scholarly journals Detection of Viable Bacteria during Sludge Ozonation by the Combination of ATP Assay with PMA-Miseq Sequencing

Water ◽  
2017 ◽  
Vol 9 (3) ◽  
pp. 166 ◽  
Author(s):  
Shaonan Tian ◽  
Zhe Tian ◽  
Hong Yang ◽  
Min Yang ◽  
Yu Zhang

Using sludge obtained from municipal sewage treatment plants, the response of viable bacterial populations during the sludge ozonation process was investigated by a combination of adenosine triphosphate (ATP) assay and propidium monoazide (PMA)-Miseq sequencing. The ATP assay was first optimized for application on sludge samples by adjusting the sludge solid contents and reaction time. PMA-modified polymerase chain reaction (PCR) was also optimized by choosing the suitable final PMA concentration. The quantity and composition of viable bacterial populations during sludge ozonation were further elucidated using the optimized ATP and PMA-modified PCR methods. The results indicated that after the sludge was exposed to ozone (O3) at 135 mg·O3/g total suspended solids (TSS), the viable biomass displayed a substantial decrease, with a reduction rate reaching 70.89%. The composition of viable bacterial communities showed a faster succession, showing that an ozone dosage of 114 mg·O3/g TSS is enough to significantly change the viable bacterial population structure. Floc-forming genera, such as Zoogloea, Ferruginibacter, Thauera and Turneriella, are sensitive to ozonation, while the relative abundances of some functional bacterial genera, including SM1A02, Nitrospira and Candidatus Accumulibacter, remained constant or increased in the viable bacterial population during sludge ozonation, indicating that they are more resistant to ozonation.

Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 876-884 ◽  
Author(s):  
H. Hu ◽  
Avijit Roy ◽  
R. H. Brlansky

Citrus huanglongbing (HLB) is a century-old destructive disease which presents an unprecedented challenge to citrus industries worldwide. In Florida, HLB is associated with the phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ and is mainly transmitted by Asian citrus psyllid (Diaphorina citri). Quantification of the pathogen population in a host aids in investigation of virulence mechanisms and disease management. Recently a procedure was developed to detect live bacterial populations using a novel DNA-binding dye, propidium monoazide, in conjunction with real-time polymerase chain reaction (PMA-qPCR). Chinese box orange (Severinia buxifolia) is a common ornamental present in Florida which could host D. citri and ‘Ca. L. asiaticus’. For 20 months, the change of the live ‘Ca. L. asiaticus’ populations in graft- and psyllid-transmitted Valencia sweet orange (Citrus sinensis ‘Valencia’) and S. buxifolia plants was monitored by PMA-qPCR. Our results showed that the live ‘Ca. L. asiaticus’ population was significantly lower in the months of December, January, and February than the rest of the year in both hosts. No statistically significant pattern in the total bacterial population was observed in either host. This pattern may indicate a seasonal growth of ‘Ca. L. asiaticus’ along with the growth of both plants. These new findings should provide useful information on HLB management.


2017 ◽  
Vol 4 (2) ◽  
pp. 87-91
Author(s):  
Ekamaida Ekamaida

The soil fertility aspect is characterized by the good biological properties of the soil. One important element of the soil biological properties is the bacterial population present in it. This research was conducted in the laboratory of Microbiology University of Malikussaleh in the May until June 2016. This study aims to determine the number of bacterial populations in soil organic and inorganic so that can be used as an indicator to know the level of soil fertility. Data analysis was done by T-Test that is by comparing the mean of observation parameter to each soil sample. The sampling method used is a composite method, which combines 9 of soil samples taken from 9 sample points on the same plot diagonally both on organic soil and inorganic soil. The results showed the highest bacterial population was found in total organic soil cfu 180500000 and total inorganic soil cfu 62.500.000


1982 ◽  
Vol 14 (4-5) ◽  
pp. 143-150 ◽  
Author(s):  
F B DeWalle ◽  
D A Kalman ◽  
R Dills ◽  
D Norman ◽  
E S K Chian ◽  
...  

A total of 25 municipal sewage treatment plants were sampled, 10 of which were resampled, to determine the quantity of phenolics in the sewage, final effluent and the anaerobically digested sludge using capillary GC/MS/DS/techniques. The study noted in decreasing order of frequency in raw sewage: phenol, pentachloro-phenol, dimethyl phenol, 3-methyl, 4-chlorophenol, 2,4,6-trichloro-phenol, 2,4-dichlorophenol, 2-nitrophenol, 2-chlorophenol, 2,4-dinitro-6-methylphenol and 2,4-dinitrophenol. The maximum concentration of phenol in sewage and sludge was 2800 ppb and 4460 respectively, while similar values for pentachlorophenol were 58 and 1200 ppb. Statistically calculated concentration reductions for phenol and dimethyl phenol were generally greater than noted for tri- and pentachlorophenol. Low decreases or increases were noted for monochlorophenol and especially for dichlorophenol as a result of the chloronation of the final effluent.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 413-420 ◽  
Author(s):  
P. C. Chiang ◽  
J. H. You

In this investigation it was found that the waste sludge obtained from a municipal sewage treatment plant could be reclaimed as an adsorbent for removal of organic vapours, i.e. toluene, methyl-ethyl-ketone and 1-1-2-trichloroethylene, through use of a pyrolysis technique. In order to find the optimum manufacturing process, several tests were performed under various conditions in which the addition of a catalyst, temperature control, and residence time in the furnace, were considered as the three major factors. Both the reclaimed adsorbent and commercially available activated carbon were evaluated to determine their adsorption capacity at various influent concentrations of organic vapours.


1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 397
Author(s):  
Dimitra Kostoglou ◽  
Parthena Tsaklidou ◽  
Ioannis Iliadis ◽  
Nikoletta Garoufallidou ◽  
Georgia Skarmoutsou ◽  
...  

Fresh vegetables and salads are increasingly implicated in outbreaks of foodborne infections, such as those caused by Listeria monocytogenes, a dangerous pathogen that can attach to the surfaces of the equipment creating robust biofilms withstanding the killing action of disinfectants. In this study, the antimicrobial efficiency of a natural plant terpenoid (thymol) was evaluated against a sessile population of a multi-strain L. monocytogenes cocktail developed on stainless steel surfaces incubated in lettuce broth, under optimized time and temperature conditions (54 h at 30.6 °C) as those were determined following response surface modeling, and in comparison, to that of an industrial disinfectant (benzalkonium chloride). Prior to disinfection, the minimum bactericidal concentrations (MBCs) of each compound were determined against the planktonic cells of each strain. The results revealed the advanced killing potential of thymol, with a concentration of 625 ppm (= 4 × MBC) leading to almost undetectable viable bacteria (more than 4 logs reduction following a 15-min exposure). For the same degree of killing, benzalkonium chloride needed to be used at a concentration of at least 20 times more than its MBC (70 ppm). Discriminative repetitive sequence-based polymerase chain reaction (rep-PCR) also highlighted the strain variability in both biofilm formation and resistance. In sum, thymol was found to present an effective anti-listeria action under environmental conditions mimicking those encountered in the salad industry and deserves to be further explored to improve the safety of fresh produce.


2003 ◽  
Vol 37 (18) ◽  
pp. 4433-4443 ◽  
Author(s):  
Anders Svenson ◽  
Ann-Sofie Allard ◽  
Mats Ek

2010 ◽  
Vol 36 (5) ◽  
pp. 685-696 ◽  
Author(s):  
XiaoHong Zhang ◽  
ShiHuai Deng ◽  
Jun Wu ◽  
Wenju Jiang

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