COVID-19 wastewater based epidemiology: long-term monitoring of 10 WWTP in France reveals the importance of the sampling context.

SARS-CoV-2 wastewater-based epidemiology (WBE) has been advanced as a relevant indicator of distribution of COVID-19 in communities, supporting classical testing and tracing epidemiological approaches. An extensive sampling campaign, including ten municipal wastewater treatment plants, has been conducted in different cities of France over a 20-week period, encompassing the second peak of COVID-19 outbreak in France. A well-recognised ultrafiltration - RNA extraction - RT-qPCR protocol was used and qualified, showing 5.

Management of Microbial Communities through Transient Disturbances Enhances the Functional Resilience of Nitrifying Gas-Biofilters to Future Disturbances.

Microbial communities have a key role for the performance of engineered ecosystems such as waste gas biofilters. Maintaining constant performance despite fluctuating environmental conditions is of prime interest, but it is highly challenging because the mechanisms that drive the response of microbial communities to disturbances still have to be disentangled. Here we demonstrate that the bioprocess performance and stability can be improved and reinforced in the face of disturbances, through a rationally predefined strategy of microbial resource management (MRM).

Understanding of polyhydroxybutyrate production under carbon and phosphorus-limited growth conditions in non-axenic continuous culture.

In a waste into resource strategy, a selection of polyhydroxybutyrate (PHB)-accumulating organisms from activated sludge was achieved in an open continuous culture under acetic acid and phosphorus limitation. Once the microbial population was selected at a dilution rate (D), an increase in phosphorus limitation degree was applied in order to study the intracellular phosphorus plasticity of selected bacteria and the resulting capacity to produce PHB. Whatever D, all selected populations were able to produce PHB.

Polyhydroxybutyrate production by direct use of waste activated sludge in phosphorus-limited fed-batch culture.

Polyhydroxybutyrate (PHB) production directly by waste activated sludge (WAS) was investigated in aerobic fed-batch conditions using acetic acid as substrate. PHB production was induced by phosphorus limitation. WAS of different origin were tested with various degrees of phosphorus limitation and PHB contents of up to 70% (gCOD PHB/gCOD particulate) were obtained.

Resistance and resilience of removal efficiency and bacterial community structure of gas biofilters exposed to repeated shock loads.

Since full-scale biofilters are often operated under fluctuating conditions, it is critical to understand their response to transient states. Four pilot-scale biofilters treating a composting gas mixture and undergoing repeated substrate pulses of increasing intensity were studied. A systematic approach was proposed to quantify the resistance and resilience capacity of their removal efficiency, which enabled to distinguish between recalcitrant (ammonia, DMDS, ketones) and easily degradable (esters and aldehyde) compounds.

Bacterial dynamics in steady-state biofilters: beyond functional stability.

The spatial and temporal dynamics of microbial community structure and function were surveyed in duplicated woodchip-biofilters operated under constant conditions for 231 days. The contaminated gaseous stream for treatment was representative of composting emissions, included ammonia, dimethyl disulfide and a mixture of five oxygenated volatile organic compounds. The community structure and diversity were investigated by denaturing gradient gel electrophoresis on 16S rRNA gene fragments.

Assessing the bias linked to DNA recovery from biofiltration woodchips for microbial community investigation by fingerprinting.

In this study, we explored methodological aspects of nucleic acid recovery from microbial communities involved in a gas biofilter filled with pine bark woodchips. DNA was recovered indirectly in two steps, comparing different methods: cell dispersion (crushing, shaking, and sonication) and DNA extraction (three commercial kits and a laboratory protocol). The objectives were (a) to optimize cell desorption from the packing material and (b) to compare the 12 combinations of desorption and extraction methods, according to three relevant criteria: DNA yield, DNA purity, and community structure representation by denaturing gradient gel electrophoresis (DGGE).

Shock loading in biofilters: impact on biodegradation activity distribution and resilience capacity.

A synthetic contaminated gas was generated, representative of gaseous emissions from sludge composting. It was composed of six volatile organic compounds (aldehyde, ketones, esters, sulphur compound) in an ammoniacal matrix. The gaseous stream was purified by biofiltration, in pilot scale biofilters filled with pine bark woodchips as organic carrier for biomass colonization.

Selective removal of 17beta-estradiol at trace concentration using a molecularly imprinted polymer.

A molecularly imprinted polymer (MIP) was synthesized with 17beta-estradiol (E2) as template. It was then capable to recover this compound by 100+/-0.6% from a 2 microg/L aqueous solution.

An operational method for the real-time monitoring of E. coli numbers in bathing waters.

The aim of this study was to investigate the potential application of the beta-d-glucuronidase (GLUase) activity measurement for the routine detection and quantification of E. coli in marine bathing waters. GLUase activity was measured as the rate of hydrolysis of 4-methylumbelliferyl-beta-d-glucuronide.

Molecular typing of the Legionella pneumophila population isolated from several locations in a contaminated water network.

The RAPD (random amplified polymorphic DNA) technique has been developed for the molecular typing of Legionella in order to characterise the populations of hot water systems. During this study, 22 primers were tested and the four most informative ones were selected. The optimisation of the PCR conditions allowed the setting up of a powerful discriminative genotyping method.

Rapid and automated detection of fluorescent total bacteria in water samples.

Traditional methods for the detection and enumeration of bacteria in water samples are growth-based and require several days to obtain the result. New techniques which reduce the time of analysis have been developed. The objective of this work was to test a rapid method for the detection and enumeration of total viable bacteria using direct fluorescent labelling and detection by laser scanning.

Analysis of the bacteriolytic enzymes of the autolytic lactococcus lactis subsp. cremoris strain AM2 by renaturing polyacrylamide gel electrophoresis: identification of a prophage-encoded enzyme.

Lactococcus lactis subsp. cremoris AM2 was previously shown to lyse early and extensively during cheese ripening (M.-P.

Characterization of cspB, a cold-shock-inducible gene from Lactococcus lactis, and evidence for a family of genes homologous to the Escherichia coli cspA major cold shock gene.

Upon temperature downshift, the major cold shock protein CspA is highly induced in Escherichia coli. This protein being conserved in other bacteria, we used a PCR-based approach with a pair of degenerate primers derived from highly conserved regions of the CspA-related proteins to evidence the presence of at least three related genes in Lactococcus lactis. One of them, cspB, was cloned and sequenced.