Simultaneously enhanced production of poly(β‐malic acid) and pullulan using a dissolved oxygen shift (DO‐shift) control strategy

Abstract

BACKGROUND Poly(β‐malic acid) (PMA) and pullulan are two valuable biopolymers that can be produced simultaneously by certain strains of pullulans. In previous studies, PMA production was successfully improved with reducing pullulan production. In the present study, a DO‐shift control strategy was developed to obtain simultaneous high yields of PMA and pullulan. RESULTS PMA and pullulan co‐production at various constant DO levels ranging from 10% to 90% saturation were carried out in a 5 L stirred tank fermentor. Based on the analysis of batch fermentation kinetics at various constant DO levels, a DO‐shift control strategy that shifted the DO level from 30% saturation to 70% saturation at 72 h was developed to effectively obtain high productions of both PMA and pullulan. CONCLUSION By applying the DO‐shift control strategy, the maximum concentrations of PMA and pullulan reached 118.6 g L−1 and 27.2 g L−1, respectively. PMA production was successfully improved without sacrificing pullulan production. © 2016 Society of Chemical Industry

Toward understanding the key enzymes involved in β‐poly (L‐malic acid) biosynthesis by Aureobasidium pullulans ipe‐1

“…However, L‐malate was widely verified and accepted as the precursor for PMLA biosynthesis . Meanwhile, a high DO level was beneficial for PMLA production . Therefore, the key enzymes activities involved in the precursor production for PMLA biosynthesis was studied under a high DO level (70% saturation) and a low DO level (10% saturation).…”

“…However, L-malate was widely verified and accepted as the precursor for PMLA biosynthesis [5,22,23]. Meanwhile, a high DO level was beneficial for PMLA production [8,24]. Therefore, the key en-A B Figure 6.…”