The ability of polysulfone-immobilized esterified Corynebacterium glutamicum (PIEC) to biosorb two reactive dyes [Reactive Black 5 (RB5) and Reactive Orange 16 (RO16)] from single- and dual-dye solutions has been investigated. Single-dye biosorption isotherm experiments revealed that PIEC performed well in the biosorption of RO16, with a higher experimental uptake of 248.1 mg/g, compared to 174.1 mg/g for RB5. Conversely, the uptake of RO16 was suppressed almost 2.5 times in the presence of RB5, whereas PIEC maintained similar RB5 uptakes in both single- and dual-dye systems. Several factors might be responsible for this effect, the most important being the number of sulfonate groups and the size of each reactive dye. An attempt to achieve the continuous biosorption of reactive dyes from single- and dual-dye solutions using an upflow packed column was successful, with PIEC being regenerated and reused for three cycles.