High molecular weight β-poly(l-malic acid) produced by A. pullulans with Ca²⁺ added repeated batch culture

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• 作者：Weifeng Cao^a ; Xiangrong Chen^a ; Jianquan Luo^a ; Junxiang Yin^b ; Changsheng Qiao^c ; Yinhua Wan^a ; ^{yhwan@ipe.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：β-poly(l-malic acid) ; Aureobasidium pullulans ; Molecular weight
• 刊名：International Journal of Biological Macromolecules
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：85
• 期：Complete
• 页码：192-199
• 全文大小：1960 K

文摘

β-Poly(malic acid) (PMLA) has attracted increasing attentions because of its potential application in medicine and other industries. In this study, the variation of PMLA molecular weight (M_w) in the batch culture and the strategies to enhance PMLA M_w were studied. Adding exogenous Ca²⁺ (0.1 g/L CaCl₂) to the medium caused a significant increase in both PMLA concentration and M_w (11.38% and 26.3%, respectively) when Na₂CO₃ was used as the neutralizer. The M_w of PMLA during the process of batch culture, which associated with the specific PMLA production per unit cell mass (Y_p/x) before glucose was depleted, increased from 12.522KDa to its maximum 18.693KDa and then kept decreasing until the end of the culture. Compared with the results in batch culture, M_w increased by 84.4% (up to 19.51 kDa) with a productivity of 1.1 g h⁻¹ L⁻¹ when the cells were maintained in exponential growth phase during Ca²⁺ added repeated batch culture. The present work provides an efficient approach to obtain superior quality PMLA product with high M_w.