Czapek-Dox Medium Research Articles

Three new species of Talaromyces sect. Talaromyces discovered in China.

Talaromyces species play an important role in the nutrient cycle in natural ecosystems, degradation of vegetal biomass in industries and the implications in medicine. However, the species diversity of this genus is still far from fully understood. The polyphasic taxonomic approach integrating morphological comparisons and molecular phylogenetic analyses based on BenA, CaM, Rpb2 and ITS sequences was used to propose three new Talaromyces species. Three new species of sect. Talaromyces isolated from soil are proposed, namely, T. disparis (ex-type AS3.26221), T. funiformis (ex-type AS3.26220) and T. jianfengicus (ex-type AS3.26253). T. disparis is unique in low growth rate, velvety texture, limited to moderate sporulation, biverticillate, monoverticillate and irregular penicilli bearing a portion of abnormally large globose conidia, it has no close relatives in phylogeny. Being a member of T. pinophilus complex, T. funiformis produces mycelial funicles on Czapek yeast autolysate agar (CYA), 5% malt extract agar (MEA) and yeast extract (YES), sparse sporulation on Czapek agar (Cz), CYA, MEA and YES while abundant on oatmeal agar (OA), bearing appressed biverticillate penicilli and globose to pyriform conida with smooth to finely rough walls. T. jianfengicus belongs to T. verruculosus complex, is characterized by velvety colony texture with moderate to abundant elm-green conidia en masse, producing biverticillate penicilli, globose conidia with verrucose walls. It is now a common practice in establishing new species of Aspergillus, Penicillium and Talaromyces based on morphological characters and phylogenetic analyses of BenA, CaM, Rpb2 and ITS sequences. The proposal of the three novelties of Talaromyces in this article is not only supported by their morphological distinctiveness, but also confirmed by the phylogenetic analyses of the concatenated BenA-CaM-Rpb2 and BenA-CaM-ITS, as well as the individual BenA, CaM, Rpb2 and ITS sequence matrices.

First Report of Rhizopus arrhizusi causing rot of Dictyophora rubrovolvata in China.

Dictyophora rubrovolvata, as an edible fungus with high medicinal value, is widely cultivated in several provinces in China (Hang et al. 2012). However, between December 2023 and March 2024, a rot disease occurred in the main production area in Fengxian District, Shanghai, China (N30°93', E121°49'). The disease incidence was 25% in the affected 1.33-ha growing area. High temperatures (>25℃) and poor ventilation provide favorable conditions for the spread of this disease. The disease mainly occurs at the stage of fruiting bodies formation of D. rubrovolvata. When the epidermis is damaged and broken, it becomes infested with mold, which then produces a layer of moldy rot with pus. The infected D. rubrovolvata tissues at the edge of the lesions were isolated, surface sterilized and cultured on potato dextrose agar (PDA) at 30 ℃ under dark conditions. Pure cultures were obtained by single-spore isolation. After 3 days, isolates were transferred to Czapek Yeast agar (CYA) (Samson et al, 2014). On CYA, the fungal colony consisted of white flocculent hyphae. Scanning electron microscopy analysis showed that the mycelium was white, and the internodes of the stolons formed characteristic pseudoroots, from which upwardly clustered erect, unbranched sporocarp peduncles expanded apically to form rounded sporocarp sacs, within which sporocarp spores were produced. (Hariprasath P, 2019). To confirm the identity of the pathogen, the genomic fragments for the internal transcribed spacer (ITS) and intergenic spacer (IGS) gene of the isolate were amplified by PCR (White et al. 1990; Liu XY. 2008). The resulting sequence was deposited in GenBank with accession PP951880 and PQ001670, respectively. PCR results and morphological observations indicated the isolated strain was a pure culture and the strain was designated as DIC01. Comparative results showed that the sequences with accession numbers MT603964.1 and DQ990323.1 showed high homology of 99.15% and 98.96% to the ITS and IGS sequences of Rhizopus arrhizusi DIC01, respectively. Phylogenetic analysis with ITS and IGS genes of the isolated strain and 7 Rhizopus spp. strains were performed using MEGAX with Neighbor-Joining (NJ) method. Based on the results of growth habits, morphological observations, and phylogenetic analysis, the pathogen was identified as R. arrhizusi. A spore suspension of the R. arrhizusi DIC01 (1 x107 conidia/mL) was inoculated back to healthy D. rubrovolvata. Five healthy fruit bodies of D. rubrovolvata were injected, and another five healthy morels were treated with potato dextrose broth (PDB) as controls. D. rubrovolvata was incubated at 25°C and 90% relative humidity without ventilation for 5 days. The pathogen successfully infected the D. rubrovolvata, which developed white moldy lesions similar to those of natural diseases. The controls remained healthy without any symptoms. The pathogen was reisolated from the affected lesions and identified as R. arrhizusi DIC01 based on its morphological characteristics and phylogenetic marker genes. R. arrhizusi has been reported to cause endothelial cell damage and mycelial invasion into blood vessels, leading to thrombosis and tissue necrosis. (Hariprasath P, 2019). To our knowledge, this is the first report of R. arrhizusi causing rot disease of D. rubrovolvata. This study confirmed that R. arrhizusi is the pathogenic fungus responsible for rotting disease in D. rubrovolvata farms in Fengxian, Shanghai.

Chemical profiling of fungal metabolites via the OSMAC approach: Novel identification of Brianthein W from an endophytic fungus, Hypomontagnella monticulosa Zg15SU

In the previous report, we reported that Hypomontagnella monticulosa originating from the rhizome of Zingiber griffithii was known to produce a marine-derived natural product. An OSMAC-based approach was designed by modifying the nutritional composition of the growth medium to investigate any possible new metabolites produced by the strain. The culture filtrate and biomass were conditioned through the use of three basal media, namely, Czapek-dox, potato dextrose, and Wickersham broth medium. GC-MS and multivariate analysis was performed to distinguish the chemicals and determine their composition in the tested extracts. Antimicrobial activity was tested against selected human pathogenic microbes using the disk-diffusion method. The MeOH extract of both culture filtrate and biomass from different fermentation media revealed that the majority of identified compounds (n=40) were found in Wickerham medium (n=23), which is later termed as MeOH-Wi. The chemical composition of MeOH-Wi was fatty acids (21.74%), followed by terpenoids (17.38%), cyclosiloxane (13.04%), aldehydes (13.04%), alkenes (8.7%), hydrocarbons (8.7%), esters (8.7%), alkaloids (4.35%), and an unclassified compound, the 9,9-Dimethyl-3,7-diazabicyclo[3.3.1]nonane. The numerous chemical compounds in MeOH-Wi corresponded with its antimicrobial activities against Micrococcus luteus NBRC 13867 (±11 mm), Candida maltosa NBRC 1977 (±9 mm), and Escherichia coli JM 109 (±5 mm) which were higher than the other tested extracts. Further purification using HPLC RP-C18 using NP-SiO2/n-Hex–EtOAc (10:2) to yield compound (1). Compound (1) was determined as an analog of briarian W—a diterpene mostly found in marine sponge, Briareum spp.—as a pure compound in the MeOH extract of H. monticulosa based on the 1D and 2D NMR analysis. The anticancer activity (IC50) of compound (1) was 0.077, 0.080, and 0.102 µg/mL against the growth of HCT-116, NBT-T2, and Panc-1, respectively. As far as we are aware, this is the first report on finding a briarian diterpene that originates from an endophytic fungus, especially by H. monticulosa.

Response of Arugula to Integrated Use of Biological, Inorganic, and Organic Fertilization.

This study evaluated the effects of solely and integrated application of inorganic (NPK), commercial organic (NC), and biological (MIX, mixed strains Ensifer meliloti and Azotobacter chroococcum) fertilizers on the chemical characteristics of arugula biomass and its yield, as well as changes in soil microbiological parameters after the experiment in relation to the control treatment (Ø). The experiment was performed in semi-controlled greenhouse conditions, in pots, from the 4th decade of March to the 2nd decade of September, in 2023, at three cutting times/swaths, during one agricultural season, with Vertisol soil. For soil characterization, the following parameters were analysed: granulometric composition using sieving and sedimentation procedure; soil acidity-potentiometrically; SOM-soil organic matter by Kotzmann method; total N using CNS analyser; available P-spectrophotometrically; available K-flame photometrically; total number of microorganisms on an agarized soil extract medium; fungi on a solid Czapek agar; actinomycetes on a solid Krasiljnikov agar with saccharose; Azotobacter spp. on a liquid Fyodorov medium with mannitol; ammonifiers on a liquid medium with asparagine; and dehydrogenase activity-spectrophotometrically. For plant characterization, the following parameters were determined: N and C, both on CNS analyser; P on spectrophotometer; K on flame photometer; air-dried yield biomass. A stimulative effect on all microbiological parameters was found in the treatment with integrated use of organic and biological fertilizer, except for fungi, which grew better in the treatments with separate inorganic and organic fertilizers. Generally, the stimulative impact on plant chemical parameters manifested in combined inorganic and biological, organic and biological, and inorganic and organic fertilization treatments, and was inhibited in treatment without fertilization, in all three swaths, which could also be stated for the plant yield. Positive influence of all fertilization treatments on chemical parameters was observed for the second swath in relation to the first and the third. The total yield in the NPK+MIX treatment was 121%, and in the NC+MIX treatment, it was 87% higher compared to the control (Ø). In general, integrated use of inorganic and biological, organic and biological, and inorganic and organic fertilizers, respectively, could be proposed as an optimal fertilization treatment in arugula cultivation.

Optimizing conditions of mycelial inoculum immobilized in Ca-alginate beads: a case study in ectomycorrhizal fungus Astraeus odoratus.

Ectomycorrhizal inoculum has emerged as a critical tool for forest restoration, especially under challenging climate change conditions. The inoculation of selective ectomycorrhizal fungi can enhance seedling survival and subsequent growth in the field. This study optimized the liquid media for mycelial growth of Astraeus odoratus strain K1 and the sodium alginate solution composition for enhanced mycelial viability after entrapment. Using Modified Melin-Norkrans as the optimal media for mycelial cultivation and 2% sodium alginate supplemented with Czapek medium, 0.25% activated charcoal, 5% sucrose, and 5% sorbitol in the alginate solution yielded the highest viability of A. odoratus mycelia. Preservation in distilled water and 10% glycerol at 25°C for 60 days proved to be the most effective storage condition for the alginate beads. Both fresh and preserved alginate beads were tested for colonizing on Hopea odorata Roxb. seedlings, showing successful colonization and ectomycorrhizal root formation, with over 49% colonization. This study fills a crucial gap in biotechnology and ectomycorrhizal inoculum, paving the way for more effective and sustainable forest restoration practices.

Antagonism and mycoparasitism mechanism of T. harzianum against pathogenic fungus species of F. oxysporum and Capnodium sp.

The purpose of this study was to test the ability of T. harzianum to inhibit the growth of pathogenic mold species and to determine the effectiveness of T. harzianum mold species in inhibiting the growth of pathogenic molds, as well as investigate how T. harzianum and pathogenic molds interact with each other. The Microbiology Laboratory of the Department of Biology, Faculty of Mathematics and Natural Sciences, State University of Malang, is where this research was conducted. The dual culture method was used for this test by using Czapek Agar (CA) medium. The isolated molds were then incubated for 4x24 hours at 25O–27OC. After that, the antagonism power was calculated. The results of macroscopic and microscopic observations were used to assess the mechanism of T. harzianum mold antagonism against pathogenic molds. The results showed that Trichoderma mold species were more resistant to the pathogenic mold Fusarium oxysporum than the pathogenic mold Capnodium. The antagonistic power of T. harzianum was 80%, with the antagonistic power of Capnodium sp. at 66.7%. The mechanism of mycoparasitism occurs when the hyphae of T. harzianum attach or entangle the hyphae of pathogenic molds, causing damage to the hyphal structure and inhibiting the growth of pathogenic molds.

Utilization of Agricultural Waste for the Cultivation of Pleurotus Mushrooms in Thailand

Thailand is one of the major agricultural production countries in the world. Therefore, large amounts of agricultural waste are generated as by-products of the agroindustry. The wastes are usually discarded or burnt, resulting in environmental pollution. The main goal of this research was to evaluate the use of agricultural waste for mushroom cultivation. A total of 15 mushroom isolates were recovered from mother spawns and basidiocarps. They were screened for their cellulolytic enzyme activity on Czapek agar using carboxymethyl cellulose (CMC) as the sole carbon source. Two isolates of the oyster mushrooms, Pleurotus pulmonarius PP6 and Pleurotus ostreatus PO3, produced the best enzyme activities. To observe the mycelial growth on agricultural waste, the two oyster mushroom candidates were cultured in jars containing five different types of agricultural waste: corn husk, rice straw, coconut meal, coconut husk and sugarcane bagasse, and the jars were incubated at 25°C for six weeks. The results show that both isolates grew best on coconut meal, producing very densely packed mycelia. Meanwhile, corn husk and rice straw were also good sources for oyster mushroom cultivation. This study shows that these three substrates have the potential to be utilized in mushroom cultivation on a commercial scale.

Improving dietary citric acid production by the wild-type Aspergillus niger ASP26 strain isolated from date by-product.

This research investigates citric acid (CA) synthesis using the indigenous strain Aspergillus niger ASP26, which was isolated from date by-products. The study initially involved isolating fungi capable of CA production and identifying the most potent strain based on its characteristic enzymatic activity. A. niger ASP26 was acknowledged in a previous study for its remarkable ability to produce extracellular enzymes, such as cellulase and amylase, which enable it to degrade organic materials effectively. After the identification phase, these isolates were screened for CA production using a modified Czapek-Dox medium. The research identified significant factors affecting CA production in submerged fermentation, including pH, carbon source, inoculum size, and fermentation time. Optimal conditions were determined for A. niger ASP26, resulting in a maximum CA yield of 16.89 g/L. These conditions included a 2.5% spore suspension at 2 × 107 spores/mL, an initial glucose concentration of 125 g/L, and incubation at 30°C for 144 h. Notably, A. niger ASP26 demonstrated the ability to produce CA under stress conditions as well. Citric acid is essential for various biological processes, such as cellular respiration, and is naturally present in citrus fruits. It also serves as a preservative and flavor enhancer in processed foods and beverages. The ability of A. niger ASP26 to produce CA from agricultural residues positions it as a viable candidate for sustainable CA production, harnessing the value from organic waste materials.

Copper ion sorption ability of Alternaria alternata (Fr.) Keissl. and Fusarium oxysporum Schltdl. micromycetes

Our analysis of metabolic and ecological features of fungi indicates a high bioremediation potential of fungal mycelium. The relevance of the problems solved in this work is conditioned by insufficiently studied mechanisms and conditions of micromycetal activity on heavy metal detoxication. The effect of copper on the development of two micromycete species, namely, melanised Alternaria alternata (Fr.) Keissl., 1912 and hyaline Fusarium oxysporum Schltdl., 1824 cultivated on Czapek agar (with 2 or 3% sucrose) was compared; the ability of mycelium to sorb copper cations when grown in a liquid culture with 0, 0.05, 0.1, 0.25, and 0.5 mg Cu2+ / L was evaluated. F. oxysporum had noticeable advantages in terms of growth rate, tolerance, conidia production on medium with Cu2+. The effective concentration of copper (EC50), indicating the resistance of the fungus, increased for F. oxysporum by 1.5 times with increasing sucrose content in the medium. The melanised culture of A. alternata was superior to F. oxysporum in terms of sorption capacity. The percentage of Cu2+ extraction by fungal mycelium from the medium reached 40% in the case of F. oxysporum and twice as much in the case of A. alternata . The vast majority of copper was sorbed by the cell walls of hyphae and washed away by water. A small amount (a maximum of 0.16 µg Cu2+ /g dry mycelium of A. alternate ) penetrated inside the mycelial cells. F. oxysporum, which had no intracellular protective melanins, accumulated Cu2+ (2 to 14 times) less. The results show that the mechanisms of resistance to Cu2+ and sorption are different in the studied species: in Fusarium they are determined mainly by the barrier functions of hyphae cell walls, while in Alternaria melanin plays a significant role in protection against Cu toxic action.

Obtaining Edible Pullulan-based Films with Antimicrobial Properties

A nutrient medium was selected for the efficient production of exopolysaccharide (EPS) by A. pullulans C7 strain. The production of pullulan polysaccharide was evaluated on nutrient media with traditional carbon sources and cheap substrates that were plant wastes. For maximum EPS accumulation, we proposed an optimized Czapek-Dox medium with glucose as a carbon source, sodium nitrate as a nitrogen source, and C/N=232:1 ratio (EPS yield 12.79±0.64 g/l). Medium with grape pomace 5% (EPS yield was 15.08±0.34 g/l) and medium with topinambour tuber hydrolysate 5% (EPS yield was 14.44±0.21 g/l) was proposed as a cheap substrate. Edible films with antimicrobial activity were obtained on the basis of the isolated polysaccharide. The antibacterial activity of films against Escherichia coli 603 and Staphylococcus aureus ST228 was shown when essential oils of rosemary (zones of growth inhibition from 8.41±0.71 to 9.98±0.32 mm) and oregano (zones of growth inhibition from 8.09±0.51 to 9.54±0.24 mm) were added to pullulan. The addition of xanthan gum and glycerol to the films increased their strength and elasticity. The infrared spectrum of the pullulan film showed absorption bands characteristic of polysaccharide structures.

Some biological properties of the Kuidusun depression soils of Oymyakon

The aim of the study. To investigate some microbiological properties of the catenal series of soils in the Kuidusun depression of the Oymyakon Highlands. Location and time of the study. The study area is located in the vicinity of the Tomtor village (N63°15'41.94''; E143°10'26.91'') of the Oymyakonsky district of the Republic of Sakha (Yakutia, Russia). Soil samples were collected in the fall of 2011 at the main positions of the catena. The length of the catena is 38 km, the altitude a.s.l. is 727–821m. Soils are classified as Cambic Cryosols (fragic, мurshic), (forest); Skeletic Cryosols (aridic), (steppe meadow), Cambic Cryosols (fluvic), (typical meadow); Folic Cryosols (swampy meadow). Methods. The content of labile soil organic matter (LOC) was determined photocalorimetrically in soil extracts with phosphate buffer (1/15 M, pH 6,8). The number of colony-forming units (CFU) was determined using standard MPA, KAA, and Czapek media. The functional spectrum of the soil microbiota was assessed using the community level physiological profile (CLPP) method. All properties were studied in 10 cm thick layers to a depth of 40 cm. Soil urease activity was assessed by ammonium production from urea. Results. At the time of sampling moisture content of soil samples down the catena increased from 5 to 20%, whereas the LOC content increased from 2 to 6 g C /kg. In the 0–10 cm layer, the greatest accumulation of LOC was observed in the soil under a typical meadow. The highest number of CFU (150 million/g soil) in a dilute MPA medium was also found there. An increase in the proportion of CFU in the dormant state was revealed in the soil series from the lower position of the catena to the upper one. In the same series, an increase in the oligotrophic index of the community was noted. The highest metabolic activity was observed in the soil under a swampy meadow, whereas the lowest was shown by the soil under a forest. The enrichment of soil organic matter with microbiota cells increased in the series of soils f in the following order: a swampy meadow – a typical meadow – a steppe meadow, whereas the specific activity of the microbiota decreased. Urease activity of the soil was detected mainly in the 0–10 cm layer; in the underlying layers the activity was more than 500 times lower. Conclusions. The biological properties of the studied soils corresponded to the known patterns established for the catenal series of soils in other soil and climatic conditions. The peculiarity of the studied soils was related to the extremely sharp differentiation of the microbiological profile. The absolute predominance of actinomycetes CFU in the soil under the steppe meadow was the major characteristic feature of the culturable part of the soil microbial community.

Comparative Analysis of Secondary Metabolites Produced by Ascochyta fabae under In Vitro Conditions and Their Phytotoxicity on the Primary Host, Vicia faba, and Related Legume Crops.

Ascochyta blight, caused by Ascochyta fabae, poses a significant threat to faba bean and other legumes worldwide. Necrotic lesions on stems, leaves, and pods characterize the disease. Given the economic impact of this pathogen and the potential involvement of secondary metabolites in symptom development, a study was conducted to investigate the fungus's ability to produce bioactive metabolites that might contribute to its pathogenicity. For this investigation, the fungus was cultured in three substrates (Czapek-Dox, PDB, and rice). The produced metabolites were analyzed by NMR and LC-HRMS methods, resulting in the dereplication of seven metabolites, which varied with the cultural substrates. Ascochlorin, ascofuranol, and (R)-mevalonolactone were isolated from the Czapek-Dox extract; ascosalipyrone, benzoic acid, and tyrosol from the PDB extract; and ascosalitoxin and ascosalipyrone from the rice extract. The phytotoxicity of the pure metabolites was assessed at different concentrations on their primary hosts and related legumes. The fungal exudates displayed varying degrees of phytotoxicity, with the Czapek-Dox medium's exudate exhibiting the highest activity across almost all legumes tested. The species belonging to the genus Vicia spp. were the most susceptible, with faba bean being susceptible to all metabolites, at least at the highest concentration tested, as expected. In particular, ascosalitoxin and benzoic acid were the most phytotoxic in the tested condition and, as a consequence, expected to play an important role on necrosis's appearance.

Cultural, Morphological and Molecular Characterization of Ustilaginoidea virens Causing Rice False Smut in Tamil Nadu, India

Rice false smut, caused by the fungus Ustilaginoidea virens is one of the most destructive and re-emerging disease in many rice growing areas of Tamil Nadu, India. The current study was carried out to characterize different isolates of Ustilaginoidea virens collected from major rice growing areas in Tamil Nadu, India. The pathogen was isolated by different isolation methods, out of which inner spore dust was effective. The colony was milky white to yellowish white, fluffy, leathery and compact. The colony diameter ranged between 35.33 mm and 65.33mm. The mycelium was hyaline, septate and width of the hyphae ranged between 1.84 and 3.10 µm. The size of the conidia was also varied among the isolates and the maximum size (6.35 µm) was observed in FS 6 isolate and minimum in FS 2 (4.10 µm). The growth of fungus in different media was examined. The maximum colony diameter was observed in Potato Sucrose Agar (PSA) medium and minimum growth in Czapek Agar (CA) medium. The molecular confirmation was done through U. virens-specific internal transcribed spacer (ITS) region amplification using the primers, US 1-5/US3-3. The primers amplified a product of 380 bp which are specific for the fungus U. virens. The identity of the fungus was further confirmed through ITS sequencing which showed 98-99% sequence homology. The dendrogram showed two main clusters; cluster I comprised of five isolates (FS1, FS2, FS9, FS10 and FS3), while Cluster II consisted of five isolates (FS4, FS8, FS6, FS5 and FS7).

Two new species of Trichocomaceae (Eurotiales), accommodated in Rasamsonia and Talaromyces section Bacillispori, from the Czech Republic

During a previous study on microfungi associated with clematis roots, Penicillium-like fungi were isolated and identified based on morphology. In this study, we subjected those strains to a detailed examination which led to the proposal of two taxonomic novelties, named Rasamsonia chlamydospora and Talaromyces clematidis. The first taxon is characterized by rough-walled mycelium, acerose to flask shaped phialides, cylindrical conidia and by production of chlamydospore-like structures. The four-loci-based phylogeny analysis delineated the taxon as a taxonomic novelty in Rasamsonia. Talaromyces clematidis is characterized by restricted growth on Czapek yeast extract agar, dichloran 18% glycerol agar and yeast extract sucrose agar, and production of yellow ascomata on oatmeal agar. Phylogenetic analyses placed this taxon as a taxonomic novelty in Talaromyces sect. Bacillispori. Both taxa are introduced here with detailed descriptions, photoplates and information on their phylogenetic relationship with related species.

Antioxidant potential of L-asparaginase and L-glutaminase excreted by Monascus sp.

The L-asparaginases and L-glutaminases can be excreted by various organisms such as bacteria and fungi, but also by animal and plant tissues. Studies indicate that these enzymes can be used in the food industry to improve the flavor of foods and in pharmaceuticals as an ally in the treatment of some types of cancer. This article aimed to select a fungal strain that produces these amidohydrolases, investigate the potential production of said enzyme by submerged fermentation and whether the partially purified enzyme has biological activities. Initially, 19 fungal strains were selected by Submerged Fermentation in modified Czapek's Dox medium. The best extracellular enzyme producer, Monascus sp., was tested in Solid State Fermentation and Supplemented Submerged Fermentation, and enzymes extracted both extracellularly and intracellularly. The best yield of Monascus sp. was in Submerged Fermentation supplemented with glutamine (1% v/v), glucose (1% v/v) and meat extract (1% v/v), at pH 7.0 at 30 °C for 72h. Partial purification of the crude extract by ion exchange chromatography (DEAE SP) resulted in 19 fractions that were evaluated for their ability to hydrolyze glutamine and asparagine as substrate. The determination of the antioxidant activity was carried out, which presented an IC50 of 11.83 mg/mL by the DPPH method and 2.87 mg/mL by the ABTS method. In that study it was observed that Monascus sp. was able to excrete these amidohydrolases with affinities to hydrolyze glutamine and asparagine. Despite presenting good antioxidant activity, more studies must be carried out to determine its biotechnological potential.

Passive fungal spore release from fruit and vegetable solid waste

Food substrates in municipal solid wastes processing facilities and open dumpsites are a source for the release of fungal spores into air and can cause potential health and climate effects. Experiments were conducted in a laboratory scale flux chamber to measure the fungal growth and spore release from representative exposed cut fruit and vegetable substrates. The aerosolised spores were measured using an optical particle sizer. The results were compared to experiments conducted previously with a test species (Penicillium chrysogenum) on a synthetic media (czapek yeast extract agar). Significantly higher surface spore densities were observed for the fungi on the food substrates as compared to that on the synthetic media. The spore flux was high initially and then decreased on continued exposure to air. The spore emission flux normalised to the surface spore densities indicated that the emission from the food substrates was lower than the emissions from the synthetic media. A mathematical model was applied to the experimental data and the observed flux trends were explained in terms of the model parameters. A simple application of the data and the model to release from a municipal solid waste dumpsite was shown.

Antifungal synergic activity of essential olive oil and alcoholic turmeric extracts against isolates from the dried grapes raisins

Fungi are responsible for a wide variety of harm to humans, including food spoilage and infections. Using chemicals to restrict fungal development or infections has negative repercussions, such as human health dangers from the chemical applications and rising antifungal-drug resistance, so this study aimed to use medicinal plants and their extracts as an alternative method to restrict fungal growth. Ten isolates of the genus Aspergillus were identified from the fruits of dried grapes (raisins) of all kinds (Iraqi black raisins, Iranian yellow raisins, and brown raisins) at the species level using three – differential media: Czapek Yeast Extract Agar( CYA), Malt Extract Agar( MEA), and 25% Glycerol nitrate agar (G25N) incubated in 5, 25 and 37 ºC. Aspergillus niger was the most common isolated species. The number of A. niger isolates reached seven from all types of dried grapes, while A. flavus recorded three isolates from black raisins and brown raisins. Aspergillus Flavus Parasiticus Agar (AFPA) was used to detect the ability of A. flavus isolates to produce aflatoxin at 25-30 ºC for one week. Alcoholic extract of turmeric showed a significant inhibitory effect on the colony diameter of both A. flavus and A. niger isolated from the fruit of Iraqi black raisins with an inhibition rate of 86.6% and 68.8 %, respectively, at 4 mg/ ml concentration. The mixture of turmeric and essential olive oil gave a distinct inhibitory effect, reaching a 100% inhibition rate from the lowest to highest concentration for both A. niger and A. flavus .

Production profile and comparison analysis of main toxin components of Fusarium oxysporum f. sp. sesami isolates with different pathogenicity levels

Fusarium wilt is a common fungal disease in sesame caused by Fusarium oxysporum f. sp. sesami (FOS). To determine the toxin production profiles of the FOS isolates with different pathogenicity levels under various culture conditions, we assessed the content variation of fusaric acid (FA) and 9, 10-dehydrofusaric acid (9, 10-DFA) produced by the four representative FOS isolates. Results indicated that the concentration of FA reached to a maximum of 2848.66 ​μg/mL in Czapek medium, while 9, 10-DFA was mainly produced in Richard and Low-carbon Richard medium. The concentration of 9, 10-DFA on Richard culture medium varied from 0 ​μg/mL to 716.89 ​μg/mL. Of the five culture media used in this study, Czapek culture medium was the most conductive to produce FA. FA production was significantly affected by culture medium, culture time, and their interactions. Results suggest that there is no correlation between toxin production and pathogenicity level of FOS isolates. These findings provide key information for the mechanism analysis of FOS- sesame interaction and pathogen control.

The quantity of OA and activity of cellulase and polygalacturonase are involved in variation of virulence in Sclerotium rolfsii

In order to understand the pathogenic mechanisms of Sclerotium rolfsii on peanut and to analyze the variation of virulence in S. rolfsii strains, the highly virulent strain (ZY2) and weakly virulent strain (GP3-1) were investigated under both in vivo and in vitro conditions. The results indicated that S. rolfsii directly infected peanut by producing infection cushions. ZY2 formed infection cushions earlier than GP3-1, and ZY2 produced a greater number of infection cushions compare to GP3-1. Both strains could utilize cellulose, xylose, or polygalacturonic acid in the Czapek medium. The activities of cellulase (CL) and polygalacturonase (PG) in the inoculated peanut stems increased significantly at 9 ​h after inoculation. The activities of CL and PG produced by ZY2 in the inoculated stems were significantly higher than that produced by GP3-1. Both strains could produce oxalic acid (OA), and the content of OA produced by ZY2 in the inoculated stems was higher than that produced by GP3-1. In summary, it suggested that S. rolfsii destroyed peanut cells through physical and biochemical factors by secreting a large amount of OA, CL and PG during the formation of infection cushions. The difference in OA content, activity of CL and PG produced by highly and weakly virulent strains played important roles in variation of virulence.

Tolerance of microorganisms to residual herbicides found in eucalyptus plantations

Competition with weeds is one of the main factors that limit the development of forest species. Some herbicides used to control these plants have a residual effect on the soil. Bioremediation is an alternative to decontaminate these areas. The aim of this study was to evaluate the tolerance of Aspergillus niger, Penicillium pinophilum and Trichoderma sp. and its degrading potential on residual effect herbicides. The tolerance of Bacillus subtilis, Pseudomonas sp. and Azospirillum brasilense to herbicides was also evaluated. The herbicides used in this study were indaziflam, sulfentrazone, sulfentrazone + diuron, clomazone and glyphosate + s-metolachlor. The analysis of the tolerance and degradation potential of fungi was carried out in Czapek Dox medium and the growth was evaluated by determining the biomass. Bacterial tolerance analysis was performed in Luria Bertani medium and growth monitored by optical density. The data were applied to the Gompertz model to evaluate the behavior of bacteria. Bacterial growth parameters were not influenced by the presence of herbicides. All fungi were tolerant to the herbicides tested and there was an increase in the growth of Trichoderma sp. Thus, the analysis of the degrading potential was performed only for Trichoderma sp. in the presence of herbicides that potentiated its growth. In this analysis, there was no effect of herbicides on fungal growth; the fungus was unable to use the carbon present in the herbicide to enhance its growth; and there was no significant effect of nitrogen in the presence of the herbicide. It is concluded, therefore, that the tested residual herbicides do not interfere with the development of the evaluated microorganisms.