A fedbatch strategy for optimal red pigment production by monascus ruber

According to the measurement of the pigment production and some material balance treatments, the monosodium glutamate (MSG), which represents a main substrate involved in the production of red pigment by Monascus ruber, is recovered on-line. Fedbatch operation then represents an alternative for increasing the production of pigment. A nonlinear quotient control scheme is expressed to regulate the monosodium glutamate substrate at an optimal value determined from batch studies.List of Symbols A absorbancy units (AU) - L lightness parameter - Pig red pigment quantity (Gmol) - vol fermentor active volume (1) - empirical coefficient - MW_pig red pigment molecular weight (g) - E elementary matrix - E^# pseudo-inverse elementary matrix - r conversion rates vector (g· l^–1·h^–1) - E_m measured part of the elementary matrix - r_m measured conversion rates vector - E_c non-measured part of the elementary matrix - r_c non-measured conversion rates vector - v fictitious controller input - h fictitious controller output - u controller input - y controller output - y controller setpoint - k₁ controller parameter - k₂ controller parameter - k time iteration - MSG monosodium glutamate concentration (g·l^–1) - MSG_init monosodium glutamate initial quantity (g) - MSG_added total quantity of monosodium glutamate added (g) - MSG_cons total quantity of monosodium glutamate consumed (g) - MW_msg monosodium glutamate molecular weight (g)