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The metabolism of 1‐(ϵ‐ N ‐Lysyl)‐1‐deoxy‐ D ‐fructose by Escherichia coli
Author(s) -
Griffiths David R.,
Pridham John B.
Publication year - 1980
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740311113
Subject(s) - hexose , escherichia coli , biochemistry , fructose , extracellular , chemistry , anaerobic exercise , intracellular , metabolism , moiety , bacteria , cleavage (geology) , enzyme , biology , stereochemistry , physiology , genetics , gene , paleontology , fracture (geology)
A study has been made of the growth curves of Escherichia coli B cultures incubated with glucose in a simple salt solution in the presence and absence of 1‐(ϵ‐ N ‐lysyl)‐1‐deoxy‐D‐fructose (‘fructoselysine’; ‘FL’) in the medium. Some increase in overall growth was observed in the presence of FL under both aerobic and anaerobic conditions. Heated FL samples caused a depression of growth rate. The bacterium was impermeable to FL but was able to grow on FL supplied as the sole carbon source after an induction period of 8 h (aerobic). The subsequent disappearance of FL was shown to be due to extracellular degradation (rather than cell permeation) by an enzyme that was entirely cell‐bound and which, once induced, became a permanent feature of the cell. Studies with FL samples, [U −14 C] labelled in either the lysyl or fructosyl moiety, showed that cleavage of the hexose‐lysine C—N bond occurred with the release of lysine which remained unmetabolised in the external medium. Radioactivity derived from the hexose moiety was absorbed by E. coli cells and was metabolised with the appearance of several labelled intracellular compounds and the evolution of 14 CO 2 .