Histone H2B lysine 122 and lysine 130, as the putative targets of Penicillium oxalicum LaeA, play important roles in asexual development, expression of secondary metabolite gene clusters, and extracellular glycoside hydrolase synthesis.

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.

Control of postharvest diseases caused by Penicillium spp. with myrtle leaf phenolic extracts: in vitro and in vivo study on mandarin fruit during storage.

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.

Novel Chitosan-Riboflavin Conjugate with Visible Light-Enhanced Antifungal Properties against Penicillium digitatum.

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.

Antifungal activity of an allicin derivative against Penicillium expansum via induction of oxidative stress.

The application of natural preservatives has become an attractive method for controlling postharvest decay of fruits and vegetables. Allicin, the main active ingredient of allium plants, has broad-spectrum antifungal activity. However, the unstable properties of allicin limit its wide application. In this study, 1-[(R)-ethylsulfinyl]sulfanylethane, a structurally stable derivative of allicin, was used to explore its antifungal activity and potential mechanism on the expansion of Penicillium expansum. We demonstrated the antifungal activity of 1-[(R)-ethylsulfinyl]sulfanylethane through in vitro antifungal experiments. At the concentration is 2 mg/L, 1-[((R)-ethylsulfinyl]sulfanyl]ethane can completely inhibit spore germination and mycelial growth, whereas the concentration of allicin needs to reach 16 mg/L. Fungal Biochemical assay indicated that decrease of mitochondrial membrane potential, overgeneration of reactive oxygen species, decrease of adenosine triphosphate and glutathione content, increase of superoxide dismutase, catalase, and malondialdehyde content. The results revealed that 1-[(R)-ethylsulfinyl]sulfanylethane induced mitochondrial dysfunction and oxidative stress in P. expansum. Due to its excellent antifungal activity, 1-[((R)-ethylsulfinyl]sulfanyl]ethane might be developed as a substitute for fungicides against P. expansum in postharvest fruit storage.

Targeted versus Nontargeted Green Strategies Based on Headspace-Gas Chromatography-Ion Mobility Spectrometry Combined with Chemometrics for Rapid Detection of Fungal Contamination on Wheat Kernels.

Conventional methods for detecting fungal contamination are generally time-consuming and sample-destructive, making them impossible for large-scale nondestructive detection and real-time analysis. Therefore, the potential of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was examined for the rapid determination of fungal infection on wheat samples in a rapid and nondestructive manner. In addition, the validation experiment of detecting the percent A. flavus infection presented in simulated field samples was carried out. Because the dual separation of HS-GC-IMS could generate massive amounts of three-dimensional data, proper chemometric processing was required. In this study, two chemometric strategies including: (i) nontargeted spectral fingerprinting and (ii) targeted specific markers were introduced to evaluate the performances of classification and prediction models. Results showed that satisfying results for the differentiation of fungal species were obtained based on both strategies (>80%) by the genetic algorithm optimized support vector machine (GA-SVM), and better values were obtained based on the first strategy (100%). Likewise, the GA-SVM model based on the first strategy achieved the best prediction performances (R2 = 0.979-0.998) of colony counts in fungal infected samples. The results of validation experiment showed that GA-SVM models based on the first strategy could still provide satisfactory classification (86.67%) and prediction (R2 = 0.889) performances for percent A. flavus infection presented in simulated field samples at day 4. This study indicated the feasibility of HS-GC-IMS-based approaches for the early detection of fungal contamination in wheat kernels.

Hatsusamides A and B: Two New Metabolites Produced by the Deep-Sea-Derived Fungal Strain Penicillium steckii FKJ-0213.

Two new nitrogen-containing metabolites, designated hatsusamide A (1) and B (2), were isolated from a culture broth of Penicilliumsteckii FKJ-0213 together with the known compounds tanzawaic acid B (3) and trichodermamide C (4) by physicochemical (PC) screening. The structures of 1 and 2 were determined as a tanzawaic acid B-trichodermamide C hybrid structure and a new analog of aspergillazines, respectively. The absolute configuration of 1 was determined by comparing the values of tanzawaic acid B and trichodermamide C in the literatures, such as 1H-nuclear magnetic resonance (1H-NMR) data and optical rotation, after hydrolysis of 1. Compounds 1-4 were evaluated for cytotoxicity and anti-malarial activities. Compounds 1 and 3 exhibited weak anti-malarial activity at half-maximal inhibitory concentration (IC50) values of 27.2 and 78.5 µM against the K1 strain, and 27.9 and 79.2 µM against the FCR3 strain of Plasmodium falciparum, respectively. Furthermore, 1 exhibited cytotoxicity against HeLa S3, A549, Panc1, HT29 and H1299 cells, with IC50 values of 15.0, 13.7, 12.9, 6.8, and 18.7 µM, respectively.

Enhanced bio-recovery of aluminum from low-grade bauxite using adapted fungal strains.

Filamentous fungi have been proved to have a pronounced capability to recover metals from mineral ores. However, the metal recovery yield is reduced due to toxic effects triggered by various heavy metals present in the ore. The current study highlights the fungal adaptations to the toxic effects of metals at higher pulp densities for the enhanced bio-recovery of aluminum from low-grade bauxite. In the previous studies, a drastic decrease in the aluminum dissolution was observed when the bauxite pulp density was increased from 1 to 10% (w/v) due to the high metal toxicity and low tolerance of Aspergillus niger and Penicillium simplicissium to heavy metals. These fungi were adapted in order to increase heavy metal tolerance of these fungal strains and also to get maximum Al dissolution. A novel approach was employed for the adaptation of fungal strains using a liquid growth medium containing 5% bauxite pulp density supplemented with molasses as an energy source. The mycelia of adapted strains were harvested and subsequently cultured in a low-cost oat-agar medium. Batch experiments were performed to compare the aluminum leaching efficiencies in the direct one-step and the direct two-step bioleaching processes. FE-SEM analysis revealed the direct destructive and corrosive action by the bauxite-tolerant strains due to the extension and penetration of the vegetative mycelium filaments into the bauxite matrix. XRD analysis of the bioleached bauxite samples showed a considerable decline in oxide minerals such as corundum and gibbsite. Results showed a high amount of total Al (≥ 98%) was successfully bioleached and solubilized from low-grade bauxite by the adapted fungal strains grown in the presence of 5% pulp density and molasses as a low-cost substrate. Graphical abstract.

Optimization of aqueous two-phase micellar system for partial purification of L-asparaginase from Penicillium sp. grown in wheat bran as agro-industrial residue.

L-asparaginase has been used in the remission of malignant neoplasms such as acute lymphoblastic leukemia. The search for new sources of this enzyme has become attractive for therapeutics. Traditional methods for biomolecule purification involve several steps. A two-phase system may be a good strategy to anticipate one of these stages. This study aimed to produce and purify a fungal L-asparaginase through an aqueous two-phase micellar system (ATPMS) using Triton X-114. The fungus Penicillium sp.-encoded 2DSST1 was isolated from Cerrado soil. Plackett-Burman design followed by a 24 full factorial design was used to determine the best conditions to produce L-asparaginase. The evaluated variables were L-asparagine, L-proline, wheat bran, potato dextrose broth, ammonium sulfate, yeast extract, sucrose and glucose concentrations, incubation temperature, incubation period, and initial pH of the culture medium. L-asparaginase quantification was valued by the formation of ß-aspartyl hydroxamate. The significant positive variables, L-asparagine, L-proline, potato dextrose broth, and sucrose concentrations, were evaluated at 2 levels (+ 1 and - 1) with triplicate of the central point. After 34 runs, maximum activity (2.33 IU/mL) was achieved at the factorial design central point. A central composite design was performed in ATPMS at two levels (+ 1 and - 1) varying Triton X-114 concentration (w/v), separation phase temperature, and crude extract concentration (w/v). The L-asparaginase partition coefficient (K) was considered the experimental design response. Out of the 16 systems that were examined, the most promising presented a purification factor of 1.4 and a yield of 100%.

Effectiveness of essential oil extracted from pompia leaves against Penicillium digitatum.

BACKGROUND: In recent years, interest in the use of natural compounds as possible substitutes for chemicals, to prevent microbial food spoilage has grown. The antimicrobial activity of the essential oils (EOs) is well known and nowadays there is renewed interest in their application as natural preservatives in postharvest management. The aims of this study were to characterize the EO extracted from pompia leaves and to evaluate its effectiveness for the control of the postharvest decay agent Penicillium digitatum, when applied as vapor contact in new airtight boxes, supplied with a heating system. RESULTS: Fumigation was performed in vitro and on food using two concentrations of the EO, heated at controlled temperature. The headspace analysis revealed that the heating of the EO favored the evaporation of the volatile compounds, without altering their functionality. The treatments reduced the pathogen growth in vitro and rot on inoculated food by about 50%. CONCLUSION: The chemical analysis of the vapor composition demonstrated that heating the oil did not alter the components and thus the antimicrobial effect of the oil. The treatment by vapor contact with the EO was effective in controlling the pathogen growth in vitro but, above all, it was successful in halving rot in vivo. Due to their bioactivity in the vapor phase, EOs could be delivered as fumigants during postharvest protection; however, the techniques commonly employed are not ideal for simulating real pre-treatment conditions. The new device allows real large-scale conditions to be reproduced. © 2020 Society of Chemical Industry.

Seasonal changes in indoor airborne fungal concentration in a hematology ward.

Invasive fungal disease (IFD) is an important infectious complication of hematological disorders, especially in hematopoietic stem cell transplantation recipients. Evidences suggest seasonal and/or geographical variations in the airborne fungal counts and a relationship between those counts and the incidence of IFD. We evaluated the concentrations of indoor airborne fungi quantitated over the course of one year in a hematology ward in Japan. In January, April, July, and October, fixed volumes of air samples were obtained by an air sampler in a hematology ward not equipped with a high-efficiency particulate air filter and incubated in fugal cultures. Samples were also obtained from a protective environment in the same ward and were evaluated. The number of fungal colonies per 50 L of sampled air was highest in October (median 2.25 (range, 0.2-7.0)), which was significantly higher than those in the other three months (0.1 (range, 0-1.0) in January; 0 (0-0) in April; 0.55 (0-2.5) in July; P < 0.01)). Commonly identified pathogens included Penicillium and Cladosrporium species, but Aspergillus species was detected only in July and October samples. These results suggest a seasonal variation in indoor airborne fungal concentrations in Japan, which could affect the epidemiology of IFD.

A Case Series and Literature Review of Isavuconazole Use in Pediatric Patients with Hemato-oncologic Diseases and Hematopoietic Stem Cell Transplantation.

We analyzed the use of isavuconazole (ISA) as treatment or prophylaxis for invasive fungal disease (IFD) in children with hemato-oncologic diseases. A multicentric retrospective analysis was performed among centers belonging to the Italian Association for Pediatric Hematology and Oncology (AIEOP). Pharmacokinetic (PK) monitoring was applied by a high-performance liquid chromatography-tandem mass spectrometry (HLPC-MS/MS) assay. Twenty-nine patients were studied: 10 during chemotherapy and 19 after allogeneic hematopoietic stem cell transplantation (HSCT). The patients consisted of 20 males and 9 females with a median age of 14.5 years (age range, 3 to 18 years) and a median body weight of 47 kg (body weight range, 15 to 80 kg). ISA was used as prophylaxis in 5 patients and as treatment in 24 cases (20 after therapeutic failure, 4 as first-line therapy). According to European Organization for Research and Treatment of Cancer (EORTC) criteria, we registered 5 patients with proven IFD, 9 patients with probable IFD, and 10 patients with possible IFD. Patients with a body weight of <30 kg received half the ISA dose; the others received ISA on the adult schedule (a 200-mg loading dose every 8 h on days 1 and 2 and a 200-mg/day maintenance dose); for all but 10 patients, the route of administration switched from the intravenous route to the oral route during treatment. ISA was administered for a median of 75.5 days (range, 6 to 523 days). The overall response rate was 70.8%; 12 patients with IFD achieved complete remission, 5 achieved partial remission, 5 achieved progression, and 3 achieved stable IFD. No breakthrough infections were registered. PK monitoring of 17 patients revealed a median ISA steady-state trough concentration of 4.91 mg/liter (range, 2.15 to 8.54 mg/liter) and a concentration/dose (in kilograms) ratio of 1.13 (range, 0.47 to 3.42). Determination of the 12-h PK profile was performed in 6 cases. The median area under the concentration-time curve from 0 to 12 h was 153.16 mg·h/liter (range, 86.31 to 169.45 mg·h/liter). Common Terminology Criteria for Adverse Events grade 1 to 3 toxicity (increased transaminase and/or creatinine levels) was observed in 6 patients, with no drug-drug interactions being seen in patients receiving immunosuppressants. Isavuconazole may be useful and safe in children with hemato-oncologic diseases, even in the HSCT setting. Prospective studies are warranted.

Development of a Microbial Decontamination System Combining Washing with Highly Activated Calcium Oxide Solution and Antimicrobial Coating for Improvement of Mandarin Storability.

A new microbial decontamination system combining washing with a natural antimicrobial solution and coating with a carnauba wax (CW)-based antimicrobial coating was developed and its effects on mandarin storability were investigated. Mandarins were washed with an antimicrobial solution and/or coated with grapefruit seed extract-CW (GSE/CW). Values for the disease incidence of Penicillium digitatum in untreated mandarins; mandarins coated with GSE/CW without washing; and mandarins coated with GSE/CW after washing with a fumaric acid (FA) solution of slightly acidic electrolyzed water, a highly activated calcium oxide (CaO) aqueous solution, or CaO solution followed by FA solution were 96.0, 70.0, 78.8, 50.0, and 72.2%, respectively. GSE/CW coating after CaO washing was most effective in inhibiting P. digitatum growth during storage at 25 °C. Compared to untreated samples, GSE/CW coating alone or after CaO washing retained CO2 generation, firmness, and total polyphenol content of mandarins at 25 °C. Such treatments also effectively maintained mandarin pH, ascorbic acid concentration, and antioxidant capacity at both 4 and 25 °C. Moreover, GSE/CW coating after CaO washing more effectively inhibited P. digitatum growth at 25 °C and maintained ascorbic acid concentration and antioxidant capacity at 4 and 25 °C than GSE/CW coating alone. The microbial decontamination system integrating CaO washing and GSE/CW coating demonstrates potential for improving mandarin storability by inhibiting P. digitatum growth and improving the preservation of quality properties and sensory characteristics. PRACTICAL APPLICATION: This is the first study to develop a microbial decontamination system involving both washing with a natural antimicrobial solution and carnauba wax coating containing grapefruit seed extract to improve the storability of fruits. This system demonstrated a primary effect of inhibiting fungi that cause mandarin surface decay at 25 °C via the highly activated calcium oxide wash and secondary effects of delaying quality degradation and inhibiting fungal growth by the action of the antimicrobial coating. These effects led to improvements in mandarin storability, along with enhanced visual appeal while not affecting taste, flavor, or texture.

Tyrosine Induced Metabolome Alterations of Penicillium roqueforti and Quantitation of Secondary Key Metabolites in Blue-Mold Cheese.

To map qualitative and quantitative metabolome alterations when Penicillium roqueforti is grown in an environment where l-tyrosine levels are perturbed, the recently established differential off-line LC-NMR (DOLC-NMR) approach was successfully applied in connection with an absolute metabolite quantitation using a quantitative 1H NMR protocol following the ERETIC 2 (Electronic REference To access In vivo Concentrations) methodology. Among the 23 influenced metabolites, amino acid degradation products like 2-(4-hydroxyphenyl)acetic acid and 2-(3,4-dihydroxyphenyl)acetic acid underwent a tremendous upregulation in the amino acid perturbed approach. Moreover, the output of secondary metabolites like andrastin A, eremofortin B, and the tetrapeptide d-Phe-l-Val-d-Val-l-Tyr was affected in the case of the presence or absence of the added aromatic amino acid. Furthermore, the isolated secondary metabolites of P. roqueforti have been quantified for the first time in five divergent Penicillium isolates by means of a validated LC-ECHO-MS/MS method. This technique is used to compensate the effect of co-extracted matrix compounds during the analysis and to utilize quasi-internal standards to quantify all metabolites of interest accurately. This screening outlined the great variety between the different fungi of the same species. The metabolite spectra of wild-type fungi included more toxic intermediates compared to a selected fungi used as a starter culture for blue-mold cheese production. In addition, these secondary metabolites were quantified in commercially available white- and blue-mold cheese samples. The main differences between the analyte profiles of white and blue cheeses were linked to the impact of the used starter culture. Specific metabolites detected from P. roqueforti like andrastin A and B or roquefortine C could not be detected in white cheese. Among the blue cheese samples, different metabolite pattern could be observed regarding various P. roqueforti starter cultures.

Growth/no-growth models of in-vitro growth of Penicillium paneum as a function of thyme essential oil, pH, aw, temperature.

The aims of this study were (i) screening of antifungal activity of thyme essential oil on Penicillium paneum; (ii) development of growth/no-growth models (G/NG); and (iii) validation of the G/NG models by performing bread baking trials. The screening method was based on the measurement of fungal growth in a semi-solid medium through optical density. The combined influence of aw (0.88-0.97), pH (4.8-7.0), temperature (22 and 30 °C), time (0-144 h) and varying concentrations of thyme oil (0-2 µL/mL YES) were assessed. Growth of P. paneum at aw 0.88 was significantly reduced compared to aw 0.93-0.97. A slight pH effect was observed at aw 0.93; growth was delayed at pH 6 compared to pH 4.8. The lowest concentration of thyme oil preventing growth during 144 h of incubation was 1 µL/mL medium. According to the results of the shelf-life test of par-baked bread, fungal growth was inhibited for more than 45 days using 0.3 mL thyme oil/100 g dough. To conclude, this study recognized the potential of using G/NG models to develop better product formulations and to facilitate product innovation.

Acceleration of fungal spore production by embedding a hydrophobic polymer net in a nutrient agar plate.

A simple and novel procedure for the acceleration of fungal spore production was developed. A net of hydrophobic polymer such as polypropylene (PP) and polytetrafluoroethylene (PTFE) was embedded in a nutrient agar plate, and effect of the polymer net on spore production by 6 fungal strains, such as Aspergillus terreus, Penicillium multicolor, and Trichoderma virens were estimated. The effect of hydrophobic polymer net was insufficient in a liquid-surface immobilization (LSI) system with fungal cells immobilized on a ballooned microsphere layer formed on a liquid medium surface. On the other hand, the embedding of a PTFE net in an agar plate remarkably enhanced the spore production in all 6 strains tested to produce 2.0-8.5 × 107 spores/cm2-agar plate surface. Especially, the spore production by A. terreus ATCC 20542 in the presence of a PTFE net was 7.7 times as much than that in no net. Positive correlations between the hydrophobicity of net and the spore production were observed in all 6 strains (R2, 0.653-0.999).

Antioxidant and antimicrobial markers by UPLC®-ESI-Q-TOF-MSE of a new multilayer active packaging based on Arctostaphylos uva-ursi.

49 different non-volatile compounds were determined in Spanish Arctostaphylos uva-ursi leaves using UPLC®-ESI-Q-TOF with MSE technology. Both positive and negative electrospray ionization were applied. MarkerLynx® was proposed as a powerful tool to distinguish samples from eight wild populations of Spain by determining their non-volatile markers. Development of HRMS methods let to analysis of metabolites in plants. Antioxidant and antimicrobial capacities of different extracts were evaluated. Plant extract with the strongest antioxidant and simultaneous good antimicrobial capacity (Lierta) was chosen and incorporated in a multilayer packaging. Then, antioxidant capacity of the new packaging was evaluated and the efficient free radical scavenging properties were demonstrated.

Enhancing laccase production by white-rot fungus Funalia floccosa LPSC 232 in co-culture with Penicillium commune GHAIE86.

To obtain enzymatic preparations with higher laccase activity levels from Funalia floccosa LPSC 232, available for use in several applications, co-cultures with six filamentous microfungi were tested. A laccase non-producing soil fungus, identified as Penicillium commune GHAIE86, showed an outstanding ability to increase laccase activity (3-fold as compared to that for monoculture) when inoculated in 6-day-old F. floccosa cultures. Maximum laccase production with the F. floccosa and P. commune co-culture reached 60 U/mL, or twice that induced by chemical treatments alone. Our study demonstrated that co-culture with soil fungi might be a promising method for improving laccase production in F. floccosa. Although the enhancement of laccase activity was a function of P. commune inoculation time, two laccase isoenzymes produced by F. floccosa remained unchanged when strains were co-cultured. These data are compatible with the potential of F. floccosa in agricultural applications in soil, whose enzyme machinery could be activated by soil fungi such as P. commune.

Essential oils of Tahiti lemon and cinnamon bark in control of storage fungi and the physiological and sanitary quality of beans / Óleos essenciais de limão Taiti e canela em casca no controle de fungos de armazenamento e na qualidade fisiológica e sanitária de feijão

With the objective to evaluate the efficiency of essential oils of Citrus latifolia (Tahiti lemon) and Cinnamomum zeylanicum (cinnamon bark) in the control of plant pathogens Penicillium sp. and Aspergillus sp. and the quality of the bean seeds, two experiments were conducted. In the first one, the effect of essential oils of C. latifolia and C. zeylanicum was evaluated in vitro development of the fungi Penicillium sp. and Aspergillus sp. and, in the second one, the influence of essential oils on the physiological and sanitary quality of bean seeds. The variables mycelial growth, conidial germination and sporulation of Penicillium sp. and Aspergillus sp. were measured in the first experiment, while the seed germination test, first count of germination, germination speed index (GSI) and sanity test of bean seeds were measured in the second. The essential oil (EO) of C. zeylanicum was more efficient than C. latifolia in the control of Aspergillus sp. and Penicillium sp., but decreased the physiological quality of the beans seeds. The fungal diversity identified in the seed health test was composed by fungi of the genera Aspergillus, Penicillium, Cladosporium, Fusarium, Chaetomium and Rhizopus. The results indicate the potential of the use of these EOs in the seeds treatment.(AU)

Com o objetivo de avaliar a eficiência dos óleos essenciais de Citrus latifolia (limão taiti) e Cinnamomum zeylanicum (canela em casca) no controle dos fitopatógenos Penicillium sp. e Aspergillus sp. e na qualidade das sementes de feijão, foram conduzidos dois experimentos. No primeiro, avaliou-se o efeito dos óleos essenciais de C. latifolia e C. zeylanicum no desenvolvimento in vitro dos fungos Penicillium sp. e Aspergillus sp. e, no segundo, a influência dos óleos essenciais sobre a qualidade fisiológica e sanitária das sementes de feijão. As variáveis crescimento micelial, germinação de conídios e esporulação de Penicillium sp. e Aspergillus sp. foram aferidas no primeiro experimento, enquanto o teste de germinação de sementes, primeira contagem de germinação, índice de velocidade de germinação (IVG) e teste de sanidade de sementes de feijão foram aferidas no segundo. O óleo essencial (OE) de C. zeylanicum foi mais eficiente que C. latifolia no controle dos fungos Aspergillus sp. e Penicillium sp., mas diminuiu a qualidade fisiológica das sementes de feijão. A diversidade fúngica identificada no teste de sanidade de sementes foi composta por fungos dos gêneros Aspergillus, Penicillium, Cladosporium, Fusarium, Chaetomium e Rhizopus. Os resultados indicam o potencial do uso desses óleos essenciais no tratamento de sementes.(AU)

The effect of Zataria multiflora Boiss Essential oil on the growth and citrinin production of Penicillium citrinum in culture media and cheese.

The effect of Zataria multiflora Boiss Essential oil (EO) on the growth, spore production, and citrinin production of Penicellium citrinum PTCC 5304 in the culture media as well as Iranian ultra-filtered white cheese in brine was investigated. Radial growth and spore production on the potato dextrose agar (PDA) were effectively inhibited by EO in a dose-dependent manner. At 200 ppm, the radial growth and sporulation declined by 92% and 100%, respectively. The growth was completely prevented at 400 ppm of EO on PDA and the minimum fungicidal concentration (MFC) of the oil was estimated at 400 ppm. Furthermore, the Zataria multiflora also significantly suppressed the mycelial growth and citrinin production in broth medium at all investigated concentrations (P < 0.05). At 150 ppm of EO, the citrinin accumulation and mycelial growth reduced by 88.6% and 89.6%, respectively. The EO was tested at all concentrations and the findings show an inhibitory effect of P. citrinum against the radial fungal growth and citrinin production in cheese. However, no concentration of EO could completely inhibit the growth and production of citrinin in cheese. We therefore concluded that Zataria multiflora has the potential to substitute the antifungal chemicals as a natural inhibitor to control the growth of molds in foods such as cheese.

Antifungal activity of Gallesia integrifolia fruit essential oil.

Gallesia integrifolia (Phytolaccaceae) is native to Brazil and has a strong alliaceous odor. The objective of this study was to identify the chemical composition of G. integrifolia fruit essential oil and evaluate fungicidal activity against the main food-borne diseases and food spoilage fungi. The essential oil was extracted by hydrodistillation and identified by GC-MS. From 35 identified compounds, 68% belonged to the organosulfur class. The major compounds were dimethyl trisulfide (15.49%), 2,8-dithianonane (52.63%) and lenthionine (14.69%). The utilized fungi were Aspergillus fumigatus, Aspergillus niger, Aspergillus ochraceus, Aspergillus versicolor, Penicillium funiculosum, Penicillium ochrochloron, Penicillium verrucosum var. cyclopium, and Trichoderma viride. Minimal fungicidal concentration for the essential oil varied from 0.02 to 0.18mg/mL and bifonazole and ketoconazole controls ranged from 0.20 to 3.50mg/mL. The lower concentration of the essential oil was able to control P. ochrochloron, A. fumigatus, A. versicolor, A. ochraceus and T. viride. This study shows a high fungicidal activity of G. integrifolia fruit essential oil and can support future applications by reducing the use of synthetic fungicides.