Growth characteristics of a methionine-requiring mutant strain of <i>M. oryzae</i>.

<p>(<b>A</b>) In addition to media containing methionine, Δ<i>str3</i> strains can also grow on media containing homocysteine but not cysteine as sole nitrogen source (10 mM). Plate tests also suggest a cystathionine beta-lyase-independent pathway operates in <i>M. oryzae</i> to produce homocysteine from O-acetyl-L-homoserine, resulting in the growth of Δ<i>str3</i> strains on plates containing aspartate. Growth of Δ<i>str3</i> strains on complete media (CM) requires no additional supplementation. (<b>B</b>) Supplements found in CM, such as vitamins, casamino acids (CA), peptone, yeast extract (YE) and yeast nitrogen base without amino acids (YE-AA), were added in the same amounts to GMM (containing 10 mM NH₄⁺) to determine what component(s) of CM remediated Δ<i>str3</i> growth.