Evaluation of bacteriophages during the treatment of sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 189-194 ◽  
Author(s):  
B. Mignotte-Cadiergues ◽  
C. Gantzer ◽  
L. Schwartzbrod
Keyword(s):  
Bacteroides Fragilis ◽  
Temperature Dependent ◽  
Treatment Methods ◽  
Somatic Coliphages ◽  
Viral Contamination ◽  
Log Reduction ◽  
Ph Dependent ◽  
Somatic Coliphage ◽  
Phage Inactivation

The aim of this work was to determine the effect of liming and composting on the fate of three bacteriophages (somatic coliphages, F-RNA phages, Bacteroides fragilis phages) considered as potential indicators of viral contamination. It was shown that the three bacteriophages studied exhibited variable densities in sludge. Somatic coliphages were most abundant (104 to 105 .10 g−1 DM) then F-RNA bacteriophages (102 to 104.10 g−1 DM) and Bacteroides fragilis phages (101 to 102.10 g−1 DM). The efficacy of liming was found to be pH dependent but also sludge dependent. The pH allowing 99% elimination of somatic coliphage is close to 9 for solid sludges and close to 13.5 for liquid sludges. For composting, our findings clearly demonstrated that phage inactivation is very clearly temperature-dependent. For temperatures reaching 70°, there is a 5 log reduction in somatic coliphages while for temperature in the 50-55°C range, the drop off is only 2 log. Considering the efficacy of the treatment methods, it is clear that the well-established industrial procedures that reach temperatures in the 60-70°C range totally inactivate all 3 phages tested and present in sludge before composting.

Detection of Infectious Enteroviruses, Enterovirus Genomes, Somatic Coliphages, and Bacteroides fragilis Phages in Treated Wastewater

1998 ◽  
Vol 64 (11) ◽  
pp. 4307-4312 ◽  
Author(s):  
C. Gantzer ◽  
A. Maul ◽  
J. M. Audic ◽  
L. Schwartzbrod
Keyword(s):  
Bacteroides Fragilis ◽  
Treated Wastewater ◽  
Most Probable Number ◽  
Host Bacterium ◽  
Secondary Treatment ◽  
Experimental Conditions ◽  
Probable Number ◽  
Somatic Coliphages ◽  
The Mean ◽  
Somatic Coliphage

ABSTRACT In this study, three types of treated wastewater were tested for infectious enteroviruses, the enterovirus genome, somatic coliphages, and Bacteroides fragilis phages. The aim of this work was to determine whether the presence of the two types of bacteriophages or of the enterovirus genome was a good indicator of infectious enterovirus contamination. The enterovirus genome was detected by reverse transcription-polymerase chain reaction. Infectious enteroviruses were quantified by cell culturing (BGM cells), and the bacteriophages were quantified by plaque formation on the host bacterium (Escherichia coli or B. fragilis) in agar medium. Forty-eight samples of treated wastewater were analyzed. Sixteen samples had been subjected to a secondary treatment for 8 to 12 h (A), 16 had been subjected to a secondary treatment for 30 h (B1), and 16 had been subjected to both secondary and tertiary treatments (B2). The mean concentrations of somatic coliphages were 4.9 × 104 PFU · liter−1 for treatment line A, 9.8 × 103PFU · liter−1 for B1, and 1.4 × 103 PFU · liter−1 for B2, with all the samples testing positive (100%). The mean concentrations of B. fragilis phages were 1.7 × 103 PFU · liter−1 for A (100% positive samples), 17 to 24 PFU · liter−1 for B1 (44% positive samples), and 0.8 to 13 PFU · liter−1 for B2 (6% positive samples). The mean concentrations of infectious enteroviruses were 4 most probable number of cytopathogenic units (MPNCU) · liter−1 for A (31% positive samples) and <1 MPNCU · liter−1 for B1 and B2 (0% positive samples). The percentages of samples testing positive for the enterovirus genome were 100% for A, 56% for B1, and 19% for B2. The percentages of samples testing positive for the enterovirus genome were significantly higher than those for infectious enteroviruses. This finding may have been due to the presence of noninfectious enteroviruses or to the presence of infectious enteroviruses that do not multiply in BGM cell cultures. However, under our experimental conditions, nondetection of the genome implies the absence of infectious viruses. There was a significant correlation between the concentration of somatic coliphages orB. fragilis phages and the presence of infectious enteroviruses or the presence of the enterovirus genome. However, the somatic coliphage concentration did not lead to fluctuations in the infectious enterovirus concentration, whereas the B. fragilis phage concentration did.

Bacteriophage removal in water treatment plants

1995 ◽  
Vol 31 (5-6) ◽  
pp. 69-73 ◽  
Author(s):  
J. Jofre ◽  
E. Ollé ◽  
F. Lucena ◽  
F. Ribas
Keyword(s):  
Water Treatment ◽  
Distribution Network ◽  
Bacteroides Fragilis ◽  
The Other ◽  
Model Organisms ◽  
Raw Water ◽  
Somatic Coliphages ◽  
Treatment Processes ◽  
Water Treatment Plants ◽  
Human Enteric Viruses

Presence of bacteriophages was evaluated at different stages of two water treatment plants in order to investigate the usefulness of phages as model organisms for assessing the efficiency of the processes. Bacteriophages tested were somatic coliphages, F-specific coliphages and phages infecting Bacteroides fragilis. The presence of human enteric viruses was determined as well in the raw water, the finished water and in samples taken in the distribution network. Results show that in these particular treatment plants, which include prechlorination, phages infecting B. fragilis are more resistant to the treatment processes than the other two phages studied.

Adsorption, desorption, and activity of glucose oxidase on selected clay species

1976 ◽  
Vol 22 (5) ◽  
pp. 684-693 ◽  
Author(s):  
H. W. Morgan ◽  
C. T. Corke
Keyword(s):  
Hydrogen Bonding ◽  
Protein Structure ◽  
Cation Exchange ◽  
Glucose Oxidase ◽  
Isoelectric Point ◽  
Active Form ◽  
Temperature Dependent ◽  
Specific Activities ◽  
Ph Dependent ◽  
Adsorption Desorption

The adsorption of the enzyme glucose oxidase (EC 1.1.3.4) to clays followed the pattern described for other proteins as being pH dependent. Maximum adsorption occurred at or below the isoelectric point of the enzyme. The amount of enzyme adsorbed to clay was influenced by the type of clay used, and also the saturating cations. Initially adsorbed enzyme showed low specific activities, and as amounts of enzyme adsorbed approached maximum saturation of clay, specific activities increased approaching that determined for free enzyme.The adsorption of glucose oxidase involved a temperature-independent cation-exchange mechanism, and enzyme adsorbed to surfaces of clay could be desorbed in active form by elevation of pH of suspending solution. This was followed by a slower temperature-dependent fixation, probably by hydrogen bonding, which resulted in protein being irreversibly adsorbed to clay surfaces.It is proposed that on adsorption of glucose oxidase to clay surfaces unravelling of the protein structure occurred, which allowed penetration of protein into the interlamellar spaces of montmorillonite. This proposal was based on the observed expansion of montmorillonite to 23 Å, and the decreases in amount of a second-protein lysozyme adsorbed with extended incubation times of glucose oxidase – clay complexes at pH 4.5.

scholarly journals Effect of polyamines on the stability of brain-cortex ribosomes

1969 ◽  
Vol 114 (4) ◽  
pp. 847-854 ◽  
Author(s):  
R. K. Datta ◽  
Suchandra Sen ◽  
J. J. Ghosh
Keyword(s):  
Melting Temperature ◽  
Brain Cortex ◽  
Temperature Dependent ◽  
Enzymic Digestion ◽  
Ph Dependent ◽  
High Concentrations ◽  
The Stability ◽  
Goat Brain

1. Ribosomes isolated from the cortex tissue of goat brain contain very small amounts of spermidine and spermine. Ribosomes isolated from spermidine-treated slices have a higher spermidine content. 2. The polyamines partially prevent the temperature-dependent breakdown of ribosomes into acid-soluble nucleotides. 3. The ‘melting’ temperature of ribosomes rises slightly when the ribosomes are heated slowly in the presence of polyamines. 4. The pH-dependent breakdown of ribosomes into protein, RNA and acid-soluble nucleotide is markedly decreased by polyamines present in media in which ribosomes are suspended. 5. The breakdown of ribosomes in the presence of high concentrations of salts and EDTA is partially checked by the concurrent presence of polyamines. 6. Spermidine and spermine make ribosomes less susceptible to enzymic digestion by crystalline trypsin and ribonuclease.

scholarly journals Concentration- and pH-Dependent Oligomerization of the Thrombin-Derived C-Terminal Peptide TCP-25

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1572
Author(s):  
Ganna Petruk ◽  
Jitka Petrlova ◽  
Firdaus Samsudin ◽  
Rita Del Giudice ◽  
Peter J. Bond ◽  
...  
Keyword(s):  
Tryptophan Fluorescence ◽  
Helical Structure ◽  
High Concentration ◽  
Temperature Dependent ◽  
Preclinical Development ◽  
Intrinsic Tryptophan Fluorescence ◽  
Ph Dependent ◽  
High Concentrations ◽  
Dose Dependent Increase ◽  
Dose Dependent

Peptide oligomerization dynamics affects peptide structure, activity, and pharmacodynamic properties. The thrombin C-terminal peptide, TCP-25 (GKYGFYTHVFRLKKWIQKVIDQFGE), is currently in preclinical development for improved wound healing and infection prevention. It exhibits turbidity when formulated at pH 7.4, particularly at concentrations of 0.3 mM or more. We used biochemical and biophysical approaches to explore whether the peptide self-associates and forms oligomers. The peptide showed a dose-dependent increase in turbidity as well as α-helical structure at pH 7.4, a phenomenon not observed at pH 5.0. By analyzing the intrinsic tryptophan fluorescence, we demonstrate that TCP-25 is more stable at high concentrations (0.3 mM) when exposed to high temperatures or a high concentration of denaturant agents, which is compatible with oligomer formation. The denaturation process was reversible above 100 µM of peptide. Dynamic light scattering demonstrated that TCP-25 oligomerization is sensitive to changes in pH, time, and temperature. Computational modeling with an active 18-mer region of TCP-25 showed that the peptide can form pH-dependent higher-order end-to-end oligomers and micelle-like structures, which is in agreement with the experimental data. Thus, TCP-25 exhibits pH- and temperature-dependent dynamic changes involving helical induction and reversible oligomerization, which explains the observed turbidity of the pharmacologically developed formulation.

scholarly journals A Somatic Coliphage Threshold Approach To Improve the Management of Activated Sludge Wastewater Treatment Plant Effluents in Resource-Limited Regions

2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Luz Chacón ◽  
Kenia Barrantes ◽  
Carolina Santamaría-Ulloa ◽  
Melissa Solano ◽  
Liliana Reyes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Water Reuse ◽  
Enteric Viruses ◽  
World Health ◽  
Wastewater Management ◽  
Log Reduction ◽  
Conventional Activated Sludge ◽  
Health Organization ◽  
Somatic Coliphage

ABSTRACT Effective wastewater management is crucial to ensure the safety of water reuse projects and effluent discharge into surface waters. Multiple studies have demonstrated that municipal wastewater treatment with conventional activated sludge processes is inefficient for the removal of a wide spectrum of viruses in sewage. In this study, a well-accepted statistical approach was used to investigate the relationship between viral indicators and human enteric viruses during wastewater treatment in a resource-limited region. Influent and effluent samples from five urban wastewater treatment plants (WWTPs) in Costa Rica were analyzed for somatic coliphage and human enterovirus, hepatitis A virus, norovirus genotypes I and II, and rotavirus. All WWTPs provide primary treatment followed by conventional activated sludge treatment prior to discharge into surface waters that are indirectly used for agricultural irrigation. The results revealed a statistically significant relationship between the detection of at least one of the five human enteric viruses and somatic coliphage. Multiple logistic regression and receiver operating characteristic curve analysis identified a threshold of 3.0 × 103 (3.5 log10) somatic coliphage PFU per 100 ml, which corresponded to an increased likelihood of encountering enteric viruses above the limit of detection (>1.83 × 102 virus targets/100 ml). Additionally, quantitative microbial risk assessment was executed for farmers indirectly reusing WWTP effluent that met the proposed threshold. The resulting estimated median cumulative annual disease burden complied with World Health Organization recommendations. Future studies are needed to validate the proposed threshold for use in Costa Rica and other regions. IMPORTANCE Effective wastewater management is crucial to ensure safe direct and indirect water reuse; nevertheless, few countries have adopted the virus log reduction value management approach established by the World Health Organization. In this study, we investigated an alternative and/or complementary approach to the virus log reduction value framework for the indirect reuse of activated sludge-treated wastewater effluent. Specifically, we employed a well-accepted statistical approach to identify a statistically sound somatic coliphage threshold value which corresponded to an increased likelihood of human enteric virus detection. This study demonstrates an alternative approach to the virus log reduction value framework which can be applied to improve wastewater reuse practices and effluent management.

Relationship between the morphology of bacteriophages and their persistence in the environment

1997 ◽  
Vol 35 (11-12) ◽  
pp. 129-132 ◽  
Author(s):  
J. Lasobras ◽  
M. Muniesa ◽  
J. Frías ◽  
F. Lucena ◽  
J. Jofre
Keyword(s):  
Water Treatment ◽  
Bacteroides Fragilis ◽  
Coli Strain ◽  
Somatic Coliphages ◽  
E Coli ◽  
Treatment Processes ◽  
Morphological Differences ◽  
Myoviridae Family ◽  
Siphoviridae Family

The aim of the present work was to observe the morphological differences between bacteriophages from sewage, recent pollution and those from samples that contain microorganisms that have survived either natural inactivation or water treatment processes (persistent pollution). We studied the occurrence of bacteriophages infecting Bacteroides fragilis (HSP40 strain), F-specific coliphages (HS(pFamp)R strain) and somatic coliphages (CN13 strain). Phages isolated with B. fragilis in both wastewater and samples with persistent pollution were in all cases members of the Siphoviridae group with flexible tails. With E. coli strain HS(pFamp)R we detected F-specific coliphages in 97.7% wastewater. However, the percentage decreased to 76.9% in samples with persistent pollution. In the case of somatic coliphages in wastewater, detected using E. coli CN13, 91% of the phages belonged to the Myoviridae family and a 6% to the Siphoviridae family. In contrast, in persistent pollution samples, an increase of Siphoviridae phages was observed (up to 26.4%).

Bactericidal effect of lactoferrin on Legionella pneumophila: effect of the physiological state of the organism

1989 ◽  
Vol 35 (11) ◽  
pp. 1048-1051 ◽  
Author(s):  
Carol A. Bortner ◽  
Roland R. Arnold ◽  
Richard D. Miller
Keyword(s):  
Legionella Pneumophila ◽  
Immunofluorescence Microscopy ◽  
Physiological State ◽  
Bactericidal Effect ◽  
Growth Conditions ◽  
Temperature Dependent ◽  
Killing Activity ◽  
Ph Dependent

Lactoferrin has been previously shown to be bactericidal for Legionella pneumophila. The current study showed that CaCl2, Mg(NO3)2, and MgCl2, but not NaCl, blocked killing. Activity was pH dependent with the greatest activity at 5.0. Sensitivity of the organism was dramatically affected by the growth conditions. Log phase 12 h, broth-grown cells were most sensitive, with older cultures becoming more resistant. Plate-grown cells were completely resistant. Lactoferrin binding, as detected by immunofluorescence microscopy, was temperature dependent (no binding at 4 °C), but was independent of killing.Key words: Legionella pneumophila, lactoferrin, mucosal proteins.

Activation and Inactivation of Talaromyces macrosporus Ascospores by High Hydrostatic Pressure

2003 ◽  
Vol 66 (6) ◽  
pp. 1035-1042 ◽  
Author(s):  
KRISTIEN M. F. A. REYNS ◽  
E. A. VERAVERBEKE ◽  
C. W. MICHIELS
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Barrier Properties ◽  
Spore Wall ◽  
Pressure Treatment ◽  
Lytic Enzymes ◽  
Temperature Dependent ◽  
Ph Dependent ◽  
Ph Range ◽  
Cell Wall Lytic Enzymes

The effect of high hydrostatic pressure treatment (with pressures of up to 700 MPa) on Talaromyces macrosporus ascospores was investigated. At 20°C, pressures of ≥200 MPa induced the activation and germination of dormant ascospores, as indicated by increased colony counts for ascospore suspensions after pressure treatment and the appearance of germination vesicles and tubes. Pressures of &gt;400 MPa additionally sensitized the ascospores to subsequent heat treatment. At pressures of &gt;500 MPa, activation occurred in a few minutes but was followed by inactivation with longer exposure. However, even with the most extreme pressure treatment, a fraction of the ascospore population appeared to resist both activation and inactivation, and the maximal achievable reduction of ascospores was on the order of 3.0 log10 units. Pressure-induced ascospore activation at 400 MPa was temperature dependent, with minimum activation at 30 to 50°C and ≥10-fold higher activation levels at 10 to 20°C and at 60°C, but it was not particularly pH dependent over a pH range of 3.0 to 6.0. Pressure inactivation at 600 MPa, in contrast, was pH dependent, with the inactivation level being 10-fold higher at pH 6.0 than at pH 3.0. Observation of pressure-treated and subsequently dried spores with the use of light and scanning electron microscopy revealed a collapse of the spore structure, indicating a loss of the spore wall barrier properties. Finally, pressure treatment sensitized T. macrosporus ascospores to cell wall lytic enzymes.

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