Organic nitrogen-containing composition and fertilizer comprising the same

摘要

An organic nitrogen-containing composition comprising fermentation mother liquor obtained by culturing a microorganism having L-glutamic acid-producing ability in a liquid medium of which pH is adjusted to a condition under which L-glutamic acid is allowed to be precipitated, to allow L-glutamic acid to be produced and accumulated with precipitation of L-glutamic acid accompanied, and then separating L-glutamic acid from the medium.