Role of biotin in the production of lysine by Brevibacterium lactofermentum.

To investigate the role of biotin in lysine production, Brevibacterium lactofermentum ATCC 21086 was grown in an acid-hydrolysed whey permeate medium with and without added biotin. Added biotin stimulated lysine production and growth of B. lactofermentum. Five micrograms of biotin/100 ml was the optimum level of addition. Biotin increased the uptake of 14C-glucose and affected fatty acid composition of cell wall lipids. Cell walls of test organisms contained less 16:0 and more 18:2 fatty acids than did those from control cells. However, biotin did not substantially affect the phospholipid content of cell walls and whole cells, and the intracellular free lysine level. It was concluded that the promotive effect of biotin in lysine production might be due to the stimulatory effect of biotin on the growth of B. lactofermentum. Alteration of the cell surface caused by biotin did not appear to affect the release or accumulation of lysine.