Pleurotus

The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4–8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were...

Pleurotus is one of the most important and widely use mushroom in the world it contributed about 25% of the world total mushroom production. It can utilize agricultural waste and converted into a highly nutritious food. Now a days for strain improvement in mushrooms several modified breedings techniques such as selection and hybridization by the process of Protoplast fusion, use of chemical mutagenesis, use of resistance markers, have been employed with new findings of high yielding, more nutritious, disease resistance and more biological efficiency.

Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Bjerkandera sp. BOL13 were tested for their ability to degrade the endocrine-disrupting compound nonylphenol at an initial concentration of 100 mg l−1. The highest removals were achieved with T. versicolor and Bjerkandera sp. BOL13, which were able to degrade 97 mg l−1 and 99 mg l−1 of nonylphenol in 25 days of incubation, respectively. Nonylphenol removal was associated with the production of laccase by T. versicolor, but the levels of laccase, manganese peroxidase and lignin peroxidase produced by Bjerkandera sp. BOL13 were very low. At 14°C, T. versicolor and Bjerkandera sp. BOL13 sustained the removal of 88 mg l−1 and 79 mg l−1 of nonylphenol, respectively. No pollutant removal was recorded at 4°C, although both fungi could grow at this temperature in the absence of nonylphenol. A microtoxicity assay showed that the fungi produced compounds that were toxic to Vibrio fischerii; and thus a reduction in toxicity could not be correlated with nonylphenol metabolism. T. versicolor and Bjerkandera sp. BOL13 were capable of colonizing soil artificially contaminated with 430 mg kg−1 of nonylphenol. Only 1.3±0.1% of nonylphenol remained in the soil after 5 weeks of incubation.

In order to improve the digestibility and nutrient availability in rumen, wheat straw was subjected to solid state fermentation (SSF) with white-rot fungi (i.e. Pleurotus ostreatus and Trametes versicolor) and the fermented biomass (called myco-straw) was evaluated for biochemical, enzymatic and nutritional parameters. The fungal treatment after 30 days led to significant decrease (P < 0.05) in cell wall constituents viz, acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, lignin and cellulose to the extent of 35.00, 38.88, 45.00, 37.48 and 37.86%, respectively in P. ostreatus fermented straw, while 30.04, 33.85, 39.90, 31.29 and 34.00%, respectively in T. versicolor fermented straw. However, maximum efficiency of fermentation in terms of low carbohydrate consumption per unit of lignin degradation, favoring cattle feed production was observed for P. ostreatus on the 10th day (17.12%) as compared with T. versicolor on the 30th day (16.91%). The myco-straw was found to contain significantly high (P < 0.05) crude protein (CP; 4.77% T. versicolor, 5.08% P. ostreatus) as compared to control straw (3.37%). Metabolizable energy (ME, MJ/kg DM), percent organic matter digestibility (OMD) and short chain fatty acids (SCFAs; mmol) production also increased considerably from control straw (4.40, 29.91 and 0.292) to a maximum up to P. ostreatus fermented straw (4.92, 33.39 and 0.376 on 20th day) and T. versicolor fermented straw (4.66, 31.74 and 0.334 on 10th day), respectively. Moreover, the myco-straw had lower organic carbon and was rich in nitrogen with lower C/N ratio as compared to control wheat straw. Results suggest that the fungal fermentation of wheat straw effectively improved CP content, OM digestibility, SCFAs production, ME value and simultaneously lowered the C/N ratio, thus showing potential for bioconversion of lignin rich wheat straw into high energy cattle feed.

The Pleurotus eryngii species-complex comprises choice edible mushrooms growing on roots and lower stem residues of Apiaceae (umbellifers) plants. Material deriving from extensive sampling was studied by mating compatibility, morphological and ecological criteria, and through analysis of ITS1-5.8S-ITS2 and IGS1 rRNA sequences. Results revealed that P. eryngii sensu stricto forms a diverse and widely distributed aggregate composed of varieties elaeoselini, eryngii, ferulae, thapsiae, and tingitanus. Pleurotuseryngii subsp. tuoliensis comb. nov. is a phylogenetically sister group to the former growing only on various Ferula species in Asia. The existence of Pleurotusnebrodensis outside of Sicily (i.e., in Greece) is reported for the first time on the basis of molecular data, while P. nebrodensis subsp. fossulatus comb. nov. is a related Asiatic taxon associated with the same plant (Prangos ferulacea). Last, Pleurotusferulaginis sp. nov. grows on Ferulago campestris in northeast Italy,...

Mushroom cultivation of the Shimeiji group (Pleurotus spp.) uses the most diverse substrates. In Brazil, bamboo has not been tested. Mushroom growers always have to buy new seed for the inoculation of a new cycle, making the process more expensive; planters must also use plastic containers that contaminate final products. Bamboo has been widely planted on small rural properties and is often available for other uses. To solve these problems, a sawdust-based formulation of Eucalyptus introduced in approximately 30 cm bamboo stalks was tested. In an initial test conducted with bamboo stalks, the mushrooms were formed after 48 days of inoculation, which reduced the production time by half and proved viable. The new plantings resulted in the successful colonization of the substrate, indicating the viability of new production batches using the same stem without the need for new seed.

Pleurotus ostreatus is one of the most extensively cultivated mushrooms in the world; however, the success of cultivation often depends on the proliferation of different bacterial pathogens. Pseudomonas tolaasii is thought as the major cause of brown blotch disease of Agaricus bisporus and yellowing of Pleurotus ostreatus. In this study we examined the pathogenicity and assessed the industrial damage causing effect of 41 Pseudomonas strains isolated from deformed, yellowing oyster mushroom (P. ostreatus) sporocarps. Identification of the isolates at species level by the partial sequence analysis of the hypervariable region of the rpoB gene revealed nine Pseudomonas sps. We analyzed the presence of the tolaasin gene-cluster, the production of fluorescent pigments, the oxidase- and nitrite reductase activities, the growth at restrictive temperatures and the carbon source utilizing abilities of each strain. Complex lipopeptide production (including tolaasin) was examined with thin layer chromatography and a novel in vitro necrosis-test was developed and evaluated for the investigation of the pathogenic effect of Pseudomonas strains. Our results underline the importance of extracellular enzyme production in the sporocarp decaying process. Strong correlations were found between the secretion of trypsin-like proteases and lipases and the necrotic effect of these bacteria. All the results clearly established that besides Ps. tolaasii, Ps. fluorescens biovar V strains were pathogenic to P. ostreatus and cause serious losses during mushroom production. Our results underline the importance of extracellular enzyme production in the sporocarp decaying process, especially the trypsin-like proteases and lipases.

The industrial production of edible basidiomycetes is increasing every year as a response to the increasing public demand of them because of their nutritional properties. About a dozen of fungal species can be currently produced for food with sound industrial and economic bases. Notwithstanding, this production is threatened by biotic and abiotic factors that make it necessary to improve the fungal strains currently used in industry. Breeding of edible basidiomycetes, however, has been mainly empirical and slow since the genetic tools useful in the selection of the new genetic material to be introduced in the commercial strains have not been developed for these fungi as it was for other organisms. In this review we will discuss the main genetic factors that should be considered to develop breeding approaches and tools for higher basidiomycetes. These factors are (i) the genetic system controlling fungal mating; (ii) the genomic structure and organisation of these fungi; and (iii) th...

Technical scale (≥5l) cultivations of shear stress sensitive microorganisms are often difficult to perform, as common bioreactors are usually designed to maximize the oxygen input into the culture medium. This is achieved by mechanical stirrers, causing high shear stress. Examples for shear stress sensitive microorganisms, for which no specific cultivation systems exist, are many anaerobic bacteria and fungi, such as basidiomycetes. In this work a disposable bag bioreactor developed for cultivation of mammalian cells was investigated to evaluate its potential to cultivate shear stress sensitive anaerobic Eubacterium ramulus and shear stress sensitive basidiomycetes Flammulina velutipes and Pleurotus sapidus. All cultivations were compared with conventional stainless steel stirred tank reactors (STR) cultivations. Good growth of all investigated microorganisms cultivated in the bag reactor was found. E. ramulus showed growth rates of μ=0.56 h⁻¹ (bag) and μ=0.53 h⁻¹ (STR). Differences concerning morphology, enzymatic activities and growth in fungal cultivations were observed. In the bag reactor growth in form of small, independent pellets was observed while STR cultivations showed intense aggregation. F. velutipes reached higher biomass concentrations (21.2 g l⁻¹ DCW vs. 16.8 g l⁻¹ DCW) and up to 2-fold higher peptidolytic activities in comparison to cell cultivation in stirred tank reactors.

A process of solid state fermentation (SSF) on tomato pomace was developed with the white-rot fungi Pleurotus ostreatus and Trametes versicolor, using sorghum stalks as support. Operative parameters (humidity, water activity, and size of substrate particles) guaranteeing a good colonization of tomato pomace by both fungi were defined and conditions for production at high titers of the industrially relevant enzymes laccase, xylanase and protease were identified. Significant laccase activity levels (up to 36 U g−1 dry matter) were achieved without any optimization of culture conditions, neither by nutrient addition nor by O2 enrichment. Furthermore, protease activity levels up to 34,000 U g−1 dry matter were achieved, being higher than those reported for the fungi typically considered as the best protease producers such as Aspergillus strains. Moreover, as one of the most significant results of this study, analysis of P. ostreatus tomato SSF samples by zymogram revealed two bands with laccase activity which had not been detected so far.

Although oyster mushroom (Pleurotus spp.) is a valuable food, cultivated worldwide on an industrial scale, still very little is known about the microbial dynamics during oyster mushroom substrate preparation. Therefore, the characterization of the microbial dynamics by chemical and biological tools was the objective of this study. During substrate preparation, enzymatic digestibility of the substrate improved by 77%, whereas the cellulose and hemicellulose to lignin ratios decreased by 9% and 19%, respectively. Fluorescein diacetate hydrolysis reached its minimum value at the temperature maximum of the process during the composting phase and exceeded the initial level at the end of the process. Fungal species played part in the initial mesophilic phase of the substrate preparation process, but they disappeared after pasteurization in tunnels at constant elevated temperatures. Changes in the microbiota showed a marked bacterial community succession during substrate preparation investigated by 16S ribosomal deoxyribonucleic acid-based terminal restriction fragment length polymorphism (T-RFLP). Mature samples represented the least variance, which indicated the effect of the standardized preparation protocol. The relation between mushroom yield and the bacterial community T-RFLP fingerprints was investigated, but the uniformity of mushroom yields did not support any significant correlation.

Pleurotus ostreatus var. florida known as Hiratake has a high nutritional value, presents medicinal and nutraceutical properties and it is one of the consumed mushrooms in Brazil. Thus, the aim of this study was to characterize the chemical structure of polysaccharides found in mycelial biomass produced by submerged culture of P. ostreatus var. florida in order to compare with those found in P. ostreatus var. florida fruit bodies. Aqueous and alkali extracts obtained from mycelial biomass were purified, 13C NMR, GC-MS and chemical techniques were used to characterize three polysaccharide structures: a mannogalactan (MG-PfM) with α-D-Galp and 3-O-Me-α-D-Galp units, both (1→6)-linked, highly substituted at O-2 by D-Manp, a glycogen-like polymer (GLY-PfM) with α-D-Glp (1→4)-linked main chain, partially substituted at O-6 by α-D-Glcp side chains and a (1→3), (1→6) β-D-glucan (βGLC-PfM) with a main chain of β-D-Glcp (1→3)-linked units, partially substituted at O-6 by side chains of 6-O-s...

The fungi are a very large kingdom of organisms and are fascinating for their unique appearance and biological characteristics as well as being valuable to our own species. They have been found to be a functional food source and are recognized for their ability to produce valuable enzymes and other medicinal compounds. They have a role as recyclers of organic debris such as pasteurized corn stalks, wheat straw and by-products of paper and pulp operations. Their ability to break down hydrocarbon based toxic wastes as well as to sequester heavy metal toxins make fungi valuable aids in environmental clean up of polluted areas (Stamets, 2000; Adenipekun and Lawal, 2012). Within the fungi, many of the species within class Basidiomycota are characterized by a mushroom which appears briefly and is supported by the mycelium, a delicate, expansive network of cells that functions to absorb nutrients. The mycelium supports the development of the mushroom in response to environmental stimuli such as humidity or drop in temperature. The mushroom itself develops from a dense clustering of the mycelial network and subsequent differentiation into mushroom structures such as cap and gills. Ultimately the mushroom is a reproductive structure where spores are produced. When the spores are released they form hyphae or elongated cells that contain half the genetic material needed to form a new organism. As the hyphae divide they elongate, possibly bringing them into proximity of a hyphae with a compatible genetic make up with which to form the new mycelium. Pleurotus pulmonarius: a good choice for cultivation Pleurotus pulmonarius, commonly named Indian Oyster mushroom or Phoenix Mushroom, is one of the many edible species that make up the basidiomycetes. P. pulmonarius is attractive to cultivator

Panax ginseng, commonly known as Korean ginseng, is a valued source of herbal medicine in Korea and China. We have developed and characterized 35 microsatellite markers in P. ginseng from available BAC end sequences. Characterization of these 35 SSR primer pairs in 14 cultivars of P. ginseng showed 12 primer pairs to be polymorphic and 19 primer pairs to be monomorphic, while the remaining four primer pairs did not produce any product. The number of alleles amplified ranged from 4 to 8 per primer pair, with an average of six alleles per locus. The expected and observed heterozygosities ranged from 0.7500 to 0.9678 and 0.5645 to 0.7109, respectively. None of these loci deviated from Hardy–Weinberg equilibrium. All of the functional primer pairs of P. ginseng showed cross-species transferability with Panax quinquefolium. The cross-species transferable markers could be used for ginseng cultivar identification, for genomic studies, including mapping of specific trait QTL/genes, and for measuring conservation of ginseng.