A simple procedure for elimination of fungal contamination for enumeration of iron-oxidizing bacteria from bioleaching matrix of sewage sludge

2005 ◽  
Vol 51 (8) ◽  
pp. 637-641 ◽  
Author(s):  
X Y Gu ◽  
Jonathan W.C Wong
Keyword(s):  
Sewage Sludge ◽  
Incubation Time ◽  
Simple Procedure ◽  
Fungal Growth ◽  
Growth Media ◽  
Fungal Contamination ◽  
Simple Method ◽  
Whatman Filter Paper ◽  
Iron Oxidizing Bacteria ◽  
Time Required

Enumeration of iron-oxidizing bacteria from the bioleaching matrix of sewage sludge is always confronted by fungal contamination. The objective of the present study was to find a reliable and simple method to remove fungal growth and to shorten the incubation time for facilitating enumeration of the iron-oxidizers from complex sludge samples. The results demonstrated that filtering the sludge sample through sterile No. 5 Whatman filter paper before serial dilution was effective in eliminating the fungal growth on agarose media. Both the counts and the incubation time required for enumeration were highly dependent on the medium pH, with maximum counts at pH 2.5–2.75. Medium prepared at pH values outside of this range led to lower counts and a longer lag time for colony formation. However, the introduction of heterotrophic microorganisms into the solid medium did not show further improvement in enumeration efficiency and shortening of the incubation period. By incorporating the optimal conditions obtained, the incubation time could be reduced to 7 and 10 d for pure cultures and sludge samples, respectively.Key words: Acidithiobacillus ferrooxidans, iron-based bioleaching process, growth media, sewage sludge.

scholarly journals Effective medium for in vitro sprouting of the buds and multiplication of the plantlets, and identification of the fungal contaminant associated with the explants of Gnetum

2021 ◽  
Vol 16 (2) ◽  
pp. 001-013
Author(s):  
Abwe Mercy Ngone ◽  
Lawrence Monah Ndam ◽  
Rita Mungfu Njilar ◽  
Doungous Oumar ◽  
Thomas Eku Njock
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Fungal Growth ◽  
Growth Media ◽  
Fungal Contamination ◽  
Surface Sterilization ◽  
Pure Cultures ◽  
Nodal Cuttings ◽  
Baseline Information

Plant tissue culture requires the optimization of growth media. Gnetum, known locally in Cameroon as “Eru” is an indigenous gymnospermous vegetable with diverse medicinal, nutritional, cultural and socio-economic values. This resource is over-exploited and expected to neighboring countries, resulting to increased scarcity in the forest. Preliminary work on the in vitro culture of nodal cuttings was faced by the problem of fungal contamination. It was therefore necessary to isolate and identify the fungal contaminant, optimize the surface sterilization of field material and compose an appropriate medium for sprouting. Pure cultures of the fungus were obtained and grown on Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). The identification was based on the appearance of the fungal growth on plates and also on the microscopic view. This was affected by the use of keys. Gnetum explants were disinfected with the various concentrations of disinfectants, preceded in some instances by pre-treatments, as well as incorporating fungicides in the culture medium. Two different culture media were employed: the Woody Plant Medium (WPM) and the Murashige and Skoog (MS) based establishment medium (Y-1). Gnetum was found to live in association with a complex of Microsporum species. The level of contamination of cultures was reduced from 100% to 40% when pre-treated before disinfection and even lower to 10% by incorporating fungicides in the medium. Sprouting was observed in WPM. This study provides baseline information on the in vitro propagation of Gnetum and thus opens up avenues for more research to be carried out in this field.

A modified bioassay for heat-stable Escherichia coli enterotoxin

1977 ◽  
Vol 23 (3) ◽  
pp. 331-336 ◽  
Author(s):  
S. Stavric ◽  
D. Jeffrey
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Incubation Time ◽  
Evans Blue ◽  
Room Temperature ◽  
Blue Dye ◽  
Evans Blue Dye ◽  
Heat Stable ◽  
Stomach Distention ◽  
Time Required

Infant mice were injected orally with preparations containing Escherichia coli heat-stable enterotoxin (ST) and Evans blue dye, and incubated at 22 °C. With enterotoxin-positive samples, the stomach was distended and contained essentially all of the dye. With enterotoxin-negative samples, the stomach remained normal in size and the dye passed freely into the intestines. The time required to obtain the maximum ratio of gut weight to body weight varied from 30 to 90 min and was dependent upon the concentration of enterotoxin. Heat-labile enterotoxin (LT) had no effect during this period.Based on these findings, the mouse incubation time was reduced from 4 h to 90 min, and the heating of test samples was retained only for confirmation of ST. The location of the dye and stomach distention served as an indicator of positive responses to ST. Incubation of the mice at room temperature (22 °C) was found satisfactory.

scholarly journals Heterogeneous Catalytic Synthesis of 2-Methylbenzimidazole from 2-Nitroaniline and Ethanol Over Mg Modified Cu-Pd/γ-Al2O3

Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Feng Feng ◽  
Yaqin Deng ◽  
Zheng Cheng ◽  
Xiaoliang Xu ◽  
Qunfeng Zhang ◽  
...  
Keyword(s):  
Active Sites ◽  
Hydrogen Transfer ◽  
High Efficiency ◽  
Simple Procedure ◽  
Direct Synthesis ◽  
Reaction System ◽  
Simple Method ◽  
Heterogeneous Catalytic ◽  
Coupled Reaction ◽  
Al2o3 Catalyst

The direct synthesis of benzimidazoles from 2-nitroaniline and ethanol over Cu-Pd/γ-Al2O3 catalysts has the advantages of requiring easily available starting materials, having high efficiency, and a simple procedure. The modification by Mg of the Cu-Pd/γ-Al2O3 catalyst could improve the catalytic activity significantly. The addition of Mg to the Cu-Pd/γ-Al2O3 catalyst could maintain and promote the formation of CuPd alloy active sites. Meanwhile, the basicity of the support was enhanced appropriately by Mg, which generated more basic sites (Al-Oδ−) to accelerate the dehydrogenation of alcohol and increased the rate of the whole coupled reaction. The 2-nitroaniline was completely converted over Cu-Pd/(Mg)γ-Al2O3 after reacting for six hours, and the yield of 2-methylbenzimidazole was 98.8%. The results of this work provide a simple method to develop a more efficient catalyst for the “alcohol-dehydrogenation, hydrogen transfer and hydrogenation” coupled reaction system.

scholarly journals The Monitoring of Fungal Contamination in Indoor Air of Two Hospitals in Shiraz

2019 ◽  
Author(s):  
Fariba Abbasi ◽  
Mahrokh Jalili ◽  
Mohammad Reza Samaei ◽  
Ali Mohammad Mokhtari ◽  
Elahe Azizi
Keyword(s):  
Indoor Air ◽  
High Efficiency ◽  
Health Workers ◽  
Ground Level ◽  
Growth Media ◽  
Specialist Care ◽  
Effective Parameters ◽  
Emergency Rooms ◽  
Fungal Contamination ◽  
Air Contamination

Introduction: Hospitals, as one of the important elements in the health system, play an important role in patient’s health. Fungi are one of the effective parameters on indoor air quality. This study aimed to compare of fungal contamination of two hospitals in Shiraz City. Materials and Methods: Sampling was conducted based on NIOSH 0800 standard (1.5 meters above the ground level with one stage Anderson and Sabaroud dextrose agar enriched chloramphenicol as the growth media) in January-September 2017. The investigated wards included pathological laboratory, emergency rooms, neonatal specialist care, radiology, operating room, and maternity ward. The results showed that the variation and concentration of fungi were higher in hospital X than hospital Y, which was located in an agricultural area far from the city center. Results: The predominant fungi were Monillia, Aspergillus, and Penicillium in hospital Y, while they were Aspergillus and Penicillium in hospital X. The highest concentrations were found in emergency and laboratory wards. With regard to higher fungal contamination of hospital X and its different location, it can be concluded that the geographical properties and outdoor air are effective factors on indoor air contamination at hospitals.   Conclusion: Appropriate management of patients' admission and visiting time can be effective on indoor air contamination at hospitals. Furthermore, efficient ventilation using high-efficiency particulate air and appropriate devices for elimination of fungi level are recommended to this end. Moreover, these parameters can provide physical and psychometric health problems for patients’ careers and other health workers.

scholarly journals Fatty Acids and Oxylipins as Antifungal and Anti-Mycotoxin Agents in Food: A Review

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 852
Author(s):  
Mei Qiu ◽  
Yaling Wang ◽  
Lijun Sun ◽  
Qi Deng ◽  
Jian Zhao
Keyword(s):  
Fatty Acids ◽  
Control Systems ◽  
Molecular Mechanisms ◽  
Antifungal Agents ◽  
Recent Literature ◽  
Fungal Growth ◽  
Food Control ◽  
Fungal Contamination ◽  
Mycotoxigenic Fungi

Fungal contamination of food, especially by mycotoxigenic fungi, not only reduces the quality of the food, but can also cause serious diseases, thus posing a major food safety challenge to humans. Apart from sound food control systems, there is also a continual need to explore antifungal agents that can inhibit fungal growth and mycotoxin production in food. Many types of fatty acids (FAs) and their oxidized derivatives, oxylipins, have been found to exhibit such effects. In this review, we provide an update on the most recent literature on the occurrence and formation of FAs and oxylipins in food, their effects on fungal growth and mycotoxin synthesis, as well as the genetic and molecular mechanisms of actions. Research gaps in the field and needs for further studies in order to realizing the potential of FAs and oxylipins as natural antifungal preservatives in food are also discussed.

A simple method of polyamine purification

1985 ◽  
Vol 38 (4) ◽  
pp. 633 ◽  
Author(s):  
IW Stapleton
Keyword(s):  
Aqueous Solution ◽  
Anion Exchange ◽  
Large Scale ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Simple Procedure ◽  
Crystalline Solid ◽  
Simple Method

A simple procedure for the large-scale purification of commercial polyethyleneamines (H2N[CH2CH2NH]nH where n = 2-5) is described in which the per- tosylate salt separates as a crystalline solid from aqueous solution. The salts require no further purification except for pentaethylenehexamine (n = 5), which requires recrystallization from water. The free bases are regenerated from the tosylate salt by an anion-exchange resin.

The Determination of Triglycerides in Plasma and Tissues

1968 ◽  
Vol 14 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Vishwanath M Sardesai ◽  
Joan A Manning
Keyword(s):  
Human Subjects ◽  
Plasma Samples ◽  
Simple Method ◽  
Glycerol Moiety ◽  
Normal Human ◽  
Time Required ◽  
Colored Compound

Abstract A simple method for the determination of plasma and tissue triglycerides is described. This procedure involves the extraction and saponification of triglycerides, the oxidation of the glycerol moiety to formaldehyde, and the conversion of formaldehyde to a yellow-colored compound, 3,5 diacetyl-1-4 dihydrolulidine, the intensity of which is determined spectrophotometrically. The recoveries of triglycerides added to plasma and tissues have been satisfactory. Plasma samples obtained from normal human subjects are found to have triglycerides in the range 83-200 mg./100 ml. From the standpoint of sensitivity, simplicity, and time required, this technic is believed to be an improvement over previously described procedures for triglyceride determination.

scholarly journals A screening test for assessing iron status

Blood ◽  
1982 ◽  
Vol 59 (1) ◽  
pp. 110-113 ◽  
Author(s):  
J Pintar ◽  
BS Skikne ◽  
JD Cook
Keyword(s):  
Developing Countries ◽  
Iron Deficiency ◽  
Iron Overload ◽  
Incubation Time ◽  
Iron Status ◽  
Intervention Strategies ◽  
Deficiency Anemia ◽  
Simple Method ◽  
Hemoglobin Synthesis ◽  
Screening Programs

Abstract Intervention strategies to combat iron deficiency anemia in developing countries may hasten the development of iron overload in patients with an inherited defect in hemoglobin synthesis. This risk could be diminished if there was a rapid and simple method available for detecting iron overload in population screening programs. We have developed such a method, which is in effect a semiquantitative ferritin measurement based on a modification of a two-site enzyme-linked immunoassay. The assay requires only 2 drops of whole blood and a total incubation time of 90 min. The procedure, which can readily distinguish iron deficiency from even a modest increase in storage iron, has a potentially wide application in settings where a prompt assessment of iron status is required.

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