Extracts of leaf from five native Chilean weeds were evaluated in the biosynthesis of silver nanoparticles. The synthesis was monitored by UV-Vis spectra at 420 nm by typical formation of surface plasmon resonance. Moreover, the extract with major potential for the formation of nanoparticles was used to optimize the synthesis processes by response surface methodology, to obtain nanoparticles of small sizes by combination of three parameters (AgNO₃ and leaf extract concentrations and pH). Characterization of AgNPs was made by TEM, XRD, and DLS. The inhibitory activity was evaluated by disk diffusion method and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Only two out of five extracts evaluated (Hypericum perforatum and Malva nicaensis) showed capacity to biosynthesize AgNPs. pH 10, AgNO₃ (1 mM), and leaf extract at 5% vv⁻¹ were the optimal conditions to synthesize small AgNPs (< 40 nm). Inhibition zone from diffusion disk assay, MIC (30 μg mL⁻¹) and MBC (40 μg mL⁻¹), revealed a high antibacterial activity of AgNPs against Ralstonia solanacearum. Based on the results, the AgNPs biosynthesized from the leaf extract of H. perforatum is a promising antibacterial agent for its use in the control of R. solanacearum.

Considering the great lethality and sequels caused by meningitis, rapid diagnosis and prompt treatment initiation have a great impact on patient outcome. Here, we developed a multiplex-PCR for simultaneous detection of the four most prevalent bacterial pathogens directly in CSF samples. The multiplex-PCR was designed to detect the following genes: fbsA (Streptococcus agalactiae), lytA (Streptococcus pneumoniae), crtA (Neisseria meningitidis), p6 (Haemophilus influenzae), and 16S rRNA (any bacterial agent). The multiplex-PCR showed a DNA detection limit of 1 pg/μL. Among 447 CSF samples tested, 40 were multiplex-PCR positive, in which 27 and 13 had positive and negative bacterial culture, respectively. Our multiplex-PCR is fast, reliable, and easily implementable into a laboratory routine for bacterial meningitis confirmation, especially for patients who previously started antimicrobial therapy. Our molecular approach can substantially improve clinical diagnosis and epidemiological measures of meningitis disease burden.

This correction stands to correct the erroneous corresponding author name Rabson Chiza Chikoti. The publisher and everyone involved would like readers to know that the correct name credited should be Patrick Chiza Chikoti and not the former. The original article has been corrected.

Summary

Misidentification of taxa is understudied but has the potential to be a highly problematic issue. If misidentification is prevalent, there could be significant ramifications for work which relies upon a reliable taxonomic base, such as the description of new species, estimating the size of populations and species prioritisation. Here we used a match-mismatch experiment from psychology to determine the accuracy of species identification in 20 pairs of orchids (Angraecum spp. from Madagascar). The participants were split into specialist taxonomists and non-taxonomists. There was a 57.2% accuracy across all the participants. The specialist taxonomists had a high accuracy of 80.0%, with a sensitivity analysis producing an upper accuracy estimate of 90.7%. Non-taxonomists had a much lower accuracy of 55.9%. The results provide evidence of the need for specialist taxonomists, particularly in the case of identifying Malagasy orchids. Nevertheless, since misidentification is still prevalent for specialists, this is an issue that requires further research to understand how accurate identifications are made and also the implications of errors.

Gossypol is a toxic polyphenolic product that is derived from cotton plants. The toxicity of gossypol has limited the utilization of cottonseed meal (CSM) in the feed industry. The gene, Helicoverpa armigera CYP9A12, is a gossypol-inducible cytochrome P450 gene. The objective of our study was to obtain the functional recombinant H. armigera CYP9A12 enzyme in Pichia pastoris and to verify whether this candidate enzyme could decrease gossypol in vitro. Free and total gossypol contents were detected in the enzyme solution and in CSM. The H. armigera CYP9A12 enzyme degraded free concentration of gossypol. After optimization of the single-test and response surface method, free gossypol content could be decreased to 40.91 mg/kg in CSM by the H. armigera CYP9A12 enzyme when the initial temperature was 35 °C, the enzymatic hydrolysis time lasted 2.5 h, the enzyme addition was 2.5 mL, and the substrate moisture was 39%.

Background

European forests are considered a crucial resource for supplying biomass to a growing bio-economy in Europe. This study aimed to assess the potential availability of forest biomass from European forests and its spatial distribution. We tried to answer the questions (i) how is the potential forest biomass availability spatially distributed across Europe and (ii) where are hotspots of potential forest biomass availability located?

Methods

The spatial distribution of woody biomass potentials was assessed for 2020 for stemwood, residues (branches and harvest losses) and stumps for 39 European countries. Using the European Forest Information SCENario (EFISCEN) model and international forest statistics, we estimated the theoretical amount of biomass that could be available based on the current and future development of the forest age-structure, growing stock and increment and forest management regimes. We combined these estimates with a set of environmental (site productivity, soil and water protection and biodiversity protection) and technical (recovery rate, soil bearing capacity) constraints, which reduced the amount of woody biomass that could potentially be available. We mapped the potential biomass availability at the level of administrative units and at the 10 km × 10 km grid level to gain insight into the spatial distribution of the woody biomass potentials.

Results

According to our results, the total availability of forest biomass ranges between 357 and 551 Tg dry matter per year. The largest potential supply of woody biomass per unit of land can be found in northern Europe (southern Finland and Sweden, Estonia and Latvia), central Europe (Austria, Czech Republic, and southern Germany), Slovenia, southwest France and Portugal. However, large parts of these potentials are already used to produce materials and energy. The distribution of biomass potentials that are currently unused only partially coincides with regions that currently have high levels of wood production.

Conclusions

Our study shows how the forest biomass potentials are spatially distributed across the European continent, thereby providing insight into where policies could focus on an increase of the supply of woody biomass from forests. Future research on potential biomass availability from European forests should also consider to what extent forest owners would be willing to mobilise additional biomass from their forests and at what costs the estimated potentials could be mobilised.

Recent genome sequencing of Trichoderma species has opened the way for their diversity in the assessment and comparative analysis of microsatellites. Here, we compared microsatellites of three taxonomically different Trichoderma species such as T. asperellum, T. citrinoviride, and T. longibrachiatum. Our results highlight abundance and diversity of microsatellite patterns in all the test genomes. The highest relative abundance (283.6) with a relative density (3424.7) of SSRs was identified in all three sequence sets of T. citrinoviride. Among all three sequence sets, selection of these isolates were based on maximum frequency of SSRs which was of trinucleotide repeats (79.8%), whereas the dinucleotide repeat represented <8%. With the help of bioinformatics tools, species-specific diagnostic primers were developed and validated by silica PCR. Out of 31 primer sets, only 18 pairs of primer indicated successful amplification among all the species tested. A total of 34 alleles were detected and 7 loci have polymorphism information content (PIC) values greater than 0.40. In cross-species examination, of 31 markers, amplification of 5 of them was in the corresponding microsatellite regions of 18 different isolates of Trichoderma and showed monomorphic banding pattern. Microsatellite locus ThSSR3 was highly specific for Trichoderma, as amplification was not detected in closely related other 29 taxa. Primer set, ThSSR3F/ThSSR3R, amplified a specific amplicon of 600 bp from all Trichoderma species. According to intensive literature survey, the motif-based comparison is first reported here and was performed in recently sequenced three different species of Trichoderma.

Background

Fire responses of species in arid environments have only been scarcely studied. We studied four species (Dasyliron lucidum Zucc., Juniperus deppeana Steud., Echinocactus platyacanthus Link & Otto, and Agave potatorum Zucc.) in the Tehuacán-Cuicatlán Biosphere Reserve, Mexico. The objectives were to describe and quantify survival and resprouting, as well as the factors determining them, for the selected species. Six months after a 330 ha wildfire in 2014, 32 plots were established on three transects. Forest dasometric and fire severity variables were recorded. Logistic regression was utilized to obtain mortality and resprouting probability models, as well as linear regression to detect relationships among post- and pre-fire variables.

Results

All species had high survival rates (74.5 to 97.7%). All surviving D. lucidum individuals resprouted apically. For J. deppeana, the probability of mortality was directly related to fire scar height on the trunk and inversely related to its diameter, whereas the probability of crown recovery was inversely related to the proportion of the tree height scorch. For E. platyacanthus, necrosed height was directly related to plant height. There was a positive relationship between basal area and the emission of new leaves for the A. potatorum.

Conclusions

In the different species, several traits that allowed high fire survival rates were observed (e.g., thick cortex or bark, fleshy non-flammable leaves, flammable leaves that reduce fire intensity, high volume to surface ratio). Many of these were primarily linked to drought resistance. All species gain fire resistance or tolerance as they increase in size. We concluded that the studied arid ecosystem of Mexico can withstand an altered or a base fire regime.

Interferon regulatory factors (IRFs) are transcription factors of the interferon (IFN)-inducible signaling pathway essential for host immunity against antimicrobial infection by virus and bacteria. Interferon regulatory factor 3 (IRF3) regulates the expression of IFNs and IFN-stimulated genes by binding to the IFN stimulatory response element (ISRE). In this study, we analyze the thymus transcriptome of the mandarin fish Siniperca chuatsi and report the functional analysis of Irf3 from the thymus as an emerging model of antiviral approaches. The predicted S. chuatsi IRF3 (Sc-Irf3) protein has 465 amino acid residues and evolutionarily conserved domains and is clustered in the IRF3 subfamily on a phylogenetic tree. Sc-Irf3 upon transgenic expression was mainly found in the cytoplasm through Western blot analysis and microscopy, but it translocated to the nucleus after polyinosinic:polycytidylic acid (ploly I:C) treatment. Endogenous Sc-irf3 RNA expression was detected in all eight adult organs examined. Importantly, Sc-irf3 RNA expression was significantly upregulated by ploly(I:C) treatment in the adult organs. Concurrently, reporter assays revealed that Sc-Irf3 increased the transcriptional activity of the ifnβ promoter, a minimal ISRE-containing promoter, and ifn promoter of mandarin fish. Therefore, Sc-Irf3 plays a major role in the IFN immune defense system against virus infection.