In conjunction with ongoing studies to develop a method for quantifying potentially biodegradable organic carbon (Rectanus et al 2005), this research was conducted to evaluate the extent to which organic carbon extracted using this method will biodegrade in anaerobic environments. The ultimate goal is to use this method for the evaluation of chloroethene contaminated sites in order to estimate the long-term sustainability of monitored natural attenuation (MNA) as a remediation strategy. Although relatively recalcitrant under aerobic conditions, the breakdown of chlorinated solvents primarily occurs through the anaerobic process of reductive dechlorination. The biodegradation of organic carbon in these anaerobic environments drives the system to reducing conditions conducive for reductive dechlorination. The extraction procedure developed by Rectanus et al. (2005) has been tested in several series of aerobic bioassays to determine the biodegradable fraction of carbon extracted. This study seeks to show that the carbon removed from the sediment by this extraction process will also degrade in anaerobic environments. Three aquifer sediment samples characterized by low, medium, and high carbon concentrations were taken from Naval Submarine Base Kings Bay, Georgia. Two sites were also sampled from Naval Amphibious Base Little Creek, Virginia. MLS20 is a site located inside of a chloroethene plume, and MLS10 is located outside of the plume. For approximately 12 weeks aqueous total organic carbon (TOC), headspace carbon dioxide (CO2), volatile fatty acids (VFAs), and headspace hydrogen concentrations were monitored for evidence of the biodegradation of organic carbon. Although few VFAs were observed throughout the experiments, their presence as early as 8 days after inoculation indicated that the bioassays were anaerobic. The fewest VFAs were seen in the MLS20 bioassays, while the most VFAs were observed in the MLS10 bioassays. MLS20 exhibited low levels of TOC loss and the low VFA levels indicate that complex organic matter was not highly degraded in these bioassays. The higher level of VFAs observed in MLS10 bioassays corresponded with little TOC degradation, indicating that although more complex organics were being broken down, conditions were not reduced enough to further oxidize the organic carbon. As much as 50% TOC loss was observed in the Kings Bay bioassays with few VFAs detected. Loss of TOC was accompanied by CO₂ generation which provides supporting evidence that organic carbon was being oxidized. Hydrogen was observed in the bioassays, suggesting that VFAs resulting from organic carbon breakdown were being oxidized. This indicates that organic carbon removed from sediment using the extraction process is biodegraded anaerobically and could lead to conditions capable of sustaining reductive dechlorination. / Master of Science

Soil microcosm experiments were conducted to identify soil amendments which enhance the biodegradation of a No. 2 (diesel) fuel in soil. Microcosm amendments in Phase 1 included yeast extract, acetate, methane, and activated sludge. Combinations of these amendments resulted in 16 different treatments. Phase 2 soil microcosms contained combinations of methane and methanotroph additions resulting in four different treatments. Gas chromatography was used to determine the time and treatment-dependent concentration of C12-C18 n-alkanes during Phase 1 and, C14-C19 n-alkanes during Phase 2. Results from Phase 1 indicated that the most extensive biodegradation occurred in methane and activated sludge-supplemented microcosms. Acetate and/or yeast extract inhibited biodegradation by soil and/or activated sludge microorganisms. Addition of methane relieved inhibition by these amendments. Methane and/or methanotroph additions to Phase 2 microcosms did not enhance biodegradation relative to unamended microcosms. In general, n-alkanes longer than n-C12 were equally degraded in soil microcosms.

In this work, a model microbial agent for bioremediation was improved using fermentation and formulation methods. The outcomes of the fermentation work include the development of a new culture medium which increased the cell productivity greater than one order of magnitude. A robust functionality to degrade the herbicide atrazine was expressed. The new medium was scaled-up to a 2L bioreactor. Liquid bacterial culture was not inherently stable and lost viability at both 4°C and 25°C storage. When liquid bacterial culture was formulated by encapsulation in a biopolymer gel and applied to zeolite the transfer of cells from bacterial culture to formulated carrier was highly efficient. No loss of viability was measured from the immobilization process, and the functionality of the agent was retained. The formulated agent expressed an extended shelf life of at least 10 weeks when stored in ambient (25°C) temperature. When the formulation granules were inoculated into sterile soil, viability of the granules was stable and also retained the maximum level of functionality for the full test period of 10 weeks. The soil surrounding the formulation granules was also enumerated. The number of cells in the soil increased after a single inoculation of the formulation and the maximum level of functionality was conveyed from the formulation to the surrounding soil. The formulated inoculant constitutes an improvement for a bioremediation strain to stabilize the agent, produce an extended shelf life at ambient temperatures, and maintain the functionality of a microbe to utilize atrazine. In this thesis we have used a biopolymer formulation in which an inoculum is simply mixed into a gel and applied directly to the surface of the zeolite with no special equipment, drying, temperatures, or secondary re-growth steps required. It is a simple model system consisting of a carrier, and a artificial biofilm. As a technique to produce stable functional inoculants for bioremediation, the work presented here demonstrates an approach that is simple, practical, effective, and robust.

No description available.

Land contamination by petroleum hydrocarbons is a widespread and global environmental pollution issue from recovery and refining of crude oil and the ubiquitous use of hydrocarbons in industrial processes and applications. Sustainable treatment of hydrocarbon-contaminated industrial land was considered with reference to seven published works on contaminated railway land including the track ballast, crude oil wastes and contaminated refinery soils. A methodology was developed to assess the level hydrocarbon contamination of track ballast (Anderson et al., 2000) and in Anderson et al. (2002, 2003) solvent and surfactant cleaning of ballast was investigated and potential environmental impacts of the processes examined. Optimisation of ex situ bioremediation of diesel-contaminated soil (Cunningham & Philp, 2000) demonstrated the efficacy of the addition of microorganisms (bioaugmentation) to enhance diesel biodegradation rates at field pilot scale. This work motivated a further study that examined a novel aeration approach incorporating ventilator turbines (cowls) for soil biopiles (Li et al., 2004). An optimised ex situ bioremediation for crude oil wastes was developed in Kuyukina et al. (2003) which demonstrated the efficacy of bioaugmentation and the application of biosurfactants. The final study investigated the potential application of biosurfactants to in situ remediation (Kuyukina et al., 2005) in laboratory soil columns contaminated with crude oil. The collected works are informative to those seeking to remediate hydrocarbon-contaminated industrial land and the sustainability of the approaches was considered.

Bioremediation tends to be an effective technology, used to remove pollutants and it involves relatively little capital. Microorganisms, especially bacteria, evolving into many types with exceedingly diverse metabolic capabilities, which can be applied in bioremediation. The two bacterial strains, Nocardioides simplex FJ2-1A and Rhodococcus opacus HL PM-1 are capable of biodegradation of 2,4,6-trinitrophenol (TNP, picric acid). In N. simplex, the biodegradation pathway is inducible while in R. opacus is constitutive. Some enzymes were identified in both strains and shown to be isofunctional. In this work, a molecular characterisation of the orfB from the npd gene cluster was achieved. The mutant R. opacus AR1 strain deficient in the orfB gene was constructed by a gene replacement method using the expression of sacB as the selectable marker. The gene was also cloned as the His tag fusion protein and expressed in E. coli. Theoretical pI / Mw predictions for the protein sequence were 5.47 / 42536.23 Da. SDS-PAGE analysis showed the size of the purified fusion protein, which was calculated to be 42.5 kDa. The protein was purified by Ni-NTA metal affinity chromatography. This study furthermore identified a DNA fragment, which encodes the nitrite-eliminating enzyme (NEE) activity. This was achieved by enriching the activity using the fast performance liquid chromatography (FPLC) and protein sequencing. The two internal peptide sequences were obtained: L P G D Y T D Q L L R and S G A I V G L G H A Q V D R. These were used to design the degenerate primers in order to pool a clone from nocardioform genome. Two different genomic libraries were constructed and screened using R. opacus HL PM-1 and N. simplex FJ2-1A total DNA, since the activity in crude extracts was reported with both strains. The partial DNA sequence of NEE was obtained (252 bp). The similarity with fatty acid hydroxylase from Nocardioides sp. JS6614 was detected.

ABSTRACT A new, non-pathogenic bioaugmentation product was formulated specifically for underground use in South African mines, using local bacterial isolates. This was designed for the remediation of various hydrocarbons via biochemical breakdown by sub-surface microorganisms. The active microorganisms were isolated from hydrocarbon-polluted areas of a gold mine. Many commercially available bioaugmentation products are already in existence however, all, to our knowledge, have been developed and tested primarily for use in the northern hemisphere. None have been formulated and tested in Africa. Our series of bacterial isolates are the first to be isolated from mine soils for hydrocarbon biodegradation purposes. Such isolates have further, not previously been tested on sub-surface contamination. The safety associated with the use of such a product in a closed mine-environment is of paramount importance. Initial batch-flask experiments were conducted using a readily-available commercial bioremediation product. This was tested on simple surfactant molecules and compared to the biodegradation observed under standard waste water treatment plant conditions. The bioremediation product increased biodegradation by 6% on average. Bacteria in the product were identified by 16S rDNA gene sequence analysis and found to be homologous to potentially pathogenic Bacillus cereus, known especially to effect immunocompromised individuals, this was of particular concern in the closed mine system. South African isolates were sourced from various hydrocarbon-polluted sources, with six bacteria ultimately being selected from deep sub-surface mine soil and water samples. The ability of these isolates to biodegrade waterborne monograde engine oil was assessed via GC-FID. The isolate showing average percentage growth increase, homologous to Pseudomonas pseudoalcaligenes, was found to degrade the motor oil by 98%. The new isolates were, on average, 16% more efficient at biodegrading petroleum hydrocarbons than the commercial bioremediation product isolates. Formulation of these isolates into the first commercially-available South African developed and tested bioaugmentation product will prove a successful conclusion to this study.

A exposição ao Bisfenol A (BFA) ocorre frequentemente no nosso dia a dia,uma vez que esse composto é um plastificante presente em muitos utensílios domésticos, como, por exemplo, embalagens e garrafas. No entanto, esta exposição, mesmo em baixas concentrações (ng.L -¹), pode causar sérios danos ao sistema endócrino. Esses danos devem-se ao fato do BFA ser um disruptor endócrino, onde os receptores hormonais o confundem com o estrogênio ou o estriol. Diante deste cenário, o estudo de formas de mitigação deste composto no meio ambiente faz-se necessário. Uma das alternativas para remoção deste contaminante do meio ambiente é a biodegradação por bactérias selecionadas de ambientes contaminados com BFA. Neste contexto, este trabalho visou isolar bactérias degradadoras de BFA, analisar o crescimento celular das bactérias usando o BFA como fonte de carbono e quantificar a biodegradação deste composto. Foram isolados nesse trabalho 15 cepas diferentes de bactérias aeróbias do Sistema Estuarino de Santos (SES), o qual possui forte impacto antrópico pelo grande fluxo de pessoas. Além disso, o SES abriga o maior porto da América Latina (Porto de Santos) e o Polo Industrial de Cubatão. Dos micro-organismos isolados, a cepa de Shewanella sp. foi escolhida para o estudo de biodegradação, uma vez que a mesma foi capaz de tolerar até 150 mg.L- ¹ de BFA. A linhagem de Shewanella sp. isolada foi capaz de biotransformar aproximadamente 75 mg.L- ¹ de BFA em 10 horas com um µ máx de 0,123 e um Y(x/s) de 14 % em meio de cultura líquido. / The exposure to Bisphenol A (BPA) occurs frequently since this compound is a plasticizer present in many households items such as packaging and bottles. However, even the low exposure (ng.L-¹) can cause severe damage to the endocrine system and these damages are due to endocrine disruptor-activity of BPA. The hormonal receptors mistake this compound as estrogen or estriol, thus, mitigation studies to remove this contaminant from the environment are essential. One of the alternatives to remove this xenobiotic from the environment is the bioremediation by selected bacteria isolated from a BPA impacted environment. In this context, this paper aimed to isolate BPAdegrading bacteria, analyze cellular growth and biodegradation hability using BPA as a carbon source. It have been isolated fifteen different aerobic bacteria strains from the Santos Estuary System (SES), which represents one of the most important Brazilian examples of environmental degradation due to water or atmospheric pollution of industrial origin in coastal environment. In addition, SES it is home to the largest port in South America (Port of Santos) and a large industrial pole located in Cubatão. The isolated strain Shewanella halioti was chosen to this work, once is a few explored micro-organism regarding biodegradation of hydrocarbons. Shewanella halioti was able to tolerate up to 150 mg.L-¹ of BPA and biotransform 75 mg.L-¹ in 10 hours in liquid culture medium.

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2016. / Environmental remediation of organic and inorganic contaminants such as hydrocarbons has been a research focus area of interest. Chemical surfactants have been extensively used for the remediation of contaminated sites for immobilisation of hydrocarbons from environmental matrices. The focus has been on the impact of chemical surfactants on the environment. These petroleum-based chemical surfactants have raised serious environmental concerns as: 1) they are toxic, 2) they deteriorate the environment owing to their non-biodegradability, 3) they are costly, and 4) most are not intended for environmental applications. As such, alternatives had to be found to mitigate concerns associated with the application of such synthetic surfactants in bioremediation. Biosurfactants produced by microorganisms are a potential alternative to these synthetic surfactants. They have minimal environmental impact, are biodegradable and can withstand extreme conditions. However, biosurfactants are associated with high production costs and low production yield. Currently, large-scale production of biosurfactants cannot be achieved. Most research focuses on improving production yield which will contribute to the reduction in production costs. A lichenysin lipopeptide biosurfactant producing Bacillus sp., which grew exclusively on Beta vulgaris agrowaste, was identified. The microorganism was found to be an effective emulsifier for high molecular weight hydrocarbons such as, lubricant oil and diesel. The aim of this study was to improve biosurfactant production yield from this Bacillus sp., including emulsification efficacy by optimising fermentation conditions by supplementing the broth with biocompatible nanoparticles synthesised using a green chemistry approach with B. vulgaris (B. vulgaris) extracts. This study also aimed at reducing production costs by using B. vulgaris agrowaste exclusively as the production medium, both for the biosurfactant and the nanoparticles.

I det här projektet har halten tungmetaller, miljöfarliga metaller och andra metallföroreningar undersökts i fiberhaltiga bottensediment längs Norrlandskusten i syfte att bredda förståelsen för saneringsbehovet. Industrier har använt olika processer i sin verksamhet som släppt ut fiberrikt avfall i vilka en mängd föroreningar och däribland miljöfarliga metaller har lagrats. Metallerna ansamlas i sedimenten och bör påvisas vid provtagning, men så är enligt denna studie inte alltid fallet. Många faktorer spelar in i om tungmetallerna lagrats och finns kvar i sedimenten eller inte. Två av dessa faktorer skulle kunna vara halten organiskt kol i sedimenten samt svavelhalten, alternativt de båda i relation till varandra. För att ta reda på vad som finns i sedimenten har data från Sveriges Geologiska Undersökning (SGU) använts. Samma data ligger till grund för den stora studie och riskklassning som genomfördes av SGU, Havs- och vattenmyndigheten och fem länsstyrelser i Norrland, projektet FIN15. I projektet har data från fem undersökta områden analyserats. Områdena är Norrsundet, Ljusnefjärden, Iggesund, Marmen och Yttre fjärden. Datan har analyserats med avseende på vilken industri som funnits i vilket område, i vilka sediment vilka metaller finns samt om det går att påvisa någon koppling mellan vilken industri som använts på platsen. I syfte att avgöra om metallkoncentrationerna i sedimentenär betydligt högre än de naturliga bakgrundsnivåerna har jämförvärden från Bottniska viken använts som referensvärden för "neutral metallkoncentration" i sedimenten. Resultatet visar att det i många fall kan dras kopplingar mellan typ av industri och metallhalt, men att det finns många faktorer som är avgörande för huruvida metallerna finns kvar i sedimenten eller inte. Svavlet och det totala organiska kolets (TOC) påverkan på metallernas koncentration visade sig vara mer komplex än vad som framställdes enligt teorin. Vid vissa områden ökade metallkoncentrationerna med ökad kolhalt, i andra minskade den. Det går i denna undersökning heller inte att påvisa ett starkt samband mellan svavelhalten och halten förorening. Metoden som använts går att utveckla och fler faktorer bör beaktas för att få en bättre helhetsbild. De fem analyserade områdena har alla varierande geologi och har haft en kombination av flera olika industrier. Det går inte att med säkerhet fastställa att en viss metall kommer från en viss industrityp, men det går att se samband mellan förhöjda halter metaller och industriområden med gemensamma industrityper i allmänhet.