Wastewater-based surveillance (WBS) allows the analysis of pathogens, chemicals or other biomarkers in wastewater to derive unbiased epidemiological information at population scale. After re-gaining attention during the SARS-CoV-2 pandemic, the field holds promise as a surveillance and early warning system by tracking emerging pathogens with pandemic potential. Expanding the current toolbox of analytical techniques for wastewater analysis, we explored the use of Hyperplex PCR (hpPCR) to analyse SARS-CoV-2 mutations in wastewater samples collected weekly in up to 22 sites across Sweden between October 2022 and December 2023. The samples were tested using a probe panel ranging from 10- to 18-plex, continuously adapted within 1–2 weeks to quantify relevant mutations of concern over time. For cross-validation, the samples were simultaneously analysed with commonly used methods including quantitative PCR (qPCR) and next-generation sequencing (NGS). hpPCR is demonstrated herein to provide (1) systematic single nucleotide specificity with a straightforward probe design, (2) high multiplexity with minimal panel re-optimization requirements and (3) 4–5-week earlier mutation detection relative to NGS with comparable performance of mutation frequency quantification (Pearson r = 0.88, n = 50). Hence, hpPCR is shown to be a powerful complementary tool to the current workflow involving NGS and qPCR by facilitating the assembly of dynamic high-plex panels compatible with high-frequency monitoring of multiple key pathogens and/or variants in WBS.

Human adenovirus (HAdV) type F41 has been identified as a possible cause of the non-A-to-E hepatitis outbreak. This study uses wastewater monitoring to track HAdV F40 and F41, supporting clinical investigations and providing insights into the pathogen's role in the outbreak. Given the limited clinical monitoring in Sweden of HAdV-F40/41, this approach also helps estimate the true infection burden of this pathogen during the outbreak. This study developed three qPCR assays for the hexon, penton, and fiber genes of HAdV F40 and F41. The hexon assay was F41-specific, while the fiber assay detected multiple HAdV-F strains. Comprehensive monitoring of HAdV-F40/41 levels in Stockholm's wastewater was conducted over 1.5 years, capturing the period before, during, and after the outbreak. A significant infection wave was observed in spring 2022, with strains beyond lineage 2 contributing to the outbreak. Moreover, simultaneous SARS-CoV-2 surveillance revealed that HAdV-F infections peaked at different times from COVID-19, but the HAdV-F wave aligned with the relaxation of pandemic restrictions. These findings offer valuable insights for future HAdV-F investigations and confirm its role in the non-A-to-E hepatitis outbreak.

Global usage of pharmaceuticals has led to the proliferation of bacteria that are resistant to antimicrobial treatments, creating a substantial public health challenge. Here, we investigate the emergence of sulfonamide resistance genes in groundwater and surface water in Patna, a rapidly developing city in Bihar, India. We report the first quantification of three sulfonamide resistance genes (sulI, sulII and sulIII) in groundwater (12-107 m in depth) in India. The mean relative abundance of gene copies was found to be sulI (2.4 x 10(-2) copies/16S rRNA gene) > sulII (5.4 x 10(-3) copies/16S rRNA gene) > sulIII (2.4 x 10(-3) copies/16S rRNA gene) in groundwater (n = 15) and surface water (n = 3). A comparison between antimicrobial resistance (AMR) genes and wastewater indicators, particularly tryptophan:fulvic-like fluorescence, suggests that wastewater was associated with AMR gene prevalence. Urban drainage channels, containing hospital and domestic wastes, are likely a substantial source of antimicrobial resistance in groundwater and surface water, including the Ganges (Ganga) River. This study is a reference point for decision-makers in the fight against antimicrobial resistance because it quantifies and determines potential sources of AMR genes in Indian groundwater.

This study examined the anaerobic release of phosphorus (P) from two different Baltic Sea sediments (B and F), focusing on the impact of initial concentration of externally introduced waste-derived volatile fatty acids (VFA) as the carbon source, temperature, pH, and mixing conditions. The first batch bioreactor set was operated to demonstrate the effect of VFA on anaerobic P release at different concentrations (1000–10000 mg/L as COD) at 20 °C. A notable P release of up to 15.85 mg/L PO4–P was observed for Sediment B at an initial carbon concentration of 10000 mg COD/L. However, VFA consumption in the bioreactors was minimal or no subsequent. The second batch bioreactor set was carried out to investigate the effect of temperature (20 °C-35 °C), pH (5.5, 7.0 and 8.5) and mixing conditions on P release by introducing lower initial carbon concentration (1000 mg COD/L) considering the potential risk for VFA accumulation in the bioreactors. Maximum P releases of 4.4 mg/L and 3.5 mg/L were for Sediment B and Sediment F, respectively. Two-way ANOVA tests revealed that the operation time and pH and their interactions were statistically significant (p < 0.05) for both sediments while the effect of mixing was not statistically significant. Most of the sulfate was reduced during batch bioreactor operation and Desulfomicobiaceae became dominant among other sulfate-reducing bacteria (SRB) possibly shows the importance of SRB in terms of anaerobic P release. This study gives an insight into future implementations of phosphorus mining from eutrophic environment under anaerobic conditions.

To evaluate the feasibility of enriching polyphosphate-accumulating organisms (PAOs) within marine sediment for achieving phosphorus (P) recovery, two sediment-inoculated sequencing batch reactors (SBRs), fed with propionic acid (R1) and glucose (R2), were operated for 119 days. For comparison, two sewage sludge-inoculated reactors (R3 and R4) were also set up. The sediments/sludge fed with 200 mg/L chemical oxygen demand (COD) equivalent propionic acid exhibited satisfactory P release/uptake performance after 56 days of culture. The maximum P release and uptake rates for R1 were 3 mg P/g VSS•h−1 and 2.5 mg P/g VSS•h−1, respectively, while for R3 they were 2.6 mg P/g VSS•h−1 and 5.8 mg P/g VSS•h−1, respectively. Meanwhile, the PAO family (Rhodocyclaceae) in R1 increased from almost 0 % initially to 16.0 % after 42 days. However, the glucose-fed SBRs did not exhibit enhanced biological phosphorus removal (EBPR) performance throughout the operation. As the COD feeding concentration increased to 400 mg/L, the reactors showed EBPR deterioration. Total P in R1 and R3 significantly decreased from 423.7 mg to 307.2 mg and from 368.0 mg to 94.9 mg, respectively. Key intracellular polymer responses indicated that introduction of excessively high COD significantly reduced poly-P content and the anaerobic synthesis of polyhydroxyalkanoate. Microbial analysis suggested that the breakdown of EBPR performance could be attributed to glycogen-accumulating organisms outcompeting PAOs under high carbon feeding conditions. Additionally, PHREEQC simulations confirmed that P-rich supernatant from the anaerobic phase could theoretically be recovered as struvite, with a recovery efficiency of up to 94 %.

The study of how micro-organisms detect and respond to different stresses has a long history of producing fundamental biological insights while being simultaneously of significance in many applied microbiological fields including infection, food and drink manufacture, and industrial and environmental biotechnology. This is well-illustrated by the large body of work on acid stress. Numerous different methods have been used to understand the impacts of low pH on growth and survival of micro-organisms, ranging from studies of single cells to large and heterogeneous populations, from the molecular or biophysical to the computational, and from well-understood model organisms to poorly defined and complex microbial consortia. Much is to be gained from an increased general awareness of these methods, and so the present review looks at examples of the different methods that have been used to study acid resistance, acid tolerance, and acid stress responses, and the insights they can lead to, as well as some of the problems involved in using them. We hope this will be of interest both within and well beyond the acid stress research community.

To investigate the possibility of phosphorus (P) recovery from marine sediment and explore the role of the carbon: nitrogen ratio in affecting the internal P release under anaerobic conditions, we experimented with the external addition of carbon (acetic acid and glucose) and ammonia nitrogen (NH4-N) to expose P release mechanisms. The 24-day anaerobic incubations were conducted with four different carbon: nitrogen dosing groups including no NH4-N addition and COD/N ratios of 100, 50, and 10. The P release showed that extra NH4-N loading significantly suppressed the decomposition of P (p < 0.05) from the marine sediment, the maximum P release was 4.07 mg/L and 7.14 mg/L in acetic acid- and glucose-fed systems, respectively, without extra NH4-N addition. Additionally, the results exhibited that the imbalance of carbon: nitrogen not only failed to induce the production of organic P mineralization enzyme (alkaline phosphatase) in the sediment but also suppressed its activity under anaerobic conditions. The highest enzyme activity was observed in the group without additional NH4-N dosage, with rates of 1046.4 mg/(kg∙h) in the acetic acid- and 967.8 mg/(kg∙h) in the glucose-fed system, respectively. Microbial data analysis indicated that a decrease in the abundance of P release-regulating bacteria, including polyphosphate-accumulating organisms (Rhodobacteraceae) and sulfate-reducing bacteria (Desulfosarcinaceae), was observed in the high NH4-N addition groups. The observed reduction in enzyme activity and suppression of microbial activity mentioned above could potentially account for the inhibited P decomposition in the presence of high NH4-N addition under anaerobic conditions. The produced P-enriched solution from the bioreactors may offer a promising source for future recovery endeavors.

This study investigated the efficiency of the treatment processes of wastewater treatment plants (WWTPs) to remove severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and pepper mild mottle virus (PMMoV) from the wastewater and sewage sludge, as well as the influence of the mode of operation on the quality of the treated wastewater. SARS-CoV-2 and PMMoV were detected and quantified at different stages of the wastewater and sludge treatment process of three major WWTPs in Stockholm, Sweden. The results showed that primary, biological, and advanced membrane treatment processes are effective in removing SARS-CoV-2 from the wastewater with removal efficiencies of 99–100 % for all WWTPs, while the virus was accumulated in the primary and waste-activated sludges due to higher affinity to biosolids. Operation strategies such as bypass reintroduced the virus into the treated wastewater. The WWTPs achieved relatively low PMMoV removal efficiencies (63–87 %) most probably due to the robust capsid structure of the virus. Anaerobic digestion could not completely remove SARS-CoV-2 and PMMoV from the sludge leading to increased levels of SARS-CoV-2 and PMMoV in dewatered sludge. The study gives an overview of WWTPs’ role in tackling pathogen spread in society in the event of a pandemic and disease breakout.

The aim of this study was recovery of phosphorus (P) from marine sediment, and our results revealed the influence of P release from the sediment stimulated with different types and concentrations of carbon sources. During the 15-day anaerobic operation, the sediments stimulated with 1 g/L propionic acid and glucose exhibited more prominent effects compared to other trials, with 5.98 mg/L and 6.44 mg/L of P released, respectively, with a total solid content of 4 %. Notably, the excessive addition of carbon sources was shown to can partially inhibit P release. As microbial activity intensified, P was utilized for microbial synthesis, resulting in a decreased P in the supernatant. For example, in glucose-fed systems with concentrations of 5 g/L and 10 g/L, the P concentration decreased from 5 mg/L on Day 3 to approximately 3 mg/L on Day 15. The sequencing results indicated distinct evolutions within different carbon source-fed systems over the 15-day operations. Feeding high concentrations of glucose resulted in rapid enrichment of fermentative bacteria under anaerobic conditions, while sulfate-reducing bacteria promoted P release in volatile fatty acids-fed systems. Metabolic analysis revealed that carbon sources not only influence gene expression in different systems, but also impact the metabolic pathways involved in nutrient cycling, which can be interrelated. For example, a significant positive correlation was observed between the abundance of P and sulfur cycling functional genes (phoD, cysD).

Shifting the concept of municipal wastewater treatment to recover resources is one of the key factors contributing to a sustainable society. A novel concept based on research is proposed to recover four main bio-based products from mu-nicipal wastewater while reaching the necessary regulatory standards. The main resource recovery units of the pro-posed system include upflow anaerobic sludge blanket reactor for the recovery of biogas (as product 1) from mainstream municipal wastewater after primary sedimentation. Sewage sludge is co-fermented with external organic waste such as food waste for volatile fatty acids (VFAs) production as precursors for other bio-based production. A por-tion of the VFA mixture (product 2) is used as carbon sources in the denitrification step of the nitrification/denitrifica-ti on process as an alternative for nitrogen removal. The other alternative for nitrogen removal is the partial nitrification/anammx process. The VFA mixture is separated with nanofiltration/reverse osmosis membrane technol-ogy into low-carbon VFAs and high-carbon VFAs. Polyhydroxyalkanoate (as product 3) is produced from the low -carbon VFAs. Using membrane contactor-based processes and ion-exchange techniques, high-carbon VFAs are recovered as one-type VFA (pure VFA) and in ester forms (product 4). The nutrient-rich fermented and dewatered bio-solid is applied as a fertilizer. The proposed units are seen as individual resource recovery systems as well as a concept of an integrated system. A qualitative environmental assessment of the proposed resource recovery units confirms the positive environmental impacts of the proposed system.