Disentangling abiotic and biotic effects of treated wastewater on stream biofilm resistomes enables the discovery of a new planctomycete beta-lactamase.

Background: Environmental reservoirs of antibiotic resistance pose a threat to human and animal health. Aquatic biofilms impacted by wastewater effluent (WW) are known environmental reservoirs for antibiotic resistance; however, the relative importance of biotic factors and abiotic factors from WW on the abundance of antibiotic resistance genes (ARGs) within aquatic biofilms remains unclear. Additionally, experimental evidence is limited within complex aquatic microbial communities as to whether genes bearing low sequence similarity to validated reference ARGs are functional as ARGs.

An assessment of latrine front-end characteristics and associated surface E. coli indicated faecal contamination in rural Fiji.

In Fiji, 90% of the population has access to basic sanitation; however, there are still persistent health risks from endemic faecal-oral diseases such as typhoid fever. There is a need to assess the contribution of existing sanitation facilities in the faecal pathogen transmission pathway. This study was conducted as part of a larger planetary health study across 29 rural communities within five river catchments.

A review of latrine front-end characteristics associated with microbial infection risk; reveals a lack of pathogen density data.

Unsafe sanitation accounts for an estimated 898,000 global deaths annually. The faecal pathogen transmission pathway is complex with several possible routes. Latrine front-end characteristics and usage behaviours are one key transmission pathway for microbial pathogens, however, there has not yet been a synthesis of the available research.

Volatile fatty acid production from food waste: The effect of retention time and lipid content.

The bioconversion of food waste to renewable products has an important role in alleviating the environmental burden of food wastage. This study evaluates the effect of solids retention time (1.5, 4, and 7 days) and lipid content (up to 30 % DS) on the solid's destruction efficiency and VFA yield from food waste fermentation.

Unravelling the removal mechanisms of bacterial and viral surrogates in aerobic granular sludge systems.

The aerobic granular sludge (AGS) process is an effective wastewater treatment technology for organic matter and nutrient removal that has been introduced in the market rapidly. Until now, limited information is available on AGS regarding the removal of bacterial and viral pathogenic organisms present in sewage. This study focussed on determining the relation between reactor operational conditions (plug flow feeding, turbulent aeration and settling) and physical and biological mechanisms on removing two faecal surrogates, Escherichia coli and MS2 bacteriophages.

Recovery of phosphorus from municipal wastewater treatment sludge through bioleaching using Acidithiobacillus thiooxidans.

Conventional wastewater treatment plants remove phosphorus, which is captured in sewage sludge. Increasing attention is paid to suitable process pathways that allow recovery and recycling of phosphorus. One of the processes under investigation is acid leaching and recovery of phosphorus, but this requires considerable chemical additives, which could be avoided by stimulating acidification via microbiological processes.

Assessing Drinking Water Quality at the Point of Collection and within Household Storage Containers in the Hilly Rural Areas of Mid and Far-Western Nepal.

Accurate assessments of drinking water quality, household hygenic practices, and the mindset of the consumers are critical for developing effective water intervention strategies. This paper presents a microbial quality assessment of 512 samples from household water storage containers and 167 samples from points of collection (POC) in remote rural communities in the hilly area of western Nepal. We found that 81% of the stored drinking water samples (mean log of all samples = 1.

Inactivation of indicator organisms on different surfaces after urban floods.

The high frequency and intensity of urban floods caused by climate change, urbanisation and infrastructure failures increase public health risks when the flood water contaminated from combined sewer overflows (CSOs) or other sources of faecal contamination remains on urban surfaces. This study contributes to a better understanding of the effects of urban and recreational surfaces on the occurrence of waterborne pathogens. The inactivation of selected indicator organisms was studied under controlled exposure to artificial sunlight for 6 h followed by 18 h in dark conditions.

Die-off of E. coli as fecal indicator organism on different surfaces after urban floods.

A better understanding of the effects of different urban and recreational surfaces on the die-off of water-borne pathogens that can cause infections after urban floods if released from surcharged combined sewers and other sources of fecal contamination is needed. The die-off of fecal indicator Escherichia coli was studied under controlled exposure to simulated sunlight on a range of different surfaces found in urban environments: gravel, sand, asphalt, pavement blocks, concrete, playground rubber tiles and grass, using glass as control. The surfaces were inoculated with artificial flooding water containing 10 colony forming units (CFU) of E.

On the evolution and physiology of cable bacteria.

Cable bacteria of the family Desulfobulbaceae form centimeter-long filaments comprising thousands of cells. They occur worldwide in the surface of aquatic sediments, where they connect sulfide oxidation with oxygen or nitrate reduction via long-distance electron transport. In the absence of pure cultures, we used single-filament genomics and metagenomics to retrieve draft genomes of 3 marine Electrothrix and 1 freshwater Electronema species.

Photo-oxygenation for nitritation and the effect of dissolved oxygen concentrations on anaerobic ammonium oxidation.

Removal of nitrogen from wastewater without using electricity consuming aerators was previously observed in photo-bioreactors with a mixed algal-bacterial biomass. Algammox is the particular process based on algae, ammonium oxidizing organisms and anammox bacteria. In this research the activity of anammox bacteria in such an oxygen-producing environment was tested, as well as the effect of short-duration increase in dissolved oxygen (DO) to values potentially inhibiting anammox activity.

Microbial Groundwater Quality Status of Hand-Dug Wells and Boreholes in the Dodowa Area of Ghana.

To assess the suitability of water sources for drinking purposes, samples were taken from groundwater sources (boreholes and hand-dug wells) used for drinking water in the Dodowa area of Ghana. The samples were analyzed for the presence of fecal indicator bacteria () and viruses (Adenovirus and Rotavirus), using membrane filtration with plating and glass wool filtration with quantitative polymerase chain reaction (PCR), respectively. In addition, sanitary inspection of surroundings of the sources was conducted to identify their vulnerability to pollution.

Two-step bioleaching of copper and gold from discarded printed circuit boards (PCB).

An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards (PCB) in a two-step bioleaching process was experimented. In the first step, chemolithotrophic acidophilic Acidithiobacillus ferrivorans and Acidithiobacillus thiooxidans were used. In the second step, cyanide-producing heterotrophic Pseudomonas fluorescens and Pseudomonas putida were used.

Effectiveness of UV-C light irradiation on disinfection of an eSOS(®) smart toilet evaluated in a temporary settlement in the Philippines.

Ultraviolet germicidal (short wavelength UV-C) light was studied as surface disinfectant in an Emergency Sanitation Operation System(®) smart toilet to aid to the work of manual cleaning. The UV-C light was installed and regulated as a self-cleaning feature of the toilet, which automatically irradiate after each toilet use. Two experimental phases were conducted i.

Lactic Acid Fermentation, Urea and Lime Addition: Promising Faecal Sludge Sanitizing Methods for Emergency Sanitation.

In this research, three faecal sludge sanitizing methods-lactic acid fermentation, urea treatment and lime treatment-were studied for application in emergency situations. These methods were investigated by undertaking small scale field trials with pit latrine sludge in Blantyre, Malawi. Hydrated lime was able to reduce the E.

Microbial carbon metabolism associated with electrogenic sulphur oxidation in coastal sediments.

Recently, a novel electrogenic type of sulphur oxidation was documented in marine sediments, whereby filamentous cable bacteria (Desulfobulbaceae) are mediating electron transport over cm-scale distances. These cable bacteria are capable of developing an extensive network within days, implying a highly efficient carbon acquisition strategy. Presently, the carbon metabolism of cable bacteria is unknown, and hence we adopted a multidisciplinary approach to study the carbon substrate utilization of both cable bacteria and associated microbial community in sediment incubations.

The metagenome of the marine anammox bacterium 'Candidatus Scalindua profunda' illustrates the versatility of this globally important nitrogen cycle bacterium.

Anaerobic ammonium-oxidizing (anammox) bacteria are responsible for a significant portion of the loss of fixed nitrogen from the oceans, making them important players in the global nitrogen cycle. To date, marine anammox bacteria found in marine water columns and sediments worldwide belong almost exclusively to the 'Candidatus Scalindua' species, but the molecular basis of their metabolism and competitive fitness is presently unknown. We applied community sequencing of a marine anammox enrichment culture dominated by 'Candidatus Scalindua profunda' to construct a genome assembly, which was subsequently used to analyse the most abundant gene transcripts and proteins.

A multi-proxy study of anaerobic ammonium oxidation in marine sediments of the Gullmar Fjord, Sweden.

Anaerobic ammonium oxidation (anammox) is an important process for nitrogen removal in marine pelagic and benthic environments and represents a major sink in the global nitrogen cycle. We applied a suite of complementary methods for the detection and enumeration of anammox activity and anammox bacteria in marine sediments of the Gullmar Fjord, and compared the results obtained with each technique. (15) N labelling experiments showed that nitrogen removal through N2 production was essentially limited to the upper 2 cm of the sediment, where anammox contributed 23-47% of the total production.

Impact of temperature on ladderane lipid distribution in anammox bacteria.

Anaerobic ammonium-oxidizing (anammox) bacteria have the unique ability to synthesize fatty acids containing linearly concatenated cyclobutane rings, termed "ladderane lipids." In this study we investigated the effect of temperature on the ladderane lipid composition and distribution in anammox enrichment cultures, marine particulate organic matter, and surface sediments. Under controlled laboratory conditions we observed an increase in the amount of C(20) [5]-ladderane fatty acids compared with the amount of C(18) [5]-ladderane fatty acids with increasing temperature and also an increase in the amount of C(18) [5]-ladderane fatty acids compared with the amount of C(20) [5]-ladderane fatty acids with decreasing temperature.

Physiology and behaviour of marine Thioploca.

Among prokaryotes, the large vacuolated marine sulphur bacteria are unique in their ability to store, transport and metabolize significant quantities of sulphur, nitrogen, phosphorus and carbon compounds. In this study, unresolved questions of metabolism, storage management and behaviour were addressed in laboratory experiments with Thioploca species collected on the continental shelf off Chile. The Thioploca cells had an aerobic metabolism with a potential oxygen uptake rate of 1760 micromol O2 per dm(3) biovolume per h, equivalent to 4.

Revising the nitrogen cycle in the Peruvian oxygen minimum zone.

The oxygen minimum zone (OMZ) of the Eastern Tropical South Pacific (ETSP) is 1 of the 3 major regions in the world where oceanic nitrogen is lost in the pelagic realm. The recent identification of anammox, instead of denitrification, as the likely prevalent pathway for nitrogen loss in this OMZ raises strong questions about our understanding of nitrogen cycling and organic matter remineralization in these waters. Without detectable denitrification, it is unclear how NH(4)(+) is remineralized from organic matter and sustains anammox or how secondary NO(2)(-) maxima arise within the OMZ.

Enrichment and characterization of marine anammox bacteria associated with global nitrogen gas production.

Microbiological investigation of anaerobic ammonium oxidizing (anammox) bacteria has until now been restricted to wastewater species. The present study describes the enrichment and characterization of two marine Scalindua species, the anammox genus that dominates almost all natural habitats investigated so far. The species were enriched from a marine sediment in the Gullmar Fjord (Sweden) using a medium based on Red Sea salt.

Ladderane lipid distribution in four genera of anammox bacteria.

Intact ladderane phospholipids and core lipids were studied in four species of anaerobic ammonium oxidizing (anammox) bacteria, each representing one of the four known genera. Each species of anammox bacteria contained C18 and C20 ladderane fatty acids with either 3 or 5 linearly condensed cyclobutane rings and a ladderane monoether containing a C20 alkyl moiety with 3 cyclobutane rings. The presence of ladderane lipids in all four anammox species is consistent with their putative physiological role to provide a dense membrane around the anammoxosome, the postulated site of anammox catabolism.

Physiological and phylogenetic study of an ammonium-oxidizing culture at high nitrite concentrations.

Oxidation of high-strength ammonium wastewater can lead to exceptionally high nitrite concentrations; therefore, the effect of high nitrite concentration (> 400 mM) was studied using an ammonium-oxidizing enrichment culture in a batch reactor. Ammonium was fed to the reactor in portions of 40-150 mM until ammonium oxidation rates decreased and finally stopped. Activity was restored by replacing half of the medium, while biomass was retained by a membrane.

Candidatus 'Brocadia fulgida': an autofluorescent anaerobic ammonium oxidizing bacterium.

Anaerobic ammonium oxidizing (anammox) bacteria are detected in many natural ecosystems and wastewater treatment plants worldwide. This study describes the enrichment of anammox bacteria in the presence of acetate. The results obtained extend the concept that the anammox bacteria can be enriched to high densities in the presence of substrates for heterotrophic growth.