Break Point Assay
The preliminary study from the disc assay indicated the
toxic properties of various organic acids and the relative
toxicity of each acid. To further establish the correct
dilution of organic acids to control the growth of V. harveyi
in liquid media, macro dilution with organic acid was done
with V. harveyi and control. The break point for formic
acid was chosen between 0.025 and 0.05%. In the case of
other acids, the breakpoints were chosen between 0.05 and
0.1% as they were relatively less toxic compared to formic
acid. The break point results are given in Table 1, which
indicated a breakpoint of 0.025–0.05% for formic acid.
This means there was growth at 0.025% formic acid and no
growth at 0.05%. This result indicated that the range of
concentration to be tested lie in between 0.025 and 0.05%
for formic acid. Similarly for other acids the break point
range was between 0.05 and 0.1%.