and clay in a glasshouse. Four different soils namely; sandy clay loam, loam, clayey loam and silty clay loam from were formulated were used for cultivation with the unfractionated soil which was the control. Crude extracts obtained from the plant shoots harvested at different growth stages were tested on some certain gram-negative and gram-positive bacteria and some fungi via agar dilution assay. The toxicity of the water and ethanol extracts was also examined via Artemia salina assay and the level of lethality was measured against Clarkson's lethality scale. All aqueous samples, as well as ethanol extracts of flowering and pre-flowering harvests of control soil tested, were non-toxic (LC50 > 1 mg/mL). At post flowering, the ethanolic extracts were highly toxic mostly in clayey loam, control, sandy-clayey loam soils (LC50 < 0.5 mg/mL). Also, antifungal effects of the plant revealed that extracts inhibited the growth of Candida albicans significantly with mild effect on Candida glabrata, Penicillium chrysogenum and Penicillium aurantiogriseum suggesting that the plant is a promising pharmacological candidate in the treatment of candidiasis. For an optimal yield of non-toxic supplement for household consumption which may also serve as pharmacological precursors, clayey loam soil is recommended for cultivation and harvesting may occur at pre-flowering or flowering stage using ethanol and water as solvents of extraction.


Assuntos
Agricultura/métodos , Amaranthus , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Penicillium/efeitos dos fármacos , Solo , Amaranthus/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Argila , Flores , Penicillium/crescimento & desenvolvimento , Penicillium chrysogenum/efeitos dos fármacos , Penicillium chrysogenum/crescimento & desenvolvimento , Extratos Vegetais/farmacologia , Brotos de Planta , Areia
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