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Although significant technological advancements have been made in the development of analytical biosensor chips for detecting bacterial strains (E. coli, S. Mutans and B. Subtilis), critical requirements i.e. limit of detection (LOD), fast time of response, ultra-sensitivity with high reproducibility and good shelf-life with robust sensing capability have yet to be met within a single sensor chip. In order to achieve these criteria, we present an electrically-receptive thermally-responsive (ER-TR) sensor chip comprised of simple filter paper used as substrate coated with composite of poly(N-isopropylacrylamide) polymer (PNIPAm) - graphene nanoplatelet (GR) followed by evaporation of Au electrodes for capturing both Gram-positive (S. mutans and B. subtilis) and Gram-negative (E. coli) bacterial cells in real-time. Autoclave water, tap water, lake water and milk samples were tested with ER-TR chip with and without bacterial strains at varying concentration range 101-105 cells/mL. The sensor was integrated with in-house built printed circuit board (PCB) to transmit/receive electrical signals. The interaction of E. coli, S. mutans and B. subtilis cells with fibers of PNIPAm-GR resulted in a change of electrical resistance and the readout was monitored wirelessly in real-time using MATLAB algorithm. Finally, prepared ER-TR chip exhibited the reproducibility of 85-97% with shelf-life of up to four weeks after testing with lake water sample.

Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reductive amination to evaluate the multiplexing capacity of luminescence resonance energy transfer (LRET) between UCNPs and quantum dots (QDs). This is the first account of a multiplexed bioassay strategy that demonstrates the principle of use of a single form of UCNP as donor and three different color emitting QDs as acceptors to concurrently determine three analytes. Broad absorbance profiles of green, orange and red QDs that spanned from the first exciton absorption peak to the UV region were in overlap with a blue emission band from UCNPs composed of NaYF4 that was doped with 30% Yb3+, 0.5% Tm3+, allowing for LRET that was stimulated using 980 nm near-infrared radiation. The characteristic narrow and well-defined emission peaks of UCNPs and QDs allowed for the collection of luminescence from each nanoparticle using a band-pass optical filter and an epi-fluorescence microscope. The LRET system was used for the concurrent detection of uidA, Stx1A and tetA gene fragments with selectivity even in serum samples, and reached limits of detection of 26 fmol, 56 fmol and 76 fmol, respectively.

There is a critical and urgent demand for a simple, rapid and specific qualitative and quantitative colorimetric biosensor for the detection of the food contaminant Escherichia coli O157:H7 (E. coli O157:H7) in complex food products due to the recent outbreaks of food-borne diseases. Traditional detection techniques are time-consuming, require expensive instrumentation and are labour-intensive. To overcome these limitations, a novel, ultra-rapid visual biosensor was developed based on the ability of E. coli O157:H7 proteases to change the optical response of a surface-modified, magnetic nanoparticle-specific (MNP-specific) peptide probe. Upon proteolysis, a gradual increase in the golden color of the sensor surface was visually observed. The intensification of color was correlated with the E. coli O157:H7 concentration. The color change resulting from the dissociation of the self-assembled monolayer (SAM) was detected by the naked eye and analysed using an image analysis software (ImageJ) for the purpose of quantitative detection. This biosensor demonstrated high sensitivity and applicability, with lower limits of detection of 12 CFU mL−1 in broth samples and 30–300 CFU mL−1 in spiked complex food matrices. In conclusion, this approach permits the use of a disposable biosensor chip that can be mass-produced at low cost and can be used not only by food manufacturers but also by regulatory agencies for better control of potential health risks associated with the consumption of contaminated foods.

Developing sensors for food safety, soil analysis, water quality monitoring and healthcare often requires distinguishing between different species of bacteria. The most rapid, sensitive and specific method to identify bacteria is to analyse their DNA sequence, which comprises of disinfection and lysis of bacterial cells, amplification of the isolated DNA and detection of the amplified sequence. Seamless integration of these steps on a paper substrate is a big challenge. This problem is even more complex for mycobacteria as its thick cell wall structure impedes lysis and the high GC-content of the genome requires careful optimization of enzymatic denaturation. Here we successfully combine thermal lysis and loop-mediated isothermal amplification (LAMP) into a single reaction step on paper. We demonstrate our integrated assay by amplifying DNA from 100 CFU/mL of Escherichia coli (MG1655) and Mycobacterium smegmatis (mc2155) cells in 30 min on a paper substrate. We also confirm that E. coli and M. smegmatis can be completely disinfected on paper by heating at 60 °C for 5 min and 15 min respectively, making this assay safe and suitable for incorporation into diverse paperfluidic sensors for field use.

As a cost-effective alternative to silver nanoparticles, we have investigated the use of copper nanoparticles in paper filters for point-of-use water purification. This work reports an environmentally benign method for the direct in situ preparation of copper nanoparticles (CuNPs) in paper by reducing sorbed copper ions with ascorbic acid. Copper nanoparticles were quickly formed in less than 10 minutes and were well distributed on the paper fiber surfaces. Paper sheets were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and atomic absorption spectroscopy. Antibacterial activity of the CuNP sheets was assessed for by passing Escherichia coli bacteria suspensions through the papers. The effluent was analyzed for viable bacteria and copper release. The CuNP papers with higher copper content showed a high bacteria reduction of log 8.8 for E. coli. The paper sheets containing copper nanoparticles were effective in inactivating the test bacteria as they passed through the paper. The copper levels released in the effluent water were below the recommended limit for copper in drinking water (1 ppm).

The present work describes ceric ammonium nitrate (CAN) initiated graft copolymerization of acrylamide onto cellulose-based filter paper followed by entrapment of silver nanoparticles. The copolymerization was carried out in aqueous solution, containing 2M acrylamide monomer and 16mM N,N'-methylene bisacrylamide (MB) crosslinker. The optimum initiation time and grafting reaction temperature were found to be 15min and 30 degrees C, respectively. The silver nanoparticles were loaded into grafted filter paper by equilibration in silver nitrate solution followed by citrate reduction. The formation of silver nanoparticles has been confirmed by TEM and SAED analysis. The novel nano silver loaded filter paper has been investigated for its antimicrobial properties against E.coli. This newly developed material shows strong antibacterial property and thus offers its candidature for possible use as antibacterial food-packaging material.

Bacteria identification has predominantly been conducted using specific bioreceptors such as antibodies or nucleic acid sequences. This approach may be inappropriate for environmental monitoring when the user does not know the target bacterial species and for screening complex water samples with many unknown bacterial species. In this work, we investigate the supervised machine learning of the bacteria-particle aggregation pattern induced by the peptide sets identified from the biofilm-bacteria interface. Each peptide is covalently conjugated to polystyrene particles and loaded together with bacterial suspensions onto paper microfluidic chips. Each peptide interacts with bacterial species to a different extent, leading to varying sizes of particle aggregation. This aggregation changes the surface tension and viscosity of the liquid flowing through the paper pores, altering the flow velocity at different extents. A smartphone camera captures this flow velocity without being affected by ambient and environmental conditions, towards a low-cost, rapid, and field-ready assay. A collection of such flow velocity data generates a unique fingerprinting profile for each bacterial species. Support vector machine is utilized to classify the species. At optimized conditions, the training model can predict the species at 93.3% accuracy out of five bacteria: Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium, Enterococcus faecium, and Pseudomonas aeruginosa. Flow rates are monitored for less than 6 s and the sample-to-answer assay time is less than 10 min. The demonstrated method can open a new way of analyzing complex biological and environmental samples in a biomimetic manner with machine learning classification.

A strain of Bacillus subtilis IARI-SP-1 isolated from soil long term irrigated with effluents of paper and pulp mill showed high β-1, 4-endoglucanase (2.5 IU/ml) but low activity of β-1, 4-exoglucanase (0.8 IU/ml) and β-glucosidase (0.084 IU/ml). The β-1, 4-endoglucanase gene of IARI-SP-1 was amplified using degenerate primers designed based on sequences already available in NCBI GenBank. A full length gene of β-1, 4-endonuclease consisting of 1499 nucleotides was identified through sequence analysis of the amplified product. The ORF encoded for a protein of 500 amino acids with a predicted molecular weight of 55 kDa. The gene was cloned in pET-28a and over expressed in Escherichia coli BL21 (DE3). In comparison to wild strain ( B. subtilis ), the transformed E. coli exhibited four times increase in cellulase production. Higher enzyme activity was observed in supernatant (8.2 IU/ml) than cell pellet (2.8 IU/ml) suggesting more extracellular production of β-1, 4-endoglucanase. SDS-PAGE and CMC plate assay also confirmed the overproduction by the transformed E. coli . The pH and temperature optima of expressed β-1, 4-endoglucanase enzyme was identical to that of wild strain and was 8 and 50–60 °C, respectively.

The use of surface and recycled water sources for irrigation can reduce demand on critical groundwater resources. Treatment or mitigation may be necessary for the use of these alternative water sources in order to reduce risk associated with microbial pathogens present in the water. In this study, the efficacy of a zero-valent iron (ZVI) sand filter was assessed for the reduction of Listeria monocytogenes and Escherichia coli in surface water. Water recovered from an agricultural pond was inoculated with E. coli TVS353 and an environmental L. monocytogenes isolate at 7 Log10 CFU/mL and horizontally filtered over a six-month period through a PVC pipe filter, filled with 35%:65% (volume:volume) ZVI:sand or sand alone. Filtered water was used to irrigate lettuce and bacterial persistence on lettuce leaves was determined for 7 days post-irrigation. Both ZVI:sand-filtered water and sand-filtered water contained significantly (p

Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a highresolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay, n ¼ 154)), fRNA phage MS2 (plaque assay/RT-qPCR, n ¼ 87) and E. coli (Colilert-18, n ¼ 73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics. Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wavelike manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simultaneously with turbidity. Ripening for E. coli took longer than ripening for turbidity, but the bacteria broke through before turbidity breakthrough. Instantaneous log-removal peaked at 3.2, 3.0 and 4.5 for 28B, MS2 and E. coli, respectively. However, true average logremoval during the period of stable effluent turbidity was significantly lower at 2.5, 2.3 and 3.6, respectively. Peak observed filter coefficients l were higher than predicted by ideal filtration theory. This study demonstrates the importance of carefully designed sampling regimes when characterizing microorganism removal efficiencies of deep bed filters., Research Council of Norway (grant no. 226750/O30) and Norconsult AS consultancy firm, 14 Páginas

Summary The ability to identify single-nucleotide mutations is critical for probing cell biology and for precise detection of disease. However, the small differences in hybridization energy provided by single-base changes makes identification of these mutations challenging in living cells and complex reaction environments. Here, we report a class of de novo-designed prokaryotic riboregulators that provide ultraspecific RNA detection capabilities in vivo and in cell-free transcription-translation reactions. These single-nucleotide-specific programmable riboregulators (SNIPRs) provide over 100-fold differences in gene expression in response to target RNAs differing by a single nucleotide in E. coli and resolve single epitranscriptomic marks in vitro. By exploiting the programmable SNIPR design, we implement an automated design algorithm to develop riboregulators for a range of mutations associated with cancer, drug resistance, and genetic disorders. Integrating SNIPRs with portable paper-based cell-free reactions enables convenient isothermal detection of cancer-associated mutations from clinical samples and identification of Zika strains through unambiguous colorimetric reactions., Graphical Abstract, Highlights • SNIPRs are riboregulators with single-nucleotide-specific RNA detection capabilities • They operate in live cells and in paper-based cell-free reactions • Automated in silico design allows SNIPRs to detect many different harmful mutations • Isothermal SNIPR tests enable portable human genotyping and viral strain detection, The development of high-specificity RNA toehold-based sensors allows for the discrimination of point mutations and RNA base modifications and enables genotypic diagnosis for E. coli, human samples, and Zika virus strains

In the pulp bleaching industry, enzymes with robust activity at high pH and temperatures are desirable for facilitating the pre-bleaching process with simplified processing and minimal use of chlorinated compounds. To engineer an enzyme for this purpose, we determined the crystal structure of the Xyn12.2 xylanase, a xylan-hydrolyzing enzyme derived from the termite gut symbiont metagenome, as the basis for structure-based protein engineering to improve Xyn12.2 stability in high heat and alkaline conditions. Engineered cysteine pairs that generated exterior disulfide bonds increased the kcat of Xyn12.2 variants and melting temperature at all tested conditions. These improvements led to up to 4.2-fold increases in catalytic efficiency at pH 9.0, 50°C for 1h and up to 3-fold increases at 60°C. The most effective variants, XynTT and XynTTTE, exhibited 2-3-fold increases in bagasse hydrolysis at pH 9.0 and 60°C compared to the wild-type enzyme. Overall, engineering arginines and phenylalanines for increased pKa and hydrogen bonding improved enzyme catalytic efficiency at high stringency conditions. These modifications were the keys to enhancing thermostability and alkaliphilicity in our enzyme variants, with XynTT and XynTTTE being especially promising for their application to the pulp and paper industry.

The application of aerobic granular sludge (AGS) technology has increased in popularity, largely due to the smaller physical footprint, enhanced biological nutrient removal performance and ability to perform with a more stable operation when compared to conventional activated sludge (CAS) systems. To date,the ability of AGS to remove microbial pathogens such as; Escherichia coli, Giardia, and Cryptosporidium has not been reported. This study compared the log₁₀ removal performance of commonly used pathogen surrogates (sulfite-reducing clostridia spores, f-RNA bacteriophage, E. coli and total coliforms) by AGS and CAS during the start-up phase, through to maturation. Results showed that AGS performed as well as CAS for the log₁₀ removal performance of all microbial surrogates, except for spores which were removed more effectively by AGS most likely due to greater adherence of spores to the AGS biomass compared to CAS mixed liquor. Results suggest that AGS is capable of meeting or exceeding CAS-equivalent health based targets for pathogen removal in the context of water recycling as well as not adversely affecting the secondary effluent water quality (suspended solids, turbidity and particle size) in terms of ultraviolet light transmissivity (254 nm). These findings confirmed for the first time that the adoption of AGS operation would not adversely impact downstream tertiary disinfection processes from altered water quality, nor would it require further pathogen treatment interventions in addition to what is already required for CAS systems. Refereed/Peer-reviewed

New disinfection procedures are being developed and proposed for use in drinking-water production. Authorising their use requires an effective test strategy that can simulate conditions in practice. For this purpose, we developed a test rig working in a flow-through mode similar to the disinfection procedures in waterworks, but under tightly defined conditions, including very short contact times. To quantify the influence of DOC, temperature and pH on the efficacy of two standard disinfectants, chlorine and chlorine dioxide, simulated use tests were systematically performed. This test rig enabled quantitative comparison of the reduction of four test organisms, two viruses and two bacteria, in response to disinfection. Chlorine was substantially more effective against Enterococcus faecium than chlorine dioxide whereas the latter was more effective against the bacteriophage MS2, especially at pH values of >7.5 at which chlorine efficacies already decline. Contrary to expectation, bacteria were not generally reduced more quickly than viruses. Overall, the results confirm a high efficacy of chlorine and chlorine dioxide, validating them as standard disinfectants for assessing the efficacy of new disinfectants. Furthermore, these data demonstrate that the test rig is an appropriate tool for testing new disinfectants as well as disinfection procedures.

In previous works, a low-cost predisinfection column that combined coagulation-flocculation and GAC filtration was proposed for combination with electrodisinfection in the successful treatment of highly faecal polluted surface water. In this work, this column is adapted for the treatment of pore water by transforming the coagulation chamber into a chemical reactor with lime and replacing the GAC of the filter with ion exchange resins. This adapted system can soften water, remove nitrate and condition water for very efficient electrochemical disinfection, where 4 logs and 3 logs in the removal of E. coli and P. aeruginosa, respectively, were reached using commercial electrochemical cells, i.e., CabECO ® or MIKROZON®. The availability and low cost of the technology are strong points for usage in poor areas of developing countries., En trabajos anteriores, se propuso una columna de predesinfección de bajo costo que combinaba coagulación-floculación y filtración GAC para combinarla con electrodesinfección en el tratamiento exitoso de aguas superficiales altamente contaminadas con heces. En este trabajo se adapta esta columna para el tratamiento de agua intersticial transformando la cámara de coagulación en un reactor químico con cal y reemplazando el GAC del filtro por resinas de intercambio iónico . Este sistema adaptado puede ablandar el agua, eliminar el nitrato y acondicionar el agua para una desinfección electroquímica muy eficiente, donde se alcanzaron 4 logs y 3 logs en la eliminación de E. coli y P. aeruginosa , respectivamente, usando celdas electroquímicas comerciales., es decir, CabECO® o MIKROZON®. La disponibilidad y el bajo costo de la tecnología son puntos fuertes para su uso en áreas pobres de los países en desarrollo.

Highlights • Kleibsiella pneumoniae Kpn555 tolerates 900 mg/L lead. • SEM and TEM studies revealed surface deposition and bioaccumulation of lead. • Surface deposition mediated by EPS produced in response to lead stress, characterised as glycolipid with protein moieties. • Maximum biosorption ability of EPS – 475 mg/g. • Ability of lead bioaccumulation is plasmid mediated., Kleibsiella pneumoniae Kpn555, isolated from coffee waste pulp showed high level of tolerance to lead with a minimum inhibitory concentration of 900 mg/L. On its growth in nutrient broth supplemented with lead, brown clumps were visualised at the bottom of the flask. On scanning and transmission electron microscopic studies the brown clumps were corroborated to be bacterial cells with lead biosorbed on the cell surface and accumulated inside the cytoplasm. Biochemical and FT-IR analysis of the extracellular polymeric substance produced on exposure to lead revealed its chemical nature as glycolipid with protein moieties. Purified EPS (100 mg/L) could remove 50% of lead from aqueous solution (200 mg/L). Isolation of plasmid from Klebsiella pneumoniae Kpn555 revealed the presence of a plasmid of size 30–40 kb. This capability of the bacteria was proven to be plasmid mediated as the Escherichia coli DH5α cells transformed with the plasmid of Klebsiella pneumoniae Kpn555 also could tolerate 900 mg/L of lead and form brown clumps. This study shows that these bacteria, aided by EPS could serve as an effective agent for the removal of lead from contaminated water environmental samples., Graphical abstract Image, graphical abstract

The impact of cultivation strategy on the cost of recombinant protein production is crucial for defining cost-effective bioreactor operation conditions. This paper presents a methodology to estimate and compare cost impacts related to utilities as well as medium composition, using simple design equations and accessible data. Data from batch bioreactor cultures were used as case study involving the production of pneumococcal surface protein A, a soluble recombinant protein, employing E. coli BL21(DE3). Cultivation strategies and corresponding process costs covered a wide range of operational conditions, including different media, inducers, and temperatures. The core expenses were related to the medium and cooling. When the price of peptone was above the threshold value of US$ 30/kg, defined medium became the best choice. IPTG and temperatures around 32 °C led to shorter cultures and lower PspA4Pro production costs. The procedure offers a simple, accessible theoretical tool to identify cost-effective production strategies using bioreactors.

Mercury pollutants such as mercuric chloride (HgCl2), mercurous chloride (Hg2Cl2) and mercuric ammonium chloride (Hg(NH2)Cl) are often found in cosmetics. Previous attempts at the on-site detection of mercury were hindered by the complicated and dangerous pretreatment procedure of converting various forms of mercury to Hg (II) ions. In this study, a test strip platform was developed based on a whole-cell microbial biosensor for the simultaneous detection of soluble and insoluble inorganic mercury pollutants in cosmetics without the need for predigestion. The genetic circuits with constitutively expressed MerR as sensor proteins and inducible red fluorescent protein (RFP) as the reporter were introduced into Escherichia coli to construct the mercury detection biosensor. The RFP fluorescence intensity of this biosensor showed a excellent linear relationship (R2 = 0.9848) with the Hg (II) concentration ranging from 50 nM to 10 μM in Luria-Bertani (LB) broth. Further research indicated that this biosensor could respond not only to Hg (II) ions but also to insoluble Hg2Cl2 and Hg2Cl2. The transcriptomic results confirmed the mercury conversion ability of the whole-cell biosensor from a gene expression perspective. This biosensor was embedded on filter paper to form a test strip, which could be used to determine whether the total inorganic mercury pollutants in cosmetics exceeded 1 mg/kg. Therefore, this strip provided a low cost, easy-to-use, and instrument-independent method for the detection of mercury pollution in cosmetics, while this study revealed the unique advantages of microbial biosensors in the automatic bioconversion of targets.

The use of composts or vermicomposts derived from organic fraction of Municipal Solid Waste (OFMSW) brought about certain disagreement in terms of high level of bacterial pathogens, thereby surpassing the legal restrictions. This preliminary study was undertaken to compare the evolution of pathogenic bacteria on OFMSW compost against vermicompost (generated by Eudrilus eugeniae ) with promises of achieving sanitation goals. Analysis to quality data showed that OFMSW vermicomposting caused a moderately higher reduction in total coliforms in contrast to composting. E. coli in OFMSW composts was found to be in the range of 4.72–4.96 log 10 CFU g −1 whilst on a clear contrary, E. coli was undetectable in the final vermicomposts (6.01–6.14 logs of reduction) which might be explained by the involvement of the digestive processes in worms' guts. Both OFMSW composts and vermicomposts generated Salmonella -free products which were acceptable for agricultural usage and soil improvement. In comparison to compost, the analysis of this research indicated that earthworm activity can effectively destroy bacterial pathogenic load in OFMSW vermicomposts. But still, this study necessitates extra research in order to comprehend the factors that direct pathogenic bacteria in vermicomposting and earthworm-free decomposition systems.

The presence of antibiotic resistant bacteria (ARB) in wastewater was investigated and the role of wastewater treatment plants (WWTPs) in promoting or limiting antibiotic resistance was assessed. Escherichia coli (E. coli) and total heterotrophic bacteria (THB) resistance to ampicillin, chloramphenicol and tetracycline was monitored in three WWTPs located in Milan urban area (Italy), differing among them for the operating parameters of biological process, for the disinfection processes (based on sodium hypochlorite, UV radiation, peracetic acid) and for the discharge limits to be met. Wastewater was collected from three sampling points along the treatment sequence (WWTP influent, effluent from sand filtration, WWTP effluent). Antibiotic resistance to ampicillin was observed both for E. coli and for THB. Ampicillin resistant bacteria in the WWTP influents were 20–47% of E. coli and 16–25% of THB counts. A limited resistance to chloramphenicol was observed only for E. coli, while neither for E. coli nor for THB tetracycline resistance was observed. The biological treatment and sand filtration led to a decrease in the maximum percentage of ampicillin-resistant bacteria (20–29% for E. coli, 11–21% for THB). However, the conventionally adopted parameters did not seem adequate to support an interpretation of WWTP role in ARB spread. Peracetic acid was effective in selectively acting on antibiotic resistant THB, unlike UV radiation and sodium hypochlorite. The low counts of E. coli in WWTP final effluents in case of agricultural reuse did not allow to compare the effect of the different disinfection processes on antibiotic resistance.

The rapid increase of agricultural waste is becoming a burgeoning problem and considerable efforts are being made by numerous researchers to convert it into a high-value resource material. Onion waste is one of the biggest issues in a world of dwindling resource. In this study, the potential of onion juice residue (OJR) for producing valuable rare sugar or bioethanol was evaluated. Purified Paenibacillus polymyxaL-arabinose isomerase (PPAI) has a molecular weight of approximately 53kDa, and exhibits maximal activity at 30°C and pH 7.5 in the presence of 0.8mM Mn2+. PPAI can produce 0.99g D-tagatose from 10g OJR. In order to present another application for OJR, we produced 1.56g bioethanol from 10g OJR through a bioconversion and fermentation process. These results indicate that PPAI can be used for producing rare sugars in an industrial setting, and OJR can be converted to D-tagatose and bioethanol.

An ultrasound/ultraviolet (US/UV) baffled reactor was developed to fill the gap in ultraviolet (UV) disinfection associated with disinfection efficiency. According to the previously selected operational condition, a continuous-flow US/UV baffled reactor was continuously operated in a wastewater treatment plant at a pilot scale for nearly three months, and the disinfection influent and effluent were analyzed, including fecal coliforms, Escherichia coli , and fecal streptococci . The US/UV baffled reactor could guarantee a high effluent disinfection performance in terms of fecal coliforms removal even with the fluctuation of the secondary effluent. All the disinfected effluents satisfied the requirement of the “Pollutants Discharge Standard of Municipal Wastewater Treatment Plant in China” (fecal coliforms below 1000 CFU/L for class 1A), and 87% of the tested fecal coliforms concentration in the disinfected effluent was below 100 CFU/L, nearly eliminating all fecal coliforms. Further analysis of the E. coli and fecal streptococci showed the broad disinfection ability and high disinfection efficiency of the US/UV baffled reactor. The flexibility of the specific energy consumption for the disinfection system depends on the water quality.

The Advanced Glycation and Lipoxidation End products (AGEs and ALEs) are a heterogeneous class of compounds derived from the non-enzymatic glycation or protein adduction by lipoxidation break-down products. The receptor for AGEs (RAGE) is involved in the progression of chronic diseases based on persistent inflammatory state and oxidative stress. RAGE is a pattern recognition receptor (PRR) and the inhibition of the interaction with its ligands or of the ligand accumulation have a potential therapeutic effect. The N-terminal domain of RAGE, the V domain, is the major site of AGEs binding and is stabilized by the adjacent C1 domain. In this study, we set up an affinity assay relying on the extremely specific biological interaction AGEs ligands have for the VC1 domain. A glycosylated form of VC1, produced in the yeast Pichia pastoris, was attached to magnetic beads and used as insoluble affinity matrix (VC1-resin). The VC1 interaction assay was employed to isolate specific VC1 binding partners from in vitro generated AGE-albumins and modifications were identified/localized by mass spectrometry analysis. Interestingly, this method also led to the isolation of ALEs produced by malondialdehyde treatment of albumins. Computational studies provided a rational-based interpretation of the contacts established by specific modified residues and amino acids of the V domain. The validation of VC1-resin in capturing AGE-albumins from complex biological mixtures such as plasma and milk, may lead to the identification of new RAGE ligands potentially involved in pro-inflammatory and pro-fibrotic responses, independently of their structures or physical properties, and without the use of any covalent derivatization process. In addition, the method can be applied to the identification of antagonists of RAGE-ligand interaction., Graphical abstract fx1, Highlights • A new VC1 interaction affinity assay was validated using model AGE-albumins. • In vitro modifications of the interacting partners were identified/localized by MS. • The VC1-pull down assays captures AGE-albumins in simulated complex mixtures • ALEs produced by malondialdehyde treatment were mapped in VC1-interacting albumins. • The molecular interactions of MDA-induced adduct-VC1 complexes were rationalized.

Ultraviolet (UV) disinfection is highly recommended owing to its high disinfection efficiency and disinfection by-products free, and UV Light-Emitting Diodes (UV LEDs) is increasingly becoming an alternative of mercury UV lamps for water disinfection owing to its long lifetime, low input power, and absence of problems on disposal. However, renovation of existing UV lamps faces the challenges for UV disinfection associated with disinfection efficiency and photoreactivation, and modified UV disinfection process is required for practical application. In this study, mathematical rule of disinfection and photoreactivation in a US enhanced UV disinfection system was investigated. UV LED with peak emission at 254nm (UV-C LED) was selected as representative for UV lamps, and a low frequency US was used as pretreatment followed by UV disinfection. The disinfection efficiency of Escherichia coli in deionized water (DI), DI water with kaoline suspension (DIK), and secondary effluent (SE) of municipal wastewater treatment plant were analyzed. Moreover, photoreactivation of E. coli in DIK water within 6h after disinfection was conducted. The experimental results showed that the disinfection efficiencies had good fit with Chick-Watson first-order linear model, and US pretreatment increased the inactivation rate constant for E. coli, which increased from 0.1605 to 0.1887 in the DIK water. Therefore, US pretreatment with UV disinfection have potential to shorten the retention time and reduce the reactor volume. Moreover, the number of photoreactivated E. coli in effluent was reduced under UV-C LED disinfection with US pretreatment compared with that under UV-C LED disinfection alone. The order of maximum percentage of photo-reactivated E. coli was as follows: UV-C LED disinfection alone at 30mJ/cm2>UV-C LED disinfection at 25mJ/cm2 with US pretreatment>UV-C LED disinfection at 30mJ/cm2 with US pretreatment. The survival ratio versus photoreactivation time showed a good fit to second-order logistic model. US pretreatment in UV-C LED disinfection could improve disinfection efficiency, reducing photoreactivation in the effluent as well, which offers a promising practical application technology.

This study evaluated the dual-function of ferrate as a coagulant and disinfectant for chemically-enhanced primary treatment during wet weather flow (WWF). For the first time, ferrate was thoroughly examined as a coagulant aid with aluminum sulfate (alum) to minimize the organic and inorganic contents along with microbial level during WWF. Ferrate as a coagulant was evaluated based on a two-level factorial design. At an optimized condition, a ferrate dose of 0.5 mg/L Fe with a cationic polymer (1.25 mg/L) removed 83% of turbidity, 87% of total suspended solids (TSS), 70% of chemical oxygen demand (COD), and 23% of ortho-phosphate (OP). Linear models were developed and used to adequately predict the removals. Ferrate as a coagulant aid added with alum showed better removal of TSS while no improvement was observed in the removals of turbidity and COD. The disinfection capacity of ferrate was evaluated at different dosing points when it was used as a coagulant, coagulant aid and as post dosed as a disinfectant. In particular, ferrate dose of 8 mg/L Fe removed only 2 logs of E. coli when it was used as a coagulant compared to more than 3-log removal of E. coli when ferrate was used as a coagulant aid and as a disinfectant. At optimal ferrate dose of 10 mg/L Fe as a coagulant aid with 6 mg/L Al achieved the target levels of turbidity (

First flush or the first pore volume of effluent eluted from biofilters at the start of rainfall contributes to most pollution downstream because it typically contains a high concentration of bacterial pathogens. Thus, it is critical to evaluate designs that could minimize the release of bacteria during a period of high risk. In this study, we test the hypothesis of whether an addition of iron-based media to biofilter could limit the leaching of Escherichia coli (E. coli), a pathogen indicator, during the first flush. We applied E. coli-contaminated stormwater intermittently in columns packed with a mixture of sand and compost (70:30 by volume, respectively) and iron filings at three concentrations: 0% (control), 3%, and 10% by weight. Columns packed with a mixture of sand and iron (3% or 10%) without compost were used to examine the maximum capacity of iron to remove E. coli. In columns with iron, particularly 10% by weight, the leaching of E. coli during the first flush was 32% lower than the leaching from compost columns, indicating that the addition of iron amendments could decrease first-flush leaching of E. coli. We attribute this result to the ability of iron to increase adsorption and decrease growth during antecedent drying periods. Although the addition of iron filings increased E. coli removal, the presence of compost decreased the adsorption capacity: exposure of 1 g of iron filings to 1 mg of DOC reduces E. coli removal by 8%. The result was attributed to the alteration of the surface charge of iron and blocking of adsorption sites shared by E. coli and DOC. Collectively, these results indicate that the addition of sufficient amounts of iron media could decrease pathogen leaching in the first flush effluent and increase the overall biofilter performance and protect downstream water quality.

Intracellular pH (pHi) is a crucial parameter in cell biology; thus, a series of pH probes have been developed to determine pHi changes in living cells. However, more sensitive and non-perturbing ratiometric pH probes are needed for accurate pHi measurements. While the fluorescence of circular permutated YFP (cpYFP) is hypersensitive to pH changes due to its intrinsic properties, the single excitation peak of this protein restricts its capacity of becoming a rational type of pH sensor. Herein, we collected several cpYFP-based probes with dual excitation peaks and constructed their corresponding loss-of-function mutants to screen for a potential competent pH probe. The most sensitive probe was named NocPer. NocPer consists of cpYFP inserted into inactive-mutated GAF and AAA+, which are two regulatory domains of E. coli NorR, a nitric oxide (NO)-specific transcription factor. Fluorescence emission of NocPer peaks at 517 nm while exhibiting dual excitation peaks at 420 and 495 nm, which can be used for ratiometric imaging. This new pH sensor has a large ratio response dynamic (pH range of 7.0–11.0), which covers the physiological pH range (pH 7.0–8.0), and exhibits an approximately 3-fold higher fluorescent signal in response to a pH increase from 7.0 to 8.0 than that of pHluorin. Using NocPer, we discovered a new biological phenomenon in which NO exposure decreases the E. coli pHi, which led to the hypothesis that pathogens decrease their own pHi during infection. Further, we elucidated that the NO-induced inhibition of cytochrome c oxidase in the respiratory chain is responsible for the decline in pHi, which might represent a protective strategy of E. coli under NO stress conditions. Our results demonstrated that NocPer is a ratiometric pH probe with high sensitivity for the physiological pH range., Highlights • Circular permutated YFP was modified to be an a supersensitive and ratiometric pH probe NocPer. • Nitric oxide (NO) lowering intracellular pH (pHi) was discovered as a new biological phenomenon. • NO-induced inhibition of cytochrome c oxidase is responsible for the decline in pHi. • pHi decrease by NO might represent a bacterial protective mechanism.

This work aimed to assess the elimination and inactivation of resistance-conferring plasmids (RCPs) present in suspension in secondary wastewater by solar photo-Fenton as these are important vectors for the dissemination of antimicrobial resistance. Experiments were performed in synthetic secondary wastewater (SWW) and municipal wastewater treatment plant effluent (MWWTPE). Solar photo-Fenton (50 mg L−1 of H2O2 and 30 mg L−1 of Fe2+) was carried out for 60 min at neutral pH by applying the intermittent iron addition strategy. The removal of RCPs was assessed by Real-Time Polymerase Chain Reaction (qPCR). The transformation of competent non-resistant E. coli was used to evaluate the inactivation of target RCPs harboring antibiotic resistance genes (ARGs) to ampicillin (pSB1A2) or kanamycin (pSB1K3) after treatment and controls. Solar photo-Fenton completely removed RCPs initially present in both matrixes (SWW and MWWTPE), showing enhanced performance compared to the dark Fenton process. Both RCPs were inactivated after 30 min of solar photo-Fenton treatment, while 60 min were necessary to achieve the same effect for the dark Fenton reaction under similar conditions. These results indicate the potential of solar photo-Fenton to improve wastewater quality and reduce the spread of antimicrobial resistance in the environment by hampering the discharge of cell-free RCPs present in suspension in MWWTP onto environmental waters., Graphical abstract Image 1, Highlights • Inactivation of plasmid via solar photo-Fenton assessed via E coli transformation. • Elimination of plasmid from wastewater via solar photo-Fenton assessed via qpCR. • Solar photo-Fenton removes plasmids carrying antibiotic resistance genes. • Solar photo-Fenton inactivates plasmids carrying antibiotic resistance genes. • Higher plasmid removal via solar photo-Fenton in simulated than real wastewater.

Swine manure and corn stover are abundant agricultural wastes which contribute to greenhouse gas (GHG) emissions, nutrient runoff leading to eutrophication, and a biosafety risk with respect to improper swine manure handling. Anaerobic co-digestion (AcoD) of swine manure and corn stover can mitigate these negative impacts while producing biogas as a renewable energy source. Semi-continuous mesophilic plug flow reactor (PFR operation) was studied during a step-wise increase in organic loading rate (OLR) over the range of 0.25–4.7 kg volatile solids added (VS) m−3 d−1, which corresponded to total solids content (TS) of 1.5–9.0%. Process stability was observed at all OLR, with the highest total biogas yield and methane content of 0.674 ± 0.06 m−3 kg−1 and 62%, respectively, at 0.25 kg m−3 d−1. As OLR and TS increased, VS reduction decreased and volatile fatty acids (VFA) increased due to shorter hydraulic retention times (HRT). Hygienization potential was assayed using fecal indicator bacteria (FIB), with some groups being reduced (E. coli, fecal coliforms) and others not (Clostridia spp., fecal enterococci). Lignocellulolytic enzyme activity trended upward as OLR was increased, highlighting changes in microbial activity in response to feeding rate.

Human enteric pathogens are a major global concern, as they are responsible for thousands of preventable deaths every year. New pathogens in wastewater are constantly emerging. For example, SARS-CoV-2 has been recently detected in domestic sewage and primary sludge. Knowledge about the reduction of viruses in wastewater treatment and their partitioning between the treated liquid effluent versus the sludge or biosolids is still very scarce, especially in countries with emerging economies and tropical climates. Upflow anaerobic sludge blanket (UASB) reactors are among the top three most commonly used technologies for the treatment of sewage in Latin America and the Caribbean, and their use has become increasingly common in many other low- and middle-income countries. High-rate algal ponds (HRAP) are regarded as a sustainable technology for the post-treatment of UASB effluent. This study evaluated the overall reduction and the liquid-solid partitioning of somatic coliphages, F-specific coliphages, and E. coli in a pilot-scale system comprised of a UASB reactor followed by HRAPs treating real wastewater. Average log removal for somatic and F-specific coliphages were 0.40 and 0.56 for the UASB reactor, and 1.15 and 1.70 for HRAPs, respectively. The overall removal of both phages in the system was 2.06-log. Removal of E. coli was consistently higher. The number of viruses leaving the system in the UASB solids and algal biomass was less than 10% of the number leaving in the clarified liquid effluent. The number of E. coli leaving the system in solids residuals was estimated to be approximately one order of magnitude higher than the number of E. coli leaving in the liquid effluent. Results from this study demonstrate the suitability of UASB-HRAP systems to reduce viral and bacterial indicators from domestic sewage and the importance of adequately treating sludge for pathogen reduction before they are used as biosolids.

In many nations industrial scale AD of non-agricultural waste materials (such as MSW) has not yet reached its full potential, often constrained by the lack of secure, inexpensive, high quality AD feedstocks, and markets for the resulting digestate material. We tested the output material of a high throughput novel industrial process to define its potential as an AD feedstock (based on quality and consistency). This process, designed to circumvent the constraints of source segregation while still generating segregated waste streams, resulted in the production of a temporally homogenous fibrous material with: an average moisture content of 44.2 (±2.33)%; C:N ratio of ∼32.9:1 (±3.46:1), C:P ratio of ∼228:1 and gross calorific value of 17.4 (±0.29) MJ/kg(DM). This material provided a CH4 yield of between 201 and 297 m3 CH4/tonne(DM) (271–401 m3 CH4/tonne(vs)) comparable to commonly used AD feedstocks. Material contaminant levels were temporally consistent (P > 0.05), (average values being Cd 0.63 (±0.19), Cu 56.3 (±7.45), Crtot 51.4 (±4.41), Hg < 0.3, Ni 28.9 (±5.17), Pb 79.2 (±23.71), Zn 202 (±44.5), total polyaromatic hydrocarbons (PAH) 2.2 (±0.3), and total polychlorinated biphenyls (PCB) (

One way to make bioactive paper is to incorporate in it bacteriophages, which can capture and deactivate bacteria. The release of newly assembled phages from lysed bacteria can also serve as a measure of the number of bacteria that were deactivated. We have studied the deposition of genetically modified phages, containing cellulose binding modules, on model cellulose surfaces by evanescent wave light scattering. It was shown that unassembled protein complexes, released with the phages during the lysis of bacteria, limit the deposition of phages to about one per 10–20 μm 2 , as there are far more unassembled protein complexes than phages. The implication is that a few thousand phages can attach to a cellulose fiber, with most of the surface area taken up by protein complexes. This is more than sufficient for the production of bioactive paper. The unassembled protein complexes may be beneficial, as they will prevent non-specific deposition of bacteria. Thus, it may not be necessary to separate the protein complexes from phages in an expensive purification operation.

The aim of this study was to evaluate the effectiveness of the novel aerobic granular sludge (AGS) wastewater treatment technology in removing faecal indicator organisms (FIOs) compared to the conventional activated sludge (CAS) treatment system. The work was carried out at two full-scale wastewater treatment plants (WWTP) in the Netherlands, Vroomshoop and Garmerwolde. Both treatment plants have a CAS and AGS system operated in parallel. The parallel treatment lines are provided with the same influent wastewater. The concentrations of the measured FIOs in the influent of the two WWTPs were comparable with reported literature values as follows: F-specific RNA bacteriophages at 106 PFU/100 mL, and Escherichia coli (E. coli), Enterococci, and Thermotolerant coliforms (TtC) at 105 to 106 CFU/100 mL. Although both systems (CAS and AGS) are different in terms of design, operation, and microbial community, both systems showed similar FIOs removal efficiency. At the Vroomshoop WWTP, Log10 removals for F-specific RNA bacteriophages of 1.4 ± 0.5 and 1.3 ± 0.6 were obtained for the AGS and CAS systems, while at the Garmerwolde WWTP, Log10 removals for F-specific RNA bacteriophages of 1.9 ± 0.7 and 2.1 ± 0.7 were found for the AGS and CAS systems. Correspondingly, E. coli, Enterococci, and TtC Log10 removals of 1.7 ± 0.7 and 1.1 ± 0.7 were achieved for the AGS and CAS systems at Vroomshoop WWTP. For Garmerwolde WWTP Log10 removals of 2.3 ± 0.8 and 1.9 ± 0.7 for the AGS and CAS systems were found, respectively. The measured difference in removal rates between the plants was not significant. Physicochemical water quality parameters, such as the concentrations of organic matter, nutrients, and total suspended solids (TSS) were also determined. Overall, it was not possible to establish a direct correlation between the physicochemical parameters and the removal of FIOs for any of the treatment systems (CAS and AGS). Only the removal of TSS could be positively correlated to the E. coli removal for the AGS technology at the evaluated WWTPs., Graphical abstract Image 1, Highlights • No difference in removal efficiencies (α = 5%) of FIOs was found for the studied AGS and CAS systems. • 1.3 to 2.1 Log10 removals for F-specific RNA bacteriophages were found for the CAS and AGS systems. • 1.1 to 2.3 Log10 removals for E. coli, Enterococci, and TtC were obtained for the AGS and CAS systems. • The two stage CAS performed better than the carrousel CAS in removing F-specific RNA bacteriophages. • A positive correlation was found between the TSS and E. coli removal, and COD and TtC removal in the AGS systems.

Background: To deeply understand the role of antibodies in the context of Trypanosoma cruzi infection, we decided to characterize A2R1, a parasite antibody selected from single-chain variable fragment (scFv) phage display libraries constructed from B cells of chronic Chagas heart disease patients. Methods: Immunoblot, ELISA, cytometry, immunofluorescence and immunohistochemical assays were used to characterize A2R1 reactivity. To identify the antibody target, we performed an immunoprecipitation and two-dimensional electrophoresis coupled to mass spectrometry and confirmed A2R1 specific interaction by producing the antigen in different expression systems. Based on these data, we carried out a comparative in silico analysis of the protein target´s orthologues, focusing mainly on post-translational modifications. Findings: A2R1 recognizes a parasite protein of ~50 kDa present in all life cycle stages of T. cruzi, as well as in other members of the kinetoplastid family, showing a defined immunofluorescence labeling pattern consistent with the cytoskeleton. A2R1 binds to tubulin, but this interaction relies on its post-translational modifications. Interestingly, this antibody also targets mammalian tubulin only present in brain, staining in and around cell bodies of the human peripheral and central nervous system. Interpretation: Our findings demonstrate for the first time the existence of a human antibody against T. cruzi tubulin capable of cross-reacting with a human neural protein. This work re-emphasizes the role of molecular mimicry between host and parasitic antigens in the development of pathological manifestations of T. cruzi infection. Fil: Niborski, Leticia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Potenza, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Chirivi, Renato G.S.. No especifíca; Fil: Simonetti, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Ossowski, Micaela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Grippo, Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: May, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Staquicini, Daniela I.. Universidade Federal de Sao Paulo; Brasil Fil: Parodi Talice, Adriana. Universidad de la República; Uruguay. Instituto Pasteur de Montevideo; Uruguay Fil: Robello, Carlos. Universidad de la República; Uruguay Fil: Comini, Marcelo. Universidad de la Republica; Uruguay Fil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Raats, Jos M.H.. Universidad de la República; Uruguay Fil: Gomez, Karina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina

Background Gut microbes play a crucial role in the maintenance of human health. Components in the diet of the host affect their metabolism and diversity. Here, we investigated the influences of three commonly used non-caloric artificial sweeteners-aspartame, acesulfame K and sucralose-on the growth and metabolism of an omnipresent gut microbe Escherichia coli K-12. Methods: Growth of E. coli in the presence of aspartame, acesulfame K and sucralose in media was assessed and the influences of these artificial sweeteners on metabolism were investigated by relative expression analysis of genes encoding the rate limiting steps of important metabolic pathways as well as their global metabolomic profiles. Results: As a whole, E. coli growth was inhibited by aspartame and induced by acesulfame potassium, while the effect of sucralose on growth was less prominent. Although the expressions of multiple key enzymes that regulate important metabolic pathways were significantly altered by all three sweeteners, acesulfame K caused the most notable changes in this regard. In multivariate analysis with the metabolite profiles, the sucralose-treated cells clustered the closest to the untreated cells, while the acesulfame potassium treated cells were the most distant. These sweeteners affect multiple metabolic pathways in E. coli, which include propanoate, phosphonate, phosphinate and fatty acid metabolism, pentose phosphate pathway, and biosynthesis of several amino acids including lysine and the aromatic amino acids. Similar to the gene expression pattern, acesulfame potassium treated E. coli showed the largest deviation in their metabolite profiles compared to the untreated cells., Highlights • Aspartame, acesulfame K and sucralose modulate growth and metabolism of the common gut microbe Escherichia coli K-12. • These sweeteners affect multiple metabolic pathways in E. coli. • Sucralose appears to have the least deviating impact on E. coli growth and metabolism under in vitro condition. • Acesulfame potassium appears to have the largest deviating impact on E. coli growth and metabolism under in vitro condition.

Made available in DSpace on 2020-12-12T02:05:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The demand for systems that efficiently and sustainably recover value-added compounds and materials from waste streams is a major challenge. The use of wastewater as a source for recovery of carbon and nutrients is an attractive and sustainable alternative. In this study, anaerobically treated black water was treated in photobioreactors (PBRs) inoculated with Chlorella sorokiniana, and the process was investigated in terms of phosphorus and nitrogen removal, biomass growth, and the removal of pathogens. The consumption of bicarbonate (alkalinity) and acetate (volatile fatty acids) as carbon sources by microalgae was investigated. The average nutrient removal achieved was 66% for N and 74% for P. A high consumption of alkalinity (83%) and volatile organic acids (76%) was observed, which suggests that these compounds were used as a source of carbon. The biomass production was 73 mg L−1 day−1, with a mean biomass of 0.7 g L−1 at the end of the batch treatment. At the end of the experiments, a log removal/inactivation of 0.51 log for total coliforms and 2.73 log for Escherichia coli (E. coli) was observed. The configuration used, a flat-panel PBR operated in batch mode without CO2 supplementation, is a cost-effective and environmentally sustainable method for recovering of nutrients and production of algal biomass. Department of Hydraulics and Sanitation University of São Paulo (EESC-USP) Department of Environmental and Civil Engineering São Paulo State University (UNESP), Bauru Department of Aquatic Ecology Netherlands Institute of Ecology (NIOO-KNAW) Department of Environmental and Civil Engineering São Paulo State University (UNESP), Bauru FAPESP: 2013/50351–4 FAPESP: 2015/04594–8 FAPESP: 2018/13581–5 CNPq: 302412/2017–4

Today’s wastewater utilities are facing the dilemma of balancing pathological threats of bacteria and viruses in their effluent against health threats associated with the byproducts of disinfection. A possible solution to this dilemma is to adopt secondary treatment technologies capable of concurrent pathogen reduction, minimizing the demand for external disinfectants. Towards this end, bacterial and viral reductions possible in algal wastewater treatment (WWT) systems are highlighted here and compared with those in conventional activated sludge (AS) systems and membrane bioreactor (MBR) systems. High log reduction values (LRV) of E. coli [>5] and fecal coliform [>7] have been achieved without any external disinfectants in the classical photoautotrophic algal WWT systems and in an emerging mixotrophic algal WWT system. LRVs of E. coli, fecal coliform, and somatic coliphages in the mixotrophic system are higher than those in AS systems and, comparable to those in MBRs. But, LRVs of F-specific coliphages, Enterovirus and Norovirus GI are greater in MBRs than in the mixotrophic and AS systems. The low-energy algal WWT systems providing high inherent reductions of bacteria and viruses can serve as affordable alternatives to the capital- and energy-intensive AS and MBR systems for greener WWT, meeting several of the United Nation’s Sustainable Development Goals.

A point-of-use household water treatment technology, the biosand filter (BSF), has been widely adopted across over 180 countries (CAWST, 2020). However, it has a poor Escherichia coli (E. coli) removal efficiency during the first few weeks of its use. This study investigated the potential of biochar on E. coli removal in a laboratory-modified biosand filtering system. Two biochars, produced from wheat straw and willow wood feedstocks, were used and their effects were compared. Only the coarser fraction of both biochars (1–4 mm) was used in order to minimize its impact on the filtration rate. It was observed that the filter amended with wheat straw biochar exhibited a higher mean E. coli removal rate (84%) than the filter amended with willow wood biochar (79%); however, both biochar-amended filters had lower mean E. coli removal rates than the sand-only control filter (88%), over a 5-week filtration experiment. The E. coli adsorption of biochar and sand were examined at the end of the filtration experiment. Both biochars were shown to have a larger total amount of E. coli adsorption (7.4 log10) than sand (6.8 log10). The two biochars showed comparable E. coli adsorption capacities of 5.7 log10 CFU/g, although their specific surface areas varied greatly (55.24 m2/g for wheat straw biochar and 380.00 m2/g for willow wood biochar). The discrepancy between the results of E. coli removal and E. coli adsorption might indicate the importance of biochar straining; the absence of fine biochar particles (

STSM Grant from the COST Action CA15202. Spanish Ministry of Economy - project BIA2017-83526-R. project DB-Heritage – Database of building materials with historical and heritage interest (PTDC/EPH-PAT/4684/2014). IF/01054/2014/CP1224/CT0005. FCT/MCTES (UID/QUI/50006/2019; UID/Multi/04378/2019). POCI-01-0145-FEDER-007728. Nídia Almeida is supported by the Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT-PD/00193/2012; UCIBIO-UID/Multi/04378/2019 and by a PhD fellowship from FCT/MCTES (PD/BD/106034/2015). Surface treatment technology is instrumental to construction material conservation and more specifically to preventing decay and improving durability. Surface treatments help protect and consolidate the built heritage against material damage, reducing repair and replacement costs. This study assessed the effect of two eco-friendly healing agents, one generated by iron-enriched Escherichia coli and the other by mixed microbial cultures that metabolise glycerol, a biodiesel processing by-product, to produce polyhydroxyalkanoates. Healing was monitored by measuring the water drop absorption rate in cement mortar, air lime mortar, ceramic brick, limestone, adobe and compressed earth block. The agents tested lengthened water absorption times in all the materials studied, confirming their efficacy as external repair treatments for construction materials. authorsversion published

The Produce Safety Rule, part of the Food Safety Modernization Act, mandates zero detectable generic Escherichia coli for certain agriculture wash water applications: hand-washing, food-contact surface washing, or any water which directly contacts produce, including ice. This requirement emphasizes the need to assess and propose mitigation strategies to control E. coli levels in agriculture wash water. As such, this study investigated the relationship between common sanitizers hydrogen peroxide (H2O2) and peracetic acid (PAA) at varying ratios and the influence of concentration, organic load, temperature, and pH on these sanitizers’ stability and efficacy against Escherichia coli O157:H7, including re-inoculation to simulate the reintroduction of pathogens during processing. Generally, sanitizers with PAA as the dominant component were more efficient at reducing E. coli O157:H7 levels over time, compared to those with H2O2 as the dominant component. Of all of the treatments tested, 50/50 H2O2/PAA at 80 ppm in the wash water was the most stable over time and had the highest efficacy against E. coli O157:H7 with organic load capacity below 750 mg/l chemical oxygen demand (COD). Organic loads at 750COD were not able to eliminate E. coli after 3.5 h of treatment, compared to all parameters tested. Based on the results of this study, sanitizer composition, concentration, presence of organic load, temperature and pH have the potential to significantly decrease the efficacy and stability of PAA systems over time, indicating that these parameters should be monitored in agriculture wash water utilization to ensure that water quality and safety are maintained.

Background: Alteration of commensal bacterial composition is associated with many inflammatory diseases. However, few studies have pinpointed the specific bacterial genes that may suppress host immune responses against microbes and maintain homeostasis in the host intestine. Methods: High-throughput screening was performed in Caenorhabditis elegans with a single gene knockout ut screening was performed in Caenorhabditis elegans with a single gene knockout Escherichia coli (E. coli) library and identified the immune suppression gene blc. The coding sequences of blc among different kinds of E. coli strains were aligned to identify the single nucleotide polymorphisms (SNPs). Physiological and biochemical experiments were performed in C. elegans and mice to explore the function of the blc variant. Findings: By screening 3983 E. coli mutants, we discovered that 9 bacterial genes, when deleted, activate innate immunity in the host C. elegans. Among these 9 genes, the gene encoding blc showed a distinctive SNP in many clinically pathogenic bacteria. We found that bacteria with this SNP, which converts Blc G84 to Blc E84, are highly enriched in the faeces of patients with inflammatory bowel disease (IBD). Exposure to BlcE84-encoding bacteria resulted in epithelial barrier disruption and immune activation in both worms and mice. Detailed analysis indicated that infection with BlcE84-encoding bacteria causes a significant decrease in LPE levels in the intestine and subsequently disrupts gut epithelial integrity in mice. Consistently, the levels of LPE in patients with IBD are significantly lower than those in healthy people. Finally, supplementation with LPE, which activates LPA1/PLCβ/PKC signaling, reversed the defects induced by BlcE84-encoding bacteria. Interpretation: Our results identified a novel bacterial gene, blc, in E. coli that regulates host gut integrity and immunity. Fund: The Ministry of Science and Technology of China; the National Natural Science Foundation of China; and the Natural Science Foundation of Jiangsu Province. Keywords: Bacterial lipocalin, Gut homeostasis, Epithelial barrier, lysophosphatidylethanolamine (LPE), Keio collection

A new electrocoagulation reactor (EC), which utilises the concepts of baffle-plates, has been applied to remove Escherichia coli (E. coli) from wastewater. This new aluminium-based EC reactor utilises perforated baffle-plates electrodes to mix water, which reduces the need for mechanical or magnetic mixers that require extra power to work. This new reactor has been used to treat E. coli containing wastewater samples, considering the effects of different parameters such as treatment time (TT), inter-electrode distance (IED), and current density (CD). A statistical analysis has also been commenced to evaluate the influence of each parameter on the removal of E. coli. Additionally, an economic study has been conducted to assess the operating cost of the new reactor. The outcomes of the experimental work confirmed that the new reactor removes as high as 96 % of the E. coli within 20 min of electrolysis at IED of 0.5 cm, and CD of 1.5 m A / c m 2 . Additionally, it has been found that the operating cost of the new reactor is 0.11 US $/m3 (for E. coli removal), which is less than operating cost of traditional reactors. Finally, it has been found that the effect of the studied parameters on E. coli removal followed the order: T T > C D > I E D .

In this work, an intensive assessment of solar disinfection of secondary wastewater was elaborated in controlled laboratory conditions. Batch tests of Escherichia coli-spiked synthetic secondary effluent, at nine different constant intensity levels, were followed by a 48-h dark storage. Solar disinfection was monitored in half-hourly intervals demonstrating distinct phases of lag followed by sharp inactivation. The results were fit to a shoulder log-linear and a Weibull distribution model. The solar-driven inactivation, the latency period and the effective disinfection time (for 4-log reduction) were correlated properly with the applied irradiance, resulting in a common, standardized dose for all intensities. Evolution of bacterial response in the dark was monitored for 48 h, and was in each case characterized as growth or decay. Also, the energy threshold, which was able to shift post-irradiation behavior from growth to decay, was analytically studied. In all intensity levels, this standard was approximately constant, as an effective bacteriostatic dose (EBD). Finally, similar dose-related disinfection and regrowth effects were observed, suggesting compliance with the reciprocity law, with minor deviations.

Using arsenic (As) contaminated groundwater for drinking or irrigation has caused major health problems for humans around the world, raising a need to monitor As level efficiently and economically. This study developed a color-based bacterial biosensor which is easy-to-use and inexpensive for measuring As and could be complementary to current As detecting techniques. The arsR-lacZ recombinant gene cassette in nonpathogenic strain Escherichia coli DH5α was used in the color-based biosensor which could be observed by eyes or measured by spectrometer. The developed bacterial biosensor demonstrates a quantitative range from 10 to 500μgL(-1) of As in 3-h reaction time. Furthermore, the biosensor was able to successfully detect and estimate As concentration in groundwater sample by measuring optical density at 595nm (OD595). Among different storage methods used in this study, biosensor in liquid at 4°C showed the longest shelf life about 9d, and liquid storage at RT and cell pellet could also be stored for about 3-5d. In conclusion, this study showed that the As biosensor with reliable color signal and economical preservation methods is useful for rapid screening of As pollutant, providing the potential for large scale screening and better management strategies for environmental quality control.

Whatman 3MM paper was chemically modified to generate nickel-charged iminodiacetic acid paper (Ni2+-IDA paper). Bacteria were transformed with Escherichia coli expression plasmids coding for either unmodified proliferating cell nuclear antigen (PCNA) or PCNA containing a genetically engineered polyhistidine tract (his-tag) located at its NH2 terminus. They were then grown, induced, and lysed, and macromolecules were transferred to Ni2+-IDA paper. After exhaustive washing, his-tagged PCNA but not unmodified PCNA remained bound to the paper. Moreover, bound his-tagged PCNA was biochemically active in an in situ DNA synthesis assay with exogenous template-primer and purified calf thymus DNA polymerase delta (pol delta). Ni2+-IDA paper was used to identify a PCNA- point mutant that, relative to wild-type PCNA, promotes increased DNA synthesis by pol delta beyond a model abasic template site. In addition, metal-charged IDA paper promises to be generally useful for functional screening of cells expressing cloned proteins.

Minimising the usage of potable water in industrial and cleaning processes is essential to conserve fresh water. Recycling treated wastewater will help to do so. However, high quality treated wastewater is required for reuse and recycling. This study evaluated the performance of an enhanced membrane bioreactor (eMBR) in treating car wash wastewater for the purpose of reuse. The eMBR consisted of an anaerobic tank, an anoxic tank, an aerobic membrane bioreactor (AMBR) and a UV disinfection unit. The effects of hydraulic retention time of the eMBR on the treated water quality parameters and operating parameters were evaluated. The eMBR produced high quality recyclable water (0.5–10.2 mg/L of COD, 0.18–0.83 NTU of turbidity, 0 org. of E. Coli/100 mL) meeting Class A recycle water standards. Decrease in the mixed liquor suspended solids concentration in the AMBR (from 294 to 117 mg/L) reduced the fouling of the membrane which increased the permeate flux (from 5.9 to 6.7 L/m2h). This is unique to the eMBR system used in this study. However, when the flux exceeded the critical flux, the trans-membrane pressure increased significantly.

Microbial fermentation is emerging as an increasingly important resource for the production of fatty acids to serve as precursors for renewable diesel as well as detergents, lubricants and other industrial chemicals, as an alternative to traditional sources of reduced carbon such as petroleum. A major disadvantage of fuels derived from biological sources is their undesirable physical properties such as high cloud and pour points, and high viscosity. Here we report the development of an Escherichia coli strain that efficiently produces anteiso-branched fatty acids, which can be converted into downstream products with lower cloud and pour points than the mixtures of compounds produced via the native metabolism of the cell. This work addresses a serious limitation that must be overcome in order to produce renewable biodiesel and oleochemicals that perform as well as their petroleum-based counterparts.

With the depletion of the nonrenewable petrochemical resources and the increasing concerns of environmental pollution globally, biofuels and biobased chemicals produced from the renewable resources appear to be of great strategic significance. The present review described the progress in the biosynthesis of fatty acid and its derivatives from renewable biomass and emphasized the importance of fatty acid serving as the platform chemical and feedstock for a variety of chemicals. Due to the low efficient conversions of lignocellulosic biomass or carbon dioxide to fatty acid, we also put forward that rational strategies for the production of fatty acid and its derivatives should further derive from the consideration of whole bioprocess (pretreatment, saccharification, fermentation, separation), multiscale analysis and interdisciplinary combinations (omics, kinetics, metabolic engineering, synthetic biology, fermentation and so on).

In most resource-oriented sanitation (ROS) systems, the composting process has been a sustainable treatment method for source separated feces. Nonetheless, a slow and low degradation efficiency-combined with hygienic concerns, especially for the high amount of waste produced -makes the selection of the composting bulk additives a critical decision for the process. This study presents the efficiency improvement of adding different natural additives to enhance the composting process of the source separated feces in ROS systems. Three different natural additives, including sawdust, rice husk, and rice husk charcoal were utilized for the composting process of fresh feces with an additive w/w ratio of 2:1. To evaluate the impact of additives on compost properties, chemical, physical, and biological characteristics of composting materials were measured. Results indicated that using rice husk charcoal as an additive of the process was effective and generated a degradation of more than 40% of total organic carbon (TOC), reduced the nitrogen loss to less than 0.2%, and improved the germination index (GI) to more than 80%. Moreover, in terms of fecal indicators, the Escherichia coli (E. coli) stains were totally removed after five weeks. The efficacy of utilizing rice husk charcoal as a composting matrix in resource oriented sanitation systems can be, therefore, demonstrated as a nature-based treatment for source separated feces.

Shiga toxin-producing Escherichia coli (STEC) cause gastrointestinal illnesses including non-bloody or bloody diarrhoea, haemorrhagic colitis (HC), and the haemolytic uremic syndrome (HUS). To investigate the occurrence of STEC among grazing dromedaries from Kenya, E. coli isolated from fecal matter collected from 163 dromedaries on a large ranch were screened for the presence of stx1 and stx2. STEC strains were isolated and serotyped. Isolates were subjected to PCR for the subtyping of stx genes and for the detection of eae and ehx. In addition, whole genome sequencing (WGS) was carried out to detect further virulence genes and to determine the multilocus sequence types (MLST). Antimicrobial resistance profiles were determined by disk diffusion.STEC was isolated from 20 (12.3%) of the fecal samples. Thereof, nine (45%) isolates were STEC O156:H25, three (15%) isolates typed STEC O43:H2. The remaining isolates occurred as single serotypes or were O non-typeable. Eleven (55%) of the isolates harboured stx2a, nine (45%) eae, and 14 (70%) ehx, respectively. WGS revealed the presence of iss in 16 (80%), subAB in four (20%) and astA in two (10%) of the isolates, Furthermore, espA, tccP, nleA, nleB, tccP, and tir were found exclusively among STEC O156:H25.Eleven different sequence types (ST) were detected. The most prominent was ST300/ST5343, which comprised STEC O156:H25. All STEC isolates were pan susceptible to a panel of 16 antimicrobial agents. Overall, the results indicate that dromedary camels in Kenya may be reservoirs of STEC, including serotypes possessing virulence markers associated to disease in humans, such as STEC O156:H25. STEC in camels may represent a health hazard for humans with close contact to camels or to consumers of camel derived foodstuffs, such as unpasteurised camel milk. Keywords: Camels, STEC, Serotypes, Virulence genes, Whole genome sequencing