Plant growth regulators from the fruiting bodies of Tricholoma flavovirens

A novel indole derivative (1) and three known compounds (2-4) were isolated from the fruiting bodies of Tricholoma flavovirens. Their structures were determined or identified by the interpretation of spectroscopic data. Compounds 1 and 2 promoted root growth of lettuce and inhibited hypocotyl growth at 1 μmol/paper. Compound 3 inhibited hypocotyl and root growth at 100 nmol/paper.

Bioremediation of the neonicotinoid insecticide clothianidin by the white-rot fungus Phanerochaete sordida

Clothianidin (CLO) is a member of the neonicotinoid pesticides, which have been widely used worldwide over the last two decades. However, its toxicity for bees and neurological toxicity for humans are urgent problems. Here, the degradation of CLO by the white-rot fungus Phanerochaete sordida was examined in nitrogen-limited liquid medium. After incubation for 20days at 30°C, 37% of CLO was degraded in the cultures. High-resolution ESI-MS and NMR analyses of the culture supernatant identified N-(2-chlorothiazol-5-yl-methyl)-N'-methylurea (TZMU) as a metabolite of CLO degradation. The addition of cytochrome P450 inhibitors to the culture medium markedly reduced the degradation of CLO by P. sordida. And manganese peroxidase, a major ligninolytic enzyme secreted by this fungus, were not carried out CLO degradation. The effects of CLO and TZMU on the viability of the neuronal cell line Neuro2a demonstrated that P. sordida effectively degrades CLO into a metabolite that lacks neurotoxicity.

Bioconversion of AHX to AOH by resting cells of Burkholderia contaminans CH-1

Fairy rings are zones of stimulated grass growth owing to the interaction between a fungus and a plant. We previously reported the discovery of two novel plant-growth regulating compounds related to forming fairy rings, 2-azahypoxanthine (AHX) and 2-aza-8-oxohypoxanthine (AOH). In this study, a bacterial strain CH-1 was isolated from an airborne-contaminated nutrient medium containing AHX. The strain converted AHX to AOH and identified as Burkholderia contaminans based on the gene sequence of its 16S rDNA. The quantitative production of AOH by resting cells of the strain was achieved. Among seven Burkholderia species, two bacteria and two yeasts tested, B. contaminans CH-1 showed the highest rate of conversion of AHX to AOH. By batch system, up to 10.6 mmol AHX was converted to AOH using the resting cells. The yield of this process reached at 91%.

Analysis of ethanol fermentation mechanism of ethanol producing white-rot fungus Phlebia sp. MG-60 by RNA-seq

Background

The white-rot fungus Phlebia sp. MG-60 shows valuable properties such as high ethanol yield from several lignocellulosic materials, although white-rot fungi commonly degrade woody components to CO₂ and H₂O. In order to identify genes involved in ethanol production by Phlebia sp. MG-60, we compared genes differentially expressed by the ethanol producing fungus Phlebia sp. MG-60 and the model white-rot fungus Phanerochaete chrysosporium under ethanol fermenting and non-fermenting conditions using next-generation sequencing technologies.

Results

mRNAs from mycelia of Phlebia sp. MG-60 and P. chrysosporium under fermenting and non-fermenting conditions were sequenced using the MiSeq system. To detect differentially expressed genes, expression levels were measured in fragments per kilobase of exon per million mapped reads (FPKM). Differentially expressed genes were annotated using BLAST searches, Gene Ontology classifications, and KEGG pathway analysis. Functional analyses of differentially expressed genes revealed that genes involved in glucose uptake, glycolysis, and ethanol synthesis were widely upregulated in Phlebia sp. MG-60 under fermenting conditions.

Conclusions

In this study, we provided novel transcriptomic information on Phlebia sp. MG-60, and these RNA-seq data were useful in targeting genes involved in ethanol production for future genetic engineering.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2977-7) contains supplementary material, which is available to authorized users.

Molecular breeding of lignin-degrading brown-rot fungus Gloeophyllum trabeum by homologous expression of laccase gene

The basidiomycete Gloeophyllum trabeum KU-41 can degrade Japanese cedar wood efficiently. To construct a strain better suited for biofuel production from Japanese cedar wood, we developed a gene transformation system for G. trabeum KU-41 using the hygromycin phosphotransferase-encoding gene (hpt) as a marker. The endogenous laccase candidate gene (Gtlcc3) was fused with the promoter of the G. trabeum glyceraldehyde-3-phosphate dehydrogenase-encoding gene and co-transformed with the hpt-bearing pAH marker plasmid. We obtained 44 co-transformants, and identified co-transformant L#61, which showed the highest laccase activity among all the transformants. Moreover, strain L#61 was able to degrade lignin in Japanese cedar wood-containing medium, in contrast to wild-type G. trabeum KU-41 and to a typical white-rot fungus Phanerochaete chrysosporium. By using strain L#61, direct ethanol production from Japanese cedar wood was improved compared to wild type. To our knowledge, this study is the first report of the molecular breeding of lignin-degrading brown-rot fungus and direct ethanol production from softwoods by co-transformation with laccase overproduction constructs.

The development of laboratory tests for cancer in Japan with special reference to carcinoembryonic proteins

The present paper describes the present status of clinical tests for cancer in Japan. Since no cancer-specific substance has been found so far the clinical tests for cancer at present are always quantitative but not qualitative. Among these substances, alpha-fetoprotein is one of the most specific substances for cancer and its test is essential for diagnosis of hepatoma beins used worldwide. AFP is a specific product of liver cancer cells. The measurement of carcinoembryonic antigen in patient blood is a hopeful method for cancer diagnosis. This substance is not specifically produced by cancer cells, but the phenomenon of appearance in bloodstream appears to be cancer-specific. This may reflect the invasion of blood vessels in tissues such as colorectum, lung, etc., by infiltration of cancer cell. This is the reason for the appearance of CEA in a wide variety of cancers. There are many other clinical tests at present but these are only secondary aids for the diagnosis of cancer. This is the reason why the description concentrates mostly on AFP and CEA. The companies manufacturing the kits for these tests in Japan are also listed in this paper.

Erinaceolactones A to C, from the culture broth of Hericium erinaceus

Three novel compounds, erinaceolactones A to C (1-3), and a known compound (4) were isolated from the culture broth of Hericium erinaceus. The planar structures of 1-3 were determined by the interpretation of spectroscopic data. The absolute configuration of 3 was determined by X-ray crystallography. Although compound 4 had been synthesized, it was isolated from a natural source for the first time. In the bioassay examining plant-growth regulatory activity of these compounds (1-4) and other components of the fungus (5-8), compounds 1, 2, and 4-8 suppressed the growth of lettuce.

Bioactive sesquiterpene aryl esters from the culture broth of Armillaria sp

Two new compounds, 10-dehydroxymelleolide D (1) and 13-hydroxymelleolide K (2), along with seven known compounds, 5'-O-methylmelledonal (3), melleolide D (4), 13-hydroxydihydromelleolide (5), melleolide (6), armillarinin (7), armillaridin (8), and armillarikin (9), were isolated from the culture broth of Armillaria sp. Their structures were determined by spectroscopic data analysis. All the compounds inhibited plant growth of lettuce. Melleolide (6) and armillarikin (9) inhibited mycelial growth of Coprinopsis cinerea and/or Flammulina velutipes.

A-WINGS: an integrated genome database for Pleurocybella porrigens (Angel's wing oyster mushroom, Sugihiratake)

BACKGROUND

The angel's wing oyster mushroom (Pleurocybella porrigens, Sugihiratake) is a well-known delicacy. However, its potential risk in acute encephalopathy was recently revealed by a food poisoning incident. To disclose the genes underlying the accident and provide mechanistic insight, we seek to develop an information infrastructure containing omics data. In our previous work, we sequenced the genome and transcriptome using next-generation sequencing techniques. The next step in achieving our goal is to develop a web database to facilitate the efficient mining of large-scale omics data and identification of genes specifically expressed in the mushroom.

FINDINGS

This paper introduces a web database A-WINGS (http://bioinf.mind.meiji.ac.jp/a-wings/) that provides integrated genomic and transcriptomic information for the angel's wing oyster mushroom. The database contains structure and functional annotations of transcripts and gene expressions. Functional annotations contain information on homologous sequences from NCBI nr and UniProt, Gene Ontology, and KEGG Orthology. Digital gene expression profiles were derived from RNA sequencing (RNA-seq) analysis in the fruiting bodies and mycelia. The omics information stored in the database is freely accessible through interactive and graphical interfaces by search functions that include 'GO TREE VIEW' browsing, keyword searches, and BLAST searches.

CONCLUSIONS

The A-WINGS database will accelerate omics studies on specific aspects of the angel's wing oyster mushroom and the family Tricholomataceae.

Improvement of ligninolytic properties by recombinant expression of glyoxal oxidase gene in hyper lignin-degrading fungus Phanerochaete sordida YK-624

Glyoxal oxidase (GLOX) is a source of the extracellular H2O2 required for the oxidation reactions catalyzed by the ligninolytic peroxidases. In the present study, the GLOX-encoding gene (glx) of Phanerochaete chrysosporium was cloned, and bee2 promoter of P. sordida YK-624 was used to drive the expression of glx. The expression plasmid was transformed into a P. sordida YK-624 uracil auxotrophic mutant (strain UV-64), and 16 clones were obtained as GLOX-introducing transformants. These transformants showed higher GLOX activities than wild-type P. sordida YK-624 and control transformants harboring marker plasmid. RT-PCR analysis indicated that the increased GLOX activity was associated with elevated recombinant glx expression. Moreover, these transformants showed higher ligninolytic activity than control transformants. These results suggest that the ligninolytic properties of white-rot fungi can be improved by recombinant expression of glx.

Metabolism of bisphenol A by hyper lignin-degrading fungus Phanerochaete sordida YK-624 under non-ligninolytic condition

Recently, we reported the conversion of bisphenol A (BPA) to 4-(2-(4-hydroxyphenyl)propan-2-yl)benzene-1,2-diol (hydroxy-BPA) by hyper lignin-degrading fungus Phanerochaete sordida YK-624 under non-ligninolytic condition. In the present study, the metabolism of hydroxy-BPA by P. sordida YK-624 was demonstrated under non-ligninolytic condition. Under these conditions, approximately 66% of hydroxy-BPA was degraded after 7 d of incubation. High-resolution electrospray ionization mass spectra and nuclear magnetic resonance analyses of the metabolites isolated from the culture broth indicated that hydroxy-BPA was metabolized to 4-(2-(4-hydroxyphenyl)propan-2-yl)-2-methoxyphenol (methoxy-BPA) and to 4-(2-(3,4-dimethoxyphenyl)propan-2-yl)phenol (dimethoxy-BPA) by sequential methylation events. These metabolites showed reduced estrogenic activity compared to BPA. These results suggested that the hydroxy BPA is methylated to two low toxic-methylation metabolites.

Endoplasmic reticulum stress suppressive compounds from the edible mushroom Mycoleptodonoides aitchisonii

Two novel compounds, 1 and 7, along with six known compounds (2-6 and 8), were isolated from the edible mushroom Mycoleptodonoides aitchisonii (bunaharitake in Japanese). The structures of the new compounds were determined by the interpretation of spectroscopic data. Compounds 1-4 and 6-8 showed protective activity against endoplasmic reticulum stress-dependent cell death.

Identification of novel glycosyl hydrolases with cellulolytic activity against crystalline cellulose from metagenomic libraries constructed from bacterial enrichment cultures

To obtain cellulases that are capable of degrading crystalline cellulose and cedar wood, metagenomic libraries were constructed from raw soil sample which was covered to pile of cedar wood sawdust or from its enrichment cultures. The efficiency of screening of metagenomic library was improved more than 3 times by repeating enrichment cultivation using crystalline cellulose as a carbon source, compared with the library constructed from raw soil. Four cellulase genes were obtained from the metagenomic libraries that were constructed from the total genome extracted from an enrichment culture that used crystalline cellulose as a carbon source. A cellulase gene and a xylanase gene were obtained from the enrichment culture that used unbleached kraft pulp as a carbon source. The culture supernatants of Escherichia coli expressing three clones that were derived from the enrichment culture that used crystalline cellulose showed activity against crystalline cellulose. In addition, these three enzyme solutions generated a reducing sugar from cedar wood powder. From these results, the construction of a metagenomic library from cultures that were repetition enriched using crystalline cellulose demonstrated that this technique is a powerful tool for obtaining cellulases that have activity toward crystalline cellulose.

A new compound from the mushroom Tricholoma flavovirens

A novel compound (1) and a known one (2) were isolated from the fruiting bodies of Tricholoma flavovirens. Their structures were determined by the interpretation of spectroscopic data. Both compounds showed inhibition effects on the growth of hypocotyl of lettuce with significant differences. In addition, compound 1 showed a promotion effect on the growth of root with significant differences and 2 had the similar tendency to promote the growth.