during this phase. Subsequently, a second phase was used to impose
the desired P growth-limitation. P was thus fed together with
AA at a constant ratio noted (P/C)app. For all WAS and for the full
duration of each fed-batch culture, the AA feeding rate was
adapted to the substrate consumption rate in order to have C in excess.
The controlled feeding strategy was based on the evolution of
both OUR and pH. A small volume of the concentrated feeding
solutions (AA and P) was added when a significant decrease in
OUR value was detected or when pH rose to a value of 7.8 corresponding
to C limitation. If AA accumulated excessively in the
supernatant, the reactor feeding (both AA and P) was stopped until
AA concentration in the supernatant returned to a value below
50 mg/L to avoid growth inhibition by AA. Consequently, it was
important to differentiate the P and carbon (AA) supplied (given
by the ratio (P/C)app) from the P and carbon consumed ((P/C)cons).
When AA and/or P accumulated in the supernatant, (P/C)app was
different from (P/C)cons, the latter depending both on the biological
demand and on (P/C)app. According to the microbial culture, different
(P/C)app ratios were imposed to assess the effect of the degree
of P limitation on the performance of the culture.
during this phase. Subsequently, a second phase was used to impose
the desired P growth-limitation. P was thus fed together with
AA at a constant ratio noted (P/C)app. For all WAS and for the full
duration of each fed-batch culture, the AA feeding rate was
adapted to the substrate consumption rate in order to have C in excess.
The controlled feeding strategy was based on the evolution of
both OUR and pH. A small volume of the concentrated feeding
solutions (AA and P) was added when a significant decrease in
OUR value was detected or when pH rose to a value of 7.8 corresponding
to C limitation. If AA accumulated excessively in the
supernatant, the reactor feeding (both AA and P) was stopped until
AA concentration in the supernatant returned to a value below
50 mg/L to avoid growth inhibition by AA. Consequently, it was
important to differentiate the P and carbon (AA) supplied (given
by the ratio (P/C)app) from the P and carbon consumed ((P/C)cons).
When AA and/or P accumulated in the supernatant, (P/C)app was
different from (P/C)cons, the latter depending both on the biological
demand and on (P/C)app. According to the microbial culture, different
(P/C)app ratios were imposed to assess the effect of the degree
of P limitation on the performance of the culture.
การแปล กรุณารอสักครู่..
