BIOSYNTHESIS OF SUGARS FOUND IN BACTERIAL POLYSACCHARIDES: PART I. BIOSYNTHESIS OFL-RHAMNOSE

Abstract

Azotobacter indicil~iz was grown on ~nedia which contained D -g l~~~~e -l -c " ,The radioactive polysaccharides produced were hydrolyzed and the specific activities of the isolated D-glucose and L-rhamnose were measured. The sugars were degraded and the distribution of activity in the individual carbon atoms was determined.The results suggest that some L-rharnnose is formed froin D-glucose by a pathway which involves the breakdown of the glucose carbon slceleton.

NADH oxidase from the extreme thermophile Thermus aquaticus YT‐1

“…Various enzymatic methods have been described 111, although in recent years attention has also been paid to chemical methods [2,31. The regeneration of NAD' from NADH formed by alcohol dehydrogenase has been shown to be important in the development of sensitive immunoassays [4 -61.…”

The biosynthesis of l-rhamnose of plum-leaf polysaccharides

“…Investigating L-rhamnose synthesis by a streptococcus, Southard, Hayashi & Barkulis (1959) also found that this monosaccharide attained a higher specific activity when D-[6-14C]glucose was the precursor than when D-[1-14Clglucose was the precursor. On the other hand, Watkin & Neish (1961) and Jones et al (1962) made the opposite observation for L-rhamnose synthesis in buckwheat and Azotobacter indicum respectively. Apart from differences in hexose metabolism in these organisms, the contributions of two pathways for the biosynthesis of L-rhamnose, varying from one organism to another, would also account for these observations.…”

“…We found that, for degradation of acetaldehyde, oxidation to acetate followed by the Schmidt reaction gave better and more consistent yields of products than did the iodoform reaction. Jones et al (1962) enumerate the several published degradation schemes for L-rhamnose. Degradation according to our Scheme 1 is probably as simple and as satisfactory in terms of yields as any of them, and gives information on 14C-labelling that is sufficient for many investigations of rhamnose biosynthesis.…”

“…Jones et al 1962), the major route for the biosynthesis of Lrhamnose from D-glucose evidently involves neither scission nor inversion of the carbon chain. Presumably in plum leaves the interconversion occurs while glucose, rhamnose and the intermediate monosaccharides are in the form of UDP derivatives (Barber, 1963), rather than thymidine diphosphate or GDP derivatives as in bacteria (Pazur & Shuey, 1960, 1961Blumson & Baddiley, 1961;Glaser & Kornfeld, 1961;Markovitz, 1961).…”

BIOSYNTHESIS OF PLANT CONSTITUENTS: I. THE COMPLETE DEGRADATION OF 2-DEOXY-D-RIBOSE AND SOME 2-DEOXY-D-HEXOSES

“…In either case, when C14-labelled possible precursors are considered or used to determine the biosynthetic pathway, a procedure whereby the products may be degraded in some detail is essential. Recently, Jones and associates have reported on the biosynthesis of rhamnose and a heptose in a bacterial species in which they describe in some detail the degradation of these particular sugars (9).…”