Finally, in order to better attempt the value of this industrial
residue, the substrate conversion rates, BC production
rates and yields for the extract DOR40 (with no supplementation)
and of the HS medium were determined (Table 2).
The degree of conversion of substrate obtained was 82%
and 90% for DOR40 and HS, respectively. In relation to the BC
yield, the value was a slightly higher for the test with HS
medium, 0.138 g BC per g of substrate, than for the test with
DOR40 extract, 0.099 g BC per g of substrate, which represents 72% of BC production using this extract. This difference
probably resulted from the fact that in HS medium, glucose
was the only substrate while in DOR40 extract other sugars
were present and probably yielded lower BC productions.
The productivity values obtained with DOR40, 0.008 g L"1h"1
were in the same order of magnitude of those we have previously
reported [22] using the same microorganism, but using
pulp and wine residues, between (0.0013 and 0.005 g L"1
h"1
).
In this context [22], we have obtained a degree of conversion
of substrates between 5 and 30%, which were much lower
than those presented by olive oil residues, 82% and 90%