TY - JOUR
T1 - Intensification of β-poly(l-malic acid) production by Aureobasidium pullulans ipe-1 in the late exponential growth phase
AU - Cao, Weifeng
AU - Luo, Jianquan
AU - Zhao, Juan
AU - Qiao, Changsheng
AU - Ding, Luhui
AU - Qi, Benkun
AU - Su, Yi
AU - Wan, Yinhua
PY - 2012
Y1 - 2012
N2 - β-Poly(malic acid) (PMLA) has attracted industrial interest because this polyester can be used as a prodrug or for drug delivery systems. In PMLA production by Aureobasidium pullulans ipe-1, it was found that PLMA production was associated with cell growth in the early exponential growth phase and dissociated from cell growth in the late exponential growth phase. To enhance PMLA production in the late phase, different fermentation modes and strategies for controlling culture redox potential (CRP) were studied. The results showed that high concentrations of produced PMLA (above 40 g/l) not only inhibited PMLA production, but also was detrimental to cell growth. Moreover, when CRP increased from 57 to 100 mV in the late exponential growth phase, the lack of reducing power in the broth also decreased PMLA productivity. PMLA productivity could be enhanced by repeated-batch culture to maintain cell growth in the exponential growth phase, or by cell-recycle culture with membrane to remove the produced PMLA, or by maintaining CRP below 70 mV no matter which kind of fermentation mode was adopted. Repeated-batch culture afforded a high PMLA concentration (up to 63.2 g/l) with a productivity of 1.15 g l−1 h−1. Cell-recycle culture also confirmed that PMLA production by the strain ipe-1 was associated with cell growth.
AB - β-Poly(malic acid) (PMLA) has attracted industrial interest because this polyester can be used as a prodrug or for drug delivery systems. In PMLA production by Aureobasidium pullulans ipe-1, it was found that PLMA production was associated with cell growth in the early exponential growth phase and dissociated from cell growth in the late exponential growth phase. To enhance PMLA production in the late phase, different fermentation modes and strategies for controlling culture redox potential (CRP) were studied. The results showed that high concentrations of produced PMLA (above 40 g/l) not only inhibited PMLA production, but also was detrimental to cell growth. Moreover, when CRP increased from 57 to 100 mV in the late exponential growth phase, the lack of reducing power in the broth also decreased PMLA productivity. PMLA productivity could be enhanced by repeated-batch culture to maintain cell growth in the exponential growth phase, or by cell-recycle culture with membrane to remove the produced PMLA, or by maintaining CRP below 70 mV no matter which kind of fermentation mode was adopted. Repeated-batch culture afforded a high PMLA concentration (up to 63.2 g/l) with a productivity of 1.15 g l−1 h−1. Cell-recycle culture also confirmed that PMLA production by the strain ipe-1 was associated with cell growth.
U2 - 10.1007/s10295-012-1111-3
DO - 10.1007/s10295-012-1111-3
M3 - Journal article
C2 - 22395899
SN - 1367-5435
VL - 39
SP - 1073
EP - 1080
JO - Journal of Industrial Microbiology and Biotechnology
JF - Journal of Industrial Microbiology and Biotechnology
IS - 7
ER -