Microbial ecology and bio-monitoring of total petroleum contaminated soil environments

The contamination of environmental media by total petroleum hydrocarbons (TPH) is a concern in many parts of the world; particularly as most petroleum components like polycyclic aromatic hydrocarbons (PAHs) are either toxic or carcinogens. In South Africa, the sale of major petroleum products by the South African Petroleum Industry Association (SAPIA) reveals that about 21 billion litres of petroleum products are sold per year. These products include bitumen, diesel, fuel oil, illum paraffin, jet fuel and petrol. In addition, 19.5 million tonnes of crude oil are brought into South Africa annually to feed the country’s four refineries. The production of oily sludges at refineries, transportation, storage, and handling of petroleum products by end users, results in environmental contamination. The soil environment is particularly vulnerable to hydrocarbon contamination as most of the accidental spillages by trucks, rail locomotives and pipelines have a direct impact on the soil medium. As most of the petroleum compounds are either toxic or carcinogenic, their removal from the soil is necessary. The literature reveals that biological treatment of hydrocarbons is cost effective compared to other treatment options. However, in order to improve the efficiency of biological treatments, there is a need to understand the microbial diversity of TPH stressed environments and how simple biomonitoring ‘instruments’ can be used to evaluate the removal of hydrocarbons from the soil. The message from the literature indicates some potential solutions to the existing problems associated with soil microbial diversity and biotreatment of hydrocarbon contaminated soil, which must be investigated. The main aim of this work was to evaluate the microbial diversity of the different soil environments disturbed by Total Petroleum Hydrocarbons (TPHs) and the potential use of plants and microorganisms in monitoring and removing hydrocarbons from the soil. In addition, the potential of the culture-independent methods in complementing, the culture-dependent methods when evaluating soil microbial diversity were also evaluated. The polyphasic approach was successfully used in evaluating microbial diversity in both hydrocarbon-contaminated and uncontaminated soils. The approach involved the use of community level physiological profiles (CLPP) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to evaluate the effects of hydrocarbons on the soil microbial communities of both the contaminated and non-contaminated soil layers at a diesel contaminated site. Because of the ability of the molecular methods (PCR-DGGE) to complement the CLPP, the polyphasic approach is recommended when evaluating soil microbial diversity and the effect of pollutants on microbial community structure as the approach appears to compensate for the limitations of each of the methods of evaluating microbial diversity. However, further work is needed to improve the recovery of bacteria from the soil, particularly where the interest is to evaluate the availability of the indigenous microbial populations for bioremediation. The substrate utilisation pattern and 16S DNA fragments of the soil microbial communites in different soil layers at a diesel contaminated site were different. The substrate utilisation pattern of the topsoil was different from the substrate utilisation pattern of the soil layers below 1m. In addition, the substrate utilisation pattern of the contaminated and uncontaminated soil layers were different. 16S DNA fragments of the different soil layers were also different. While the metabolic activities of different samples as reflected by CLPP does not necessarily imply the difference in community structure of the samples, PCR-DGGE revealed differences in 16S DNA fragments and this complemented the results of the culture based methods. The results suggest that the use of functional and genetic approaches (in combination) have a better chance of revealing a ‘clearer’ picture of soil microbial diversity. The distribution of hydrocarbon-utilising bacteria and the efficiency of biodegradation of hydrocarbons vary with soil depth. The biodegradation rate of hydrocarbon was highest in the topsoil compared to other soil layers and this was supported by the high number of hydrocarbon-degrading bacteria in the topsoil compared to soil layers at and below 1m. The results suggest that the biological removal of hydrocarbons varies in different soil layers and that microbial diversity as measured by CLPP and PCR-DGGE varies with depth in hydrocarbon-contaminated soil. The information about metabolic activities of different soil layers is important when assessing the footprints of degradation processes during monitored natural attenuation (MNA). However, further studies are required to understand the effect of (not only) other pollutants, but the influence of soil components (pore volume, level of adsorbents and other environmental factors) on the microbial diversity of different soil layers in both ‘shallow’ and deep aquifers. The microbial diversity of different environments contaminated by hydrocarbons has different community level physiological profiles. At diesel depots where similar hydrocarbons are used for maintenance of locomotives, the number of bacteria (both total culturable heterotrophic bacteria and hydrocarbon-degrading bacteria) was proportional to the level of hydrocarbon contamination. However, there was no significant difference in the level of total culturable heterotrophs (TCHs) and the hydrocarbon degrading bacteria. In addition, the biological activities as evaluated by CO2 production were higher in nutrient amended treatments in which high numbers of TCHs were present. Microbial diversity of polluted surfaces needs to be studied further to investigate the concentration or the thickness of the hydrocarbons layer on the rock surfaces that encourages the attachment or colonization of the TCHs and the hydrocarbon-degrading bacteria. The hydrocarbons rather than the geographical origin of the soil sample appear to be more important in determining functional or species diversity within the bacterial communities. The samples from different locations were as different as samples from the same location but from contaminated versus uncontaminated soil. The results of the soils from different locations artificially contaminated by different hydrocarbons also reached the same conclusion. However, further work is required to investigate the importance of soil heterogeneity in community studies of soil environments contaminated by similar hydrocarbons. The removal of Polycyclic Aromatic Hydrocarbons (PAHs) in multi-planted soil microcosm was higher compared to PAHs removal in monoculture soil microcosms. In addition, the PAH removal was higher in the vegetated soil microcosms compared to the non-vegetated microcosms. There was however, no significant difference in the PAH removal in the soil microcosms planted with Branchiaria serrata and the microcosm with Eulisine corocana. The Principle Component Analysis (PCA) and Cluster analysis used to analyse the functional diversity of the different treatments revealed differences in the metabolic fingerprints of the PAH contaminated and non-contaminated soils. However the differences in metabolic diversity between the multi-planted and mono-planted treatments were not clearly revealed. The results suggest that multi-plant rhizoremediation using tolerant plant species rather than monoculture rhizoremediation have the potential to enhance pollutant removal in moderately contaminated soils. Lepidium sativum, a plant with short germination period, was successfully used to monitor, the removal of Polycyclic Aromatic Hydrocarbons (PAHs) from the soil. The sensitivity of L. sativum eased with increasing concentration of the polycyclic aromatic hydrocarbons in the artificially contaminated soil while no germination occurred in the historically polluted soil. When used during phytoremediation of PAH, the germination level of L. sativum was inhibited during the first weeks, after which germination increased, possibly due to PAH dissipation from the soil. The methodology based on the sensitivity of L. sativum to PAH can be used as a monitoring tool in bioremediation of soil contaminated with PAH. However, the methodology should be developed further to gain more knowledge on aspects of bioavailability of PAH in both the aged as well as the freshly spiked soil. Also critical is the sensitivity of the seeds to other pollutants (e.g. heavy metals), which are most likely to occur in the presence of the PAHs. Although the biological activities have the potential to monitor the removal of hydrocarbons from the soil, the methodologies have not been developed sufficiently to cater for the heterogeneity of the soil and to differentiate toxicity by the parent compound and the metabolites. At present, it is best that they be used to complement existing conventional monitoring instruments. Finally, the biological removal of hydrocarbons is cost-effective compared to other treatments. However, inherent physical, chemical and biological limitation hampers the efficient utilisation of the bioremediation technologies. Biostimulation approaches involving the stimulation of indigenous pollutant-degrading bacteria should be preferred ahead of bioaugumentation. The latter approach should be considered when the contaminated site does not have the indigenous pollutant-degrading bacteria. Even in this case, the aim should be to ‘seed’ the biodegradation knowledge to the indigenous microbial populations due to poor survival of the added strains.Thesis (PhD (Biotechnology))--University of Pretoria, 2007.Microbiology and Plant Pathologyunrestricte

Monitoring of microbial hydrocarbon remediation in the soil

Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively. Provided the polluted soil has requisite values for environmental factors that influence microbial activities and there are no inhibitors of microbial metabolism, there is a good chance that there will be a viable and active population of hydrocarbon-utilizing microorganisms in the soil. Microbial methods for monitoring bioremediation of hydrocarbons include chemical, biochemical and microbiological molecular indices that measure rates of microbial activities to show that in the end the target goal of pollutant reduction to a safe and permissible level has been achieved. Enumeration and characterization of hydrocarbon degraders, use of micro titer plate-based most probable number technique, community level physiological profiling, phospholipid fatty acid analysis, 16S rRNA- and other nucleic acid-based molecular fingerprinting techniques, metagenomics, microarray analysis, respirometry and gas chromatography are some of the methods employed in bio-monitoring of hydrocarbon remediation as presented in this review

REVIEW OF THE CENTRAL AND SOUTH ATLANTIC SHELF AND DEEP-SEA BENTHOS: SCIENCE, POLICY, AND MANAGEMENT

The Central and South Atlantic represents a vast ocean area and is home to a diverse range of ecosystems and species. Nevertheless, and similar to the rest of the global south, the area is comparatively understudied yet exposed to increasing levels of multisectoral pressures. To counteract this, the level of scientific exploration in the Central and South Atlantic has increased in recent years and will likely continue to do so within the context of the United Nations (UN) Decade of Ocean Science for Sustainable Development. Here, we compile the literature to investigate the distribution of previous scientific exploration of offshore (30 m+) ecosystems in the Central and South Atlantic, both within and beyond national jurisdiction, allowing us to synthesise overall patterns of biodiversity. Furthermore, through the lens of sustainable management, we have reviewed the existing anthropogenic activities and associated management measures relevant to the region. Through this exercise, we have identified key knowledge gaps and undersampled regions that represent priority areas for future research and commented on how these may be best incorporated into, or enhanced through, future management measures such as those in discussion at the UN Biodiversity Beyond National Jurisdiction negotiations. This review represents a comprehensive summary for scientists and managers alike looking to understand the key topographical, biological, and legislative features of the Central and South Atlantic.This paper is an output of the UN Ocean Decade endorsed Challenger 150 Programme (#57). Challenger 150 is supported by the Deep Ocean Stewardship Initiative (DOSI) and the Scientific Committee on Oceanic Research’s (SCOR) working group 159 (NSF Grant OCE-1840868) for which KLH is co-chair. AEHB, KLH, KAM, SBu, and KS are supported by the UKRI funded One Ocean Hub NE/S008950/1. TA is supported by the BiodivRestore ERA-NET Cofund (GA N°101003777) with the EU and the following funding organisations: FCT, RFCT, AEI, DFG, and ANR. TA also acknowledges financial support to CESAM by FCT/MCTES (UIDP/50017/2 020+UIDB/50017/2020+ LA/P/0094/2020) through national funds. NB is supported by the John Ellerman Foundation. AB is supported by the German Research Foundation. DH, CO, AFB, LA, SBr, and KS received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818123 (iAtlantic); this output reflects only the author’s view and the European Union cannot be held responsible for any use that may be made of the information contained therein. DH, AF, JT, and CW were additionally supported through the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface” (EXC-2077 – 390741603 by Deutsche Forschungsgemeinschaft). CO also extends thanks to the HWK – Institute for Advanced Study, and PM to Dr. Alberto Martín, retired professor of Universidad Simón Bolívar in Caracas, Venezuela for facilitating references used in the Venezuela section.Peer reviewe

SWOT analyses of infrastructure networks’ ownership and governance models

Abstract Municipalities in Finland are facing several challenges of which, curiously enough, many are self-made. These include issues such as increasing maintenance backlogs, limited asset management understanding, difficult to plan and levy fees and tariffs to match full cost recovery, problems in valuation of required maintenance and investment needs and costs, and focus on short-term management (resulting partially from the political cycles). Combined with restructuring and governance issues in the municipality infrastructures, the challenges can become even greater in the future. In various sectors of the municipal infrastructure networks (waterworks, roads, rail and ports) several ownership and governance models are utilized, and pose different types of challenges for the municipalities. This report highlights these issues by presenting the results of SWOT analyses, which represents the strengths, weaknesses, opportunities and threats of infrastructure networks’ ownership and governance models from the point of view of the owner. The analyses are based on interviews of infrastructure network, municipal and state department executives. In addition two stakeholder workshops were arranged in spring 2010. In general the most important strengths of the infrastructure networks’ ownership, governance and operation are related to the stable and secure ownership from the municipal involvement and good knowledge of day-to-day operations. Bureaucracy, lengthy decision-making and political interference are however tough to overcome weaknesses. Combined with a lack of transparency and accountability, sustainable development and maintenance of infrastructure networks, services are endangered. This can lead to deterioration of physical condition and diminished value of infrastructure. In addition, taxation differences; payment of interest without payments on the loan principal; and the maintenance backlog are the most disturbing findings in this study. Improved asset management and cost awareness are crucial issues in all the sectors. It is important to have the motivation and incentives to acquire cost knowledge and use of modern methods of asset management and pricing. In this challenging environment, good management would be a plus. In the future, changes in the concept, way of thinking, management, governance, and stewardship of the infrastructure networks are required

Technical networks’ ownership, governance and procurement

Abstract Communities’ technical networks such as electricity, heating, water, sewage, telecommunications and transport networks have traditionally been owned and operated by public sector. Current economic theories and market situation, however, argues that many public utilities and services can be delivered more efficiently when private sector is involved or when fully privatised. Privatisation, public ownership and public-private partnerships have all found their supporter and opponents over the years. The literature related to ownership and governance of technical networks is, however, patchy and sector and mode specific. This paper presents a literature review on models considered to be suitable for arranging technical networks ownership and governance. It concentrates on defining and modelling the different ownership and governance structure variants and models for technical networks. Objective is to create a coherent picture of the different ownership models, their prerequisites, disadvantages and benefits and the structural changes made during the 20th century. It describes different alternatives from which the municipalities and state authorities are able to determine the preferred structure for each situation. Different approaches should be analysed and weighted in order to find the best possible solution. It has been observed that one size does not fit all and one needs to carefully make conclusions before undertaking any paradigm change. This research is part of a more extensive research project named C-Business – Communities’ technical networks ownership, governance and operation, which aims to investigate the pros and cons of different ownership and governance models of communities’ technical networks. The project assesses the public and business risks of different O&G models and defines a common frame – business architecture – to these models. It further attempts to point out the weak and strong points of both market-oriented and public models of the networks, and to identify prospective business potential in operating and owning the networks. This paper gives a good starting point for further research in the area of ownership, governance and partnerships

Value-creating networks – a conceptual model and analysis

Abstract Value and supply chains have been studied widely in the field of strategic management. Value nets and networks are most familiar in the fields of e-commerce and mobile-commerce. None of these, however, have been studied widely in the field of infrastructure and technical networks. Studies have mostly been theoretical in nature and there is a lack of empirical studies concerning value creation. Objective of this research is to understand communities’ technical networks value creation processes and networks providing the value to the end customers. Starting point is to understanding what value creation and value-creating networks are and how they can advance firms operational efficiency and effectiveness. In this theoretical research a conceptual and analysis model for value-creating networks was created. The conceptual model consists of four critical elements, namely customer value, core competencies, relationships and interaction. These four elements where used when the analysis model was created. The analysis model consists of five questions: 1) Who is the customer and what is considered valuable? 2) What activities are needed to create the value? 3) What resources are needed to carry out the activities? 4) Who are able to utilise these resources? and 5) How actors interact and influence each other? When these questions are answered related to a certain product or service the current state of the value-creation can be determined and the future possibilities discovered. Objective of all network actors should be satisfied, internal or external, customers. The network should work together to deliver the product or service to the customer at the right time, to the right place and at the right price. The analysis of value-creating networks gives possibilities to realise customers’ needs and find the main actors in the network. The analysis makes the relationships and interaction of the different actors clearer and gives the opportunity to find the underlying problems and objectives for future development. When the customer, customer’s needs and the value-creating network has been identified it is possible to make improvements and increase the value created to the customer. This research is part of a more extensive research project named C-Business – Communities’ technical networks ownership, governance and operation, which aims to investigate the pros and cons of different ownership and governance models of communities’ technical networks

Modification of cellulose fibres with organosilanes: under what conditions does coupling occur?

Different cellulose substrates and organosolv lignin were treated heterogeneously with organic solutions of trialkoxysilanes bearing vari- able function on the forth substituent. It was shown unambiguously for the first time that Si–OR does not react with the hydroxy groups of cellulose even at high temperature, whereas it condenses with the phenolic OH of lignin. The addition of moisture to these systems induces the partial hydrolysis of the siloxane moieties and the ensuing silanol groups can then react with the cellulose OH, but only at high tempera- ture. Using the latter systems and a siloxane bearing a polymerizable function, it was possible to attach poly(methylmethacrylate) chains to the surface of cellulose fibres through a two-step procedure