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The contamination of soil with petrogenic hydrocarbons represents a significant human health concern as a result of the carcinogenic and mutagenic properties of a number of compounds commonly found in petroleum products such as polycyclic aromatic hydrocarbons (PAHs). Although it is known that soil fungal communities play an important role in the degradation of highly branched petroleum hydrocarbons and high molecular weight PAHs, little information is available regarding the impact of petrogenic contamination on the structure and diversity of the fungal community and the impact of soil type on the fungal community response. Here, the aim of this study was to evaluate the impact of petrogenic contamination on fungal communities in two soil types. In sandy soils, the most contaminated test pit had the highest fungal diversity. Fungal profiles were dominated by species from the class Eurotiomycetes and included the well-known hydrocarbon-degrading species of Aspergillus and Eurotiales. The dominance of these species did not change with contamination concentration,suggesting a level of adaptability to multiple carbon sources. There appeared to be no correlation between fungal species diversity and contaminant concentration in the clayey soil. Similar dominant fungal species were identified in the clay and sandy soils, all of which were part of the phylum Ascomycota. The clayey soils had a higher species diversity and range-weighted richness compared to sandy soils, which may be a result of the pore connectivity theory i.e. as a result of low water connectivity in soils the formation of diverse communities is promoted through creation of microhabitats. Refereed/Peer-reviewed

Understanding and managing the risk posed by helminth eggs (HE) is a key concern for wastewater engineers and public health regulators. The treatment processes that produce recycled water from sewage at wastewater treatment plants (WWTPs) rely on achieving a defined log10 reduction value (LRV) in HE concentration during the production of recycled water from sewage to achieve the guideline concentration of ≤1.0 HE/L. The total concentration of HE in sewage reaches thousands of HE/L in developing countries and therefore, an LRV of 4.0 is generally accepted to achieve a safe concentration in recycled water, as this will meet the guideline value. However, in many developed countries with good sanitation and public health standards, the HE concentration in sewage is generally

Here we examine recent research on the degradation of polyaromatic hydrocarbons (PAHs) by fungi and bacteria. In addition, we provide information regarding the role that omics tools (next-generation sequencing) can play in the future development of bioremediation of PAHs. The toxicity of petrogenic wastes containing PAHs to biotic communities, including humans, is well established. Bioremediation strategies based on the use of microorganisms represent an economic and environmentally friendly approach (compared with other remediation methods) which is increasingly being applied for the treatment of PAH-contaminated soils. Biological treatments or bioremediation exploits the hydrocarbon-degrading abilities of microorganisms, resulting in destruction of the contaminants and significant detoxification of the contaminated material. To further develop this approach as a consistent commercial technology, it is important to understand the microbial ecology of the remediation process, determining the key microorganisms which drive the underlying PAH degradation processes.

Per- and polyfluoroalkyl substances (PFAS) are Synthetic Organic Compounds (SOCs) which are of current concern as they are linked to a myriad of adverse health effects in mammals. They can be found in drinking water, rivers, groundwater, wastewater, household dust, and soils. In this review, the current challenge and status of bioremediation of PFAs in soils was examined. While several technologies to remove PFAS from soil have been developed, including adsorption, filtration, thermal treatment, chemical oxidation/reduction and soil washing, these methods are expensive, impractical for in situ treatment, use high pressures and temperatures, with most resulting in toxic waste. Biodegradation has the potential to form the basis of a cost-effective, large scale in situ remediation strategy for PFAS removal from soils. Both fungal and bacterial strains have been isolated that are capable of degrading PFAS; however, to date, information regarding the mechanisms of degradation of PFAS is limited. Through the application of new technologies in microbial ecology, such as stable isotope probing, metagenomics, transcriptomics, and metabolomics there is the potential to examine and identify the biodegradation of PFAS, a process which will underpin the development of any robust PFAS bioremediation technology.

Balneotherapy is an ancient practice which remains commonplace throughout the world due to perceived health benefits that include relief of arthritis, fibromyalgia and relaxation. However, bathing environments are not sterile and natural spring waters may harbour natural microbial populations that include potential pathogens. We elucidated the microbial community from water taken from the borehole, pre-filter water (chlorinated, cold and post-bathing water) and post-filter water at a commercial Australian natural hot spring bathing facility. Thiobacillus, Sphingobium and Agrobacterium were the predominant genera in samples collected from the borehole. The predominant genera changed to Sphingobium, Parvibaculum and Achromobacter following chloride treatment and Azospira replaced the Achromobacter once the water reached ambient temperature and was stored ready to be used by bathers. The microbial community changed again following use by bathers, dominated by Pseudomonas, although Sphingobium persisted. No total or faecal coliforms were observed in any of the samples except for the post-bathing water, even there, their presence was at very low concentration (2.3 cfu/mL). These results confirm the lack of pathogens present in these hot spring waters but also suggests that good management of post-bathing water is required especially if the water is used for borehole water recharge.

Contamination of water systems can not only entail high risks to human health but can also result in economic losses due to closure of beaches and shellfish harvesting areas. Understanding the origin of fecal pollution at locations where shellfish are grown is essential in assessing associated health risks&mdash, as well as the determining actions necessary to remedy the problem. The aim of this work is to identify the species-specific source(s) of fecal contamination impacting waters overlying the shellfisheries in the Blackwater Estuary, East Anglia, UK. Over a twelve-month period, water samples were taken from above the oysters and from a variety of upstream points considered to be likely sources of fecal microorganism, together with oyster samples, and the number of fecal streptococci and E. coli were determined. Transition from low to high tide significantly decreased the concentration of fecal streptococci in waters overlying the oyster beds, indicative of a freshwater input of fecal pollution in oyster bed waters. In 12 months, the number of E. coli remained constant throughout, while fecal streptococci numbers were generally higher in the winter months. Analyses of upstream samples identified a sewage outfall to be the main source of E. coli to the oyster beds, with additional fecal streptococci from agricultural sources. The findings may assist in developing approaches for assessing the risks to shellfishery industries of various fecal inputs into an estuary, which could then help local governmental authorities address the problem.

Bioaugmentation or the addition of microbes to contaminated sites has been widely used to treat contaminated soil or water; however this approach is often limited to laboratory based studies. In the present study, large scale bioaugmentation has been applied to total petroleum hydrocarbons (TPH)-contaminated groundwater at a petroleum facility. Initial TPH concentrations of 1564 mg L?1 in the field were reduced to 89 mg L?1 over 32 days. This reduction was accompanied by improved ecotoxicity, as shown by Brassica rapa germination numbers that increased from 52 at day 0 to 82% by the end of the treatment. Metagenomic analysis indicated that there was a shift in the microbial community when compared to the beginning of the treatment. The microbial community was dominated by Proteobacteria and Bacteroidetes from day 0 to day 32, although differences at the genus level were observed. The predominant genera at the beginning of the treatment (day 0 just after inoculation) were Cloacibacterium, Sediminibacterium and Brevundimonas while at the end of the treatment members of Flavobacterium dominated, reaching almost half the population (41%), followed by Pseudomonas (6%) and Limnobacter (5.8%). To the author's knowledge, this is among the first studies to report the successful large scale biodegradation of TPH-contaminated groundwater (18,000 L per treatment session) at an offshore petrochemical facility.

Relatively high E. coli and Faecal Streptococci (FS) numbers have been reported in the waters surrounding Blakeney Point, East Anglia, UK, an area containing significant shellfishery industries including mussels and cockles, despite the implementation of development works aimed at reducing residual contamination problems. The aim of this study was to evaluate the potential of using bacterial analyses and sterol profiling to assess the current levels and source of faecal pollution at Blakeney Point. No evidence of significant human faecal contamination of water in and around Blakeney Point could be found using either traditional microbiological analyses or sterol profile analysis. The presence of significant quantities of sitosterol, however, suggests that faecal contamination of water from birds does occur but at the concentration detected would not affect water quality. Analysis of cockles and mussels taken from the area show that negligible levels of coprostanol were present, confirming that faecal pollution was not causing any contamination issues. Apart from cholesterol, brassicasterol, an algal biomarker, as expected was dominant in shellfish flesh. The results confirm that current water treatment processes are successful in ensuring water quality at Blakeney Point and that a combination of microbial testing with sterol profile analysis confirmed that low microbial concentrations of faecal contaminants present in and around Blakeney Point most probably originate from migratory and/or resident bird species.

Singapore is a highly industrialised country with an important oil industry resulting in a significant environmental impact, creating vast amounts of hydrocarbon waste that needs to be remediated. Here we report on the commercial scale bioremediation of a soil contaminated with processed petroleum hydrocarbons at a petroleum facility located offshore from Singapore. Initial laboratory results indicated the efficacy of an adapted consortium in terms of degradation of petroleum hydrocarbons, with complete degradation of the contaminants occurring after 21 days. Microbial counts confirmed a bacterial increase during the degradation and an ecotoxicological assessment using Brassica rapa confirmed a reduction in the toxicity of the treated soil. In field studies for example, initial processed petroleum hydrocarbon concentrations of 26,240; 622,657; and 978,399 mg kg −1 in 250 tonnes of soil were degraded to −1 in 9, 12 and 17 weeks, respectively following the bioaugmentation treatment. A 100% germination rate of Brassica rapa was also observed in the field for all the treated soil batches except for soils further contaminated with oil tank bottom sludge. Moreover, further total petroleum hydrocarbons (TPH) analysis performed 3 years after the treatment confirmed that their concentrations have remained low (7–35 mg kg −1 ) all over the site. To the author's knowledge, this is among the first studies to report large scale successful bioaugmentation of TPH-contaminated soil in Singapore.

With the ever increasing population growth in urban areas, stakeholders have adopted numerous water sensitive urban design (WSUD) measures to enable the recycling and reuse of stormwater for a range of non-potable fit-for-purpose uses. This chapter highlights the most common measures adopted across Australia in the recent past, their benefits and limitations. Findings suggest that the adoption of WSUD measures have provided multiple tangible and intangible benefits from a social, environmental and economic context. For further expansion and adoption of WSUD measures, the multiple benefits need to be communicated and shared with the scientific and the broader community further to create sustainable and water resilient urban areas.

Bioremediation is a broadly applied environmentally friendly and economical treatment for the clean-up of sites contaminated by petroleum hydrocarbons. However, the application of this technology to contaminated soil in Libya has not been fully exploited. In this study, the efficacy of different bioremediation processes (necrophytoremediation using pea straw, bioaugmentation and a combination of both treatments) together with natural attenuation were assessed in diesel contaminated Libyan soils. The addition of pea straw was found to be the best bioremediation treatment for cleaning up diesel contaminated Libyan soil after 12 weeks. The greatest TPH degradation, 96.1% (18,239.6mgkg(-1)) and 95% (17,991.14mgkg(-1)) were obtained when the soil was amended with pea straw alone and in combination with a hydrocarbonoclastic consortium respectively. In contrast, natural attenuation resulted in a significantly lower TPH reduction of 76% (14,444.5mgkg(-1)). The presence of pea straw also led to a significant increased recovery of hydrocarbon degraders; 5.7log CFU g(-1) dry soil, compared to 4.4log CFUg(-1) dry soil for the untreated (natural attenuation) soil. DGGE and Illumina 16S metagenomic analyses confirm shifts in bacterial communities compared with original soil after 12 weeks incubation. In addition, metagenomic analysis showed that original soil contained hydrocarbon degraders (e.g. Pseudoxanthomonas spp. and Alcanivorax spp.). However, they require a biostimulant (in this case pea straw) to become active. This study is the first to report successful oil bioremediation with pea straw in Libya. It demonstrates the effectiveness of pea straw in enhancing bioremediation of the diesel-contaminated Libyan soil.

Graphical abstract, Polycyclic aromatic hydrocarbons (PAHs) are major pollutants globally and due to their carcinogenic and mutagenic properties their clean-up is paramount. Bioremediation or using PAH degrading microorganisms (mainly bacteria) to degrade the pollutants represents cheap, effective methods. These PAH degraders harbor functional genes which help microorganisms use PAHs as source of food and energy. Most probable number (MPN) and plate counting methods are widely used for counting PAHs degraders; however, as culture based methods only count a small fraction (

This work aimed to identify the major source(s) of faecal pollution impacting Salcott Creek oyster fisheries in the UK through the examination of the sterol profiles. The concentration of the major sewage biomarker, coprostanol, in water overlying the oysters varied between 0.01 &mu, g L&minus, 1 and 1.20 &mu, 1. The coprostanol/epicoprostanol ratio ranged from 1.32 (September) to 33.25 (February), suggesting that human sewage represents the key input of faecal material into the estuary. However, a correlation between the sterol profile of water above the oysters with that of water that enters from Tiptree Sewage Treatment Works (r = 0.82), and a sample from a site (Quinces Corner) observed to have a high population of Brent geese (r = 0.82), suggests that both sources contribute to the faecal pollution affecting the oysters. In identifying these key faecal inputs, sterol profiling has allowed targeted management practices to be employed to ensure that oyster quality is optimised.

Petroleum hydrocarbons (PHC) enter the environment due to exploration, transportation, usage and spills. PHC contamination is of major concern worldwide due to the damage they cause to the environment. Clean up of hydrocarbon-contaminated sites is expensive and time-consuming; however, bioremediation represents a cost-effective and environmentally safe approach to clean up PHC contamination. Many bioremediation strategies can be applied depending on the contaminated site and the surrounding environment. In addition, a variety of technologies are used to assess the efficiency of bioremediation of contaminated environments through analysis of the concentration of the pollutant. Other technologies are applied to study the microbial communities in the contaminated sites since they represent the backbone of any bioremediation process. One of the most convenient technologies in this regard is next-generation sequencing (NGS) since it is cost-effective and provides comprehensive information regarding diversity and therefore bioremediation potential of microbial communities. Bioremediation, however, is not always a straightforward approach, especially when another contaminant (e.g. heavy metals) is associated with PHC. In this chapter, the concept of bioremediation of hydrocarbon-contaminated environments is illustrated. Moreover, the most common technologies applied in bioremediation are explained. In addition, the most recent tools for assessing the microbial ecology are described. Finally, current challenges and limitations of bioremediation are presented.

Singapore is an island city state with an economy dependent on petrochemicals and shipping, but with severely limited water resources. This study aimed to establish a suitable methodology specifically for the translation of a laboratory-scale system to an industrial scale for the treatment of phenol-contaminated wastewater. A habitat-specific microbial consortium was developed and reconstituted from 22 pure cultures dominated by Acinetobacter sp., Bacillus sp. and Pseudomonas sp. to form a synthetic biofilm-forming community with the capacity to degrade phenol-contaminated wastewater. The laboratory experiment was scaled-up to 400 m3 by using biotrickling reactors to reduce the phenol level from 407 mg L−1 to below detection limit over 104 days incubation. The results showed that the microbial consortia could also reduce the toxicity of the wastewater while degrading the phenol and lowering the wastewater COD. Further, this approach could be translated into the field without the need for a purpose-built primary treatment facility preventing the generation of excessive biomass and eliminating the need for sludge disposal.

Despite the many positive impacts of petroleum hydrocarbons to human industrialization and activity, environmental contamination by petroleum hydrocarbons represents a major cause of marine and terrestrial pollution. Petroleum hydrocarbons contain various compounds such as alkanes, light aromatics (MAHs), cycloalkanes, heavy aromatics (PAHs) and asphaltenes, among others. A number of these compounds are potentially carcinogenic and mutagenic. Among the various remediation technologies, bioremediation or the use of microorganisms to degrade the hydrocarbons is considered a clean, cost-effective and environmentally friendly approach. Unlike other physical and chemical methods, it does not lead to secondary contamination, generally resulting in the complete mineralization of hydrocarbons. Several reports have now confirmed bioremediation as a promising technology to clean up the environments. This chapter presents an overview of current bioremediation approaches for the treatment of petroleum hydrocarbons.

Petroleum hydrocarbons represent the most frequent environmental contaminant. The introduction of petroleum hydrocarbons into a pristine environment immediately changes the nature of that environment, resulting in reduced ecosystem functionality. Natural attenuation represents the single, most important biological process which removes petroleum hydrocarbons from the environment. It is a process where microorganisms present at the site degrade the organic contaminants without the input of external bioremediation enhancers (i.e., electron donors, electron acceptors, other microorganisms or nutrients). So successful is this natural attenuation process that in environmental biotechnology, bioremediation has developed steadily over the past 50 years based on this natural biodegradation process. Bioremediation is recognized as the most environmentally friendly remediation approach for the removal of petroleum hydrocarbons from an environment as it does not require intensive chemical, mechanical, and costly interventions. However, it is under-utilized as a commercial remediation strategy due to incomplete hydrocarbon catabolism and lengthy remediation times when compared with rival technologies. This review aims to describe the fate of petroleum hydrocarbons in the environment and discuss their interactions with abiotic and biotic components of the environment under both aerobic and anaerobic conditions. Furthermore, the mechanisms for dealing with petroleum hydrocarbon contamination in the environment will be examined. When petroleum hydrocarbons contaminate land, they start to interact with its surrounding, including physical (dispersion), physiochemical (evaporation, dissolution, sorption), chemical (photo-oxidation, auto-oxidation), and biological (plant and microbial catabolism of hydrocarbons) interactions. As microorganism (including bacteria and fungi) play an important role in the degradation of petroleum hydrocarbons, investigations into the microbial communities within contaminated soils is essential for any bioremediation project. This review highlights the fate of petroleum hydrocarbons in tertial environments, as well as the contributions of different microbial consortia for optimum petroleum hydrocarbon bioremediation potential. The impact of high-throughput metagenomic sequencing in determining the underlying degradation mechanisms is also discussed. This knowledge will aid the development of more efficient, cost-effective commercial bioremediation technologies.

Aims: To achieve the functional specialization of a microalgae community through operational tuning of an open photobioreactor used for biogas upgrading under alkaline conditions. Methods and Results: An open photobioreactor was inoculated with an indigenous microalgae sample from the Texcoco Soda Lake. A microalgae community was adapted to fix CO2 from synthetic biogas through different culture conditions reaching a maximum of 220 mg CO2 l?1 per day. Picochlorum sp. and Scenedesmus sp. were identified as the prominent microalgae genera by molecular fingerprinting (partial sequencing of 16S rRNA and 18S rRNA genes) but only the first was detected by microscopy screening. Changes in the microalgae community profile were monitored by a range-weighted richness index, reaching the lowest value when biogas was upgraded. Conclusions: A robust microalgae community in the open photobioreactor was obtained after different culture conditions. The specialization of microalgae community for CO2 fixation under H2S presence was driven by biogas upgrading conditions. Significance and Impact of the Study: The alkaline conditions enhance the CO2 absorption from biogas and could optimize specialized microalgae communities in the open photobioreactor. Denaturing gradient gel electrophoresis fingerprinting and richness index comparison are useful methods for the evaluation of microalgae community shifts and photosynthetic activity performance, particularly in systems intended for CO2 removal from biogas where the CO2 assimilation potential can be related to the microbial richness.

Controlling the safe disposal of Municipal Solid Waste (MSW), especially the biodegradable fraction, is an important goal of waste management. This study reports the effects of using composting to biostabilize the biodegradable fraction of MSW sourced from an Advanced Waste Treatment plant in Australia. The impact of biostabilization on the initial aerobic degradation of the material showed a reduction in oxygen consumption of 30% (230 g O 2 /kg loss of ignition (LOI)) in immature compost and 45% (181 g O 2 kg −1 LOI) in mature compost when compared with the input material (330 g O 2 /kg LOI). Anaerobic tests showed a reduction in biodegradability of 40% in the immature compost with biogas production 250 L/kg LOI compared with 50% in mature compost with biogas production of 218 L/kg LOI. The results confirm that the biostabilization of the biodegradable fraction of MSW diverted from landfill can result in a significant reduction of greenhouse gas emission.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are two major environmental contaminants which threaten our health and environment. The removal of these key environmental pollutants from the environment is therefore paramount. Among the cleanup methods currently being used, traditional methods such as chemical and physical treatments tend to be expensive, laborious and may cause secondary contamination. Phytoremediation, the use of plants and associated microorganisms, represents a promising, nondestructive and cost-effective in situ technology for the degradation or removal of contaminants. Grasses belonging to the Poaceae family have drawn significant attention in this regard due to their fast growth, dense, fibrous root systems, and the demonstrated fast removal of PAH and PCB compounds from soils in which these plants have been grown. In this review, we review research on the use of grasses for the degradation of PAHs and PCBs and highlight the benefits of this phytoremediation approach.

The main source of energy supply worldwide is generated from fossil fuels, which undoubtedly are finite and non-environmental friendly resources. Bioethanol generated from edible resources also has economic and environmental concerns. Despite the immense attention to find an alternative (inedible) source of energy in the last two decades, the total commercial production of 1st generation biofuels is limited and equivalent only to approximately 3% of the total road transport fuel consumption. Lignocellulosic waste represents the most abundant biomass on earth and could be a suitable candidate for producing valuable products including biofuels. However, cellulosic bioethanol has not been produced on a large scale due to the technical barriers involved that make the commercial production of cellulosic bioethanol not economically feasible. This review examines some of the current barriers to commercialization of the process.

Chlorinated ethenes are of environmental concern with most reports of successful microbial-mediated remediation being associated with major dechlorinating groups such as Dehalococcoides (Dhc) species. However, limited information is available on the community dynamics and dechlorinating activities of indigenous non-Dhc groups. Here, we present evidence of dechlorination of tetrachloroethene (perchloroethylene, PCE) in groundwater samples by indigenous microbial communities. 100 % PCE conversion to ethene was observed in acetate-stimulated 24 week-microcosms (controls; 15 %). Microbial community profiles showed dominance by groups such as Proteobacteria, Spirochaetes, Firmicutes, Methanomicrobiaceae and Methanosarcinaceae. Pareto-Lorenz (PL) analyses suggested an adapted (45 % PL value) but variable bacterial community (55.5 % Δ t(week)) compared to Archaea (25 % PL value; 46.9 % Δ t(week)). Our findings provide evidence of dechlorinating potential of indigenous microorganisms and useful information on their dynamics which may be exploited for in situ groundwater bioremediation.