APPLICATION AND CONTROL OF ETHYL-ETHER–WATER INTERFACE EFFECTS TO THE SEPARATION OF RICKETTSIAE FROM YOLK SAC SUSPENSIONS

1945 ◽  
Vol 23e (3) ◽  
pp. 104-114 ◽  
Author(s):  
James Craigie
Keyword(s):  
Ethyl Ether ◽  
Maximum Yield ◽  
Yolk Sac ◽  
Ion Concentration ◽  
Acetate Buffer ◽  
Small Samples ◽  
Physical Factors ◽  
Hydrogen Ion Concentration ◽  
Aqueous Fraction ◽  
Ether Treatment

Purified suspensions of rickettsiae may be obtained by shaking impure suspensions with ethyl ether. When such mixtures separate, tissue particles remain at the interface and the organisms are found in the underlying aqueous fraction. If crude yolk sac preparations of rickettsiae, grown by the method of Cox (4), are shaken with ethyl ether, a complex physical system is created, and the results obtained may be variable. In order that ether treatment may yield sufficiently consistent results to be of practical value, it is necessary to control certain physical factors during emulsion formation and subsequent separation of the aqueous phase. The result obtained depends mainly on the initial hydrogen ion concentration of the suspension, although other factors may also be involved. Studies of some of these factors have been undertaken and two methods of purifying rickettsiae have been developed. In Method A, the material is centrifuged and the sediment of rickettsiae, tissue debris, and yolk granules is suspended in saline buffered with phosphate at pH 7.0. This partially purified suspension of rickettsiae is then emulsified with ethyl ether, and the rickettsiae are recovered in the aqueous fraction that separates as the unstable emulsion breaks down.Preliminary centrifugation is dispensed with in Method B. The separation of the aqueous fraction, with maximum yield of rickettsiae, is controlled by the addition of a suitable proportion of acetate buffer to the crude yolk sac suspension. The optimum proportion of acetate buffer is determined in a preliminary titration with small samples of the yolk sac suspension.

scholarly journals Environmental Factors Causing the Development of Microorganisms on the Surfaces of National Cultural Monuments Made of Mineral Building Materials—Review

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1203
Author(s):  
Elżbieta Stanaszek-Tomal
Keyword(s):  
Environmental Factors ◽  
Building Materials ◽  
Ion Concentration ◽  
Physical Factors ◽  
Comprehensive Overview ◽  
Hydrogen Ion Concentration ◽  
Factors Affecting ◽  
Stone Concrete ◽  
The Impact ◽  
Cultural Monuments

The ability of microorganisms to degrade building materials depends on several factors. Biological corrosion occurs in close dependence with chemical and physical factors affecting microorganisms. The growth and development of microorganisms is stimulated by external stimuli, i.e., environmental factors. Microorganisms have a relatively large tolerance range for changes in environmental conditions. Under the right conditions, microorganisms thrive very well. The adverse effects may cause the inhibition of cell growth, damage, or lead to the death of the microorganism. Considering the impact of environmental factors on microorganisms, it is not possible to identify the most important of them. The result effect of overlapping factors determines the possibility of the growth of certain microorganisms. The main factors affecting the growth are temperature, humidity, hydrogen ion concentration in the environment, oxidoreductive potential, water activity in the environment, and hydrostatic pressure. This article provides a comprehensive overview of the factors causing biodeterioration. The influence of external/internal environment on the surface of cultural monuments made of mineral building materials, i.e., stone, concrete, mortar, etc., is presented.

INVESTIGATION OF BEE BREAD AND DEVELOPMENT OF ITS DOSAGE FORMS

2014 ◽  
Vol 21 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Ilze Barene ◽  
Irena Daberte ◽  
Sanita Siksna
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Potato Starch ◽  
Microscopic Analysis ◽  
Stability Study ◽  
Ion Concentration ◽  
Wet Granulation ◽  
Hydrogen Ion Concentration ◽  
Bee Bread ◽  
Layer Chromatography

The aim of the study. The objective of this study was to investigate microscopic, physical and chemical properties of bee bread collected in three regions of Latvia in order to compare the quality and to investigate the possibility of producing granules containing bee bread. Material and methods. Microscopic analysis of bee bread samples was performed. Plant herbaria, special literature and internet sources were used for identification of pollen. Thin layer chromatography was used for identification of carotenoids and flavonoids. Granules were prepared by wet granulation method. Lactose, calcium lactate, calcium carbonate, potato starch and purified water were used as excipients. Appearance, loss on drying, pH of aqueous solution and content of carotenes were estimated. Results. Microscopic analysis showed mostly native pollen identified as willow pollen. Beta-carotene identified and 2 carotenoids found by thin layer chromatography. Two zones of flavonoids found on chromatograms at day light and 6 zones at ultra violet light. The comparison of bee bread samples of 3 regions of Latvia showed insignificant differences in appearance and consistency, hydrogen ion concentration 3.93–4.23, loss on drying 7.72–11.07 %; content of carotenes calculated to bcarotene 6.77–9.35 mg%. Stability study of bee bread samples showed greater changes after storage at 40ºC temperature. All compositions of granules showed appropriate appearance and flowability. Quality of granules: loss on drying 5.48–13.5%, content of carotenes calculated to b-carotene 5.77–6.75 mg%. Conclusions. Pollen of willow can be considered as an indicator of the origin of bee bread in Latvia. Bee bread samples of three regions of Latvia have insignificant differences in physical, chemical parameters.

Hydro-geochemical properties with respect to landuse in the southernmost river of Kerala

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S
Keyword(s):  
Organic Carbon ◽  
Drainage Basin ◽  
Anthropogenic Activities ◽  
Oxygen Demand ◽  
Ion Concentration ◽  
Total Hardness ◽  
Hydrogen Ion Concentration ◽  
Geochemical Properties ◽  
Quality Of Water

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.

EFFECTS OF SOIL ACIDITY ON RHIZOBIA NUMBERS, NODULATION AND NITROGEN FIXATION BY ALFALFA AND RED CLOVER

1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG
Keyword(s):  
Nitrogen Fixation ◽  
Soil Ph ◽  
Soil Acidity ◽  
Field Experiments ◽  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Red Clover ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Greenhouse Experiments

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.

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