Solar disinfection for household treatment of roof-harvested rainwater

2008 ◽  
Vol 8 (2) ◽  
pp. 153-160 ◽  
Author(s):  
V. Meera ◽  
M. M. Ahammed
Keyword(s):  
Prolonged Exposure ◽  
Heterotrophic Bacteria ◽  
Inactivation Kinetics ◽  
Bacterial Inactivation ◽  
Solar Disinfection ◽  
Complete Inactivation ◽  
Naturally Occurring ◽  
Significant Difference ◽  
Solar Intensity ◽  
Inactivation Efficiency

The effectiveness of solar disinfection in treating roof-harvested rainwater contaminated with microorganisms was evaluated with a view to its use as a household technology. Coliform and heterotrophic bacteria inactivation kinetics were studied using bottles with different backing surfaces. The effects of various parameters such as turbidity, solar intensity, type of organisms (naturally occurring versus laboratory grown) and bottle volume on bacterial inactivation were studied. Complete inactivation of total coliforms was observed in 6 h when solar radiation exceeded ∼500 W/m2.Under high contamination and overcast conditions, prolonged exposure was needed. Moderate turbidity (38 NTU) did not reduce the inactivation efficiency, but slightly enhanced it. No regrowth of microorganisms was observed after 24 h following solar disinfection. No significant difference in the inactivation kinetics was observed for bottle sizes in the range of 0.5 to 2.0 L. Tests with naturally occurring and laboratory-grown organisms indicated that laboratory-grown organisms were inactivated faster than naturally occurring organisms.

Effect of source water quality on solar disinfection rate under multiple experimental conditions

2014 ◽  
Vol 4 (4) ◽  
pp. 714-719
Author(s):  
M. Mansoor Ahammed ◽  
Shilpa Dave
Keyword(s):  
Natural Waters ◽  
Municipal Wastewater ◽  
Heterotrophic Bacteria ◽  
Exposure Period ◽  
Most Probable Number ◽  
Experimental Conditions ◽  
Probable Number ◽  
Solar Disinfection ◽  
Complete Inactivation ◽  
Naturally Occurring

Water samples from four different sources of varying physico-chemical and microbial quality with their naturally occurring microorganisms were exposed to sunlight in polyethylene terephthalate bottles under similar conditions. Up to 3-log10 reduction of total coliforms (TC) was observed during a 6-h exposure period under weak/moderate radiation conditions (<600 W/m2). Complete inactivation of TC was not achieved in 6 h of exposure for waters with larger initial TC such as river water (1 × 103 most probable number [MPN]/100 mL) and treated municipal wastewater (2 × 105 MPN/100 mL) under these conditions. Heterotrophic bacteria showed lower inactivation rates than did TC. The inactivation rate for spiked Escherichia coli was faster than for naturally occurring coliforms. Further tests with compound parabolic collectors showed that complete inactivation of naturally occurring TC could be achieved within 6 h of exposure for all the natural waters tested. The results of the study thus indicate the need to use naturally occurring organisms in testing the effectiveness of solar disinfection, and the importance of source quality on the inactivation rates of microorganisms.

scholarly journals Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine® on MSSA and MRSA Strains

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 869
Author(s):  
Beatriz Müller Nunes Souza ◽  
Juliana Guerra Pinto ◽  
André Henrique Correia Pereira ◽  
Alejandro Guillermo Miñán ◽  
Juliana Ferreira-Strixino
Keyword(s):  
Staphylococcus Aureus ◽  
Photodynamic Therapy ◽  
Antimicrobial Photodynamic Therapy ◽  
Bacterial Inactivation ◽  
Bacterial Reduction ◽  
Complete Inactivation ◽  
Opportunistic Bacteria ◽  
Significant Difference ◽  
Mrsa Strains

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

Comparative Study for the Assay of Plant Derived Chemicals in Pharmaceutical Formulation Using Methods Dependent on Factorized Spectra

2021 ◽  
Author(s):  
Nesma M Fahmy ◽  
Adel M Michael
Keyword(s):  
Pharmaceutical Formulations ◽  
Pharmaceutical Formulation ◽  
Ternary Mixtures ◽  
Ratio Method ◽  
The Novel ◽  
Naturally Occurring ◽  
Accuracy And Precision ◽  
Validation Parameters ◽  
Significant Difference

Abstract Background Modern built-in spectrophotometer software supporting mathematical processes provided a solution for increasing selectivity for multicomponent mixtures. Objective Simultaneous spectrophotometric determination of the three naturally occurring antioxidants—rutin(RUT), hesperidin(HES), and ascorbic acid(ASC)—in bulk forms and combined pharmaceutical formulation. Method This was achieved by factorized zero order method (FZM), factorized derivative method (FD1M), and factorized derivative ratio method (FDRM), coupled with spectrum subtraction(SS). Results Mathematical filtration techniques allowed each component to be obtained separately in either its zero, first, or derivative ratio form, allowing the resolution of spectra typical to the pure components present in Vitamin C Forte® tablets. The proposed methods were applied over a concentration range of 2–50, 2–30, and 10–100 µg/mL for RUT, HES, and ASC, respectively. Conclusions Recent methods for the analysis of binary mixtures, FZM and FD1M, were successfully applied for the analysis of ternary mixtures and compared to the novel FDRM. All were revealed to be specific and sensitive with successful application on pharmaceutical formulations. Validation parameters were evaluated in accordance with the International Conference on Harmonization guidelines. Statistical results were satisfactory, revealing no significant difference regarding accuracy and precision. Highlights Factorized methods enabled the resolution of spectra identical to those of pure drugs present in mixtures. Overlapped spectra of ternary mixtures could be resolved by spectrum subtraction coupled FDRM (SS-FDRM) or by successive application of FZM and FD1M.

Coupling Extracts of Plant Coagulants With Solar Disinfection Showed a Complete Inactivation of Faecal Coliforms

2018 ◽  
Vol 47 (1) ◽  
pp. 1700450
Author(s):  
Moa Megersa ◽  
Abebe Beyene ◽  
Argaw Ambelu ◽  
Ludwig Triest
Keyword(s):  
Faecal Coliforms ◽  
Solar Disinfection ◽  
Complete Inactivation

scholarly journals Bacterial microbiota present in the gallbladder of cattle and antimicrobial resistance of Staphylococcus isolates

2014 ◽  
Vol 66 (3) ◽  
pp. 641-647
Author(s):  
F.S. Dias ◽  
I.F. Santos ◽  
R.M. Franco ◽  
E.R. Nascimento
Keyword(s):  
Antimicrobial Resistance ◽  
Heterotrophic Bacteria ◽  
Penicillin G ◽  
Gallbladder Epithelium ◽  
Salmonella Spp ◽  
Bacterial Microbiota ◽  
Significant Difference ◽  
Enterococcus Spp ◽  
Persistent Carrier ◽  
Sanitary Conditions

Pathogenic microorganisms can reside transiently or permanently in the gallbladder of cattle. Thus, during slaughter, more attention should be given to the gastrointestinal tract, especially to the accessory organ, the gallbladder. The main aim of this study was to characterize the bacterial microbiota present in bile and gallbladder epithelium of cattle slaughtered in a slaughtering plant under sanitary conditions and to evaluate the antimicrobial resistance in strains of the genus Staphylococcus. Thirty intact gallbladders were collected and the in bile and epithelium were researched for the presence of Aerobic Mesophilic Heterotrophic Bacteria (AMHB), Staphylococcusspp., total Enterobacteriaceae, Enterococcus spp. and Salmonella spp. The frequency of isolation of the microorganism mentioned above were, respectively: 23.02%, 14.39%, 13.67%, 24.46%, 0% and 24.46%. Concerning both gallbladder environments, the frequency of isolation of the microorganisms in the epithelium was 64.03%, and in the bile 35.97%, with no statistical difference, but with significant difference between the population averages. In antimicrobial susceptibility testing, strains of Staphylococcusfrom both bile and gallbladder epithelium showed sensitivity to the antimicrobials: penicillin G, ceftriaxone, chloramphenicol and gentamicin. The observation that the gallbladder supports a high frequency of microorganisms brings us to the possible fact that cattle might be a persistent carrier of pathogens of great importance to public health.

scholarly journals Heterotrophic Bacteria Play an Important Role in Endemism of Cephalostachyum pingbianense (Hsueh & Y.M. Yang ex Yi et al.) D.Z. Li & H.Q. Yang, 2007, a Full-Year Shooting Woody Bamboo

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 121
Author(s):  
Tize Xia ◽  
Lushuang Li ◽  
Bin Li ◽  
Peitong Dou ◽  
Hanqi Yang
Keyword(s):  
Bacterial Community ◽  
Soil Microbes ◽  
Heterotrophic Bacteria ◽  
Ph Value ◽  
Germplasm Conservation ◽  
Plant Distribution ◽  
Soil Bacterial Diversity ◽  
Significant Difference ◽  
Woody Bamboos ◽  
Soil Bacterial

The previous studies show soil microbes play a key role in the material and nutrient cycles in the forest ecosystem, but little is known about how soil microbes respond to plant distribution, especially in the soil bacterial community in woody bamboo forests. Cephalostachyum pingbianense (Hsueh & Y.M. Yang ex Yi et al.) D.Z. Li & H.Q. Yang, 2007 is known as the only bamboo species producing shoots all year round in natural conditions. Endemic to the Dawei mountain in Yunnan of China, this species is a good case to study how soil bacteria respond to plant endemic distribution. In this work, we assayed the soil chemical properties, enzyme activity, changes in the bacterial community along the distribution range of the C. pingbianense forest. The results showed that soil nutrients at the range edge were nitrogen-rich but phosphorus-deficient, and soil pH value and soil urease activity were significantly lower than that of the central range. No significant difference was detected in soil bacterial diversity, community composition, and function between the central and marginal range of C. pingbianense forest. Notably, the relative abundance of heterotrophy bacteria, such as Variibacter and Acidothermus, in the soil of the C. pingbianense forest was significantly higher than that of the outside range, which may lead to a higher soil organic carbon mineralization rate. These results imply that abundant heterotrophy bacteria were linked to the endemism and full-year shooting in C. pingbianense. Our study is amongst the first cases demonstrating the important role of heterotrophy bacteria in the distribution formation of endemic woody bamboos in special soil habitats, and provides insight into germplasm conservation and forest management in woody bamboos.

ANTIBODY RESPONSES OF YOUNG INFANTS TO NATURALLY OCCURRING VIRAL INFECTIONS

PEDIATRICS ◽  
1966 ◽  
Vol 38 (4) ◽  
pp. 564-570
Author(s):  
Hugh L. Moffet ◽  
Henry G. Cramblett
Keyword(s):  
Neutralizing Antibodies ◽  
Virus Isolation ◽  
Viral Infections ◽  
Low Frequency ◽  
Severity Of Illness ◽  
Antibody Responses ◽  
Older Children ◽  
Young Infants ◽  
Naturally Occurring ◽  
Significant Difference

A fourfold rise in neutralizing antibodies was demonstrated for 45% of infants 1 through 6 months of age compared to 63% of older children or adults from whom an adenovirus or an enterovirus was recovered. This difference appeared to be related to severity of illness rather than to age, as there was no significant difference between young infants and older patients when only clinically severe illnesses were analyzed. The isolation of virus from more than one specimen increased the probability of a significant response in either age group. Infants with minor symptoms had a low frequency of significant fourfold antibody responses after virus isolation, but this was not significantly different from older children with minor symptoms. Failure to develop an increase in antibody titer could not be related to the presence of maternal antibodies.

scholarly journals Assessment of the nitrification process in a culture of pacific white shrimp, using artificial substrate and bacterial inoculum in a biofloc technology system (BFT)

2019 ◽  
Vol 49 (6) ◽  
Author(s):  
Nathalia Brenda Veiga dos Santos ◽  
Plínio Schmidt Furtado ◽  
Dionéia Evangelista César ◽  
Wilson Wasielesky Junior
Keyword(s):  
Heterotrophic Bacteria ◽  
Pacific White Shrimp ◽  
Production Performance ◽  
Artificial Substrates ◽  
Nitrifying Bacteria ◽  
Clear Water ◽  
Technology System ◽  
Working Volume ◽  
Significant Difference ◽  
Nitrification Process

ABSTRACT: Litopenaeus vannamei is the most cultured marine shrimp in all types of systems including the Bioflocs Technology System (BFT). Bioflocs are formed by microorganisms, among these, autotrophic bacteria are responsible for the nitrification process. This study aimed to identify and promote the development of nitrifying bacteria by adding artificial substrates and biofloc inoculum in L. vannamei culture in a BFT system. The experiment consisted of four treatments with three replics (4x3) as follows: (1) Control: clear water in which bioflocs were formed; (2) IN (10%): clear water with biofloc inoculum (10%); (3) IB: clear water with substrate (immature “bioballs”); and (4) MB: clear water with mature “bioballs” inoculum from a recirculation system. Treatments were stocked with shrimp juveniles (4.92±0.45 g) in 12 tanks with 200 L working volume at a stocking density of 200 shrimp/m³. Shrimps were fed twice a day with a commercial feed (38% CP) following a feeding table, and daily observations intake were made over the four weeks of the experiment. Biofloc and “bioballs” samples were collected to detect the growth of the population of nitrifying and heterotrophic bacteria by FISH. There was no significant difference between treatments (P>0.05) for survival, obtaining mean values greater than 88%. The IN (10%) treatment had lower concentrations of ammonia and nitrite, and nitrate concentration increased, while MB had a higher weight and biomass final, productivity, weekly weight gain and lower conversion of apparent feed for production performance results.

Validation of a High-Throughput Sausage Casing Model for the Assessment of Bacterial Inactivation Affected by Salt Concentration, pH, and Temperature

2019 ◽  
Vol 82 (10) ◽  
pp. 1769-1774
Author(s):  
JORIS J. WIJNKER ◽  
PATRICK M. W. JANSSEN ◽  
SABRI CEBECI ◽  
KEVIN van KOERTEN ◽  
MARTIJN BEKKER
Keyword(s):  
High Throughput ◽  
Salt Concentration ◽  
Storage Period ◽  
Complete Removal ◽  
Inactivation Kinetics ◽  
Contamination Level ◽  
Bacterial Inactivation ◽  
Holding Period ◽  
Novel Approach ◽  
High Concentrations

ABSTRACT Previous studies have shown the efficacy of high concentrations of salt as the main preservative against vegetative bacteria present on natural sausage casings. These studies were limited in the number of variables and the interactions between these variables that were assessed. To remedy this situation, a MicroCasing high-throughput model was developed and validated to study the inactivation kinetics of various combinations of parameters (salt concentration, pH, and temperature) on eight bacterial isolates of Salmonella enterica, Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes over a prolonged period. A Weibullian power model was the best fit to show the trends in sensitivity of each bacterial isolate to salt, pH, and temperature over time. The inactivation kinetics generated with this novel approach could serve as a predictive model for the required salting period for casings. The actual bacterial contamination of the product can vary with the respective production step during processing from animal intestine into sausage casings (initial level, ∼105 CFU/g; level after salting, &lt;102 CFU/g). Subsequent selection and grading of these casings will require complete removal of all salt, and upon completion of this production step, the casings will be resalted. By determining the actual contamination level before the salting process, the minimum storage period in salt can be calculated and potentially optimized by adjusting the pH and temperature. As a result, a standard holding period of at least 30 days may no longer be necessary to produce salted natural casings in accordance with validated quality and food safety criteria.

Sign in / Sign up

Export Citation Format

Share Document