Validation of recombinant and bovine chymosin by mass spectrometry

Mass spectrometry has been used to map chymosin from a fermentative source. The copresence of the two known genetic variants A (Asp(244)) and B (Gly(244)) was ascertained in bovine chymosin. By contrast, either the A or the B genetic variant occurred in the three commercial samples of recombinant calf chymosin (RCC). Specific biomarker proteins were searched to identify the enzyme source, in both bovine chymosin and RCC samples. Analyzing the derived tryptic peptides, evidence was provided that RCC and bovine chymosin are mainly formed by (1-323), (3-323), and (40p-323) (suffix "p" denotes residues in the pro-segment region of chymosin), whereas the minor components, (4-323), (5-323), and (6-323), were only detected in bovine chymosin. Additionally, the three commercial RCC samples contained the protein species (1-323), (38p-323), (39p-323), and (40p-323) and the shorter form (3-323). Differentiation of the natural and bioengineered enzyme is based upon the detection of these unique minor components by mass spectrometry.     

Cu,Pb and Zn determination in rainwater by differential pulse anodic stripping voltammetry

The parameters affecting the determination of some heavy metals in rainwater of Florence and its suburbs are investigated The maximum sensitivity for zinc determination by DPASV is obtained for a pulse amplitude of +50 mV. Samples of rainwater, collected in the center of Florence, show a metal concentration which is higher than samples collected in the suburb for the same meteorological event. Other sampling along the Tyrrenean seashore revealed a higher metal concentration in relation to the section of the coast that receives the polluted waters of the Arno river. In samples acidified to pH = 2, Cu and Zn are partially released in a very slow process.     

Biotic interactions in Antarctic terrestrial ecosystems: Are they a factor?

Antarctic terrestrial ecosystems are noted for their relative simplicity and limited trophic structure. In this context, knowledge of biotic interactions in structuring terrestrial soil communities would seem beneficial from a theoretical perspective as well as from a conservation perspective. Unfortunately, although biotic interactions are generally seen as being insignificant in these unique ecosystems, this view is based upon few explicit studies and very little is known of the role that biotic interactions may play. Accordingly, we review our current understanding of these interactions, including analogues from other appropriate ecosystems. On the basis of this review, we conclude that: (1) Antarctic terrestrial systems are predominantly abiotically-driven systems; and (2) a network of manipulative field and laboratory experiments are needed for establishing any role for biotic interactions in structuring Antarctic soil environments.     

Antibacterial activity of Cuminum cyminum L. and Carum carvi L. essential oils

Essential oils extracted by hydrodistillation from fruits of Cuminum cyminum L. and Carum carvi L. were analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). The main components of C. cyminum oil were p-mentha-1,4-dien-7-al, cumin aldehyde, gamma-terpinene, and beta-pinene, while those of the C. carvi oil were carvone, limonene, germacrene D, and trans-dihydrocarvone. Antibacterial activity, determined with the agar diffusion method, was observed against Gram-positive and Gram-negative bacterial species in this study. The activity was particularly high against the genera Clavibacter, Curtobacterium, Rhodococcus, Erwinia, Xanthomonas, Ralstonia, and Agrobacterium, which are responsible for plant or cultivated mushroom diseases worldwide. In general, a lower activity was observed against bacteria belonging to the genus Pseudomonas. These results suggest the potential use of the above essential oils for the control of bacterial diseases.     

Antibacterial activity of Coriandrum sativum L. and Foeniculum vulgare Miller Var. vulgare (Miller) essential oils

Essential oils were extracted from the fruits of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller) and assayed in vitro for antibacterial activity to Escherichia coli and Bacillus megaterium, bacteria routinely used for comparison in the antimicrobial assays, and 27 phytopathogenic bacterial species and two mycopathogenic ones responsible for cultivated mushroom diseases. A significant antibacterial activity, as determined with the agar diffusion method, was shown by C. sativum essential oil whereas a much reduced effect was observed for F. vulgare var. vulgare oil. C. sativum and F. vulgare var. vulgare essential oils may be useful natural bactericides for the control of bacterial diseases of plants and for seed treatment, in particular, in organic agriculture. The significant antibacterial activity of essential oils to the bacterial pathogens of mushrooms appears promising.     

Large wood abundance,distribution and mobilization in a third order Coastal mountain range river system,southern Chile

Large wood (LW) abundance, longitudinal distribution and mobilization were studied in the Vuelta de la Zorra channel draining a third order catchment located in the Coastal mountain range of southern Chile. Seventy-five percent of the 586.8 ha study catchment area is covered by evergreen native rainforests, 24% by Eucalyptus nitens plantations and the remaining 1% are different sites were native tree and shrub species are regenerating in areas that were prepared for forest replacement in the late 1980s but finally left unplanted. In a segment, 1557 m in length, surveyed between November 2008 and February 2009, a total of 484 pieces representing 181 m³ of LW were measured. Using bankfull width and length this volume corresponds to 109 m³ ha⁻¹ or 11.6 m³ 100 m⁻¹. LW was distributed along the channel in correlation with bankfull width. The channel segment was re-surveyed in December 2009 and we found that after one winter season 12% of the LW were transported downstream the river channel and 9 new wood elements were recruited. The LW traveled distance and traveled distance/piece diameter ratio decreased with increasing piece length/mean bankfull ratio. These results contribute to understand the complexity of LW abundance, mobilization and recruitment processes, and their effects on channel morphology, sediment routing and ecology in Chilean catchments.     

Development of specific primers for cpSSR analysis in caper,olive and grapevine using consensus chloroplast primer pairs

Chloroplast SSR (cpSSR) markers have demonstrated utility in studying genetic relationships. DNA sequence information of the chloroplast genome is necessary for the development of cpSSR primer pairs. To overcome this limitation, “consensus” primers have been developed to amplify the homologous regions in plants where chloroplast sequences are not available. However, 80% Pinus thunbergi and Nicotiana tabacum developed “consensus” primers tested with grapevine, olive and caper showed multi-locus patterns. The presence of multi-locus patterns requires the use of agarose gel electrophoresis followed from isolation and sequencing of the bands. Herein, a PCR-strategy is proposed to construct specific cpSSR primer pairs without genomic sequence information, giving single-band amplifications that can be directly sequenced. Twelve new specific cpSSR primer pairs were developed for Capparis spinosa L., Olea europea L. and Vitis vinifera L. PCR products were sequenced to confirm the presence of microsatellite sequences, and their transportability was tested on six V. vinifera cultivars. Both single-nucleotide polymorphisms and polymorphic cpSSR were observed in the six grapevine cultivars using the specific cpSSR primers.     

Genetic diversity of Grapevine rupestris stem pitting-associated virus isolates from Tunisian grapevine germplasm

Grapevine rupestris stem pitting-associated virus (GRSPaV) is one of the most widespread grapevine viruses and is transmitted mainly by grafting. GRSPaV presence was tested in 487 samples representative of the Tunisian grapevine germplasm (including autochthonous, table, wine, wild grape, and rootstock varieties) from different Tunisian regions. GRSPaV infection was detected in 51.3% of samples from different Tunisian regions, among which the table grapevine cultivars were the most commonly infected (68.7%). Genetic variability of GRSPaV isolates from wild and cultivated grapevines was assessed by sequencing the partial capsid protein (CP) gene of 19 Tunisian isolates and 1 Italian GRSPaV isolate from Sicily, and the partial RNA-dependent RNA polymerase (RdRp) gene of 13 Tunisian GRSPaV isolates. According to phylogenetic analysis of CP nucleotide sequences obtained in this study and sequences retrieved from GenBank, Tunisian isolates fell into four phylogenetic groups already described (I, II, III, and IV) and two new phylogenetic groups (VI and VIII). Phylogenetic analysis of the partial RdRp gene revealed that Tunisian isolates of GRSPaV are distributed into four phylogroups. This study highlights the importance of regular monitoring of GRSPaV infections in Tunisia, with special regard to those grapevine accessions employed in conservation and selection programmes. In particular, the presence of new GRSPaV genetic variants and infection of wild grapevines must be taken into account in order to choose a correct control strategy.     

The plant functional traits that explain species occurrence across fragmented grasslands differ according to patch management,isolation, and wetness

Context

Landscape fragmentation significantly affects species distributions by decreasing the number and connectivity of suitable patches. While researchers have hypothesized that species functional traits could help in predicting species distribution in a landscape, predictions should depend on the type of patches available and on the ability of species to disperse and grow there.

Objectives

To explore whether different traits can explain the frequency of grassland species (number of occupied patches) and/or their occupancy (ratio of occupied to suitable patches) across a variety of patch types within a fragmented landscape.

Methods

We sampled species distributions over 1300 grassland patches in a fragmented landscape of 385 km² in the Czech Republic. Relationships between functional traits and species frequency and occupancy were tested across all patches in the landscape, as well as within patches that shared similar management, wetness, and isolation.

Results

Although some traits predicting species frequency also predicted occupancy, others were markedly different, with competition- and dispersal-related traits becoming more important for occupancy. Which traits were important differed for frequency and occupancy and also differed depending on patch management, wetness, and isolation.

Conclusions

Plant traits can provide insight into plant distribution in fragmented landscapes and can reveal specific abiotic, biotic, and dispersal processes affecting species occurrence in a patch type. However, the importance of individual traits depends on the type of suitable patches available within the landscape.

     

Modelling giant red shrimp larval dispersal in the Sardinian seas: density and connectivity scenarios

The connectivity and three‐dimensional (3D) dispersion of the larvae of giant red shrimp, potentially released from known spawning areas along the Sardinia slope in the western Mediterranean Sea, were assessed using Lagrangian simulations forced by a 3D submesoscale permitting a regional ocean model. Biophysical simulations using the hydrodynamic conditions of the year 2012 were run to track propagules released from known spawning areas during the spawning period (May to September). Passive transport (PT) and vertical migration (VM) scenarios were tested, each with two possible pelagic larval durations (PLDs) of 21 or 42 days. Dispersion of propagules in the PT and VM scenarios differed in terms of travelled distance, export out of the domain (larger for VM), and depth distribution (shallower and bimodal for VM due to the larger variability of encountered currents). Connectivity patterns were investigated among eight release areas, and four predetermined Eco‐Regions, and results showed strong connectivity among the North‐Western (NW), Western (W), and Southern (S) regions of Sardinia, whereas the Eastern region was more segregated. Differences in connectivity patterns among scenarios were related mainly to the tendency of greater retention of propagules in the release area for the PT scenarios. This finding, together with existing hypotheses of vertical migration likely occurring during first egg‐larval phases, suggest that the VM scenarios are the most probable of the two hypotheses tested. Strong connectivity between the W and S sides of Sardinia and the relative isolation of the E side could have significant implications for the protection of this important resource.