Immune surveillance mechanisms of the skin against the stealth infection strategy of Pseudomonas aeruginosa—Review

The present review aims to provide insight into the complex interactions between the host and Pseudomonas aeruginosa—an opportunistic microbial agent causing skin infections. Heat, humidity and skin pH are among the factors beneficial for the development of this Gram-negative agent. To cause infection, Pseudomonas aeruginosa should first overcome the primary mechanisms of defense including the cell elements and humoral factors of the skin, as well as non-specific responses—phagocytosis, inflammation, acute phase response. All they are analysed with emphasis on the fact that their detailed understanding would help revealing their potential and allow for their efficient control.     

Carotenoid profiling and biosynthetic gene expression in flesh and peel of wild-type and hp-1 tomato fruit under UV-B depletion

Although light is recognized as one of the main factors influencing fruit carotenogenesis, the specific role of UV-B radiation has been poorly investigated. The present work is addressed to assess the molecular events underlying carotenoid accumulation in presence or absence of ultraviolet-B (UV-B) light in tomato fruits of wild-type and high pigment-1 (hp-1), a mutant characterized by exaggerated photoresponsiveness and increased fruit pigmentation. Gene expression analyses indicated that in wild-type fruits UV-B radiation mainly negatively affects the carotenoid biosynthetic genes encoding enzymes downstream of lycopene both in flesh and peel, suggesting that the down-regulation of genes CrtL-b and CrtL-e and the subsequent accumulation of lycopene during tomato ripening are determined at least in part by UV-B light. In contrast to wild-type, UV-B depletion did not greatly affect carotenoid accumulation in hp-1 and generally determined minor differences in gene expression between control and UV-B-depleted conditions.     

Sequential Application of Soil Vapor Extraction and Bioremediation Processes for the Remediation of Ethylbenzene-Contaminated Soils

Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technologies is presented as a valid option but is not yet entirely studied. This work presents the study of the remediation of ethylbenzene (EB)-contaminated soils, with different soil water and natural organic matter (NOMC) contents, using sequential SVE and BR. The obtained results allow the conclusion that: (1) SVE was sufficient to reach the cleanup goals in 63% of the experiments (all the soils with NOMC below 4%), (2) higher NOMCs led to longer SVE remediation times, (3) BR showed to be a possible and cost-effective option when EB concentrations were lower than 335?mg?kg _soil ^?1 , and (4) concentrations of EB above 438?mg?kg _soil ^?1 showed to be inhibitory for microbial activity.     

Fast field cycling NMR relaxometry characterization of biochars obtained from an industrial thermochemical process

Purpose

Biochar has unique properties which make it a powerful tool to increase soil fertility and to contribute to the decrease of the amount of atmospheric carbon dioxide through the mechanisms of C sequestration in soils. Chemical and physical biochar characteristics depend upon the technique used for its production and the biomass nature. For this reason, biochar characterization is very important in order to address its use either for agricultural or environmental purposes.

Materials and methods

Three different biochars obtained from an industrial gasification process were selected in order to establish their chemical and physical peculiarities for a possible use in agronomical practices. They were obtained by charring residues from the wine-making industry (marc) and from poplar and conifer forests. Routine analyses such as pH measurements, elemental composition, and ash and metal contents were performed together with the evaluation of the cross-polarization magic angle spinning (CPMAS) ¹³C NMR spectra of all the biochar samples. Finally, relaxometry properties of water-saturated biochars were retrieved in order to obtain information on pore size distribution.

Results and discussion

All the biochars revealed basic pH values due to their large content of alkaline metals. The quality of CPMAS ¹³C NMR spectra, which showed the typical signal pattern for charred systems, was not affected by the presence of paramagnetic centers. Although paramagnetism was negligible for the acquisition of solid state spectra, it was effective in some of the relaxometry experiments. For this reason, no useful information could be retrieved about water dynamics in marc char. Conversely, both relaxograms and nuclear magnetic resonance dispersion profiles of poplar and conifer chars indicated that poplar char is richer in small-sized pores, while larger pores appear to be characteristic for the conifer char.

Conclusions

This study showed the potential of relaxometry in revealing chemical?Cphysical information on industrially produced biochar. This knowledge is of paramount importance to properly direct biochar agronomical uses.     

Experimental cultivation of the Mediterranean calanoid copepods Temora stylifera and Centropages typicus in a pilot re‐circulating system

A pilot re‐circulating system was used for the cultivation of two Mediterranean calanoid copepods: Temora stylifera and Centropages typicus. The system automatically concentrated the naupliar and copepodite stages. Temora stylifera was fed the flagellate Rhodomonas baltica or Prorocentrum minimum, whereas C. typicus was fed with a mixture of R. baltica or P. minimum and Tetraselmis suecica. Both copepods also received Isochrysis galbana. After 21 days, the T. stylifera population increased 26‐fold, reaching a density of 38 000 individuals, mostly represented by nauplii (88%). The maximum density recorded was 380 ind. L^?1, with a production of 370 nauplii L^?1. On average, the egg hatching success for this copepod during the rearing period was 54%, with the highest viability in April and May (>75%). The C. typicus population increased more than 10‐fold after 7 weeks of rearing, reaching a density of 123 000 individuals, mainly represented by nauplii (>90%). The highest naupliar production was 100 ind. L^?1, with a mean egg hatching success of 68%. This system may be useful to produce nauplii and copepodite stages to be used as live, alternative or complementary food for fish larvae or to provide a ready source of organisms for physiological and bioassay studies.     

Sponges and Their Symbionts as a Source of Valuable Compounds in Cosmeceutical Field

In the last decades, the marine environment was discovered as a huge reservoir of novel bioactive compounds, useful for medicinal treatments improving human health and well-being. Among several marine organisms exhibiting biotechnological potential, sponges were highlighted as one of the most interesting phyla according to a wide literature describing new molecules every year. Not surprisingly, the first marine drugs approved for medical purposes were isolated from a marine sponge and are now used as anti-cancer and anti-viral agents. In most cases, experimental evidence reported that very often associated and/or symbiotic communities produced these bioactive compounds for a mutual benefit. Nowadays, beauty treatments are formulated taking advantage of the beneficial properties exerted by marine novel compounds. In fact, several biological activities suitable for cosmetic treatments were recorded, such as anti-oxidant, anti-aging, skin whitening, and emulsifying activities, among others. Here, we collected and discussed several scientific contributions reporting the cosmeceutical potential of marine sponge symbionts, which were exclusively represented by fungi and bacteria. Bioactive compounds specifically indicated as products of the sponge metabolism were also included. However, the origin of sponge metabolites is dubious, and the role of the associated biota cannot be excluded, considering that the isolation of symbionts represents a hard challenge due to their uncultivable features.     

Long-term erosion of tree reproductive trait diversity in edge-dominated Atlantic forest fragments

Habitat loss and fragmentation promote relatively predicable shifts in the functional signature of tropical forest tree assemblages, but the full extent of cascading effects to biodiversity persistence remains poorly understood. Here we test the hypotheses that habitat fragmentation (a) alters the relative contribution of tree species exhibiting different reproductive traits; (b) reduces the diversity of pollination systems; and (c) facilitates the functional convergence of reproductive traits between edge-affected and early-secondary forest habitats (5-32 years old). This study was carried out in a severely fragmented 670-km² forest landscape of the Atlantic forest of northeastern Brazil. We assigned 35 categories of reproductive traits to 3552 trees (DBH ? 10 cm) belonging to 179 species, which described their pollination system, floral biology, and sexual system. Trait abundance was calculated for 55 plots of 0.1 ha across four habitats: forest edges, small forest fragments (3.4-83.6 ha), second-growth patches, and core tracts of forest interior within the largest available primary forest fragment (3500 ha) in the region. Edge-affected and secondary habitats showed a species-poor assemblage of trees exhibiting particular pollination systems, a reduced diversity of pollination systems, a higher abundance of reproductive traits associated with pollination by generalist diurnal vectors, and an elevated abundance of hermaphroditic trees. As expected, the reproductive signature of tree assemblages in forest edges and small fragments (edge-affected habitats), which was very similar to that of early second-growth patches, was greatly affected by both habitat type and plot distance to the nearest forest edge. In hyper-fragmented Atlantic forest landscapes, we predict that narrow forest corridors and small fragments will become increasingly dominated by edge-affected habitats that can no longer retain the full complement of tree life-history diversity and its attendant mutualists.     

Metal Tolerance, Accumulation and Translocation in Poplar and Willow Clones Treated with Cadmium in Hydroponics

To evaluate the phytoremediation capability of some poplar and willow clones a hydroponic screening for cadmium tolerance, accumulation and translocation was performed. Rooted cuttings were exposed for 3 weeks to 50 μM cadmium sulphate in a growth chamber and morpho-physiological parameters and cadmium content distribution in various parts of the plant were evaluated. Total leaf area and root characteristics in clones and species were affected by cadmium treatment in different ways. Poplar clones showed a remarkable variability whereas willow clones were observed to be more homogeneous in cadmium accumulation and distribution. This behaviour was further confirmed by the calculation of the bio-concentration factor (BCF) and the translocation factor (Tf). Mean values of all the clones of the two Salicaceae species showed that willows had a far greater ability to tolerate cadmium than poplars, as indicated by the tolerance index (Ti), calculated on the dry weight of roots and shoots of plants. As far as the mean values of Tf was concerned, the capacity of willows to translocate was double that of poplars. On the contrary, the mean values of total BCF in poplar clones was far higher with respect to those in willows. The implications of these results in the selection of Salicaceae clones for phytoremediation purposes were discussed.     

Spatial scaling of wildland fuels for six forest and rangeland ecosystems of the northern Rocky Mountains, USA

Wildland fuels are important to fire managers because they can be manipulated to achieve management goals, such as restoring ecosystems, decreasing fire intensity, minimizing plant mortality, and reducing erosion. However, it is difficult to accurately measure, describe, and map wildland fuels because of the great variability of wildland fuelbed properties over space and time. Few have quantified the scale of this variability across space to understand its effect on fire spread, burning intensity, and ecological effects. This study investigated the spatial variability of loading (biomass) across major surface and canopy fuel components in low elevation northern Rocky Mountain forest and rangeland ecosystems to determine the inherent scale of surface fuel and canopy fuel distributions. Biomass loadings (kg?m^?2) were measured for seven surface fuel components??four downed dead woody fuel size classes (0?C6?mm, 6?C25?mm, 25?C75?mm, and 75?+?mm), duff plus litter, shrub, and herb??using a spatially nested plot sampling design within a 1?km² square sampling grid installed at six sites in the northern US Rocky Mountains. Bulk density, biomass, and cover of the forest canopy were also measured for each plot in the grid. Surface fuel loadings were estimated using a combination of photoload and destructive collection methods at many distances within the grid. We quantified spatial variability of fuel component loading using spatial variograms, and found that each fuel component had its own inherent scale with fine fuels varying at scales of 1?C5?m, coarse fuels at 10?C150?m, and canopy fuels from 100 to 500?m. Using regression analyses, we computed a scaling factor of 4.6?m for fuel particle diameter (4.6?m increase in scale with each cm increase in particle diameter). Findings from this study can be used to design fuel sampling projects, classify fuelbeds, and map fuel characteristics, such as loading, to account for the inherent scale of fuel distributions to get more accurate fuel loading estimations.