Effects of microscope illumination on bacterial development

1970 ◽  
Vol 74 (4) ◽  
pp. 292-300 ◽  
Author(s):  
Daisy A. Kuhn ◽  
Mortimer P. Starr
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Agata Jedrzejuk ◽  
Julia Rochala ◽  
Jacek Zakrzewski ◽  
Julita Rabiza-Świder

During the vase life of cut stems obstruction of xylem vessels occurs due to microbial growth, formation of tyloses, deposition of materials in the lumen of xylem vessels and the presence of air emboli in the vascular system. Such obstructions may restrict water uptake and its transport towards upwards thus lowering their ornamental value and longevity of cut flowers.Clematisis a very attractive plant material which may be used as cut flower in floral compositions. Nothing is known about the histochemical or cytological nature of xylem blockages occurring in cut stems of this plant. This study shows that inclematis, tyloses are the main source of occlusions, although bacteria and some amorphic substances may also appear inside the vessels. A preservative composed of 200 mg dm−38-HQC (8-hydroxyquinolin citrate) and 2% sucrose arrested bacterial development and the growth of tyloses. This information can be helpful in the development of new treatments to improve keeping qualities of cutclematisstems.


1976 ◽  
Vol 22 (9) ◽  
pp. 1364-1373 ◽  
Author(s):  
J. Le Petit ◽  
M.-H. N'Guyen

The artificial stimulation of biological purification of sea-pollutant hydrocarbons requires phosphorus supply. The concentrations, corresponding to the optimal bacterial growth, depend, in particular, on ionic strength. They range between 2 and 8 × 10−4 M for waters in which the salinity is close to the mean salinity of an oceanic environment and between 1.5 and 3 × 10−3 M when these waters receive a significant supply of freshwater or when salinity is naturally weak. Inhibition of bacterial development has been observed either with a microflora, or with pure strains for concentrations higher than the upper limits of concentrations so defined.


2017 ◽  
Vol 86 (1) ◽  
pp. 777-797 ◽  
Author(s):  
Abigail J. Sporer ◽  
Lisa J. Kahl ◽  
Alexa Price-Whelan ◽  
Lars E.P. Dietrich

1971 ◽  
Vol 13 (3) ◽  
pp. 547-556 ◽  
Author(s):  
R. M. Livingstone ◽  
H. Denerley ◽  
C. S. Stewart ◽  
F. W. H. Elsley

SUMMARYForty-eight pigs were used to compare the feeding value of barley which had been stored dry, and then hammer-milled, with that of barley stored moist, either anaerobically or treated with 1·3% propionic acid, and then rolled. The pigs were fed from 30 kg live weight for a period of 11 weeks and during this period all consumed the same allowance of dry matter. The growth rate and feed conversion ratio of the pigs given the rolled moist barley were significantly poorer than those of others given dry milled or acid treated rolled barley. There were no treatment differences in carcass attributes.Microbiological counts made throughout the experiment showed that there was no significant fungal or bacterial development on the acid treated barley. Similar numbers of bacteria were present on the dry barley as on the moist, but the fungal count for the moist grain was always at least 500 times higher than that of the corresponding dry sample. The dominant organisms were identified.In a further experiment the apparent digestibility of dry matter and nitrogen of diets containing dry, moist or propionic acid treated barley, processed either by milling or rolling, were determined. The highest values were obtained for dry barley. Acid treated moist barley had lower values than moist barley. The method of processing did not affect the apparent digestibility of the dry matter, but that of the N was significantly lower for the rolled barleys.


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