Fruit Bodies Of Agaricus Bisporus Research Articles

Evaluation the pathogenicity and control of Penicillium citrinum isolates affecting the white fungus Agaricus bisporus

Five isolates of Penicillium citrinumwere isolated from casing soils, copmpost and fruiting bodies of Agaricusbisporus from several culture stations in Iraq. According to the pathogenicity test, the highest percentage of inhibition was recorded for isolate P.citrinum(B1). The causal agent was molecularly diagnosed to the level of P. citrinumaccording to the nucleotide sequence analysis of the ITS genome region and it was recorded globally on the NCBI data base under the accission number ON738710.1.The effect of the hot aqueous extract of cloves and conocarpus, and the efficacy of the biocide VEROX on the production and phenotypic characteristics of the white edable fungus Agaricusbisporus was studied with the presence of the pathogenic fungus. The results showed that the treatment of the combination of plant extracts + biocide + pathogenic fungus led to the highest rate of growth inhibition of the pathogenic fungus, increasing number of fruiting bodies up to 435 compared to the control treatment of pathogenic fungus 140. The total yield of the same treatment was 16.398 kg compared to 3.343 kg in the control treatment, and the biological efficiency was recorded by 37.2% compared to 10.2% in the control treatment. In general, this combination led to an increase in production and an improvement in the qualitative characteristics of the fruiting bodies, as the average diameter of the cap was 40.6 mm and the stalk length was 37.3 mm compared to 27.8 mm and 23.5 mm in the control treatment, respectively.

Evaluation of The Efficiency of Some Desert Plant Extracts in The Growth of Agaricus Bisporus and The Inhibition of Some of Its Pathogens

Seven isolates of Pseudomonas spp. were isolated from the casing soil and 11 fungal isolates were isolated from the spent compost in the Mushroom Farm - College of Agriculture - Tikrit University. According to the pathogenicity test against Agaricus bisporus fruit bodies, the results showed that the highest infection rate was recorded in the bacterial isolate 1077by 77.45%, while the fungal isolate 1076 showed the highest pathogenicity against Agaricus bisporus fruit bodies by recording the highest infection rate reached to 81.23%. The pathogenic bacteria and fungi isolates were phenotypically identified to the species level as Pseudomonas tolaasii and Trichoderma harzianum, respectively. The results showed the alcoholic extracts of Atriplex tatarica and Haloxylon salicornicum were superior in the active substances compared to other extracts, the highest percentage of total alkaloids, tannins, saponins, phenols and flavonoids was 35.14, 44.79, 43.47, 32.05 and 31.66 mg/g in the alcoholic extract of A. tatarica, respectively, while the alcoholic extract of H. salicornicum had the highest percentage of glycosides, which amounted to 41.89 mg/g of the extract. The highest efficiency of A. tatarica alcoholic extract in inhibiting the pathogenic fungus T. harzianum, was recorded, as the colony diameter was 3.1 cm in concentration of 4 mg/mL compared to 8.9 cm in the control treatment, while the H. salicornicum alcoholic extract was superior in inhibiting the pathogenic bacteria at the same concentration, in which the inhibition zone was 15.67 mm compared to no inhibition in the control treatment. While there was little effect of alcoholic extracts of both plants on the growth of A. bisporus. The results of the dry powders effect for both plants showed that the highest inhibition against the pathogenic fungus T. harzianum was recorded by the A. tatarica powder at 2% concentration, reaching 5.01 cm, while the H. salicornicum powder showed the highest inhibition against the bacteria P.tolaasii at the same concentration in which the number of cells reached to 3.23 x 107 cells/mL compared to 6.6 x 107 cells/mL in the control treatment. The results also showed the highest growth of A. bisporus that reached 9 cm for all powdered concentrations of both plants.

HALOTOLERANT BACILLUS SP. AS A SOURCE OF ANTIFUNGAL AGENTS AGAINST MAJOR MUSHROOM PATHOGENS

The present study focuses on bioprospecting of halotolerant bacteria from a hypersaline environment for antifungal agents against major mushroom pathogens. A total of 20 morphologically different fungi were isolated from composts and infected fruiting bodies of Agaricus bisporus; belonging to the genera Trichoderma, Penicillium, Aspergillus, Mucor and Rhizopus. In addition, 131 halotolerant bacteria out of 280 exhibited antifungal activity against phytopathogens, Trichoderma sp., and Penicillium sp. The isolates (80) showing maximum and consistent activity were screened against the isolated mushroom pathogens, Trichoderma harzianum MTCC 3178 and Lecanicillium fungicola MTCC 2016. About 33.8% halotolerant bacteria produced an antifungal metabolite that inhibited the mycelial growth of Trichoderma harzianum MTCC 3178, 20% inhibited mycelium growth of Lecanicillium fungicola MTCC 2016, 48.8% other Trichoderma spp., 26.3% Penicillium spp. and 2.5% inhibited Aspergillus spp. The bacterial isolate BGUMS93 showed highest broad spectrum activity against these pathogens. Carbohydrate utilization profile, biochemical characteristics and 16S rRNA gene sequencing revealed BGUMS93 as Bacillus sp. (KC991034.1) with 97% similarity to Bacillus subtilis. BGUMS93 produced extracellular antifungal metabolites in butanol extract showing maximum activity against Trichoderma harzianum MTCC 3178 and in chloroform extract against Lecanicillium fungicola MTCC 2016. Thus, Bacillus spp. from Goa’s salterns could be a way to provide natural fungicide as an alternative to synthetic fungicides used in mushroom cultivation.

Isolation of a protease-resistant and pH-stable α-galactosidase displaying hydrolytic efficacy toward raffinose family oligosaccharides from the button mushroom Agaricus bisporus

A 45-kDa monomeric acidic α-galactosidase with a specific activity of 193.12 units/mg was isolated from the fruiting bodies of Agaricus bisporus. Blast search of internal peptide sequences suggested that it is a member of GH family 27 and it is most similar to hypothetical protein AGABI2DRAFT_70106. The enzyme displayed maximal activity at pH 4.0 and 60°C, respectively. The enzyme remained stable within the pH range 2.0–9.0 but its activity was markedly suppressed in the presence of Cu2+, Hg2+, Fe3+ and Ag+ ions. It displayed resistance to α-chymotrypsin and neutral protease. Moreover, it manifested degradative activity toward both oligosaccharides and polysaccharides. The enzyme manifested Km values of 0.30mM, 10.65mM and 19.21mM, toward pNPGal, stachyose and raffinose respectively. These results suggest that Agaricus bisporus α-galactosidase is a promising candidate for elimination of raffinose oligosaccharides (RFOs) in biotechnological applications.

Arginase participates in the methyl jasmonate-regulated quality maintenance of postharvest Agaricus bisporus fruit bodies

It has been demonstrated that Agaricus bisporus (J.E. Kange) Imbach fruit body exerts enhanced postharvest quality retention when treated with 100μmolL−1 exogenous methyl jasmonate (MeJA) vapor. In this study, fruit bodies of A. bisporus were treated with 100μmolL−1 MeJA vapor or the combination of 100μmolL−1 MeJA and 20μmolL−1Nω-hydroxy-nor-l-arginine (nor-NOHA, an inhibitor of arginase), respectively, before they were stored for 21 d at 4°C. Our data showed that treatment with MeJA alone indeed induced the increased transcription and activity of arginase whereas this effect was largely inhibited by pretreatment with nor-NOHA. In correspondence to this observation, nor-NOHA suppressed the ability of MeJA to decrease open caps and to down-regulate malondialdehyde (MDA) production and polyphenol oxidase (PPO) and lipoxygenase (LOX) activities. Biochemical analysis further demonstrated that nor-NOHA counteracted the MeJA in stimulating antioxidant enzyme activities of catalase (CAT) and superoxide dismutase (SOD) and accumulating total phenolics and flavonoids. In addition, the effect of MeJA in slowing the decline rate of soluble protein and total sugar contents was also partially impaired by nor-NOHA. Taken together, our findings firmly showed that arginase acts as an important regulatory factor in maintaining the MeJA-induced mushroom quality retention during postharvest storage.

The removal of fluoranthene by Agaricus bisporus immobilized in Ca-alginate modified by Lentinus edodes nanoparticles

Fruiting bodies of Agaricus bisporus (A. bisporus) were entrapped in Ca-alginate modified by Lentinus edodes nanoparticles (CA-LENP) to adsorb and biodegrade fluoranthene (FLU) efficiently from an aqueous solution in a fluidized bed bioreactor.

Structural characterization of a water-soluble polysaccharide from the fruiting bodies of Agaricus bisporus.

An edible fungal polysaccharide termed as ABP was obtained by extraction with hot water, and followed successive chromatographic purification using DEAE-Sepharose Fast Flow column and Sephacryl S-300 High-Resolution column. A symmetrical peak was obtained on high-performance size-exclusion chromatography with an average molecular weight of 5.17 × 104 Da, which was named ABP, and its main components were d-glucose and d-mannose. Based on the study of methylation analysis, along with FT-IR, GC, GC-MS, 1D 1H and 13C NMR and 2D NMR (H-HCOSY, TOCSY, HMQC, and NOESY), its chemical structure was featured with a repeating unit (1→6) linking β-d-Glcp as the main backbone with (1→4)-linked α-d-Manp units. The structure of the mainly repeating units of ABP was established as: →6)-β-D-Glucp-(1→4)-α-D-Manp(1→6)-β-D-Glucp-(1→6)-β-D-Glucp-(1→

Molecular Cloning and Expression of Polyphenoloxidase Genes from the Mushroom, Agaricus bisporus

The polyphenoloxidase (PPO) is the key enzyme considered to be responsible for mushroom browning. By using homology cloning and rapid amplification of cDNA ends (RACE), two new PPO genes and the corresponding cDNA were identified from the fruit bodies of Agaricus bisporus (AbPPO3 and AbPPO4, GenBank accession nos. GU936494 and GU936493, respectively). The genomic DNA sequences of AbPPO3 and AbPPO4 are 2 080 and 2 189 bp in length, respectively, encoding putative polypeptides of approximately 66 and 68 kDa. The deduced amino acid sequences show characteristic features of two copper-binding domains conserved in the type III copper proteins including fungal polyphenol oxidases. Sequence comparisons indicate that AbPPO3 and AbPPO4 present 55.3% similarity to each other (48% identity). We also obtained more than 1.5-kb long sequences upstream of the start codon of the AbPPO3 and AbPPO4 and recognized them as their respective putative promoters. Analyses of the two PPO promoter regions show that they contain abundant cis-acting elements which are probably responsible for anaerobic induction, light, wound, stress, and auxin response. Semi-quantitative RT-PCR results indicate that AbPPO3 and AbPPO4 were highly expressed in the mature fruit bodies and up-regulated after 2-d storage of mushroom. These results suggest that AbPPO3 and AbPPO4 may play roles in A. bisporus, browning and pigmentation during development and postharvest storage and the elements in promoters may act as regulatory elements for the inducible expression of AbPPO3 and AbPPO4. The successful cloning and expression analysis of AbPPO3 and AbPPO4 warrant a further investigation on the structure and function of A. bisporus PPO which points to the possible targets for genetic manipulation.

Effect of Electron Beam Irradiation on Postharvest Quality and Selected Enzyme Activities of the White Button Mushroom,Agaricus bisporus

Agaricus bisporus fruit bodies were exposed to different doses (1, 2, 3, and 4 kGy) of electron beam irradiation (EBI), and various physiological changes associated with postharvest deterioration, as well as selected enzymes considered to play a role in senescence, were monitored over a subsequent 16-day storage period at 4 degrees C and 75-85% relative humidity. EBI retarded postharvest mushroom softening and overall increases in malondialdehyde levels were more pronounced in controls compared with those of the irradiated samples. After 10 days of storage, polyphenoloxidase activity in samples irradiated with 1-4 kGy doses was significantly (P<0.05) lower compared to that in control samples. Superoxide dismutase activity generally declined throughout the postharvest storage period in both irradiated and control samples, but no clear correlation between enzyme activity and EBI dosage was evident. Catalase activity decreased more slowly and to a lesser extent in fruit bodies exposed to 1 kGy compared with that in the controls and the other irradiated samples.

English

This study was performed to determine the effects of composts and casing materials on dry matter, protein, and carbohydrate contents of the fruit bodies of Agaricus bisporus. Results showed that Agaricus bisporus cultivated on group I and group II casing soil groups showed remarkably higher dry matter and carbohydrate contents compared to other casing groups. No significant differences were found among casing soil groups in terms of protein content of Agaricus bisporus cultivated on wheat straw. But, there were significant differences between casing soil groups in terms of protein content of Agaricus bisporus cultivated on waste tea leaves.

Double-stranded RNA elements associated with the MVX disease of Agaricus bisporus

Double-stranded RNA (dsRNA) has been isolated from Agaricus bisporus fruit bodies exhibiting a wide range of disease symptoms. The symptoms which occurred singularly or in combination included; bare cropping areas on commercial beds (primordia disruption), crop delay, premature veil opening, off- or brown-coloured mushrooms, sporophore malformations and loss of crop yield. All symptoms were associated with loss of yield and/or product quality. Collectively, these symptoms are described as mushroom virus X (MVX) disease. The dsRNA titre was much lower than that previously encountered with the La France viral disease of mushrooms and a modified cellulose CF11 protocol was used for their detection. A broad survey of cultivated mushrooms from the British industry identified dsRNA elements ranging between 640 bp and 20.2 kbp; the majority have not previously been described in A. bisporus. 26 dsRNA elements were identified with a maximum of 17, apparently non-encapsidated dsRNA elements, in any one sample. Three dsRNAs (16.2, 9.4 and 2.4 kbp) were routinely found in mushrooms asymptomatic for MVX. Previously, La France disease was effectively contained and controlled by minimising the on-farm production and spread of basidiospores. Our on-farm observations suggest that MVX could be spread by infected spores and/or mycelial fragments.

The influence of ram horn hydrolyzate on the crop yield of the mushroom Agaricus bisporus

Experiments were performed to determine the effect of spraying ram horn hydrolyzate (RHH) onto casing soil on the yield of fruit bodies of Agaricus bisporus. First, horns were ground, and 35 g of the horn flour was hydrolyzed chemically. As a result of this process, 30 g of the 35 g horn flour could be hydrolyzed. Hydrolyzed material was completed to 400 ml with deionized water, and this resulting solution was termed RHH. The contents of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of RHH were determined. The effects of different concentrations (1–7%, v/v) of RHH on the crop yield of A. bisporus were investigated. The results showed that spraying RHH solution at casing and between flushes could significantly increase the mushroom yield. An optimum effect was found at a concentration of 2%, above this concentration even a reduction in yield was found. When spraying 5000 ml of 2% RHH onto each tray (0.94 m 2), increases in mushroom yield of 38% were obtained. No significant differences were found neither the dry matter contents nor in the protein contents of fruit bodies among treatments ( p<0.01). The mechanisms of mushroom yield increase resulting from spraying 2% RHH were discussed.

Discoloration and tyrosinase activity in Agaricus bisporus fruit bodies infected with various pathogens

The discoloration of A. bisporus after infection by Pseudomonas tolaasii, P. gingeri, P. agarici, P. reactans, Verticillium fungicola and Trichoderma harzianum can be distinguished by chromametric measurements. Infection with P. tolaasii caused a specific colour change, independent of the bacterial concentration applied (Δ L = 54.7, Δ a = 16.6, Δ b = 28.7%). The colour change provoked by P. gingeri had a characteristic profile different from P. tolaasii (Δ L = 36.3, Δ a = 14.1, Δ b = 49.5%). P. agarici and P. reactans provoked only a slight increase of red colour. Response to T. harzianum was orange, and to V. fungicola brown, similar to P. tolaasii but paler and more yellowish. All pathogens except P. reactans provoked degradation of total tyrosinase to variable extents. Activation of tyrosinase was only observed after infection with P. tolaasii (to almost 7%) and V. Jungicola (to 3%).

Determination of Phase II Mushroom (Agaricus Bisporus) Compost Quality Parameters by near Infrared Spectroscopy

The microbial and biochemical characteristics of compost prepared from wheat straw and chicken litter can determine the total yield of fruiting bodies of Agaricus bisporus. With the aim of identifying key substrate parameters and their relationship with mushroom yield, compost samples were obtained from four comparative trials carried out over a seven year period. The objective of this study was to assess the use of near infrared (NIR) reflectance spectroscopy for determining important characteristics of pasteurised compost. The samples were analysed for moisture content, microbial population, pH, conductivity, nitrogen, carbon and hydrogen, nitrogen, ash, ammonia, Na, Cu, Fe, acid detergent fibre, neutral detergent fibre, lignin and fibre fractions as determined by thermal analysis. Results from conventional analytical methods were correlated with NIR data and partial least squares regression analysis used to assess the information in the absorbance spectrum, which determines the concentration of the key parameters. Visible and NIR scans of the calibration samples made over the range of 400–2498 nm indicated that best calibrations could be developed using the 1100–2498 nm segment. NIR calibration equations for predicting NDM, ash, carbon, thermophilic population and fibre fractions have been successfully developed and then validated using independent samples.

The influence of photosynthetic bacteria treatments on the crop yield, dry matter content, and protein content of the mushroom Agaricus bisporus

Experiments were performed to determine the effect of spraying suspensions of photosynthetic bacteria (PSB) onto casing soil on the yield, dry matter content, and protein content of the fruit bodies of Agaricus bisporus. The results showed that spraying PSB suspension at casing and between flushes could significantly increase the mushroom yield, and the increased rate of yield had a positive correlation with the PSB density of the suspension. When spraying 5000 ml of PSB suspension which contained 3.3 × 10 9 viable PSB cells/ml onto each tray (0.54 m 2), increases in mushroom yield of 39.53% were obtained. No significant differences were found in either the dry matter contents or the protein contents of fruit bodies among all treatments. The mechanisms of mushroom yield increase resulting from spraying PSB suspension were discussed.

Morphological studies on the life span, developmental stages, senescence and death of fruit bodies of Agaricus bisporus

In this investigation, we have determined the life span of the fruit bodies of Agaricus bisporus grown in a protected cultivation environment as 36 d. We describe the morphological changes occurring in ageing mushrooms and find that signs of senescence become visible around day 18; they steadily increase in amplitude towards the end of the fruit bodies' life. Cytologically, karyolysis and focal cytoplasmolysis were the first signs followed by indications of an increased permeability of the cytoplasmic membranes and by structural changes of the cell wall. These changes result in extracellular aggregations of the lytic cell remains encapsulating or bridging the hyphal cells. Cells of the stipe tissues were transformed to empty cylinders or had irregularly collapsed. Most basidia and subhymenial cells remained alive even on day 36. When the mushrooms were cultivated according to our usual growth procedures, about 50% of the fruit bodies were infected by Trichoderma harzianum and/or Pseudomonas tolaasii on day 18; all fruit bodies died on day 24 due to diffuse bacterial and mycotic infections manifesting themselves by tissue necrosis and discoloration of the caps and stipes. When none of the fruit bodies was harvested at the time of the first flush they soon formed a canopy of pilei and their growth ceased. On day 14, all these fruit bodies showed widespread mixed infections followed by a diffuse liquefaction necrosis of all tissues including the hymenium. Post-harvest fruit bodies kept at ambient temperature or at 2°C at low r.h., or at 20° at high r.h. revealed a diffuse cell wall destruction which was followed by cytoplasmic degeneration in due course. Fruit bodies kept refrigerated had the least gross and cell structural changes during our observation period of 7 d. We conclude that the morphological changes occurring in post-harvest and in senescent fruit bodies of Agaricus bisporus are different.

Double-stranded RNAs and proteins associated with the 34 nm virus particles of the cultivated mushroom Agaricus bisporus.

Agaricus bisporus fruit bodies affected by La France disease contain a specific set of nine dsRNA molecules. A method was developed to isolate intact virus particles containing these dsRNAs. Using precautions to limit proteolysis, virus particles 34 nm in diameter were banded in a Nycodenz gradient together with the nine disease-associated dsRNAs and three proteins of M(r) 120K, 115K and 90K. Two of these viral proteins were easily cleaved by proteases present in the fruit bodies, without affecting the morphological appearance, migration in Nycodenz density gradients or dsRNA content of the virus.

Isolation and regeneration of protoplasts from gills ofAgaricus bisporus

Protoplasts were isolated from fruit-bodies ofAgaricus bisporus, and highest yields were derived from basidia. When gill fragments were treated with a combination of Novozyme 234, chitinase, and cellulase Onozuka R-10, and with 0.35m KCl as the osmotic stabilizer, high yields (3–4×107 protoplasts/g fresh wt gills) were obtained within 1 h of incubation. About 20–30% of protoplasts regenerated in a solid MMNC medium. Investigation of specific activities of glucose-6-phosphate dehydrogenase and mannitol dehydrogenase indicated a highly active pentose phosphate pathway and a good capacity for mannitol synthesis in protoplasts, as well as in other cells of fruit-bodies of the species. The simple and efficient procedure provides a new approach for further investigation of the mushroom, and possibly of other basidiomycetes with hemiangiocarpus, by use of protoplasts.

Occurrence of agaritine and γ-glutaminyl-4-hydroxybenzene (GHB) in the fructifying mycelium of Agaricus bisporus

The amounts of agaritine and GHB, aromatic amino acids with a γ-glutamyl residue, were determined in the fructifying mycelia and the corresponding fruit bodies of Agaricus bisporus , strain Somycel 609. The fructifying mycelium appeared as a site of intense synthesis of these compounds; similar results were obtained with other commercial strains. Besides, agaritine was found throughout the sporophore with the lowest levels in the stipe base and the highest in the lamellae. GHB was present in significant amounts both in the stipe base and the hymenium but in trace amounts in the remaining fruit-body parts. Only experiments with labelled compounds will allow to verify the hypothesis of a translocation process of these molecules and determine the fate of their aromatic and γ-glutamyl moieties.

Properties of phosphofructokinase 1 from Pythium ultimum and Agaricus bisporus and comparison with other fungal phosphofructokinases 1

Phosphofructokinase 1 was partially purified from Agaricus bisporus fruit bodies and Pythium ultimum mycelium. The enzyme from A. bisporus was similar to other fungal phosphofructokinases 1: it was inhibited by ATP, had sigmoidal kinetics toward fructose-6-phosphate, and was stimulated by fructose-2,6-bisphosphate. Phosphoenolpyruvate was inhibitory, and phosphate, but not AMP, stimulated activity. The enzyme from A. bisporus was very unstable. Phosphofructokinase 1 from the Oomycete Pythium ultimum on the contrary had hyperbolic kinetics to both its substrates and was not activated by fructose-2,6-bisphosphate. The only effectors found were phosphoenolpyruvate, which inhibited, and phosphate, which slightly stimulated enzyme activity. These properties were compared with those of phosphofructokinases 1 from other fungi.