Nutrients Can Enhance the Abundance and Expression of Alkane Hydroxylase CYP153 Gene in the Rhizosphere of Ryegrass Planted in Hydrocarbon-Polluted Soil

Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination.     

Evaluation of common cocklebur Xanthium strumarium leaf extract as post‐harvest grain protectant of black gram against pulse beetle Callosobruchus chinensis (Coleoptera: Bruchidae) and isolation of crude compound

The pulse beetle Callosobruchus chinensis L. is considered the most important stored grain pest of black gram Vigna mungo Hepper in Bangladesh and other tropical and subtropical countries. Bioactive compounds derived from plants can be used to control of the pulse beetle as a potential alternative to synthetic insecticides. Therefore, aqueous extracts of common cocklebur Xanthium strumarium L. leaf was examined for insecticidal properties against C. chinensis. The extracts showed toxicity, repellent properties, inhibited fecundity and adult emergence of the insects, and protected grains. Insect mortality was accounted highest (72.6%) with 4% extract at 4 days after treatment. The beetles showed highest repellency rate (58.0%) with 4% concentration at 1 hour exposure; however insect repellency decreased with time. The beetles exerted the lowest fecundity and grain damage and produced the lowest number of offspring when they were reared on grains treated with 4% extract. The insecticidal compounds present in common cocklebur leaf were extracted in chloroform and ethanol, and isolated by thin layer chromatography (TLC) and spectral studies (¹H‐NMR and IR), which identified the presence of aromatic ester, n‐hexyl salicylate or o‐hydroxy‐n‐hexyl‐benzoate and a long‐chain ketone. Therefore, naturally occurring X. strumarium and its derivatives may be potential components for integrated management of C. chinensis.     

Anaerobic oxidation of long-chain n-alkanes by the hyperthermophilic sulfate-reducing archaeon,Archaeoglobus fulgidus

The thermophilic sulfate-reducing archaeon Archaeoglobus fulgidus strain VC-16 (DSM 4304), which is known to oxidize fatty acids and n-alkenes, was shown to oxidize saturated hydrocarbons (n-alkanes in the range C₁₀–C₂₁) with thiosulfate or sulfate as a terminal electron acceptor. The amount of n-hexadecane degradation observed was in stoichiometric agreement with the theoretically expected amount of thiosulfate reduction. One of the pathways used by anaerobic microorganisms to activate alkanes is addition to fumarate that involves alkylsuccinate synthase as a key enzyme. A search for genes encoding homologous enzymes in A. fulgidus identified the pflD gene (locus-tag AF1449) that was previously annotated as a pyruvate formate lyase. A phylogenetic analysis revealed that this gene is of bacterial origin and was likely acquired by A. fulgidus from a bacterial donor through a horizontal gene transfer. Based on three-dimensional modeling of the corresponding protein and molecular dynamic simulations, we hypothesize an alkylsuccinate synthase activity for this gene product. The pflD gene expression was upregulated during the growth of A. fulgidus on an n-alkane (C₁₆) compared with growth on a fatty acid. Our results suggest that anaerobic alkane degradation in A. fulgidus may involve the gene pflD in alkane activation through addition to fumarate. These findings highlight the possible importance of hydrocarbon oxidation at high temperatures by A. fulgidus in hydrothermal vents and the deep biosphere.     

Enhanced nutrient uptake in salt-stressed Mentha piperita using magnetically treated water

The improvement of the growth and quality of medicinal plants under stress is of significance, worldwide. The hypothesis was to alleviate salinity stress in Mentha piperita by enhancing nutrient uptake using magnetically treated water, which to our knowledge has not been previously investigated. The objective was to test the effects of magnetized water (using alternating magnetic fields) (main plots, M1-M4 representing control, 100, 200, and 300 mT, respectively), salinity (subplots, S1-S4 representing control, 40, 80, and 120 mM NaCl, respectively), and growth medium (sub-subplots, X1-X4 representing coco peat, palm, coco peat + perlite, and palm + perlite, respectively) on M. piperita nutrient uptake in the greenhouse. The M treatments, especially the 100 and 200 mT levels, significantly increased plant N (1.08%, S3M4X1), P (0.89%, S3M3X1), K (3.23%, S3M3X1), Ca (53.6 mg/kg, S4M4X4), and Mg (39.63 mg/kg, S3M3X2) concentrations (compared with control at 0.71, 0.49, 2.4, 26.63, 1.63) even at the highest level of salinity. Magnetically treated water also significantly enhanced plant Fe and Zn concentration to a maximum of 750 μg/kg (M4S3X1) and 94.67 μg/kg (S4M4X3), under salinity stress, respectively. The single and the combined use of organic and mineral media significantly affected plant nutrient uptake, especially when used with the proper rate of M treatment. If combined with the proper growth medium, the magnetized water may be more effective on the alleviation of salt stress in Mentha piperita by enhancing nutrient uptake.

     

Clavulanic Acid Attenuating Effect on the Diabetic Neuropathic Pain in Rats

Neurochemical Research - Diabetic neuropathy is one of the most common complications of diabetes mellitus. Excess glutamate release and oxidative stress are hypothesized to be involved in the...     

Do microbial protein elicitors PeaT1 obtained from Alternaria tenuissima and PeBL1 from Brevibacillus laterosporus enhance defense response against tomato aphid (Myzus persicae)?

Tomato aphid (Myzus persicae) is a destructive insect pest of tomato responsible for huge losses in the production as well in the vegetable industry. In the present in vitro study two protein elicitors, PeaT1 and PeBL1 were considered to study their efficacies to exhibit defense response against tomato aphid. Three different concentrations of both protein elicitors were applied on the tomato seedlings. After the application of PeaT1 and PeBL1, population growth rates of tomato aphid were decreased as compared to the control treatment. In host preference assay, the tomato aphid showed a preference to build a colony on the control as compared to the treated tomato plant, because tomato leaves provided hazardous surface for aphid after the formation of wax and trichome. The concentrations of protein showed significant (p < 0.05) results in life-history traits of the aphid. Jasmonic acid (JA), salicylic acid (SA) and ethylene (ET) showed significant accumulation in tomato seedlings treated with PeaT1 and PeBL1. Elicitors treated plants produced resistance against M. persicae. Our finding suggests that PeaT1 and PeBL1 have shown high potentials against the damage of M. persicae, and both elicitors could be used as novel biological tools against tomato aphid.     

Physical Stability and Interfacial Properties of Oil in Water Emulsion Stabilized with Pea Protein and Fish Skin Gelatin

Food Biophysics - This study aimed to investigate the physical stability and interfacial properties of oil-in-water (O/W) emulsions stabilized with fish skin gelatin (FG) and pea protein (PP) at...     

Screening terrestrial and aquatic strains of Dunaliella from the eco-taxonomical perspective: a comparative study on fatty acid compositions as habitat indicators

Journal of Applied Phycology - The integration of taxonomic and ecological traits is a more balanced approach in the systematic identification of living organisms. We isolated ten strains of...     

Overexpression of the Arabidopsis NPR1 gene confers enhanced salt tolerance by regulating antioxidant and starch accumulation in citrus

Plant Cell, Tissue and Organ Culture (PCTOC) - The&nbsp;Non-Expresser of Pathogenesis-Related Genes 1 (NPR1) is a principal regulator of plant responses to biotic and abiotic stresses. In this...