The effect of sugar was tested on both the mold and the yeast by adding
it to tomato bouillon. It was supposed that a low percentage of sugar
like the salt would plasmolyze the cells, and in this way check growth,
but it seemed to have no effect until the amount was increased to 25
grams per 100 cc of bouillon. In this solution growth appeared as soon
as with the weaker solutions, but there was a smaller amount. In the
25 to 40 gram solutions there was less development as the amount of
sugar increased. In the 70 and 75 gram solutions growth was delayed one
day in its appearance. In the 80, 85, and 90 gram solutions growth was
delayed two days, the colonies growing submerged at first, but after
a time forming on the surface. The mycelium remained very thin, but
a thick layer of spores formed. From this point on the amounts were
increased by 10 grams up to 200. The development became slower and less
successively until 170 grams were added. In this case a small colony
appeared on the surface in seven days, but seemed to grow less after
that. The solutions were held, and in time crystals separated from the
thick sirups. After two months dry-looking colonies developed along the
edges, forming a ring, and some formed on the surface, these occurring
also in the flasks containing 170, 180, 190, and 200 grams of sugar per
100 cc. The colonies were a dull greenish drab in spots, the remainder
being white.
For the yeast the 80-gram solution of sugar was the strongest in which
any development took place.