Abstract: The Bolivian Altiplano has an ongoing history of heavy metal pollution due to years of uncontrolled mining in this region. Heavy metals are a threat to natural environments such as lakes and soils with cultural and economic importance for the local communities. The extreme environmental conditions of the Bolivian Altiplano translate into alkaline soils with high concentration of minerals, high radiation and considerable daily temperature oscillations. Halophilic and halotolerant microorganisms isolated from such environments have interesting biotechnological applications including bioremediation of metal polluted waters and soils. Here, bacterial strains from the Bolivian Altiplano were characterized and biosorption capacity evaluated for three heavy metals (Pb+2, Cd+2 and Zn+2) in variable concentrations. Four strains were able to grow in multimetal medium with a final concentration of 100 mg. L-1, with a higher tolerance to Pb+2. The four isolates were selected for further characterization and were identified as different species of Halomonas genus. The best heavy metal biosorption rates for the four isolates were found at pH 7 and 37°C. Additionally, the fastest uptake rate for all three metals was under 120 minutes in the four chosen isolates. The biosorption process was best described by Langmuir isotherm for all isolates exposed to the three metals separately. The four Halomonas isolates showed a bioremediation potential for heavy metal polluted substrates, although the highest biosorption capacity values were from isolate Ss_is3 notably for Pb+2. This study provides new information about the potential biotechnological capacities of Halomonas strains isolated from mineral soils in the Andes.Abstract: The Bolivian Altiplano has an ongoing history of heavy metal pollution due to years of uncontrolled mining in this region. Heavy metals are a threat to natural environments such as lakes and soils with cultural and economic importance for the local communities. The extreme environmental conditions of the Bolivian Altiplano translate into alkaline s...Show More
Abstract: Wheat leaf blotch (Zymoseptoria tritici) is economically important foliar disease in major wheat growing areas of Ethiopia. The goal of the current study was to evaluate the effects of sowing dates, varieties, and fungicide frequencies on leaf blotch. In a factorial arrangement of RCBD, four fungicide frequencies with control, three planting dates, and two bread wheat varieties were combined as treatments combination. The highest AUDPC (2502.5) value was scored on the Pavon-76 control treatment at mid –June sowing date during 2020 cropping season, whereas, the lowest AUDPC (290.3) value on the Alidoro variety sprayed four times at early July sowing date during 2021 cropping season. Wheat grain yields were the lowest (0.91t/ha) from unsprayed plots of Pavon-76 susceptible wheat variety during early sowing dates. Alidoro variety treated with three times spray frequencies during late-sowing date produced the highest yield (7.1t/ha). The highest (2776.36$) net benefit was obtained from three times sprayed of Alidoro variety during late June sowing date and the lowest (674.4$) net benefit was obtained from pavon-76 variety without fungicides spray during mid-June sowing date. Therefore, controlling wheat leaf blotch by planting the Alidoro variety at the beginning of July with three fungicide sprays is crucial for Ethiopian farmers. Once more, the wheat pathologist is anticipating additional research including the screening of fungicides and wheat varieties. More study is important to identify the effects of topography and weather on this disease; as well as, the epidemiological study of the pathogen is very important.Abstract: Wheat leaf blotch (Zymoseptoria tritici) is economically important foliar disease in major wheat growing areas of Ethiopia. The goal of the current study was to evaluate the effects of sowing dates, varieties, and fungicide frequencies on leaf blotch. In a factorial arrangement of RCBD, four fungicide frequencies with control, three planting dates,...Show More
