Varying spectrum of amino acids in relation to growth in Helminthosporium oryzae Breda de Haan.

Summary Fifteen amino acids were detected in the developing mycelium of Helminthosporium oryzae Breda de Haan. During the first fortnight of mat accumulation, which was more rapid, a marked influence of amino acids on the growth pattern was discernible. A high level maintenance of dl-alanme l-cysteine, l-leucine/isoleucine, threonine, tyrosine, glutamic, and aspartic acids, as well as an increase in the amount of γ-aminobutyric acid and proline during the first fortnight of culture development were effective in initiating growth and keeping it at a more rapid pace. Glutamine and methionine appeared in the latter half of fungal growth. During this slow pace of mycelial accumulation in the latter half period, there was a general and overall decline in the amount of most of the amino acids. The amino acids started disappearing from the mycelial extract from the 20th day onwards till the end of the 30th day. In the culture filtrate, aspartic acid and proline appeared during the rapid growth phase and dl-alanine and methionine during the slower phase.