Phytoremediation of heavy metals: A green technology

The environment has been contaminated with organic and inorganic pollutants. Organic pollutants are largely anthropogenic and are introduced to the environment in many ways. Soil contamination with toxic metals, such as Cd, Pb, Cr, Zn, Ni and Cu, as a result of worldwide industrialization has increased noticeably within the past few years. There are some conventional remediation technologies to clean polluted areas, specifically soils contaminated with metals. In spite of being efficient, these methods are expensive, time consuming, and environmentally devastating. Recently, phytoremediation as a cost effective and environmentally friendly technology has been developed by scientists and engineers in which biomass/microorganisms or live plants are used to remediate the polluted areas. It can be categorized into various applications, including phytofiltration, phytostabilization, phytoextraction, and phytodegradation. A brief review of phytoremediation of soils contaminated with heavy metals has been complied to provide an extensive applicability of this green technology.Key words: Phytoremediation, heavy metals, soil pollution, toxicity

Phycodnavirus Potassium Ion Channel Proteins Question the Virus Molecular Piracy Hypothesis

Phycodnaviruses are large dsDNA, algal-infecting viruses that encode many genes with homologs in prokaryotes and eukaryotes. Among the viral gene products are the smallest proteins known to form functional K+ channels. To determine if these viral K+ channels are the product of molecular piracy from their hosts, we compared the sequences of the K+ channel pore modules from seven phycodnaviruses to the K+ channels from Chlorella variabilis and Ectocarpus siliculosus, whose genomes have recently been sequenced. C. variabilis is the host for two of the viruses PBCV-1 and NY-2A and E. siliculosus is the host for the virus EsV-1. Systematic phylogenetic analyses consistently indicate that the viral K+ channels are not related to any lineage of the host channel homologs and that they are more closely related to each other than to their host homologs. A consensus sequence of the viral channels resembles a protein of unknown function from a proteobacterium. However, the bacterial protein lacks the consensus motif of all K+ channels and it does not form a functional channel in yeast, suggesting that the viral channels did not come from a proteobacterium. Collectively, our results indicate that the viruses did not acquire their K+ channel-encoding genes from their current algal hosts by gene transfer; thus alternative explanations are required. One possibility is that the viral genes arose from ancient organisms, which served as their hosts before the viruses developed their current host specificity. Alternatively the viral proteins could be the origin of K+ channels in algae and perhaps even all cellular organisms

Analysis of sennoside in drugs contained senna leaves (Cassia sp.) in Iran

Background and objectives: The importance of Cassia angustifulia is due to its laxative properties. A large number of sennosides have been reported in senna but sennoside A and B have been reported as the main causes of its properties. The present study includes the analysis of the effective ingredients of sennosides containing senna products in Iranian pharmaceutical market using UV-Visible and HPLC methods and comparing the obtained amounts with the reported amount of pharmaceutical companies. Methods: The content of sennosides as sennoside B was calculated in drugs purchased from the Iran pharmaceutical market. They were extracted using BP method and the concentration of sennosides was measured at the 500 nm. For HPLC method, sennosides were extracted by 0.1% sodium hydrogen carbonate solution and separation was done by C18 (4.6×250 mm) column as the stationary phase and methanol: water: acetic acid as the mobile phase. The diode-array detector was used to monitor the sennosides. Results: Maximum and the minimum sennosides for both methods were similar. Maximum of sennosides by UV-visible and HPLC methods were 2.75% and 2.55%, respectively. Minimum of sennosides by UV-visible and HPLC methods were 0.8% and 0.64%, respectively. Conclusion: The developed HPLC method was valid for determination of sennosides in senna-containing formulations. Sennosides content by UV-visible method was higher than the HPLC method, because all anthraquinone were calculated by UV but HPLC method separately determines the amount of Sennosides

Ecological Health Assessment of the Surface Sediments of the Coral Reefs of Khark and Kharko Islands (Persian Gulf, Iran)

To assess the ecological risk of the coral reef habitats of Khark and Kharko islands in the Persian Gulf, (Bushehr province), the surface sediment samples were collected from seven stations, in September 2019. The islands have a great ecological value due to the presence of coral reefs. The amounts of potentially toxic elements, sediment texture, total organic matter, total phosphorus and total nitrogen in the sediments were measured by inductively-coupled plasma mass spectrometry, sieve analysis, furnace burning method, spectrophotometer, and Kjeldahl, respectively. The mean concentrations of Al, Fe (%) and Ni, Pb, Zn, V, TP and TN (mg/kg) in the sediments were recorded 0.76±0.53, 0.55±0.35, 35±19, 2.1±1.5, 22±10, 40±25, 0.7±0.3 and 14.7±6.2, respectively. Based on the amount of Ni and Zn enrichment factors (moderate to very sever, respectively), their source around Khark Island could be related to human activities, such as oil industries. Pollution load index (0.06-0.25) showed all stations without pollution. The amount of Ni in stations 1 and 7 were higher than the "range of moderate effect" and "level of possible effects", which indicates the possible biological effects of this element on the benthic organisms. In general, the ecological quality of surface sediments around Kharko was better than Khark Island