Identification, Characterization, and Modeling of a Bioinsecticide Protein Isolated from Scorpion Venom gland: A Three-Finger Protein.

Background: The majority of insecticides target sodium channels. The increasing emergence of resistance to the current insecticides has persuaded researchers to search for alternative compounds. Scorpion venom gland as a reservoir of peptides or proteins, which selectively target insect sodium channels. These proteins would be an appropriate source for finding new suitable anti-insect components. Methods: Transcriptome of venom gland of scorpion Mesobuthus eupeus was obtained by RNA extraction and complementary DNA library synthesis. The obtained transcriptome was blasted against protein databases to find insect toxins against sodium channel based on the statistically significant similarity in sequence. Physicochemical properties of the identified protein were calculated using bioinformatics software. The three-dimensional structure of this protein was determined using homology modeling, and the final structure was assessed by molecular dynamics simulation. Results: The sodium channel blocker found in the transcriptome of M. eupeus venom gland was submitted to the GenBank under the name of meuNa10, a stable hydrophilic protein consisting of 69 amino acids, with the molecular weight of 7721.77 g/mol and pI of 8.7. The tertiary structure of meuNa10 revealed a conserved LCN-type cysteine-stabilized alpha/beta domain stabilized by eight cysteine residues. The meuNa10 is a member of the 3FP superfamily consisting of three finger-like beta strands. Conclusion: This study identified meuNa10 as a small insect sodium channel-interacting protein with some physicochemical properties, including stability and water-solubility, which make it a good candidate for further in vivo and in vitro experiments in order to develop a new bioinsecticide.

Distribution of total petroleum hydrocarbons in superficial sediments of Karun River Basin, southwest of Iran: spatial and seasonal variations, source identification, and ecological risk.

Total petroleum hydrocarbons (TPHs) are common environmental pollutants in aquatic ecosystems that tend to adsorb onto the sediments. This study aimed to monitor the concentration and assessment of contamination level of TPHs in the sediments of Karun River and Bahmanshir estuary, which will eventually flow into the Persian Gulf. GIS-mapping technique was used to indicate the distribution of TPHs. The samples were collected during dry and wet seasons at 15 monitoring stations. - The maximum amount of TPHs was obtained at station No. 14 in the dry season (225.29 µg/g). The indices of determining the pollution source showed that hydrocarbons in polluted areas were mainly of biogenic origin. Compared to sediment quality guidelines (SQGs) and contamination factor (Cf), the study area sediments were in the conditions of moderate pollution and had a low ecological risk.

Petroleum Contaminated Seawater Detoxification in Microcosm by Halotolerant Consortium Isolated from Persian Gulf.

Bioremediation of a petroleum contaminated seawater from Persian Gulf was investigated and efficiency of natural attenuation by native halotolerant bacterial consortium, biostimulation by addition of macro nutrients (nitrogen and phosphorus) and surfactant and bioaugmentation by application of halotolerant hydrocarbon degrading strains were evaluated. Biodegradation rates in defined conditions were studied for 30 days. Four pure isolates including Bacillus sp. PG-1, Pseudomonas aeruginosa PG-2, Paenibacillus lautus PG-3, and Pseudomonas putida PG-4 were used to preparation of bacterial consortium. Results indicated that the bioaugmentation yielded the best TPH removal efficiency of 56.24%, followed by biostimulation with surfactant addition (removal of 31.52%). The most bacterial density was also observed for bioaugmentation bioreactor. Toxicity of reaction medium was evaluated by oxygen consumption rate inhibition, dehydrogenase activity inhibition and growth rate inhibition methods in which, the least toxicity rates of 27%, 25% and 31% were observed for bioaugmentation based bioreactor, respectively. Simultaneous bioaugmentation and biostimulation can efficiently reduce the crude oil content in the surface of seawater using halotolerant strains.