1,720,991 research outputs found
Phenotype MicroArrayTM system in the study of fungal functional diversity and catabolic versatility
No full textFungi cover a range of important ecological functions associated with nutrient and carbon cycling in leaf litter and soil. As a result, research on existing relationships between fungal functional diversity, decomposition rates and competition is of key interest. Indeed, availability of nutrients in soil is largely the consequence of organic matter degradation dynamics. The Biolog® Phenotype MicroArraysTM (PM) system allows for the testing of fungi against many different carbon sources at any one time. The use and potential of the PM system as a tool for studying niche overlap and catabolic versatility of saprotrophic fungi is discussed here, and examples of its application are provided
A simple method for measuring fungal metabolic quotient and comparing carbon use efficiency of different isolates. Application to Mediterranean leaf litter fungi
No full textThe metabolic efficiency of different microbial groups in carbon source uses and single species storage efficiency is poorly characterized and not adequately represented in most biogeochemical models. It it is proposed here a simple approach for an estimation of the metabolic quotient of fungal isolates. The method is based on the values of substrate use (respiration) and growth (biomass production) obtainable for single fungal isolates in vitro using the Phenotype MicroArrayTM system to test the metabolic performance of fungi on different substrates. As a case study, this carbon-use efficiency method was used to compare a group of leaf litter fungi. The metabolic efforts of single fungal species were measured on 95 different substrates of different complexity. The respiration to biomass ratio showed a high reliability and the possibility of being used as a measurable property of the microorganisms and an indicator of organism’s performance or fitness
Draft genome sequence of the biosurfactant producing Minimedusa polyspora FBL 503 (basidiomycota; agaricomycotina)
No full textThe soil microfungi that release biosurfactants and tolerate recalcitrant organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) may be of outstanding importance for mycoremediation of polluted sites, in a cost-efficient and environmentally friendly manner. Minimedusa polyspora FBL 503 (Agaricomycetes, Cantharellales) showed characteristics with a high biotech potential. The strain FBL 503 tolerated naphthalene, phenanthrene, pyrene, each PAH at 20 mg/L, and a mix of them (1:1:1) at 60 mg/L as well as exhibited biosurfactant activity. In particular, the production of biosurfactants was carried out in yeast extract broth (10g/L) with the addition of 40g/L of olive oil. Fourteen days after inoculation, the culture medium was recovered and the production of biosurfactants was evaluated by means of the oil dispersion test. The activity of the biosurfactants found in the culture filtrate was evaluated on olive oil, diesel oil, and exhausted motor oils from a scooter and a freeze-dryer vacuum pump. The biosurfactants from FBL 503 resulted efficient, to different extent, in displacing all the tested oils.
In this context, we obtained the draft genome sequence of the strain FBL 503 with Illumina platform. The genome was assembled denovo and was used to functionally annotate M. polyspora FBL 503. We calculated the predicted genes, including genes encoding secreted CAZymes, proteases, and lipases present in the genome. Moreover, mining the genome for genes involved in secondary metabolism biosynthesis resulted in the identification of biosynthetic gene clusters. The genes encoding enzymes for the enhanced solubility of PAHs such as biosurfactants and lipases, which could be included in the PAH degradation pathway, were found in the M. polyspora FBL 503 genome. Our genomic data on FBL 503 are a basis for transcriptomic approaches under exposure to organic pollutants.
The INAIL-DIT (PAR 2019-2021) financially supported the genome sequencing of M. polyspora FBL 503
Overlap in substrate utilisation and spatial exclusion in some microfungi which act as early cellulose colonisers in a Mediterranean environment
No full textA trapping system was set up to isolate culturable cellulolytic fungi at the soil-leaf litter interface in an area of Mediterranean maquis located in southern Italy. Seven cellulolytic taxa were isolated and cultured to represent the pioneers in the primordial phase of cellulose colonisation. The functional diversity of fungal isolates was analysed using a phenotype microarray technique to generate a profile of their functional traits. The extent of the overlap in substrate utilisation by the various species was subsequently determined. Some of the species that acted as key cellulose decomposers are considered globally distributed air-borne contaminants. Most of the cellulolytic species that were isolated during the experiment are also well known for their competitive abilities. Our study showed that at an early stage of cellulose colonisation a few fungal species with potential overlap in the overall metabolic function were able to establish themselves. The species that prevailed at the onset of cellulose colonisation did not co-occur in the field sites. A sort of “founder effect” could be hypothesised for microfungi when colonising sterile cellulose. This would suggest that scale (i.e. the spatial component) exerts a strong influence on the causative mechanisms that link genetic fungal diversity to specific ecosystem functions
Roles of saprotrophic fungi in biodegradation or transformation of organic and inorganic pollutants in co-contaminated sites
Full text linkFor decades, human activities, industrialization, and agriculture have contaminated soils and water with several compounds, including potentially toxic metals and organic persistent xenobiotics. The co-occurrence of those toxicants poses challenging environmental problems, as complicated chemical interactions and synergies can arise and lead to severe and toxic effects on organisms. The use of fungi, alone or with bacteria, for bioremediation purposes is a growing biotechnology with high potential in terms of cost-effectiveness, an environmental-friendly perspective and feasibility, and often representing a sustainable nature-based solution. This paper reviews different ecological, metabolic, and physiological aspects involved in fungal bioremediation of co-contaminated soils and water systems, not only addressing best methods and approaches to assess the simultaneous presence of metals and organic toxic compounds and their consequences on provided ecosystem services but also the interactions between fungi and bacteria, in order to suggest further study directions in this field
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Saprotrophic soil fungi to improve phosphorus solubilisation and release. In vitro abilities of several species
Full text linkModern agriculture is dependent on phosphate rock (PR), which is a nonrenewable resource. Improvement of phosphorus (P) availability for crops in agricultural soils represents a key strategy to slow down the depletion of PR. The aim of this study was to identify potential P biofertilisers among saprotrophic fungal species. We tested 30 fungal strains belonging to 28 taxa (4 Zygomycota and 24 Ascomycota) and with different life strategies. The study showed that many saprotrophic fungi have the ability to mobilise P from insoluble forms according to a variety of mechanisms. Our results expand the pool of P solubilising fungal species, also suggesting a new solubilisation index and shedding light on parameters that could be basic in the selection of efficient soil P-biofertilisers fungi. Rhizopus stolonifer var. stolonifer, Aspergillus niger and Alternaria alternata were found to be the best performing strains in terms of amounts of TCP solubilisation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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