Dynamics of diesel fuel degradation in contaminated soil using organic wastes

Bioremediation is an effective measure in dealing with such contamination, particularly those from petroleum hydrocarbon sources. The effect of soil amendments on diesel fuel degradation in soil was studied. Diesel fuel was introduced into the soil at the concentration of 5 % (w/w) and mixed with three different organic wastes tea leaf, soy cake, and potato skin, for a period of 3 months. Within 84 days, 35 % oil loss was recorded in the unamended polluted soil while 88, 81 and 75 % oil loss were recorded in the soil amended with soy cake, potato skin and tea leaf, respectively. Diesel fuel utilizing bacteria counts were significantly high in all organic wastes amended treatments, ranging from 111 × 106 to 152 × 106 colony forming unit/gram of soil, as compared to the unamended control soil which gave 31 × 106 CFU/g. The diesel fuel utilizing bacteria isolated from the oil-contaminated soil belongs to Bacillus licheniformis , Ochrobactrum tritici and Staphylococcus sp. Oil-polluted soil amended with soy cake recorded the highest oil biodegradation with a net loss of 53 %, as compared to the other treatments. Dehydrogenase enzyme activity, which was assessed by 2,3,5-triphenyltetrazolium chloride technique, correlated significantly with the total petroleum hydrocarbons degradation and accumulation of CO2. First-order kinetic model revealed that soy cake was the best of the three organic wastes used, with biodegradation rate constant of 0.148 day-1 and half life of 4.68 days. The results showed there is potential for soy cake, potato skin and tea leaf to enhance biodegradation of diesel in oil-contaminated soil

Biosurfactant production by bacillus salmalaya for lubricating oil solubilization and biodegradation

This study investigated the capability of a biosurfactant produced by a novel strain of Bacillus salmalaya to enhance the biodegradation rates and bioavailability of organic contaminants. The biosurfactant produced by cultured strain 139SI showed high physicochemical properties and surface activity in the selected medium. The biosurfactant exhibited a high emulsification index and a positive result in the drop collapse test, with the results demonstrating the wetting activity of the biosurfactant and its potential to produce surface-active molecules. Strain 139SI can significantly reduce the surface tension (ST) from 70.5 to 27 mN/m, with a critical micelle concentration of 0.4%. Moreover, lubricating oil at 2% (v/v) was degraded on Day 20 (71.5). Furthermore, the biosurfactant demonstrated high stability at different ranges of salinity, pH, and temperature. Overall, the results indicated the potential use of B. salmalaya 139SI in environmental remediation processes

Bio-enrichment of waste crude oil polluted soil: Amended with bacillus 139SI and organic waste

Biodegradation of waste crude oil contaminated soil amended by Bacillus 139SI and used tea leaf amendments was investigated to determine the rate of hydrocarbon remediation. Previously, Bacillus 139SI was isolated from an agricultural soil in the Serdang agricultural center, Malaysia. Within 60 days, 14% oil loss was recorded in unamended polluted autoclaved soil, while waste crude oil disappeared more rapidly in the soil amendment with both strain and organic waste, recorded above 89%. Utilizing bacteria counts were significantly higher in all amended treatments comparing to control soil. Dehydrogenase activity in soil was markedly enhanced by the application of amendments. Waste crude oil composition monitored by GC/FID indicated complete degradation of n-C9–C25. First-order kinetic model revealed that organic waste and strain were the best of treatments, with biodegradation rate constant of 0.17day-1and half life of 4 days. The results showed there is potential for tea leaf and Bacillus 139SI to enhance biodegradation of waste crude oil contaminated soil

Enhanced degradation of diesel-contaminated soil using organic wastes

This study was carried out to enhance the biodégradation of diesel fuel in soil contaminated with 10 %(w/w) diesel fuel amended with 10% tea leaf (TL), soy cake (SC), potato skin (PS) for a period of 3 months under laboratory condition. At the end of 84 days, the highest percentage of oil biodégradation (76%) was recorded in soil amended with SC; 64% and 53% were recorded with soil amended with PS and TL respectively, while only 27% of oil degraded in control treatment. Hydrocarbon utilizing bacteria ( HUB ) counts were high in all organic wastes amended treatments, ranging from 45×10 6 CFU/g to 90×10 6 CFU/g of soil compared to unamended control soil (4×10 6 CFU/g to 8 ×10 6 CFU/g of soil ). The count in amended soil was significantly different at (P< 0.05) compared to unamended soil. The results obtained showed 90%, 80% and 60% seed germination in remediated soil contaminated with 10% diesel fuel and amended with SC, PS and TL respectively, over the period of 84 days. The results show the high potential of SC for enhanced biodégradation of hydrocarbon in oil contaminated soil

The top 101 cited articles in environmental clean-up: oil spill remediation

The aim of this search was to identify the 101 top cited articles in the field of oil spill remediation. A search was conducted based on a database of the Web of Science included the journal citation reports from 1980 to 2013. The number of citations of the first 101 top cited articles is from 24 to 816. The decades with most top-cited articles published were 2000-2009 (47 articles) and 1990-1999 (37 articles). The most common research area of study was environmental science ecology. All the articles were published in 54 different journals in this category. Journals with the highest number of cited articles were Applied and Environmental Microbiology (10 articles), Environmental Science and Technology (6 articles), Organic Geochemistry (6 articles), Chemosphere (5 articles). Among the top cited articles the mostly named author were Sakkata Y, and Uddin MA with 6 of articles, followed by Fedorak PM with 5. Out of 101 top cited articles, 14, 13 and 12 articles originated from Canada, USA and France, respectively. Okayama and Alberta Universities were the most common productive institutions. Based on our knowledge, this is the first report of the 101 top cited articles in this category

Remediation of oil contaminated media using organic material supplementation

With the fact that anthropogenic activities are inevitable, especially with the continuous use of fossil fuels and other sources of hydrocarbons, environmental pollution appears to be a recurring issue. However, nascent science and technologies try to identify and apply varied options that can remedy polluted sites, which include oil spill situations. The present review elucidates the remediation options on the event of oil spill/contamination with emphasis on the adoption of biological treatment (supplement addition and phytoremediation), and overview on the potential relevance of remediation via advances in nanotechnology. The associated negativities and cost tend to outweigh the advantages of both methods when sustainability is considered

Prevalence and antimicrobial resistance of Staphylococcus aureus isolated from raw milk and dairy products

The objectives of this study were to determine the prevalence and antimicrobial resistance of Staphylococcus aureus isolated from raw milk (cow and sheep) and dairy products (traditional cheese and kashk) in Mazandaran Province, Iran. A total of 2650 samples, including 1930 raw milk and 720 dairy products were purchased from retail stores. Out of 2650 samples, S. aureus was detected in 328 samples (12.4%) in which 53 (16.2%) were positive for methicillin-resistant S. aureus. The S. aureus isolates showed resistance to tetracycline (56.1%), followed by penicillin G (47.3%), oxacillin (16.2%), lincomycin (11.9%), clindamycin (11.3%), erythromycin (7.9%), streptomycin (5.8%), cefoxitin (5.5%), kanamycin (4%), chloramphenicol (3.7%), and gentamicin (2.1%). A high frequency of blaZ (46%) and tetM (34.8%) resistance genes was found in S. aureus isolates. The findings of this study revealed consumption of raw milk and dairy products as a potential risk of foodborne infection in this region

Biosorption Potential of Bacillus salmalaya Strain 139SI for Removal of Cr(VI) from Aqueous Solution

The present study investigated the biosorption capacity of live and dead cells of a novel Bacillus strain for chromium. The optimum biosorption condition was evaluated in various analytical parameters, including initial concentration of chromium, pH, and contact time. The Langmuir isotherm model showed an enhanced fit to the equilibrium data. Live and dead biomasses followed the monolayer biosorption of the active surface sites. The maximum biosorption capacity was 20.35 mg/g at 25 degrees C, with pH 3 and contact time of 50 min. Strain 139SI was an excellent host to the hexavalent chromium. The biosorption kinetics of chromium in the dead and live cells of Bacillus salmalaya (B. salmalaya) 139SI followed the pseudo second-order mechanism. Scanning electron microscopy and fourier transform infrared indicated significant influence of the dead cells on the biosorption of chromium based on cell morphological changes. Approximately 92% and 70% desorption efficiencies were achieved using dead and live cells, respectively. These findings demonstrated the high sorption capacity of dead biomasses of B. salmalaya 139SI in the biosorption process. Thermodynamic evaluation (G(0), H-0, and S-0) indicated that the mechanism of Cr(VI) adsorption is endothermic; that is, chemisorption. Results indicated that chromium accumulation occurred in the cell wall of B. salmalaya 139SI rather than intracellular accumulation