High-level production of pullulan from high concentration of glucose by mutagenesis and adaptive laboratory evolution of Aureobasidium pullulans.

Xiwen Li, Shuangzhi Zhao, Leilei Chen, Qingxin Zhou, Jiying Qiu, Xue Xin, Yanhao Zhang, Wei Yuan, Chengsen Tian, Jinyu Yang, Xiaobin Yu

Carbohydrate polymers 2023 Feb 15

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The cost of carbon sources and the low efficiency of the fermentation titer limit the industrial application of pullulan. In this study, a hypertonic-tolerant strain with efficient utilization of glucose was obtained using a double strategy. Initially, a strain for efficient synthesis of pullulan from glucose was generated by mutagenesis. Subsequently, the mutant was directionally evolved on the plate containing a high glucose concentration to enhance high osmotic resistance. The enzyme activities and the transcriptional levels involved in pullulan biosynthesis and high osmotic tolerance in mutants were increased. Nitrogen source and inorganic salts also significantly affected the production of pullulan by M233-20 from high concentration of glucose. The pullulan titer of 162.1 g/L was obtained using the response surface methodology in the flask. The strain M233-20 produced 162.3 g/L pullulan in a 30-L bioreactor with a yield of 0.82 g/g glucose. Hence, this work provides a potential industrial pullulan producer M233-20 and a strategy to develop excellent strain. Copyright © 2022 Elsevier Ltd. All rights reserved.

Citation

Xiwen Li, Shuangzhi Zhao, Leilei Chen, Qingxin Zhou, Jiying Qiu, Xue Xin, Yanhao Zhang, Wei Yuan, Chengsen Tian, Jinyu Yang, Xiaobin Yu. High-level production of pullulan from high concentration of glucose by mutagenesis and adaptive laboratory evolution of Aureobasidium pullulans. Carbohydrate polymers. 2023 Feb 15;302:120426