Profiling the Linear Peptides of Venom from the Brazilian Scorpion Tityus serrulatus: Structural and Functional Characterization.

Scorpion venoms are a rich source of bioactive peptides, most of which are neurotoxic, with 30 to 70 amino acid residues in their sequences. There are a scarcity of reports in the literature concerning the short linear peptides found in scorpion venoms. This type of peptide toxin may be selectively extracted from the venom using 50% (v/v) acetonitrile. The use of LC-MS and MS/MS enabled the detection of 12 bioactive short linear peptides, of which six were identified as cryptides. These peptides were shown to be multifunctional, causing hemolysis, mast cell degranulation and lysis, edema, pain, and anxiety, increasing the complexity of the envenomation mechanism. Apparently, the natural functions of these peptide toxins are to induce inflammation and discomfort in the victims of scorpion stings.

Profiling the linear peptides of venom from the Brazilian scorpion Tityus serrulatus: structural and functional characterization

Scorpion venoms are a rich source of bioactive peptides, most of which are neurotoxic, with 30 to 70 amino acid residues in their sequences. There are a scarcity of reports in the literature concerning the short linear peptides found in scorpion venoms. This type of peptide toxin may be selectively extracted from the venom using 50% (v/v) acetonitrile. The use of LC-MS and MS/MS enabled the detection of 12 bioactive short linear peptides, of which six were identified as cryptides. These peptides were shown to be multifunctional, causing hemolysis, mast cell degranulation and lysis, edema, pain, and anxiety, increasing the complexity of the envenomation mechanism. Apparently, the natural functions of these peptide toxins are to induce inflammation and discomfort in the victims of scorpion stings.

Physical Pretreatments Applied in Three Commercial Kits for the Extraction of High-Quality DNA from Activated Sewage Sludge.

Obtaining sufficient and high-quality genomic DNA from sludge samples is a fundamental issue of feasibility and comparability in genomic studies of microbial diversity. Commercial kits for soil are often used for the extraction of gDNA from sludge samples due to the lack of specific kits. However, the evaluation of the performance of commercial kits for sludge DNA extraction is scarce and optimization of these methods to obtain a high quantity and quality of DNA is necessary, especially for downstream genomic sequencing. Sequential batch reactors (SBRs) loaded with lignocellulosic biomass are used for the synthesis of renewable resources such as levulinic acid (LA), adipic acid (AA), and polyhydroxyalkanoates (PHAs), and the biochemical synthesis of these compounds is conducted through the inoculation of microbes present in the residual activated sludge (AS) obtained from a municipal wastewater treatment plant. To characterize these microbes, the extraction of DNA from residual sewage sludge was conducted with three different commercial kits: Nucleospin® Soil from Macherey-Nagel, DNEasy® PowerSoil® from Qiagen, and E.Z.N.A.® Plant DNA Kit from Omega BIO-TEK. Nevertheless, to obtain the highest load and quality of DNA for next-generation sequencing (NGS) analysis, different pretreatments and different combinations of these pretreatments were used. The pretreatments considered were an ultrasonic bath and a temperature of 80 °C, together and separately with different incubation time periods of 30, 60, and 90 min. The results obtained suggest a significant improvement in the efficiency and quality of DNA extraction with the three commercial extraction kits when used together with the ultrasonic bath and 80 °C for 60 min. Here, we were able to prove that physical pretreatments are a viable alternative to chemical lysis for DNA extraction from complex samples such as sludge.

A temporal and spatial study of genetic structure in four species of bladed Bangiales (Rhodophyta) from the southeastern Pacific coast of Chile.

The coastline is a heterogeneous and highly dynamic environment influenced by abiotic and biotic variables affecting the temporal stability of genetic diversity and structure of marine organisms. The aim of this study was to determine how much the genetic structure of four species of marine Bangiales vary in time and space. Partial sequences of the cytochrome oxidase I (COI) gene obtained from two Pyropia (Py. sp. CHJ and Py. orbicularis) and two Porphyra (P. mumfordii and P. sp. FIH) species were used to compare the effect of the 40° S/41° S biogeographic break (spatial-regional scale) and the one of the Valdivia River discharges (spatial-local scale) and determine their temporal stability. Four seasonal samplings were taken during 1 year at five sites, one site located in Melinka (Magallanes province) and four sites along the coast of Valdivia (Intermediate area), on both sides of the river mouth. Results showed a strong genetic spatial structure at regional scale (ΦST > 0.4) in Py. sp. CHJ, Py. orbicularis, and P. mumfordii, congruent with the 41° S/42° S biogeographic break. A potential barrier to gene flow, related to the Valdivia River discharge, was detected only in P. mumfordii. In P. sp. FIH, spatial genetic structure was not detected at any scale. The genetic structure of all four species is stable throughout the year. The potential effect of main currents and river discharge in limiting the transport of Bangiales spores are discussed. We propose that both a restricted propagule dispersal and the formation potential for persistent banks of microscopic stages could lead to a temporally stable spatial partitioning of genetic variation in bladed Bangiales.

More than What Meets the Eye: Differential Spatiotemporal Distribution of Cryptic Intertidal Bangiales.

Morphologically similar but genetically distinct species have been termed cryptic and most have been assumed to be ecologically similar. However, if these species co-occur at a certain spatial scale, some niche differences at finer scales should be expected to allow for coexistence. Here, we demonstrate the existence of a disjointed distribution of cryptic bladed Bangiales along spatial (intertidal elevations) and temporal (seasons) environmental gradients. Bladed Bangiales were identified and quantified across four intertidal elevations and four seasons for one year, at five rocky intertidal sites (between 39° S and 43° S) in southern Chile. Species determination was based on partial sequences of the mitochondrial cytochrome c oxidase 1 (COI) gene amplification. To assess species gross morphology, thallus shape, color, and maximum length and width were recorded. Hundreds of organisms were classified into nine Bangiales species belonging to three genera (i.e., Fuscifolium, Porphyra, and Pyropia), including five frequent (>97% of specimens) and four infrequent species. All species, except for Pyropia saldanhae, had been previously reported along the coasts of Chile. The thallus shape and color were very variable, and a large overlap of the maximum width and length supported the cryptic status of these species. Multivariate analyses showed that the main variable affecting species composition was intertidal elevation. Species such as Py. orbicularis were more abundant in low and mid intertidal zones, while others, such as Po. mumfordii and Po. sp. FIH, were principally observed in high and spray elevations. Despite all numerically dominant species being present all year long, a slight effect of seasonal variation on species composition was also detected. These results strongly support the existence of spatial niche partitioning in cryptic Bangiales along the Chilean rocky intertidal zone.