Successful phytoremediation of crude-oil contaminated soil at an oil exploration and production company by plants-bacterial synergism

Phytoremediation is a promising approach for the cleanup of soil contaminated with petroleum hydrocarbons. This study aimed to develop plant-bacterial synergism for the successful remediation of crude oil-contaminated soil. A consortia of three endophytic bacteria was augmented to two grasses, Leptochloa fusca and Brachiaria mutica, grown in oil-contaminated soil (46.8 g oil kg^?1 soil) in the vicinity of an oil exploration and production company. Endophytes augmentation improved plant growth, crude oil degradation, and soil health. Maximum oil degradation (80%) was achieved with B. mutica plants augmented with the endophytes and it was significantly (P < 0.05) higher than the use of plants or bacteria individually. Moreover, endophytes showed more persistence, the abundance and expression of alkB gene in the rhizosphere as well as in the endosphere of the tested plants than in unvegetated soil. A positive relationship (r = 0.70) observed between gene expression and crude oil reduction indicates that catabolic gene expression is important for hydrocarbon mineralization. This investigation showed that the use of endophytes with appropriate plant is an effective strategy for the cleanup of oil-contaminated soil under field conditions.     

In-vitro and In-vivo management of Meloidogyne incognita (Kofoid and White) Chitwood and Rhizoctonia bataticola (Taub.) Butler in cotton using organic’s

Root-knot nematodes Meloidogyne incognita (Kofoid and White) Chitwood and Rhizoctonia bataticola (Taub.) Butler, fungus, are very dangerous root damaging pathogens. Present study was planned to establish a chemical control of these root deteriorating pathogens under lab conditions as well as in field. Maximum death rate of nematode juveniles and minimum numbers of nematode eggs hatched were recorded in plates treated with Cadusafos (Rugby® 100G) @12 g/100 ml and Cartap® (4% G) @9g/100 ml. Chemical treatment of Rhizoctonia bataticola with Trifloxystrobin + Tebuconazole (Nativo®) @0.2 g/100 ml and Mancozeb + Matalaxyl (Axiom) @0.25 g/100 ml significantly controlled the mycelial growth in plates. The best treatments tested in laboratory were applied in field as protective and curative treatments. Results proved that chemical control of root-knot nematode and root rot fungi by tested chemicals at recommended time and dose is a significant management technique under field conditions.     

Isolation and Characterization of Bacteria from Coal Mines of Dara Adam Khel,Pakistan

The coal fields of Pakistan and their microbiology have not been fully explored. Therefore, a study was conducted on the coal mines of Dara Adam Khel located in the Federally Administered Tribal Areas of Pakistan. For this purpose, sampling was done from nine different mines with varying depths. A total of 32 bacterial strains were isolated and their colony size, form, texture, color, margin, elevation and opacity were noted. The majority of the strains (75%) were found Gram negative. The bacterial strains were then characterized in detail by different biochemical tests including catalase, citrate, oxidase, indole, triple sugar iron, motility, methyl red-Vogues Proskeur, nitrate reduction and phenylalanine deaminase, and an enormous physiological diversity was observed. The Gram positive strains were further characterized on molecular level using 16S rRNA gene amplification and sequence analysis. Based on molecular analysis, seven strains were identified as Bacillus tequilensis, B. cereus, Janibacter melonis, Kocuria atrinae, B. anthracis, K. rosea and B. simplex. The other two strains (strains 6 and 41) had molecular similarity of only 98% and 97% with Brachybacterium spp. and Arthrobacter spp. respectively. The phylogenetic analysis further suggested that the strains 6 and 41 may be potential candidates for novel species; however, further work is needed for confirmation.     

Probing the intermolecular interactions into serum albumin and anthraquinone systems: a spectroscopic and docking approach

Intermolecular interaction study of human serum albumin (HSA) with two anthraquinones i.e. danthron and quinizarin has been performed through fluorescence, UV-vis and CD spectroscopy along with docking analysis. The titration of drugs into HSA solution brought about the quenching of fluorescence emission by way of complex formation. The binding constants were found to be 1.51 × 10⁴ L mol^?1 and 1.70 × 10⁴ L mol^?1 at λ_exc = 280 nm while at λ_exc = 295 nm, the values of binding constants were 1.81 × 10⁴ L mol^?1 and 1.90 × 10⁴ L mol^?1 which hinted toward binding of both the drugs in the vicinity of subdomain IIA. Different temperature study revealed the presence of static quenching mechanism. Moreover, more effective quenching of the fluorescence emission was observed at λ_exc = 295 nm which also suggested that both the drug molecule bind nearer to Trp-214. Thermodynamic parameters showed that hydrophobic interaction was the major force behind the binding of drugs. The UV-vis spectroscopy testified the formation of complex in both the systems and primary quenching mechanism as static one. The changes in secondary structure and α-helicity in both the systems were observed by circular dichroism spectroscopy. Furthermore, molecular docking analysis predicted the probable binding site of drugs in subdomain IIA of HSA molecule. The types of amino acid residues surrounding the drug molecule advocated that van der Waals forces, hydrophobic forces and electrostatic forces played a vital role in the stabilization of drug-protein complex formed.     

Foliar application of ascorbic acid enhances salinity stress tolerance in barley (Hordeum vulgare L.) through modulation of morpho-physio-biochemical attributes,ions uptake,osmo-protectants and stress response genes expression

Barley (Hordeum vulgare L.) is a major cereal grain and is known as a halophyte (a halophyte is a salt-tolerant plant that grows in soil or waters of high salinity). We therefore conducted a pot experiment to explore plant growth and biomass, photosynthetic pigments, gas exchange attributes, stomatal properties, oxidative stress and antioxidant response and their associated gene expression and absorption of ions in H. Vulgare. The soil used for this analysis was artificially spiked at different salinity concentrations (0, 50, 100 and 150 mM) and different levels of ascorbic acid (AsA) were supplied to plants (0, 30 and 60 mM) shortly after germination of the seed. The results of the present study showed that plant growth and biomass, photosynthetic pigments, gas exchange parameters, stomatal properties and ion uptake were significantly (p < 0.05) reduced by salinity stress, whereas oxidative stress was induced in plants by generating the concentration of reactive oxygen species (ROS) in plant cells/tissues compared to plants grown in the control treatment. Initially, the activity of antioxidant enzymes and relative gene expression increased to a saline level of 100 mM, and then decreased significantly (P < 0.05) by increasing the saline level (150 mM) in the soil compared to plants grown at 0 mM of salinity. We also elucidated that negative impact of salt stress in H. vulgare plants can overcome by the exogenous application of AsA, which not only increased morpho-physiological traits but decreased oxidative stress in the plants by increasing activities of enzymatic antioxidants. We have also explained the negative effect of salt stress on H. vulgare can decrease by exogenous application of AsA, which not only improved morpho-physiological characteristics, ions accumulation in the roots and shoots of the plants, but decreased oxidative stress in plants by increasing antioxidant compounds (enzymatic and non-enzymatic). Taken together, recognizing AsA's role in nutrient uptake introduces new possibilities for agricultural use of this compound and provides a valuable basis for improving plant tolerance and adaptability to potential salinity stress adjustment.     

Earliness index deters <Emphasis Type="Italic">Pectinophora gossypiella</Emphasis> incidence on advanced cultivars of <Emphasis Type="Italic">Bt</Emphasis> cotton

Pink bollworm (Pectinophora gossypiella) is recognized as an important pest of cotton and can damage flowers and bolls of both Bt and non-Bt cultivars. Cry-1Ac in Bt cultivars is considered very effective in controlling lepidopterous larvae; therefore, the present study was carried out to investigate the impact of Cry1-Ac and the earliness index on the natural incidence of P. gossypiella at the Cotton Research Institute, Faisalabad. During 2015–2016, ten cultivars were used to determine the incidence of pink bollworm infestation. The experiment was repeated for 2 years. During the next year, Cry1-Ac and earliness traits of selected cultivars were also observed to determine their impact on pink bollworm. Correlation coefficient results regarding days to first flower (r value = 0.66) as well as the earliness index (r value = ? 0.62) exhibited a strong association with pink bollworm, but Cry1-Ac had a weak association (r value = ? 0.058) with pink bollworm. The coefficient of determination (R ²) explained that variability of pink bollworm due to Cry1-Ac, the earliness index, and days to first flower was 18.0, 38.5, and 43.5%, respectively. Principal component analysis results showed that the first two PCs expressed 87% of the total variability. Clusters made on the basis of the studied parameters revealed that clusters 2 and 3 comprised the cotton cultivars possessing earliness traits compared with cluster 1. Therefore, it can be concluded that the earliness index in cotton is an important component for the sustainable management of pink bollworm infestation, the need for which is endless to evade the pink bollworm problem in the era of climate change.