Lampteromyces bioluminescence—1. Identification of riboflavin as the light emitter in the mushroom L. japonicus

The bioluminescence of the luminous mushroom, Lampteromyces japonicus, was studied by using the mushroom gills and also the luminous mycelia, the latter being cultured from the isolated spores and grown in a potato sucrose medium. The luminescence intensity of the mushroom gills and the cultured mycelia was measured in an aqueous suspension under various conditions. The original intensity was enhanced by exposing the luminous cells to oxygen for several hours or to acids or bases for a short period. This enhancement enabled measurement of their bioluminescence spectra which were identical to the fluorescence spectrum of riboflavin, having a maximum at 524 nm. The green fluorescent substance was extracted with cold water from the mushroom and it was identified as riboflavin by spectroscopic and chromatographic analyses. Riboflavin was concluded to be the light emitter of this mushroom.     

Effect of polysaccharides from Ganoderma applanatum on immune responses. I. Enhancing effect on the induction of delayed hypersensitivity in mice.

Prior intraperitoneal (i.p.) or oral administration of the polysaccharide preparation from a kind of mushroom, Ganoderma applanatum (Pers.) Pat. of Basidiomycetes, exerted an enhancing effect on the induction of delayed hypersensitivity (DH) to protein antigen as measured by the footpad reaction (FPR), and expanded the size of T cell memory for the IgG antibody response. One of the active principles was partially purified and found to be associated with a polysaccharide-rich fraction. The induction of DH was enhanced by treatment with an appropriate dose of the mushroom extract, whereas increasing the dose resulted in almost complete loss of the enhancing activity. The mechanism for the enhancing effect of the mushroom extract on the induction of DH was explored by the adoptive cell transfer technique. Although an i.p. injection of methylated bacterial α-amylase (M-BαA) in incomplete Freund's adjuvant (IFA) has been found to generate in the spleen the antigen-specific suppressor T cells capable of inhibiting the induction of DH 5 days after immunization, the same treatment of mice given prior injections of the mushroom extract did not raise the suppressor cell activity, but transfer of these spleen cells (6 × 10⁷) into syngeneic recipient mice which had been primed with a subcutaneous (s.c.) injection of M-BαA in complete Freund's adjuvant (CFA) resulted in substantial amplification of the expression of DH. The absence of effector T cells for DH in the transferred spleen cells was confirmed by the failure to transfer DH into cyclophosphamide (CY)-treated mice with the amplifying cells. The amplifying activity was antigen-nonspecific and mediated by cells sensitive to treatment with anti-θ antiserum plus complement. Therefore, the nonspecific enhancing effect of the mushroom extract could not be explained by the possibility that pretreatment with the extract eliminated the antigen-specific suppressor T cells. Other adoptive cell transfer experiments revealed that nylon wool-passed cells from mice unprimed but treated with the mushroom extract were able to exert an enhancing activity on the expression of effector T cells in DH. The results indicate that the treatment with an appropriate dose of the extract enhances the induction of DH by activation of the nonspecific amplifier T cells.     

The cyclic AMP phosphodiesterase encoded by the Drosophila dunce gene is concentrated in the mushroom body neuropil.

Drosophila dunce (dnc) flies are defective in learning and memory as a result of lesions in the gene that codes for a cAMP-specific phosphodiesterase (PDE). Antibodies to the dnc PDE showed that the most intensely stained regions in the adult brain were the mushroom body neuropil--areas previously implicated in learning and memory. In situ hybridization demonstrated that dnc RNA was enriched in the mushroom body perikarya. The mushroom bodies of third instar larval brains were also stained intensely by the antibody, suggesting that the dnc PDE plays an important role in these neurons throughout their development. The role of the dnc PDE in mushroom body physiology is discussed, and a circuit model describing a possible role of the mushroom bodies in mediating olfactory learning and memory is presented.     

Are mushroom bodies cerebellum-like structures?

The mushroom bodies are distinctive neuropils in the protocerebral brain segments of many protostomes. A defining feature of mushroom bodies is their intrinsic neurons, masses of cytoplasm-poor globuli cells that form a system of lobes with their densely-packed, parallel-projecting axon-like processes. In insects, the role of the mushroom bodies in olfactory processing and associative learning and memory has been studied in depth, but several lines of evidence suggest that the function of these higher brain centers cannot be restricted to these roles. The present account considers whether insight into an underlying function of mushroom bodies may be provided by cerebellum-like structures in vertebrates, which are similarly defined by the presence of masses of tiny granule cells that emit thin parallel fibers forming a dense molecular layer. In vertebrates, the shared neuroarchitecture of cerebellum-like structures has been suggested to underlie a common functional role as adaptive filters for the removal of predictable sensory elements, such as those arising from reafference, from the total sensory input. Cerebellum-like structures include the vertebrate cerebellum, the electrosensory lateral line lobe, dorsal and medial octavolateral nuclei of fish, and the dorsal cochlear nucleus of mammals. The many architectural and physiological features that the insect mushroom bodies share with cerebellum-like structures suggest that it might be fruitful to consider mushroom body function in light of a possible role as adaptive sensory filters. The present account thus presents a detailed comparison of the insect mushroom bodies with vertebrate cerebellum-like structures.     

Melanocyte-Directed enzyme prodrug therapy (MDEPT): development of second generation prodrugs for targeted treatment of malignant melanoma.

Evaluation of second generation prodrugs for MDEPT, by oximetry, has highlighted structural properties that are advantageous and disadvantageous for efficient oxidation using mushroom tyrosinase. In particular, a sterically undemanding prodrug bis-(2-chloroethyl)amino-4-hydroxyphenylaminomethanone 28 was synthesised and found to be oxidised by mushroom tyrosinase at a superior rate to tyrosine methyl ester, the carboxylic acid of which is the natural substrate for tyrosinase. The more sterically demanding phenyl mustard prodrugs 9 and 10 were oxidised by mushroom tyrosinase at a similar rate to tyrosine methyl ester. In contrast, tyramine chain elongation via heteroatom insertion was detrimental and the rate of mushroom tyrosinase oxidation of phenyl mustard prodrugs 21 and 22 decreased by 10 nanomol/min.     

Effect of age,behaviour and social environment on honey bee brain plasticity

We examined the effects of behaviour, age and social environment on mushroom body volume in adult bees. The mushroom bodies are regions of the central brain important for sensory integration and learning. Their volume was influenced by behaviour throughout life: always larger in forager bees than age-matched nurse bees, even in old bees up to 93 days of age as adults. Mushroom body development was influenced by the social environment in the first 8 days of adult life, with different environments having markedly different effects on mushroom body size. Compared to hive-reared bees, isolation slowed mushroom body growth, but bees reared in isolation confined with a single dead bee showed a dramatic increase in mushroom body volume comparable to that seen in active foragers. Despite their precocious mushroom body development, these bees did not show improved performance in an olfactory learning test. Since simple environmental manipulations can both accelerate and delay mushroom body growth in young bees, and since mushroom body volume is sensitive to behaviour throughout life, the honey bee has great potential as a model for exploring the interactions between environment, behaviour and brain structure.     

野生口蘑菌种分离及人工驯化

为了给口蘑人工驯化栽培提供依据,开展了口蘑的碳、氮源营养研究。结果表明,蔗糖和牛肉膏分别为最佳碳源和最佳氮源。经转管纯化及在不同培养基驯化培养,该菌株在PSA培养基上,生长速度快、菌丝变得较浓密。但和双孢菇的菌丝相比,无论在麦粒上还是熟料上,菌丝不够粗壮,距离出菇仍然有一定的差距。口蘑的驯化栽培难度较大,欲获得实质性的突破还在于掌握其生长规律及生态习性。温度因子是影响蒙古口蘑菌丝及子实体正常生长发育的关键因子,作为长期适应低温生态环境的结果,适当温度的摸索将是驯化栽培的关键技术。口蘑具有严格的营养要求,因而培养基的筛选至关重要。     

Factors affecting mushroom Pleurotus spp.

Pleurotus genus is one of most extensively studied white-rot fungi due to its exceptional ligninolytic properties. It is an edible mushroom and it also has several biological effects, as it contains important bioactive molecules. In basidiomycete fungi, lignocellulolytic enzymes are affected by many typical fermentation factors, such as medium composition, ratio of carbon to nitrogen, pH, temperature, air composition, etc. The survival and multiplication of mushrooms is related to a number of factors, which may act separately or have interactive effects among them. Out that understanding challenges in handling Pleurotus species mushroom requires a fundamental understanding of their physical, chemical, biological and enzymatic properties. This review presents a practical checklist of available intrinsic and extrinsic factors, providing useful synthetic information that may help different users. An in-depth understanding of the technical features is needed for an appropriate and efficient production of Pleurotus spp.     

Growth-promoting effect of thermophilic fungi on the mycelium of the edible mushroom Agaricus bisporus.

The growth-promoting effect of the thermophilic fungus Scytalidium thermophilum in mushroom compost on the mycelium of the edible mushroom Agaricus bisporus was investigated. Results obtained by others were confirmed by showing that S. thermophilum leads to an increased hyphal extension rate of the mushroom mycelium. However, it was demonstrated that hyphal extension rates were not clearly related to mushroom biomass increase rates. A number of experiments pointed strongly towards CO2 as the determinant of hyphal extension rates. In compost, CO2 is produced mainly by thermophilic fungi. Several experiments did not reveal any other specific compound produced by S. thermophilum that increases the hyphal extension rate of the mushroom mycelium.     

Growth-promoting effect of thermophilic fungi on the mycelium of the edible mushroom Agaricus bisporus.

The growth-promoting effect of the thermophilic fungus Scytalidium thermophilum in mushroom compost on the mycelium of the edible mushroom Agaricus bisporus was investigated. Results obtained by others were confirmed by showing that S. thermophilum leads to an increased hyphal extension rate of the mushroom mycelium. However, it was demonstrated that hyphal extension rates were not clearly related to mushroom biomass increase rates. A number of experiments pointed strongly towards CO2 as the determinant of hyphal extension rates. In compost, CO2 is produced mainly by thermophilic fungi. Several experiments did not reveal any other specific compound produced by S. thermophilum that increases the hyphal extension rate of the mushroom mycelium.     

Reversal of the TPA-induced inhibition of gap junctional intercellular communication by Chaga mushroom (Inonotus obliquus) extracts: effects on MAP kinases

Chaga mushroom (Inonotus obliquus) has continued to receive attention as a folk medicine with indications for the treatment of cancers and digestive diseases. The anticarcinogenic effect of Chaga mushroom extract was investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 normal rat liver epithelial cells. The cells were pre-incubated with Chaga mushroom extracts (5, 10, 20 microg/ml) for 24 h and this was followed by co-treatment with Chaga mushroom extracts and TPA (12-O-tetradecanoylphorbol-13-acetate, 10 ng/ml) for 1 h. The inhibition of GJIC by TPA (12-O-tetradecanoylphorbol-13-acetate), promoter of cancer, was prevented with treatment of Chaga mushroom extracts. Similarly, the increased phosphorylated ERK1/2 and p38 protein kinases were markedly reduced in Chaga mushroom extracts-treated cells. There was no change in the JNK kinase protein level, suggesting that Chaga mushroom extracts could only block the activation of ERK1/2 and p38 MAP kinase. The Chaga mushroom extracts further prevented the inhibition of GJIC through the blocking of Cx43 phosphorylation. Indeed cell-to-cell communication through gap junctional channels is a critical factor in the life and death balance of cells because GJIC has an important function in maintaining tissue homeostasis through the regulation of cell growth, differentiation, apoptosis and adaptive functions of differentiated cells. Thus Chaga mushroom may act as a natural anticancer product by preventing the inhibition of GJIC through the inactivation of ERK1/2 and p38 MAP kinase.     

Mushrooms, tumors, and immunity.

Medicinal properties have been attributed to mushrooms for thousands of years. Mushroom extracts are widely sold as nutritional supplements and touted as beneficial for health. Yet, there has not been a critical review attempting to integrate their nutraceutical potential with basic science. Relatively few studies are available on the biologic effects of mushroom consumption, and those have been performed exclusively in murine models. In this paper, we review existing data on the mechanism of whole mushrooms and isolated mushroom compounds, in particular (1-->3)-beta-D-glucans, and the means by which they modulate the immune system and potentially exert tumor-inhibitory effects. We believe that the antitumor mechanisms of several species of whole mushrooms as well as of polysaccharides isolated from Lentinus edodes, Schizophyllum commune, Grifola frondosa, and Sclerotinia sclerotiorum are mediated largely by T cells and macrophages. Despite the structural and functional similarities of these glucans, they differ in their effectiveness against specific tumors and in their ability to elicit various cellular responses, particularly cytokine expression and production. Unfortunately, our data base on the involvement of these important mediators is still rather limited, as are studies concerning the molecular mechanisms of the interactions of glucans with their target cells. As long as it remains unclear what receptors are involved in, and what downstream events are triggered by, the binding of these glucans to their target cells, it will be difficult to make further progress in understanding not only their antitumor mechanisms but also their other biological activities.     

An initial assessment of spent mushroom compost as a potential energy feedstock

The Irish mushroom industry has expanded rapidly in the last decade, particularly in the border counties. Its success has generated concern, however, as the production of spent mushroom compost (SMC) has increased. Until recently, SMC as an agricultural waste has been disposed of without due consideration to the environment. As County Councils increasingly address river pollution, restrictions will prevent expansion of the mushroom industry without an SMC waste management solution. This paper looks at the availability and composition of SMC and considers its potential as an energy feedstock. Variability in SMC composition was investigated by sampling from various locations over several months. Analyses showed that, on a dry ash free basis, SMC has a calorific value equivalent to sewage sludge which has been successfully fired for many years. Compositional analysis confirmed the dry fuel as consistent in make-up and showed the moisture content to vary within 60-77%, on an as-received basis.     

beta-Mannosidase from the mushroom Polyporus sulfureus.

beta-D-Mannosidase (EC 3.2.1.25), a useful tool for the structural studies of heterosaccharide chains, has been isolated in a highly purified form from the fruiting bodies of the mushroom Polyporus sulfureus. This mushroom is unique among reported sources of this enzyme in that it has the advantage of being almost free of alpha-mannosidase activity. The purification procedure involves ammonium sulfate fractionation followed by Sephadex G-100 filtration and chromatography on columns of DEAE-cellulose and hydroxylapatite. The final enzyme preparation gives essentially a single band on disc gel electrophoresis. The purified enzyme liberates the beta-D-mannopyranosyl unit from various natural substrates such as the core glycopeptide, Man(GlcNAc)2-Asn isolated from ovalbumin, from Taka-amylase A, and from human alpha1-acid glycoprotein. It also hydrolyzes (Man)2-GlcNAc from the urine of an alpha-mannosidosis patient, 1,4-D-mannobiose and mannotriose isolated from ivory nut mannan, 4-O-beta-D-mannopyranosyl-L-rhamnose, 6-O-beta-D-mannopyranosyl-D-galactose and 4-O-beta-D-mannopyranosyl-N-acetylglucosamine. The molecular weight of this enzyme is estimated to be about 64,000 by gel filtration. For p-nitrophenyl-beta-D-mannopyranoside, the pH optimum is between 2.4 and 3.4 and the Km is 1.6 mM.     

5,6-Dihydroxyindole oxidation by mammalian, mushroom and amphibian tyrosinase preparations

The oxidation of 5,6-dihydroxyindole by tyrosinases from mushroom, Harding-Passey melanoma, bovine eye and Bufo bufo embryo has been investigated. The apparent Km values for this substrate were measured and found to be of the same order of magnitude as those for L-tyrosine and L-3,4-dihydroxyphenylalanine, as reported in the literature (5 x 10(-4) M). The 5,6-dihydroxyindole oxidases of mushroom and T4 melanoma isozyme are sensitive to phenylthiourea, while, on the other hand, those from crude preparations of bovine and B. bufo tyrosinases are not sensitive to the inhibitor in an evident manner. The action of some indole derivatives on the 5,6-dihydroxyindole oxidase of mushroom has also been investigated.     

Widespread phylogenetic distribution of a protein methyltransferase that modifies L-isoaspartyl residues.

Protein L-isoaspartyl methyltransferase is implicated in the repair or degradation of age-damaged proteins that contain atypical, L-isoaspartyl residues. The enzyme has previously been demonstrated in a variety of vertebrates and in the bacterium S. typhimurium (O'Connor, C.M. and Clarke, S. (1985) Biochem. Biophys. Res. Commun. 132, 1144-1150). We report here that the enzyme is present in a mollusc (great slug), a crustacean (pill woodlouse), a fungus (mushroom), and a plant (wheat germ). Using mushroom as an example, we show that the enzyme activity may, in some instances, require a partial purification before its presence is clearly detectable. Our findings significantly extend the known phylogenetic distribution of this enzyme and suggest that it may play an indispensable role in protein metabolism.     

Studies on Amino Acids XII.

Although acylase activities in animal tissues, molds, bacteria and yeast have been clarified, nothing has been reported on the acylase activity in plants. Therefore, as a part of a series of studies intending to elucidate the biological significance of the presence of acylase activity, activity in plants was investigated.

As a result, the occurrence of acylase activity in plants such as vegetables, potatoes, pulses, cereals and fruits, has been confirmed for the first time. Besides the above higher plants a relatively higher acylase activity was also found in mushroom.     

Mushroom bodies, Ca(2+) oscillations, and the memory gene amnesiac.

The memory of odors in Drosophila is mediated by mushroom body neurons. Memory is formed, in part, by a modulation of the physiology of these neurons brought about by neuropeptides that are encoded by the amnesiac gene and released from peptidergic neurons that innervate mushroom body neurons. Slow and spontaneous oscillations of calcium levels are elevated in the mushroom body neurons of amnesiac mutants and may contribute to memory consolidation.     

Double-stranded ribonucleic acid in Agaricus bisporus.

Double-stranded ribonucleic acid present in virus-infected mushrooms of Agaricus bisporus has been resolved through polyacrylamide gel electrophoresis into six molecular-weight forms. Identification of these six double-stranded ribonucleic acids in mushrooms by this procedure has proven to be a useful and diagnostic method for viral infection in the cultivated mushroom.