Search results for "BIOREMEDIATION"

Evaluation in microcosm of biostimulation and bioaugmentation efficacy on diesel-contaminated soil

2021

Bioremediation is a promising technology for the treatment of hydrocarbon (HC) contaminated soils that is based on the biodegradation capacities of native or introduced microbial populations. Biotractability tests are essential for choosing the optimal bioremediation treatment. For this purpose, multiple microcosm tests, based on biostimulation by landfarming or bioventing and addition of nutrients, were conducted for 120 days on a soil contaminated by diesel, after assessing its intrinsic catabolic potential. An additional bioaugmentation treatment was performed for further 60 days by inoculating selected HC degrading bacteria. HC (C10-C40) concentration was monitored by GC-FID analysis an…

The bioremediation potential of the Priolo Harbour (SR, Italy): isolation, identification and catabolic ability of hydrocarbonoclastic bacteria

2013

The petrochemical site of Priolo-Augusta-Melilli (Sicily, Italy), is a Site of National Interest (SIN) due to high levels of contamination of the coastline and its remediation is urgently needed. Successful remediation strategies relying on the catabolic potential of marine hydrocarbonoclastic bacteria (HCB) have been described. HCB are specialised hydrocarbon (HC)-degrading marine bacteria that use HC almost exclusively as unique carbon and energy source and become dominant in oil-impacted environments. In order to identify the key hydrocarbon degraders and explore the natural bioremediation potential of the contaminated area, sediment cores and sea water were collected inside the Priolo H…

Isolation of Local Shewanella sp. Strain from Vezjolka River at Belgorod District in Belgorod Region, Russia

2019

EVALUATION OF AEROBIC AND ANAEROBIC BACTERIAL DECHLORINATION POTENTIAL OF A 1,2-DICHLOROETHANE CONTAMINATED AQUIFER

2023

Chlorinated solvents, belonging to the class of chlorinated aliphatic hydrocarbons (CAHs), are synthetic organohalide chemicals frequently found as contaminants of groundwater and soil, due to their widespread use in several industrial processes and improper disposal methods. These compounds pose serious health threats because of their toxic and sometimes carcinogenic effects. Among these compounds, 1,2-dichloroethane (1,2-DCA) is one of the most common aquifer contaminants, considered toxic and classified as a possible human carcinogen. Remediation approaches toward these contaminants include conventional cleanup technologies based on physical/chemical methods, and bioremediation, consider…

A battery of toxicity tests as indicators of decontamination in composting oily waste.

2000

Heterogeneous oily waste from an old dumping site was composted in three windrows constructed from different proportions of waste, sewage sludge, and bark. The objectives of this pilot study were to examine the usefulness of composting as a treatment method for this particular waste and to study decontamination in the composting process by using a battery of toxicity tests. Five samples from the windrow having intermediate oil concentrations were tested with toxicity tests based on microbes (Pseudomonas putida growth inhibition test, ToxiChromotest, MetPLATE, and three different modifications of a luminescent bacterial test), enzyme inhibition (reverse electron transport), plants (duckweed …

Genetic methods to improve Cr(VI) bioremediation in groundwater

2009

Cr(VI) contamination of groundwater and soils is a primary public health. Bioremediation is an environmental-friendly alternative for Cr(VI) removal from groundwater and soils, but Cr(VI) toxicity limits the efficiency of the process. We use the genome shuffling technique in order to improve Cr(VI) tolerance and Cr(VI) reduction capability of the strict anaerobic bacterium Geobacter metallireducens. We will investigate the mechanism of Cr(VI) reduction in the resulting G. metallireducens mutants through an innovative electrochemical approach. Finally, we will test the best performing mutants in a bench-scale Cr(VI) bioremediation process.

GEOBACTER METALLIREDUCENS MUTANTS FOR CHROMIUM BIOREMEDIATION

2011

Geobacter metallireducens is known to use oxidized metals such as Fe(III) and Mn(IV) as terminal extracellular electron acceptors. G. metallireducens can reduce the highly soluble and toxic Cr(VI) to its insoluble form Cr(III), thus enabling chromium removal from contaminated water and soil. This process is limited by the low toxicity resistance of G. metallireducens to Cr(VI). Genome shuffling can generate mutants with improved phenotype. In our work we are carrying out G. metallireducens genome shuffling, in order to increase its resistance to Cr(VI). In Geobacter species, metal toxicity resistance is correlated to the respiration rate, hence to the reduction rate of the metallic electron…

GEOBACTER METALLIREDUCENS MUTANTS FOR CHROMIUM BIOREMEDIATION

2011

Genetic technology to improve biofilms electroactivity for bioremediation applications

Genetic technology to improve biofilms electroactivity for bioremediation applications

2010

Hexavalent chromium bioremediation occurs through its reduction to Cr(III) and its following precipitation. Geobacter metallireducens is a dissimilatory metal reducing bacteria known to reduce Cr(VI) to Cr(III) through extracellular electron transfer. However, the effectiveness of this bioreduction process is limited by the low toxicity resistance of G. metallireducens to Cr(VI). G. metallireducens mutants with improved Cr(VI) toxicity resistance can be obtained by genome shuffling method. Here we present the experimental setup for genome shuffling of G. metallireducens, including the optimization of mutagenesis procedure and the respiration rate measure for G. metallireducens in potentiost…

Selecting Microbial Strains from Pine Tree Resin: Biotechnological Applications from a Terpene World

2014

Resin is a chemical and physical defensive barrier secreted by many plants, especially coniferous trees, with insecticidal and antimicrobial properties. The degradation of terpenes, the main components accounting for the toxicity of resin, is highly relevant for a vast range of biotechnological processes, including bioremediation. In the present work, we used a resin-based selective medium in order to study the resin-tolerant microbial communities associated with the galls formed by the moth Retinia resinella; as well as resin from Pinus sylvestris forests, one of the largest ecosystems on Earth and a yet-unexplored source of terpene-degrading microorganisms. The taxonomic and functional di…