Microbial Bioremediation of Fuel Oil Hydrocarbons in Marine Environment

Pollution in marine environment due to heavier petroleum products such as high-speeddiesel is known to take from days to months for complete natural remediation owing to its lowvolatility. For the survival of marine flora and fauna, it is important to control pollution causedby such recalcitrant and xenobiotic substances. Several petroleum hydrocarbons found in natureare toxic and recalcitrant. Therefore, pollution due to high-speed diesel is a cause of concern.The natural dispersion of high-speed diesel, a slow process, is attributed to an overall combinedeffect of physico-chemical and biological processes which take months for complete dispersion.History of marine oil spill bioremediation indicates limited laboratory studies. But experiencesfrom various oil spill management and field trials indicate important role of bioremediation, where,biodegradation of hydrocarbons through microbial mediators plays a major role in pollutant oildispersion. These microbial mediators such as bioemulsifiers and fimbrae, help in emulsification,dispersion, allowing attachment of bacteria to oil layers, followed by substrate-specific enzymaticbiodegradation in water

Isolation and characterization of fatty acid esters and phosphatidylethanolamine surfactants from a consortium of marine bacteria

398-404 Consortium of five bacterial isolates from marine environment produced extracellular surface-active metabolites during growth in culture medium containing High Speed Diesel (HSD) as the sole source of carbon and energy. Product obtained was characterized for its surface-active properties and chemical constituents. It was found to reduce the surface tension of distilled water from 72 to 36 mN/m. Fourier Transform Infra Red (FTIR) spectrum revealed the presence of functional groups such as alkyl, ester, carboxyl, amine and alcohol indicating its structural similarity to mixture of fatty acid esters and amino group containing lipids. Major constituent was lipids (74.49%) which on further analysis by Thin Layer Chromatography (TLC) and Gas Chromatography – Mass Spectroscopy (GCMS) showed the presence of amino group containing phospholipids and different fatty acids. Thermogravimetric analysis indicated the material to be thermostable (Initial Decomposition Temperature: IDT = 198oC). Characterization therefore indicated the reported biosurfactant to be a mixture of hydrophobic and hydrophilic moieties facilitating the amphiphilic behaviour useful for the effective emulsification and dispersion of petroleum hydrocarbons

Microbial Bioremediation of Fuel Oil Hydrocarbons in Marine Environment

Pollution in marine environment due to heavier petroleum products such as high-speeddiesel is known to take from days to months for complete natural remediation owing to its lowvolatility. For the survival of marine flora and fauna, it is important to control pollution causedby such recalcitrant and xenobiotic substances. Several petroleum hydrocarbons found in natureare toxic and recalcitrant. Therefore, pollution due to high-speed diesel is a cause of concern.The natural dispersion of high-speed diesel, a slow process, is attributed to an overall combinedeffect of physico-chemical and biological processes which take months for complete dispersion.History of marine oil spill bioremediation indicates limited laboratory studies. But experiencesfrom various oil spill management and field trials indicate important role of bioremediation, where,biodegradation of hydrocarbons through microbial mediators plays a major role in pollutant oildispersion. These microbial mediators such as bioemulsifiers and fimbrae, help in emulsification,dispersion, allowing attachment of bacteria to oil layers, followed by substrate-specific enzymaticbiodegradation in water

Facile synthesis of limeonia acidissima shell derived carbon-vanadium pentoxide nanocomposite for sensitive detection of carbofuran

Generating carbonaceous materials from agricultural waste is a sustainable and environmentally friendly method of producing activated carbon. In the current work, carbon is extracted using a tubular furnace from the shell of the wood apple (Limonia acidissima) V2O5 (C/VO) and synthesized carbon were combined to form a nanocomposite. The formation of nanocomposite is confirmed by X-ray diffraction (XRD) investigations, X-ray photoelectron spectroscopy (XPS), and other morphological characterizations. Modification of glassy carbon electrode (GCE) was done using synthesized materials (C@GCE, VO@GCE, and C/VO@GCE). The enzyme-free detection of carbofuran (CBF) in 0.1 M phosphate buffer was carried out using fabricated electrodes. Among the various electrode systems, C/VO@GCE demonstrated enhanced electrochemical performance for CBF detection using both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. V/C@GCE demonstrated its capacity to identify CBF within a 0.05–750 μM range, with a limit of detection (LOD) of 0.06 μM. Using DPV, the effect of several pesticides on CBF detection in the presence of C/V@GCE was assessed, and good anti-interfering properties were discovered. When the DPV approach was used to detect CBF in potatoes, the recovery rate ranged from 98.0 to 99.0 %. According to a stability study, C/V@GCE has an 80.8 % retention capacity and can detect CBF for up to 24 days. The promise of the constructed electrode towards sensor applications is indicated by the large linear range, low LOD, selectivity, and stability of C/V@GCE

Fluorine substituted thiomethyl pyrimidine derivatives as efficient inhibitors for mild steel corrosion in hydrochloric acid solution: Thermodynamic, electrochemical and DFT studies

Three new 5-fluoro-2- methylthio substituted pyrimidine derivatives have been synthesized and characterized by H-1 NMR spectroscopy and Mass spectrometry. Corrosion inhibition characteristics of the synthesized pyrimidine derivatives have been studied on mild steel (MS) in 0.5 M hydrochloric acid solution at various temperatures (303-333 K) using mass loss and electrochemical techniques. The obtained weight loss, electrochemical impedance and potentiodynamic polarization data indicate that the corrosion inhibition efficiency is directly proportional to concentration of the inhibitors. The Adsorption process on MS surface obeyed Langmuir isotherm model. Scanning electron microscopy (SEM) was used to characterize surface morphology of the MS specimen in absence and presence of pyrimidine derivatives. Density functional theory (DFT) calculations using B3LYP functional with 6-311+G (d,p) level was used to establish the relationship between molecular structure and corrosion inhibition efficiency. Electrochemical analysis indicated that pyrimidine derivatives inhibit the corrosion by adsorbing on the metal surface. Mixed-type of corrosion inhibition activity with anodic predominance was proposed by polarization studies. (C) 2020 Elsevier B.V. All rights reserved