title: Controlling the feed rate of propanol to optimize erythromycin fermentation by on-line capacitance and oxygen uptake rate measurement.
abstract: The aim of the present study was to optimize the feeding proportion of glucose and propanol for erythromycin biosynthesis by real-time monitoring and exploring its limited ratio by the on-line multi-frequency permittivity measurement. It was found that the capacitance values were sensitive to the variation of biomass concentration and microbial morphology as well as the true state of cell growth. It was most favorable to both cell growth and secondary metabolism to keep the ratio of glucose to propanol at 4.3 (g/g). The specific growth rate calculated by the capacitance measurement correctly and accurately reflected the cell physiological state. An appropriate feed rate of propanol was crucial for cell growth and secondary metabolism, as well as to improve the quality of erythromycin-A. In addition, the erythromycin production titer (10,950 U/mL) was further enhanced by 4 % when the propanol feed was regulated by step-down strategy based on both OUR (oxygen uptake rate) and the on-line monitoring capacitance.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 329, Shanghai, 200237, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 329, Shanghai, 200237, People's Republic of China. juchu@ecust.edu.cn.
authors.forename: Ju
authors.initials: J
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 329, Shanghai, 200237, People's Republic of China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Zhuang
authors.affiliation: Yidu HEC Biochem. Co. Ltd, Yidu, 443300, Hubei, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
mesh_terms: D000433:1-Propanol / Q000378:metabolism* / Q000494:pharmacology; D004917:Erythromycin / Q000096:biosynthesis*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D016930:Saccharopolyspora / Q000254:growth & development*
chemical_list: D004917:Erythromycin; D000433:1-Propanol
keywords: Erythromycin; Fermentation; OUR; On-line capacitance measurement; Propanol