Volume 18 - 2016

Bacteria from the genus Acinetobacter are opportunistic pathogens and cause harm to humans. In this study a new bacterial strain designated as Acinetobacter sp. 33F was isolated from municipal solid waste (MSW) leachate. This bacterium is useful as it degrades and utilizes dibutyl phthalate (DBP) as sole carbon source.  Acinetobacter sp. 33F degraded 82.45% of the initial 2000 mg/L of DBP in minimal salt medium. It degraded 54.36 % of initial DBP in samples collected from phthalate esters contaminated site. Monod model explained the growth kinetics of Acinetobacter sp. 33F. The calculated values of µ_max, K_s and yield were 0.01616 h^-1, 382.92 mg/L and 0.43 respectively. Stoichiometry of DBP degradation suggested that 43 g of microbial biomass was produced for every 100 g DBP consumed. Acinetobacter sp. 33F also grows on Di-Ethyl Phthalate (DEP), Di-Octyl Phthalate (DOP), Benzyl Butyl Phthalate (BBP), Mono-Butyl Phthalate (MBP) and Di–isodecyl Phthalate (DIDP) as sole carbon source. Five genes responsible for phthalate esters (PAEs) degradation were amplified from the genome of Acinetobacter sp. 33F. Acinetobacter sp. 33F can be considered as an important tool for remediation of sites contaminated with phthalate esters. 

In here we present a modified version of the RUSLE model, which can perform better than the original version at mountainous, Mediterranean catchments. A weighing coefficient is assigned at each factor in the model resulting into a reduction in the model residuals (difference between modeled and observed sediment yield). Observations are based on sediment discharge measurements conducted by the Greek Public Power Corporation (PPC). The study area includes the catchments of Venetikos, Kalamas, Arachthos and Acheloos Rivers, which are very important aquatic systems of northwestern Greece. The cross−evaluation between the originally simulated (no coefficients) and observed sediment yields attributed an initial error term value of 40 213.06t ha⁻¹. Subsequently, the model was modified (weighing coefficients were assigned regarding the PPC measurements) and the same procedure was followed, reducing the error term value to 25 937.07t ha⁻¹. The ambiguous reliability of the PPC measurements led to their replacement by simulations using the sediment discharge rating curves methodology. The modified RUSLE model is based on different weighing coefficients assigned regarding the rating curves estimations. Results show that the error term was moreover reduced to 5 834.78t ha⁻¹. The final equation was implemented to each subcatchment both at an annually and inter-annually scale in order to validate the model’s reliability. Overall, the results were satisfactory.

Epidemiological studies show that long-term exposure to PM is associated with an increased risk of cancer or cardiovascular and respiratory diseases. The main objective of the present study was the assessment of health outcomes related to PM₁₀ (particulate matter (PM) of aerodynamic diameter ≤ 10 µm) exposure in Tabriz, Iran. Related health impacts (relative risk and baselineincidence) due to exposure to PM₁₀ in the city of Tabriz were assessed by using the well-established AirQ2.2.3 model by the World Health Organization European Center for Environment Health. We estimated that out of 15,651 total deaths in the city, 7679 and 1020 people died due to cardiovascular and respiratory related deaths respectively. Among the 19,467 people admitted to hospital due to respiratory disease, 1114 diseases could be attributed to PM₁₀. According to this model, cases of natural mortality, cardiovascular deaths and respiratory mortality caused by PM₁₀ were about 832, 439, and 85, respectively.

Aniline is a harmful substance that pollutes the environment and seriously endangers human health. In the present study five different bacteria were enriched and isolated from the soil around Shiraz refinery (Iran) as aniline degrading bacteria. They were identified as Enterobacter ludwigii KH-5, Raoultella planticola KH-A2, Alcaligenes faecalis KH-A3, Serratia marcescens KH-A4 and Microbacterium barkeri KH-A1 based on 16S rDNA gene sequencing. The highest aniline degradation rate (96%) was observed by E. ludwigii KH-A5. This strain with the greatest amount of minimum inhibitory concentration (MIC) was the most aniline resistant bacterium. The optimum pH and temperature that supported biodegradation of aniline by strain KH-A5 were 7.0 and 28-35 °C, respectively. The maximum growth and biodegradation of aniline by KH-A5 were observed at the initial aniline concentration of 100 mg l^-1. The strain could growth on aniline up to concentration of 700 mg l^-1 with the degradation rate of 11%. Further studies demonstrated that the addition of 0.5 g l^-1 glucose or potassium nitrate as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 96.0% to 99.0%. However, even more addition of glucose or potassium nitrate could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain KH-A5. It could be concluded that these new strains, particularly E. ludwigii KH-A5, have a potential use for bioremediation of the site contaminated with aniline.