Search results for "Environmental engineering"
showing 10 items of 2674 documents
Nest-mediated parental care in a marine fish: Are large-scale nesting habitats selected and do these habitats respond to small-scale requirements?
2018
Fishes have evolved various reproductive strategies including mechanisms that involve parental care and demersal eggs laid into nests. Symphodus ocellatus has a seasonal reproduction period during which large, dominant males become territorial and build nests with fragments of algae, where they attract females to spawn and provide care to the developing eggs. Based on the hypothesis that the S. ocellatus males choose the reproductive habitat based on some characteristics of the substrate, here we assessed whether, on a coastal area scale, the distribution of this species changes during the reproductive period because of the selection of some suitable sites or substrates, and whether the nes…
Effect of Nanoaquacitrates on Physiological Parameters of Fodder Galega Infected with Phytoplasma
2018
AbstractThe laboratory experiments have been found that soaking seedsGalega orientalisL. (Fodder galega) in nanoaquacitrates solutions of Mn (10 and 20 mg/dm3), Mo (4 mg/dm3) and Mg (2 and 4 mg/dm3), has been lead to germination energy rise, while Mn (10 and 20 mg/dm3) and Mo (4 mg/dm3) concentrations has been influenced germinating ability. At the same time, the soaking seeds in solution of nanoaquacitrates Mn (20 mg/dm3) had the biggest stimulatory effect on the accumulation 7 daily sprouts mass (on 18%). It has been shown that soaking seeds in nanoparticles Mn and Mo solutions leads to the increase of catalase activities (especially under the influence of manganese) and peroxidase activi…
Importance of Endophytic Strains Pantoea agglomerans in the Biological Control of Rhizoctonia solani
2018
Abstract Antagonistic activity of microorganisms against phytopathogens is mainly the results of plants’ health improvement due to the inhibition of pathogens growth and the induction of plants resistance against diseases. The aim of the research was to determine antagonistic properties of Pantoea agglomerans against Rhizoctonia solani. The properties of two strains P. agglomerans BC17 and BC45 were assessed according to the following criteria: mycelial growth of R. solani in the presence of bacterial metabolites, an impact of P. agglomerans on the growth of sugar beet in the pots containing soil with and addition of R. solani and without it, the ability to produce indole-3-acetic acid (IAA…
The Effect of Cadmium on Oxidative Stress in Beta vulgaris
2018
Abstract As a heavy metal, cadmium has strongly toxic effects on plants and can induce oxidative stress. It is absorbed by the roots and transported to the stems and leaves. The aim of the study was to evaluate the effect of various concentrations of cadmium on the metabolic activity of Beta vulgaris and assess the dependence of these processes on the content of metal in the plants. To demonstrate the effect of cadmium on metabolism, protein and photosynthetic pigment content, lipid peroxidation, and the activity of enzymes specific for oxidative stress in roots and shoots were measured. Seeds of B. vulgaris were treated with different concentrations of Cd supplied via a CdCl2 solution: 0 (…
The combined effect on initial glucose concentration and pH control strategies for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobut…
2021
Abstract The use and depletion of fossil fuels raised the interest in biofuels like biobutanol. Clostridium acetobutylicum DSM 792 is capable of producing biobutanol through ABE fermentation. Butanol production can be influenced by low sugar concentrations, like those obtained after hydrolysis of pre-treated lignocellulosic biomass. This study aimed to evaluate the influence of the initial glucose concentrations (33, 66 and 100 g L−1) and pH control strategies on biobutanol production and glucose consumption. Uncontrolled pH fermentation exhibited low butanol production due to either glucose exhaustion (33 g L−1) or the phenomenon of acid crash (66 and 100 g L−1), which was alleviated by th…
Antioxidant Phenolic Compounds in Salvia officinalis L. and Salvia sclarea L.
2018
Abstract The differences in the chemical composition of the phenolic compounds of Salvia officinalis versus Salvia sclarea growing in different habitats, were studied. First, the optimal solvent - methanol - for ultrasonic extraction of phenolic compounds from these plants was chosen experimentally. Total phenolic content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were determined spectrophotometrically. Total phenolic content was in the range of 63.9 to 134.4 mg GAE/g of plant depending on the studied species. The highest antiradical activity was displayed by the methanol fractions of S. sclarea varieties (83 and 67%). HPLC-DAD analysis of extracts was done in order to identify the pre…
Granulation and microbial community dynamics in the chitosan-supplemented anaerobic treatment of wastewater polluted with organic solvents.
2018
Abstract The effect of chitosan on the development of granular sludge in upflow anaerobic sludge blanket reactors (UASB) when treating wastewater polluted with the organic solvents ethanol, ethyl acetate, and 1-ethoxy-2-propanol was evaluated. Three UASB reactors were operated for 219 days at ambient temperature with an organic loading rate (OLR) of between 0.3 kg COD m −3 d −1 and 20 kg COD m −3 d −1 . One reactor was operated without the addition of chitosan, while the other two were operated with the addition of chitosan doses of 2.4 mg gVSS −1 two times. The three reactors were all able to treat the OLR tested with COD removal efficiencies greater than 90%. However, the time required to…
Study of Mass Oxygen Transfer in a Biotrickling Filter for Air Pollution Control
2012
Biotrickling filtration is a potential and cost effective alternative for the treatment of volatile organic compound (VOC) emissions in air, so it is necessary to deepen into the key aspects of design and operation for the optimization of this technology. One of these factors is the oxygen mass transfer of the process. This study would facilitate the selection of the packing material and the mathematical modelling and simulation of bioreactors. Four plastic packing materials with a different specific surface area have been evaluated in terms of oxygen mass transfer. For the tested range of superficial liquid velocities, data show a relationship between the kLa and the superficial liquid vel…
Primary production calculations for sea ice from bio-optical observations in the Baltic Sea
2016
Abstract Bio-optics is a powerful approach for estimating photosynthesis rates, but has seldom been applied to sea ice, where measuring photosynthesis is a challenge. We measured absorption coefficients of chromophoric dissolved organic matter (CDOM), algae, and non-algal particles along with solar radiation, albedo and transmittance at four sea-ice stations in the Gulf of Finland, Baltic Sea. This unique compilation of optical and biological data for Baltic Sea ice was used to build a radiative transfer model describing the light field and the light absorption by algae in 1-cm increments. The maximum quantum yields and photoadaptation of photosynthesis were determined from 14C-incorporatio…
Glucosamine measurement as indirect method for biomass estimation of Cunninghamella elegans grown in solide state cultivation conditions
2001
Glucosamine measurement has been tested as the indirect method to estimate the biomass produced by Cunninghamella elegans during solid state cultivation (SSC). The independence of this cell constituent content from the age and the conditions of the culture have been verified. The influence of the medium composition, in particular the nature of the carbon source on glucosamine amount is presented. Glucosamine can be considered as a well-adapted biomass indicator, with the necessity to establish for each medium tested a prior correlation between biomass and glucosamine amount. This correlation should be defined in submerged conditions before applying the biomass estimating method in SSC.