Bioremediation potential of basidiomycetes isolated from compost

The potential of a consortium of three basidiomycete mycelia isolated from compost to degrade polycyclic aromatic hydrocarbons (PAH) was first evaluated using a test based on decolorization of Poly R-478 dye. When pre-grown on straw, the consortium decolorized the dye by 83% in 7 days and generated a laccase activity of 663 IU l-1. Its ability to degrade naphthalene was investigated in soil microcosms specially suited for this volatile PAH. The kinetic study was conducted at a maximal naphthalene concentration of 500 mg kg-1 of soil. Naphthalene concentration, CO2 evolution and phytotoxicity (germination index, GI%) on Lepidium sativum seeds were monitored. The naphthalene concentration decreased by about 70% in three weeks in the presence of metabolic activity, while the GI% increased indicating reduced phytotoxicity

Litter quality, decomposition rates and saprotrophic mycoflora in Fallopia japonica (Houtt.) Ronse Decraene and in adjacent native grassland vegetation

Fallopia japonica succeeds in invading different ecosystems likely because of its huge biomass production. This biomass is characterized by low nutritional quality and low decomposition rates but knowledge on whether these features are correlated to microbial decomposers is still lacking. The aims of this work were: i) to determine litter decomposition rates of native grassland vegetation and F.japonica under different conditions in a year-round experiment; ii) to evaluate litter quality and/or site effect on the decomposition of the invader and native vegetation and iii) to characterize mycoflora isolated from F.japonica and native vegetation litter. The results showed that F.japonica litter decomposes 3-4 times slower than that of native grassland, mainly due to its low N content and consequently high C/N ratio both in leaves and stems. As decomposition proceeds C/N in F.japonica litter decreases to values approaching those of the grassland litter. Site had no effect on the decomposition rates of F.japonica and grassland litter. Total fungal load and composition differed between F.japonica and native litter, and also varied across sites. These results indicate that the successful invasive plant F.japonica affects the structure and functions of the invaded ecosystem through a huge production of low quality, slow-decomposing litter that selects saprotrophic fungi

Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms.

BACKGROUND: The bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation) is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure) via enrichment (i.e., serial growth transfers) on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures) of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms. RESULTS: In this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms) on Diesel (G1) and HiQ Diesel (G2), respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity. ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30 degrees C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20 degrees C for several months. CONCLUSIONS: ENZ-G1 and ENZ-G2 are very similar highly enriched consortia of bacteria and a fungus capable of extensively degrading a broad range of the hydrocarbons mainly composing diesel fuels. Given their remarkable biodegradation potential, stability and resistance to cryopreservation, both consortia appear very interesting candidates for bioaugmentation operations on Diesel fuel impacted soils and sites

DYES ADSORPTION ON INACTIVATED FUNGAL BIOMASS: EQUILIBRIUM AND KINETICS STUDY.

The characterization of the dyes adsorption on granular particles of Cunninghamella elegans lyophilized biomass is reported. The adsorption process regarded a typical acid bath for wool and each of the three dye-components Acid Blue 62, Acid Red 266 and Acid Yellow 49. The process was characterized in terms of adsorption isotherm and of adsorption kinetics. Effects of granular size and initial pH have been assessed. The maximum adsorption capacity of lyophilised biomass with respect to Acid Blue 62, Acid Red 266, Acid Yellow 49 and to the model wastewater were 480, 210, 210 and 530 mgdye/gDM, respectively. A mutual interference among adsorbed dyes resulted. The adsorption kinetics for the Acid Blue 62 resulted of the first order type with a constant 0.85 - 0.27 h-1

The European Culture Collections and MIRRI: Why and how to participate?

The Microbial Resources Research Infrastructure (MIRRI) is at the end of its Preparatory Phase and ready to start the negotiations with the Member States in order to establish the legal framework, the MIRRI European Research Infrastructure Consortium (MIRRI-ERIC). A set of documents have been drafted which describe the governance structure, mechanisms for funding and criteria for partnership, namely “Statutes”, “Rules of Operation” and “Partner Charter”. These documents, together with the Financial Plan, have been discussed and mostly agreed by current MIRRI partners. MIRRI will assist its Partners in legal issues (e.g. Nagoya Protocol, Biosecurity), implementing best practices, developing business plans, as well as help those wishing to join MIRRI but need assistance meeting the Partner Charter. The Infrastructure will start operating with an Interim board as soon as five MIRRI-ERIC signatures are obtained