Distribution of plant mycorrhizal traits along an elevational gradient does not fully mirror the latitudinal gradient

The influence of mycorrhizal symbiosis on ecosystem processes depends on the mycorrhizal type and status of plants. Early research hypothesized that the proportion of arbuscular mycorrhizal (AM) species decreases and of ectomycorrhizal (ECM) and ericoid mycorrhizal (ERM) species increases along increasing elevations and latitudes. However, there is very scarce information about this pattern along elevation gradients. We aimed to test this hypothesis and to describe the trends in plant mycorrhizal status by examining the Pyrenean mountain range (from 400 to 3400 m asl). The distribution of plant mycorrhizal types: AM, ECM, ERM, and non-mycorrhizal (NM) and status (obligately, OM, or facultatively, FM mycorrhizal plants, FM) were identified based on the Pyrenean Floristic Atlas and analyzed for climatic and edaphic drivers. The proportion of AM plants decreased slightly with elevation, while ECM species peaked at 1000 m asl. The proportion of ERM and NM plant species rose with increasing elevation. The proportion of FM species increased, and OM species decreased with increasing elevation. The change of AM and ECM species, and OM and FM species, along the elevational gradient, corresponds broadly to changes along the latitudinal gradient, driven by a combination of climatic and edaphic factors. Differently, the elevational occurrence of NM plant species is mainly driven only by climatic factors (low temperature) and that of ERM species by only edaphic factors (low pH). Large-scale macroecological studies (≥ 50 km grid cell) well reflect the effects of climate on the distribution of plant mycorrhizal traits, but local data (≤ 1 km grid cell) are needed to understand the effects of soil conditions and land use.

Valorisation of biowaste digestate through solid state fermentation to produce biopesticides from Bacillus thuringiensis

The main goal of this work is the production of a biopesticide through solid-state fermentation of biowaste digestate inoculated with Bacillus thuringiensis (Bt) at pilot scale using different configurations of reactors. Fermentations were carried out using insulated and non-insulated, stirred and non-stirred reactors at different scales (10, 22 and 100 L) in order to assess the influence of the reactor configuration on the biopesticide production process. A maximum temperature of 60 °C was reached in 10-L insulated non-stirred reactors where increments of Bt viable cells and spores with respect to initial values of 1.9 and 171.6 respectively, were attained. In contrast, when temperature was regulated by using 22-L non-insulated stirred reactors the increment of viable cells and spores were 0.8 and 1.9, respectively, at a stable temperature of 27 °C. When the non-insulated stirred reactor was scaled up to 100-L, the increase of viable cells and spore counts were 1.2 and 3.8 respectively, with an average temperature of 28 °C. These results demonstrated that the election of a proper reactor configuration is important when considering the development of a new SSF process, especially when dealing with non-conventional substrates as digestate.

Normative influences: How socio-cultural and industrial norms influence the adoption of sustainability practices. A grounded theory of Cretan, small tourism firms

Previous research explains the various factors that motivate or discourage the owner-managers of small firms to behave sustainably. However, it has failed to develop a meaningful understanding of how these factors inter-relate or combine to influence their decisions. This research identifies and explains how socio-cultural and industrial norms influence the intentions and behaviours towards sustainability of owner-managers of small tourism firms. This grounded theory study shows how selective peer association allows the use of norms that match one's values to predict the difficulties, benefits and therefore justification for pro-sustainability (in)action. Locally-held socio-cultural norms determine what is commonly (dis)approved of through reflective and comparative processes. Connectedness to the locality triggers empathy for nature and the local society, but not a corresponding sense of responsibility. This dissonance is managed by allocating responsibility to industry actors perceived as more powerful, particularly tour operators and consumers, and to the widespread greed and short term culture dominating the sector.

Odours and volatile organic compounds emitted from municipal solid waste at different stage of decomposition and relationship with biological stability

Odours (OU(E)) and volatile organic compounds (VOC) emission during biological process used to treat MSW were studied under standardized conditions in order to detect potential risk for workers and population. Results obtained indicated that odours and VOCs emitted depend on the biological stability of waste measured by the dynamic respiration index (DRI) and a very good correlation were found between these parameters (OU(E) vs. DRI, r=0.96, p<0.001, n=6; VOC vs. DRI, r=0.97, p<0.001, n=6). GC-MS study of the VOCs indicated the presence of a group of molecules that were degraded during the process. On the other hand, a second group of molecules, i.e. aromatic and halogenated compounds, and furan persisted in the waste sample, although molecule concentrations were always lower than Threshold Limit Value-Time Weighted Average (TLV-TWA).

Anaerobic co-digestion of the organic fraction of municipal solid waste with FOG waste from a sewage treatment plant: recovering a wasted methane potential and enhancing the biogas yield

Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSW under mesophilic conditions (37 degrees C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5L continuous reactor. Biogas yield increased from 0.38+/-0.02 L g VS(feed)(-1) to 0.55+/-0.05 L g VS(feed)(-1) as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW.

Treatment of toxic industrial wastewater in fluidized and fixed-bed batch reactors with Trametes versicolor: influence of immobilisation

This work presents the results obtained in the treatment of industrial pulp mill wastewater (black liquor) with the white-rot fungus Trametes versicolor immobilised in nylon and polyurethane foam cubes. Reductions in colour (36%), aromatic compounds (54%) and toxicity (3.15 times reduction of the initial value) were obtained when the fungus was immobilised in nylon and good toxicity reduction (5.7-fold reduction of the initial value) when polyurethane foam was used. These results were compared with those obtained with Trametes versicolor in the form of pellets for colour and aromatic compounds (84.8% and 70.2% respectively). Correlations among different parameters have been studied. Relationships between colour and changes in the molecular weight distribution profiles, as well as a correlation between laccase production and toxicity reduction have been found. For laccase production vs. toxicity reduction a different behaviour has been observed depending on the bioreactor configuration (fixed-bed reactor with immobilised Trametes versicolor or fluidised bed reactor with pellets of Trametes versicolor).

Mechanism of textile metal dye biotransformation by Trametes versicolor

The biodegradation of Grey Lanaset G, which consists of a mixture of metal complexed dye, was studied. Experiments were carried out in a bioreactor with retained pellets of the fungus Trametes versicolor that was operated under conditions of laccase production. Although decolorization was highly efficient (90%), no direct relationship to extracellular enzyme was apparent. Moreover, the extracellular enzyme was found to be unable to degrade the dye in vitro. The process involves several steps. Thus, the initial adsorption of the dye and its transfer into cells is followed by breaking of the metal complex bond in the cells release of the components. The metal (Cr and Co) contents of the biomass and treated solutions, and their closer relationship to intracellular enzyme and degradation of the dye, confirm the initial hypothesis.

Thrombocytopathia and light-chain proteinuria in a dog naturally infected with Ehrlichia canis

A 6-year-old dog was presented for evaluation of recurrent epistaxis. Platelet counts, biochemical tests, and coagulation tests were within the normal range, but a mucosal bleeding time was prolonged; there was hyperproteinemia and a monoclonal gammopathy. Heterogeneity of light chains appeared in urine, however, thus suggesting that the gammopathy was polyclonal. Platelet aggregation tests showed decreased responsiveness to collagen. An Ehrlichia canis indirect fluorescent-antibody titer was positive (1:40). Treatment with tetracycline, melphalan, and prednisone resulted in a rapid clinical improvement that persisted for at least 3 years.