SUMMARY Methionine or ethionine, although capable of serving as sole nitrogen source for , cannot replace or spare the vitamin B nutrient requirement for the growth of this flagellate. In the presence of vitamin B methionine counteracted the inhibition of growth exerted by some vitamin B analogues which are substituted at the benzimidazole part of the molecule. No such effect was observed against the inhibition by certain other analogues. Analogue FIII (α-(5-hydroxybenzimidazolyl)-cobamide cyanide) replaced vitamin B in the presence of methionine, and to a lesser degree also in the presence of other methyl donors such as methylmethionine sulphonium iodide, dimethylpropiothetin, choline chloride and betaine. The conclusion drawn is that for analogue FIII is capable of replacing vitamin B in all the metabolic pathways other than methyl-group synthesis. For the latter process, the benzimidazole methyl groups present in vitamin B and analogue FIII (α-(5-methoxy-benzimidazolyl)-cobamide cyanide) are indispensable.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error