The phylogeny of Isopoda, a speciose order of crustaceans, remains unresolved, with different data sets (morphological, nuclear, mitochondrial) often producing starkly incongruent phylogenetic hypotheses. We hypothesized that extreme diversity in their life histories might be causing compositional heterogeneity/heterotachy in their mitochondrial genomes, and compromising the phylogenetic reconstruction. We tested the effects of different data sets (mitochondrial, nuclear, nucleotides, amino acids, concatenated genes, individual genes, gene orders), phylogenetic algorithms (assuming data homogeneity, heterogeneity, and heterotachy), and partitioning; and found that almost all of them produced unique topologies. As we also found that mitogenomes of Asellota and two Cymothoida families (Cymothoidae and Corallanidae) possess inversed base (GC) skew patterns in comparison to other isopods, we concluded that inverted skews cause long-branch attraction phylogenetic artifacts between these taxa. These asymmetrical skews are most likely driven by multiple independent inversions of origin of replication (i.e., nonadaptive mutational pressures). Although the PhyloBayes CAT-GTR algorithm managed to attenuate some of these artifacts (and outperform partitioning), mitochondrial data have limited applicability for reconstructing the phylogeny of Isopoda. Regardless of this, our analyses allowed us to propose solutions to some unresolved phylogenetic debates, and support Asellota are the most likely candidate for the basal isopod branch. As our findings show that architectural rearrangements might produce major compositional biases even on relatively short evolutionary timescales, the implications are that proving the suitability of data via composition skew analyses should be a prerequisite for every study that aims to use mitochondrial data for phylogenetic reconstruction, even among closely related taxa.

A study of the levels of six pesticide residues (endosulfan, carbofuran, cypermethrin, profenofos, triazophos, and deltamethrin) was conducted to determine possible environmental and health risks in surface waters, sediment, and fish Catla catla. Samples were analyzed by gas chromatography with an electron capture detector. The total concentration of pesticides in water, sediment, and fish ranged from 0.005 to 3.17 μg/l, 0.61 to 23.06 ng/g dry weight, and 0.35 to 19.15 μg/g lipid-normalized units, respectively. According to the concentrations and detection frequencies, endosulfan and profenofos were the most dominant pesticides recorded in fish tissue and sediment samples. Profenofos and cypermethrin, meanwhile, were the most abundant pesticides recorded in water samples at these sites. Cypermethrin and triazophos were not detected in the sediment samples. The concentration of endosulfan, carbofuran, and deltamethrin were higher than the permissible limits for fish set by international agencies and pose a potential ecological risk to the aquatic ecosystem and a consequent hazard to human health.

The temperature increase around the world is leading to generation of drought, which is a big threat to the productivity of crops. Abiotic stresses like drought increase the ethylene level in plants. In higher plants, 1-aminocyclopropane-1-carboxylate (ACC) is considered as the immediate precursor of ethylene biosynthesis. The application of ACC-deaminase (ACCD) possessing rhizobacteria could ameliorate the harmful results of drought stress by transforming ACC into non-harmful products. Biogas slurry (BGS) improves the water-holding capacity and structure of the soil. Thus, we speculated that the integrated application of ACCD possessing rhizobacteria and BGS might be an efficient approach to mitigate the drought stress for better wheat productivity. A field experiment was conducted under skipped irrigation situations. On the tillering stage (SIT) and flowering stage (SIF), the irrigations were skipped, whereas the recommended four irrigations were maintained in the control treatment. The results of this field experiment exposed that the ACCD possessing rhizobacterial inoculations with BGS considerably improved the stomatal and sub-stomatal conductance, transpiration and photosynthetic rates up to 98%, 46%, 38%, and 73%, respectively, compared to the respective uninoculated controls. The Pseudomonas moraviensis with BGS application improved the grain yield and plant height up to 30.3% and 24.3%, respectively, where irrigation was skipped at the tillering stage, as compared to the uninoculated controls. The data obtained revealed that the P. moraviensis inoculation + BGS treatment significantly increased the relative water content (RWC), catalase (CAT) activity, ascorbate peroxidase (APX) activity, as well as grain and shoot phosphorus contents, up to 37%, 40%, 75%, 19%, and 84%, respectively, at SIF situation. The results depicted that the P. moraviensis with BGS application under drought stress could be applied for enhancing the physiological, yield, and growth attributes of wheat.

No abstract

In the present investigation, the ultrasound-assisted extraction (UAE) conditions and optimization of Rhododendron arboreum polysaccharide (RAP) yield were studied by a Box–Behnken response surface design and the evaluation of its antioxidant potential. Three parameters that affect the productivity of UAE, such as extraction temperature (50–90 °C), extraction time (10–30 min), and solid–liquid ratio (1–2 g/mL), were examined to optimize the yield of the polysaccharide percentage. The chromatographic analysis revealed that the composition of monosaccharides was found to be glucose, galactose, mannose, arabinose, and fucose. The data were fitted to polynomial response models, applying multiple regression analysis with a high coefficient of determination value (R2 = 0.999). The data exhibited that the extraction parameters have significant effects on the extraction yield of polysaccharide percentage. Derringer’s desirability prediction tool was attained under the optimal extraction conditions (extraction temperature 66.75 °C, extraction time 19.72 min, and liquid–solid ratio 1.66 mL/g) with a desirability value of 1 yielded the highest polysaccharide percentage (11.56%), which was confirmed through validation experiments. An average of 11.09 ± 1.65% of polysaccharide yield was obtained in optimized extraction conditions with a 95.43% validity. The in vitro antioxidant effect of polysaccharides of R. arboreum was studied. The results showed that the RAP extract exhibited a strong potential against free radical damage.

No abstract

Selenium (Se) nanoparticles are often synthesized by anaerobes. However, anaerobic bacteria cannot be directly applied for bioremediation of contaminated top soil which is generally aerobic. In this study, a selenite-reducing bacterium, Citrobacter freundii Y9, demonstrated high selenite reducing power and produced elemental nano-selenium nanoparticles (nano-Se) under both aerobic and anaerobic conditions. The biogenic nano-Se converted 45.8-57.1% and 39.1-48.6% of elemental mercury (Hg) in the contaminated soil to insoluble mercuric selenide (HgSe) under anaerobic and aerobic conditions, respectively. Addition of sodium dodecyl sulfonate enhanced Hg remediation, probably owing to the release of intracellular nano-Se from the bacterial cells for Hg fixation. The reaction product after remediation was identified as non-reactive HgSe that was formed by amalgamation of nano-Se and Hg. Biosynthesis of nano-Se both aerobically and anaerobically therefore provides a versatile and cost-effective remediation approach for Hg-contaminated surface and subsurface soils, where the redox potential often changes dramatically.

The concentrations of nine heavy metals (Cr, Cd, Pb, Ni, Cu, Zn, Mn, As and Fe) in the muscle tissue of four fish species (Oreochromis niloticus, Clarias gariepinus, Poecilia latipinna and Aphanius dispar dispar) collected from Wadi Hanifah were detected in two different seasons. The concentrations of the studied heavy metals, except for Cd, Pb, Ni and Cu in A. d. dispar and P. latipinna, were found to be below the safe limits recommended by various authorities and thus provide an indication of the extent of pollution of these metals. The present study also demonstrates that Zn and Cr were the most and least accumulated metals, respectively, in the studied fish muscle tissues. From the standpoint of human health, this study suggests that there is a possible health risk to consumers due to the current consumption rate of A. d. dispar and P. latipinna in Saudi Arabia.