No coin nor oath required. For personal study only.
Staff) addressed a seminar group of the Biochemical Research Foundation on the subject of vibrios.
Some years ago Dr. Linton was given the opportunity of going to India to work on cholera. He chose to study the chemical structure of the vibrios, in order to see whether any conclusion could be reached as to which strains of vibrios were. dangerous and which harmless. At that time it was difficult, if not impossible, to ascertain serologically whether a given vibrio, unless isolated directly from a clinical case of the disease, would be pathogenic.
The situation was further complicated by the fact that in cholera there is no animal test for pathogenicity that can be considered reliable.
The first work concerned the structure of the polysaccharides. During the investigation of a large number of strains from diverse sources Dr. Linton was able to isolate and identify three of these polysaccharides, each organism or strain appearing to have one of them and one only. The first type of polysaccharide consisted of an easily hydrolyzable portion of galactose together with an aldobionic acid made up of galactose and glycuronic acid; the second type had a similar aldobionic acid, and the easily hydrolyzable portion in this instance was arabinose; in the hydrolysis of the third type, glucose was the only reducing substance which could be identified, although the curve of hydrolysis rate against time was not smooth, indicating that the structure was not as simple as would be obtained if a mere polymer of glucose were present. No aldobionic acid occurred in this third type.
These polysaccharides were present in the acetylated form in the living bacterial cell; they differed in specific rotation * 189
π SIMILAR VOLUMES