Increased production of alkaline polygalacturonate lyase in the recombinant Pichia pastoris by controlling cell concentration during continuous culture

► Two continuous culture strategies, CCCM and CCCD, were developed in the Pichia pastoris. ► Cell concentration is a key parameter for PGL over-production in the P. pastoris. ► Kinetic parameters for controlling cell density by CCCM and CCCD culture were solved. ► The CCCM culture exhibited higher PGL productivity and cell viability. ► Using the continuous mode, protease accumulation was decreased.