Giovanna Giomaro

Phylogenetic Characterization and In Situ Detection of a Cytophaga-Flexibacter-Bacteroides Phylogroup Bacterium in Tuber borchii Vittad. Ectomycorrhizal Mycelium

ABSTRACT Mycorrhizal ascomycetous fungi are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms. In this paper we describe a straightforward approach in which a combination of morphological and molecular methods was used to survey the presence of potentially endo- and epiphytic bacteria associated with the ascomycetous ectomycorrhizal fungus Tuber borchii Vittad. Universal eubacterial primers specific for the 5′ and 3′ ends of the 16S rRNA gene (16S rDNA) were used for PCR amplification, direct sequencing, and phylogenetic analyses. The 16S rDNA was amplified directly from four pure cultures of T. borchii Vittad. mycelium. A nearly full-length sequence of the gene coding for the prokaryotic small-subunit rRNA was obtained from each T. borchii mycelium studied. The 16S rDNA sequences were almost identical (98 to 99% similarity), and phylogenetic analysis placed them in a single unique rRNA branch belonging to theCytophaga-Flexibacter-Bacteroides (CFB) phylogroup which had not been described previously. In situ detection of the CFB bacterium in the hyphal tissue of the fungus T. borchii was carried out by using 16S rRNA-targeted oligonucleotide probes for the eubacterial domain and the Cytophaga-Flexibacter phylum, as well as a probe specifically designed for the detection of this mycelium-associated bacterium. Fluorescent in situ hybridization showed that all three of the probes used bound to the mycelium tissue. This study provides the first direct visual evidence of a not-yet-cultured CFB bacterium associated with a mycorrhizal fungus of the genusTuber.

Geographical traceability of Italian white truffle (Tuber magnatum Pico) by the analysis of volatile organic compounds

Results are presented that were obtained on the geographic traceability of the white truffle Tuber magnatum Pico. Solid-phase microextraction coupled to gas chromatography/mass spectrometry (SPME-GC/MS) was employed to characterize the volatile profile of T. magnatum white truffle produced in seven geographical areas of Italy. The main components of the volatile fraction were identified using SPME-GC/MS. Significant differences in the proportion of volatile constituents from truffles of different geographical areas were detected. The results suggest that, besides genetic factors, environmental conditions influence the formation of volatile organic compounds. The mass spectra of the volatile fraction of the samples were used as fingerprints to characterize the geographical origin. Next, stepwise factorial discriminant analysis afforded a limited number of characteristic fragment ions that allowed a geographical classification of the truffles studied.

Polyphenols profile and antioxidant activity of skin and pulp of a rare apple from Marche region (Italy)

BackgroundApples are an important source of polyphenols in the human diet and the consumption of this fruit has been linked to the prevention of degenerative diseases.ResultsCatechins, procyanidins, hydroxycinnamic acids, flavonol glycosides, dihydrochalcone glycosides and one anthocyanin: cyanidin-3-O-galactoside, were identified both in the peel and pulp. Procyanidins, catechins and flavonols represent the main constituents of peel. Concerning the antioxidant activity, in the reduction of the stable DPPH radical and in the inhibition of lipid peroxidation, the ethanolic extracts of red peel and red pulp showed a good similar activity comparable to ascorbic acid in the DPPH test and about ten times more active than BHT in the lipoxygenase test, and were much more active than aqueous extracts. The ORAC value of red pulp aqueous extract resulted comparable to that of red berries: vaccinium, rubus and ribes, foods appreciated for their health value.ConclusionThis apple contains an appreciable amount of polyphenols also in the flesh; this variety with red flesh can also be useful for researchers engaged in apples varietal innovation in addition to being used as food apple.

Cultivation of Edible Ectomycorrhizal Fungi by in Vitro Mycorrhizal Synthesis

A significant proportion of ectomycorrhizal fungal species form edible fruiting bodies, and several of these species are important commercially. The most highly regarded ectomycorrhizal fungi include truffles, in particular, the Italian white truffle (Tuber magnatum Pico) and Perigord black truffle (Tuber melanosporum Vittad.), chanterelle (Cantharellus cibarius Fr.), porcini (Boletus edulisBull.: Fr. sensu latu), andmatsutake [Tricholoma matsutake (S. Ito et Imai) Sing.]. Though generally not as highly regarded, species such as the saffronmilk cap [Lactarius deliciosus (L.: Fr.) S.F. Gray], Caesar’s mushroom [Amanita caesarea (Scop.:Fr.) Pers.], burgundy truffle (Tuber uncinatum Chatin), bianchetto truffle (Tuber borchii Vittad.) and shoro [Rhizopogon rubescens (Tul.) Tul.] are also popular in some countries. Very high prices are paid for the truffles. For example, in 2003, a year in which harvest was poor, the prized Italian white truffle (T.magnatum) sold for US

Evaluation of the enzymes involved in primary nitrogen metabolism in Tilia platyphyllos-Tuber borchii ectomycorrhizae

2,200–4,600/kg (http://www.tuber.it/pagine/comuni/borsa.php), while the Perigord black truffle retailed for US

Inhibition of Breast Cancer Cell Proliferation and In Vitro Tumorigenesis by a New Red Apple Cultivar

900–2,000/kg and the bianchetto truffle, generally modestly priced, for US

Edible Ectomycorrhizal Mushroom Molecular Response to Heavy Metals

300/kg (http://www. Acqualagna.info/). Matsutake is also very highly regarded, and grade 1 can retail forUS

Characterization of the Tuber borchii nitrate reductase gene and its role in ectomycorrhizae

1,250/kg ormore (Martinez-Carrera et al. 2002).Despite these high prices, over the past fewdecades, there has been a steady upward trend in the price paid for these fungi, due to a general decline in production (Hall et al. 2003a). Numerous factors have led to this steady decline in production, including deforestation, the introduction of exotic forest species that are not symbiotic with edible mycorrhizal mushrooms, poor forest management and indiscriminate harvesting of fruiting bodies. Other factors, such as

Estimation of fungal biomass and transcript levels in Tilia platyphyllos-Tuber borchii ectomycorrhizae.

No information is available about Tuber borchii Vittad. ammonium metabolism during its life cycle, which involves the succession of three distinct phases. In this direction, the levels of glutamine synthetase (GS; EC 6.3.1.2), glutamate synthase (GOGAT; EC 1.4.1.13-14) and glutamate dehydrogenase (GDH; EC 1.4.1.2-4) were evaluated in Tilia platyphyllos Scop.-Tuber borchii Vittad. ectomycorrhizae, free living mycelium and non-inoculated roots. In the plant roots, GS shows high specific activity and only NADH-GDH (EC 1.4.1.2) is detectable; on the other hand, in free living mycelium GS and NADPH-GDH (EC 1.4.1.4) can be detected. Ectomycorrhizal metabolism was found to be deeply influenced by the two symbiotic partners. In fact, GS and both forms of GDH are present and their specific activities are higher than those found in the plant root and in the mycelial cells.

Volatiles Profile of Red Apple from Marche Region (Italy)

Purpose The aim of this study was to evaluate the antiproliferative activity in breast cancer cells and the inhibition of tumorigenesis in pre-neoplastic cells of a new apple cultivar with reddish pulp, called the Pelingo apple. Methods The antiproliferative activity was evaluated in MCF-7 and MDA-MB-231 human breast cancer cells. The inhibition of tumorigenesis was performed in JB6 promotion-sensitive (P+) cells. Results Results showed that Pelingo apple juice is characterized by a very high polyphenol content and strongly inhibited breast cancer cell proliferation. Its antiproliferative activity was found to be higher than the other five apple juices tested. Pelingo juice induced cell accumulation in the G2/M phase of the cell cycle and autophagy through overexpression of p21, inhibition of extracellular signal-regulated kinases 1/2 (ERK1/2) activity and an increase in lipidated microtubule-associated protein-1 light chain-3 beta (LC3B). Remarkably, Pelingo juice inhibited the 12-o-tetra-decanoyl-phorbol-13-acetate (TPA)-induced tumorigenesis of JB6 P+ cells, suppressing colony formation in semi-solid medium and TPA-induced ERK1/2 phosphorylation. Conclusions Our data indicate that the Pelingo apple is rich in food components that can markedly inhibit in vitro tumorigenesis and growth of human breast cancer cells and could provide natural bioactive non-nutrient compounds, with potential chemopreventive activity.