Pressure effects on sulfur‐oxidizing activity of Thiobacillus thioparus

Biogenic sulfuric acid corrosion (BSA) is a costly problem affecting both sewerage infrastructure and sludge handling facilities such as digesters. The aim of this study was to verify BSA in full-scale digesters by identifying the microorganisms involved in the concrete corrosion process, that is, sulfate-reducing (SRB) and sulfur-oxidizing bacteria (SOB). To investigate the SRB and SOB communities, digester sludge and biofilm samples were collected. SRB diversity within digester sludge was studied by applying polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) targeting the dsrB-gene (dissimilatory sulfite reductase beta subunit). To reveal SOB diversity, cultivation dependent and independent techniques were applied. The SRB diversity studies revealed different uncultured SRB, confirming SRB activity and H2S production. Comparable DGGE profiles were obtained from the different sludges, demonstrating the presence of similar SRB species. By cultivation, three pure SOB strains from the digester headspace were obtained including Acidithiobacillus thiooxidans, Thiomonas intermedia and Thiomonas perometabolis. These organisms were also detected with PCR-DGGE in addition to two new SOB: Thiobacillus thioparus and Paracoccus solventivorans. The SRB and SOB responsible for BSA were identified within five different digesters, demonstrating that BSA is a problem occurring not only in sewer systems but also in sludge digesters. In addition, the presence of different SOB species was successfully associated with the progression of microbial corrosion.

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Effect of Sulfur-Oxidizing Bacteria Thiobacillus Thioparus and Different Levels of Agricultural Sulfur on Wheat Yield (Triticum Aestivium L.)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/923/1/012074 ◽

2021 ◽

Vol 923 (1) ◽

pp. 012074

Author(s):

Abdullah Karim Jabbar ◽

Dalia Qassem Al-Ziyadi

Keyword(s):

Wheat Yield ◽

Wheat Plant ◽

Triticum Aestivum L ◽

Bacterial Isolates ◽

Agricultural Field ◽

Thiobacillus Thioparus ◽

Sulfur Oxidizing ◽

Four Levels ◽

Different Levels ◽

Sulfur Oxidizing Bacteria

Abstract A field experiment was carried out in the agricultural season 2020-2021 in an agricultural field located in the Al-Jarboua area (Al Hafez) in Al-Muthanna Governorate to study the effect of inoculation with sulfur-oxidizing bacteria and agricultural sulfur levels and their interactions on the yield of wheat plant Triticum aestivum L. Ibaa cultivar 99. The study was carried out in two stages, the first is isolation Sulfur oxidizing bacteria and the second used as a inoculant in the agricultural experiment to study its effect on soil characteristics and its content of nutrients NPK and S. At two levels T0 without adding the bacterial inoculum and T1 adding the first isolate of bacteria The second factor included the addition of agricultural sulfur with four levels of sulfur (S0 were taken without addition, S1 added 750 kg ha−1, S2 added 1500 kg ha−1 and S3 added 2250 kg ha−1) In three replications, the number of experimental units reached 36 experimental units. The results of the study also showed that inoculation with bacterial isolates led to a significant increase in the readiness of nutrients N, P, K and S, and the highest rate of sulfur was (1895) mg. The pollination also led to a significant increase in the growth characteristics of the plant (plant height, number of spikes and grain yield), as it recorded (101.25 cm, 393.22 spike m−1 and 6.73 mcg/ha−1), respectively. The addition of agricultural sulfur at different levels affected a significant increase in the availability of nutrients N, P, K and S, and the highest rate of sulfur at the level of S3 was (1817) mg. Also, the bilateral interaction between inoculation with bacterial isolates and agricultural sulfur led to a significant increase in the availability of nutrients N, P, K and S. kg −1 soil.

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Reduction in Pain Sensitivity from Pharmacological Elevation of Blood Pressure in Persons with Chronically Low Blood Pressure

Journal of Psychophysiology ◽

10.1027/0269-8803.23.3.104 ◽

2009 ◽

Vol 23 (3) ◽

pp. 104-112 ◽

Cited By ~ 12

Author(s):

Stefan Duschek ◽

Heike Heiss ◽

Boriana Buechner ◽

Rainer Schandry

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Pain Sensitivity ◽

Pain Threshold ◽

Pain Perception ◽

Drug Effects ◽

Pressure Effects ◽

Double Blind ◽

Low Blood Pressure ◽

Present Trial

Recent studies have revealed evidence for increased pain sensitivity in individuals with chronically low blood pressure. The present trial explored whether pain sensitivity can be reduced by pharmacological elevation of blood pressure. Effects of the sympathomimetic midodrine on threshold and tolerance to heat pain were examined in 52 hypotensive persons (mean blood pressure 96/61 mmHg) based on a randomized, placebo-controlled, double-blind design. Heat stimuli were applied to the forearm via a contact thermode. Confounding of drug effects on pain perception with changes in skin temperature, temperature sensitivity, and mood were statistically controlled for. Compared to placebo, higher pain threshold and tolerance, increased blood pressure, as well as reduced heart rate were observed under the sympathomimetic condition. Increases in systolic blood pressure between points of measurement correlated positively with increases in pain threshold and tolerance, and decreases in heart rate were associated with increases in pain threshold. The findings underline the causal role of hypotension in the augmented pain sensitivity related to this condition. Pain reduction as a function of heart rate decrease suggests involvement of a baroreceptor-related mechanism in the pain attrition. The increased proneness of persons with chronic hypotension toward clinical pain is discussed.

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